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Note: This page contains sample records for the topic "neutron tube target" from the National Library of EnergyBeta (NLEBeta).
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they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
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1

Neutron tubes  

DOE Patents [OSTI]

A neutron tube or generator is based on a RF driven plasma ion source having a quartz or other chamber surrounded by an external RF antenna. A deuterium or mixed deuterium/tritium (or even just a tritium) plasma is generated in the chamber and D or D/T (or T) ions are extracted from the plasma. A neutron generating target is positioned so that the ion beam is incident thereon and loads the target. Incident ions cause D-D or D-T (or T-T) reactions which generate neutrons. Various embodiments differ primarily in size of the chamber and position and shape of the neutron generating target. Some neutron generators are small enough for implantation in the body. The target may be at the end of a catheter-like drift tube. The target may have a tapered or conical surface to increase target surface area.

Leung, Ka-Ngo (Hercules, CA); Lou, Tak Pui (Berkeley, CA); Reijonen, Jani (Oakland, CA)

2008-03-11T23:59:59.000Z

2

EA-1131: Relocation of Neutron Tube Target Loading Operation, Los Alamos Laboratory, Los Alamos, New Mexico  

Broader source: Energy.gov [DOE]

This EA evaluates the environmental impacts of the proposal to relocate the Neutron Tube Target Loading operations at the U.S. Department of Energy Los Alamos National Laboratory in New Mexico from...

3

Horizontal Beam Tubes - HFIR Technical Parameters | ORNL Neutron...  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

Beam Tubes The reactor has four horizontal beam tubes that supply the neutrons to the neutron scattering instruments. Details for each beam tube and instrument can be found on...

4

Neutron producing target for accelerator based neutron source for  

E-Print Network [OSTI]

therapy [1, 2]. Lithium targets for two modes of neutron beam production are developed. The first one. Target will be created as a 2 ­ 3 µm thick lithium layer on the surface of tungsten disk cooled by liquidW cm­2 . ii) Production of target with lithium layer thickness of 2 ­ 3 µm. #12;248 iii) Evaporation

Taskaev, Sergey Yur'evich

5

Delayed neutrons measurement at the MEGAPIE target  

E-Print Network [OSTI]

In the framework of the Neutronic and Nuclear Assessment Task Group of the MEGAPIE experiment we measured the delayed neutron (DN) flux at the top of the target. The measurement was proposed mainly for radioprotection purposes since the DN flux at the top of the target has been estimated to be of the same order of magnitude as the prompt neutron flux. Given the strong model-dependence of DN predictions, the measurement of DN contribution to the total neutron activity at the top of the target was thus desired. Moreover, this measurement is complementary to the DN experiments performed at PNPI (Gatchina) on solid lead and bismuth targets. The DN measurement at MEGAPIE was performed during the start-up phase of the target. In this paper we present a detailed description of the experimental setup and some preliminary results on decay spectra.

Stefano Panebianco; Pavel Bokov; Diane Dore; Xavier Ledoux; Alain Letourneau; Aurelien Prevost; Danas Ridikas

2007-05-25T23:59:59.000Z

6

Delayed neutrons measurement at the MEGAPIE target  

E-Print Network [OSTI]

In the framework of the Neutronic and Nuclear Assessment Task Group of the MEGAPIE experiment we measured the delayed neutron (DN) flux at the top of the target. The measurement was proposed mainly for radioprotection purposes since the DN flux at the top of the target has been estimated to be of the same order of magnitude as the prompt neutron flux. Given the strong model-dependence of DN predictions, the measurement of DN contribution to the total neutron activity at the top of the target was thus desired. Moreover, this measurement is complementary to the DN experiments performed at PNPI (Gatchina) on solid lead and bismuth targets. The DN measurement at MEGAPIE was performed during the start-up phase of the target. In this paper we present a detailed description of the experimental setup and some preliminary results on decay spectra.

Panebianco, Stefano; Dore, Diane; Ledoux, Xavier; Letourneau, Alain; Prevost, Aurelien; Ridikas, Danas

2007-01-01T23:59:59.000Z

7

Uranium Neutron Coincidence Collar Model Utilizing Boron-10 Lined Tubes  

SciTech Connect (OSTI)

The Department of Energy Office of Nuclear Safeguards and Security (NA-241) is supporting the project Coincidence Counting With Boron-Based Alternative Neutron Detection Technology at Pacific Northwest National Laboratory (PNNL) for the development of a 3He proportional counter alternative neutron coincidence counter. The goal of this project is to design, build and demonstrate a system based upon 10B-lined proportional tubes in a configuration typical for 3He-based coincidence counter applications. This report, providing results for model development of Alternative Boron-Based Uranium Neutron Coincidence Collar (ABUNCL) designs, is a deliverable under Task 2 of the project.

Rogers, Jeremy L.; Ely, James H.; Kouzes, Richard T.; Lintereur, Azaree T.; Siciliano, Edward R.

2012-09-18T23:59:59.000Z

8

Behaviour of Magnetic Tubes in Neutron Star's Interior  

E-Print Network [OSTI]

It is found from Maxwell's equations that the magnetic field lines are good analogues of relativistic strings. It is shown that the super-conducting current in the neutron star's interior causes local rotation of magnetic flux tubes carrying quantized flux.

R. S. Singh; B. K. Sinha; N. K. Lohani

2002-12-31T23:59:59.000Z

9

Neutron single target spin asymmetries in SIDIS  

SciTech Connect (OSTI)

The experiment E06-010 in Hall A at Jefferson Lab took data between November 2008 and February 2009 to directly measure, for the first time, the pion (and kaon) single "neutron" target-spin asymmetry (SSA) in semi-inclusive DIS from a polarized 3He target. Collins, Sivers (and Pretzelosity) neutron asymmetries are going to be extracted from the measured SSA. Details of the experiment are described together with the preliminary results of the ongoing analysis. Near future Hall A experiments on transverse nucleon spin structure are shorty reviewed.

Evaristo Cisbani

2010-04-01T23:59:59.000Z

10

A neutron producing target for BINP accelerator-based neutron source B. Bayanova  

E-Print Network [OSTI]

A neutron producing target for BINP accelerator-based neutron source B. Bayanova , E. Kashaeva b l e i n f o Keywords: Target Lithium Neutron capture therapy Epithermal neutrons a b s t r a c t An innovative accelerator-based neutron source for BNCT has just started operation at the Budker Institute

Taskaev, Sergey Yur'evich

11

Project of Rotating Carbon High-Power Neutron Target. Research of Graphite Properties for Production of High Intensity Neutron Source  

E-Print Network [OSTI]

Project of Rotating Carbon High-Power Neutron Target. Research of Graphite Properties for Production of High Intensity Neutron Source

Gubin, K V; Bak, P A; Kot, N K; Logatchev, P V

2001-01-01T23:59:59.000Z

12

Cyclotrons to Make Neutrons & Radioactive Targets for SBSS at...  

Office of Science (SC) Website

Cyclotrons to Make Neutrons & Radioactive Targets for SBSS at LBNL Nuclear Physics (NP) NP Home About Research Facilities Science Highlights Benefits of NP Applications of Nuclear...

13

Neutrons from the SNS's target are channeled  

E-Print Network [OSTI]

of Science. The five instruments under the SING (SNS Instruments - Next Generation) project the project. SCIENCE Project's completion gives neutron science community reason to SING Table of Contents Project's completion gives neutron science community reason to SING . . . . . . . . . . . 1 Oral

Pennycook, Steve

14

Development of a Permanent-Magnet Microwave Ion Source for a Sealed-Tube Neutron Generator  

SciTech Connect (OSTI)

A microwave ion source has been designed and constructed for use with a sealed-tube, high-yield neutron generator. When operated with a tritium-deuterium gas mixture the generator will be capable of producing 5*1011 n/s in non-proliferation applications. Microwave ion sources are well suited for such a device because they can produce high extracted beam currents with a high atomic fraction at low gas pressures of 0.2-0.3 Pa required for sealed tube operation. The magnetic field strength for achieving electron cyclotron resonance (ECR) condition, 87.5 mT at 2.45 GHz microwave frequency, was generated and shaped with permanent magnets surrounding the plasma chamber and a ferromagnetic plasma electrode. This approach resulted in a compact ion source that matches the neutron generator requirements. The needed proton-equivalent extracted beam current density of 40 mA/cm^2 was obtained at moderate microwave power levels of 400 W. Results on magnetic field design, pressure dependency and atomic fraction measured for different wall materials are presented.

Waldmann, Ole; Ludewigt, Bernhard

2011-03-31T23:59:59.000Z

15

Thick-Target Neutron Yield from the 19F(alpha,n) Reaction  

E-Print Network [OSTI]

Thick-target neutron yields from the 19F(alpha,n) reaction are reported for E(alpha) = 3.5 - 10.0 MeV.

E. B. Norman; T. E. Chupp; K. T. Lesko; G. L. Woodruff; P. J. Grant

2014-11-01T23:59:59.000Z

16

Behavior of structural and target materials irradiated in spallation neutron environments  

SciTech Connect (OSTI)

This paper describes considerations for selection of structural and target materials for accelerator-driven neutron sources. Due to the operating constraints of proposed accelerator-driven neutron sources, the criteria for selection are different than those commonly applied to fission and fusion systems. Established irradiation performance of various alloy systems is taken into account in the selection criteria. Nevertheless, only limited materials performance data are available which specifically related to neutron energy spectra anticipated for spallation sources.

Stubbins, J.F. [Univ. of Illinois, Urbana, IL (United States). Dept. of Nuclear Engineering; Wechsler, M. [North Carolina State Univ., Raleigh, NC (United States). Dept. of Nuclear Engineering; Borden, M.; Sommer, W.F. [Los Alamos National Lab., NM (United States)

1995-05-01T23:59:59.000Z

17

WATER PURITY DEVELOPMENT FOR THE COUPLED CAVITY LINAC (CCL) AND DRIFT TUBE LINAC (DTL) STRUCTURES OF THE SPALLATION NEUTRON SOURCE (SNS) LINAC  

SciTech Connect (OSTI)

The Spallation Neutron Source (SNS) is a facility being designed for scientific and industrial research and development. SNS will generate and use neutrons as a diagnostic tool for medical purposes, material science, etc. The neutrons will be produced by bombarding a heavy metal target with a high-energy beam of protons, generated and accelerated with a linear particle accelerator, or linac. The low energy end of the linac consists of two room temperature copper structures, the drift tube linac (DTL), and the coupled cavity linac (CCL). Both of these accelerating structures use large amounts of electrical energy to accelerate the proton beam. Approximately 60-80% of the electrical energy is dissipated in the copper structure and must be removed. This is done using specifically designed water cooling passages within the linac's copper structure. Cooling water is supplied to these cooling passages by specially designed resonance control and water cooling systems. One of the primary components in the DTL and CCL water cooling systems, is a water purification system that is responsible for minimizing erosion, corrosion, scaling, biological growth, and hardware activation. The water purification system consists of filters, ion exchange resins, carbon beds, an oxygen scavenger, a UV source, and diagnostic instrumentation. This paper reviews related issues associated with water purification and describes the mechanical design of the SNS Linac water purification system.

D. KATONAK; J. BERNARDIN; S. HOPKINS

2001-06-01T23:59:59.000Z

18

Neutron measurements from beam-target reactions at the ELISE neutral beam test facility  

SciTech Connect (OSTI)

Measurements of 2.5 MeV neutron emission from beam-target reactions performed at the ELISE neutral beam test facility are presented in this paper. The measurements are used to study the penetration of a deuterium beam in a copper dump, based on the observation of the time evolution of the neutron counting rate from beam-target reactions with a liquid scintillation detector. A calculation based on a local mixing model of deuterium deposition in the target up to a concentration of 20% at saturation is used to evaluate the expected neutron yield for comparison with data. The results are of relevance to understand neutron emission associated to beam penetration in a solid target, with applications to diagnostic systems for the SPIDER and MITICA Neutral Beam Injection prototypes.

Xufei, X., E-mail: xiexufei@pku.edu.cn; Fan, T. [State Key Laboratory of Nuclear Physics and Technology, Peking University, Beijing 100871 (China); Nocente, M.; Gorini, G. [Dipartimento di Fisica “G. Occhialini”, Universitŕ di Milano-Bicocca, Milano 20216 (Italy); Istituto di Fisica del Plasma “P. Caldirola”, Milano 20216 (Italy); Bonomo, F. [Consorzio RFX, Padova 35100 (Italy); Istituto Gas Ionizzati, CNR, Padova 35100 (Italy); Franzen, P.; Fröschle, M. [Max-Planck-Institut für Plasmaphysik, Garching 84518 (Germany); Grosso, G.; Tardocchi, M. [Istituto di Fisica del Plasma “P. Caldirola”, Milano 20216 (Italy); Grünauer, F. [Physics Consulting, Zorneding 85604 (Germany); Pasqualotto, R. [Consorzio RFX, Padova 35100 (Italy)

2014-11-15T23:59:59.000Z

19

Three-dimensional computational fluid dynamics for the Spallation Neutron Source liquid mercury target  

SciTech Connect (OSTI)

The Spallation Neutron Source (SNS) is a high-power accelerator-based pulsed spallation source being designed by a multilaboratory team led by Oak Ridge National Laboratory (ORNL) to achieve high fluxes of neutrons for scientific experiments. Computational fluid dynamics (CFD) is being used to analyze the SNS design. The liquid-mercury target is subjected to the neutronic (internal) heat generation that results from the proton collisions with the mercury nuclei. The liquid mercury simultaneously serves as the neutronic target medium, transports away the heat generated within itself, and cools the metallic target structure. Recirculation and stagnation zones within the target are of particular concern because of the likelihood that they will result in local hot spots. These zones exist because the most feasible target designs include a complete U-turn flow redirection. Although the primary concern is that the target is adequately cooled, the pressure drop from inlet to outlet must also be considered because pressure drop directly affects structural loading and required pumping power. Based on the current design, a three-dimensional CFD model has been developed that includes the stainless steel target structure, the liquid-mercury target flow, and the liquid-mercury cooling jacket that wraps around the nose of the target.

Wendel, M.W.; Siman-Tov, M.

1998-11-01T23:59:59.000Z

20

Neutron energy spectrum from 120 GeV protons on a thick copper target  

E-Print Network [OSTI]

Neutron energy spectrum from 120 GeV protons on a thick copper target was measured at the Meson Test Beam Facility (MTBF) at Fermi National Accelerator Laboratory. The data allows for evaluation of neutron production process implemented in theoretical simulation codes. It also helps exploring the reasons for some disagreement between calculation results and shielding benchmark data taken at high energy accelerator facilities, since it is evaluated separately from neutron transport. The experiment was carried out using a 120 GeV proton beam of 3E5 protons/spill. Since the spill duration was 4 seconds, proton-induced events were counted pulse by pulse. The intensity was maintained using diffusers and collimators installed in the beam line to MTBF. The protons hit a copper block target the size of which is 5cm x 5cm x 60 cm long. The neutrons produced in the target were measured using NE213 liquid scintillator detectors, placed about 5.5 m away from the target at 30^{\\circ} and 5 m 90^{\\circ} with respect to the proton beam axis. The neutron energy was determined by time-of-flight technique using timing difference between the NE213 and a plastic scintillator located just before the target. Neutron detection efficiency of NE213 was determined on basis of experimental data from the high energy neutron beam line at Los Alamos National Laboratory. The neutron spectrum was compared with the results of multi-particle transport codes to validate the implemented theoretical models. The apparatus would be applied to future measurements to obtain a systematic data set for secondary particle production on various target materials.

Nobuhiro Shigyo; Toshiya Sanami; Tsuyoshi Kajimoto; Yosuke Iwamoto; Masayuki Hagiwara; Kiwamu Saito; Kenji Ishibashi; Hiroshi Nakashima; Yukio Sakamoto; Hee-Seock Lee; Erik Ramberg; Aria A. Meyhoefer; Rick Coleman; Doug Jensen; Anthony F. Leveling; David J. Boehnlein; Nikolai V. Mokhov

2012-02-07T23:59:59.000Z

Note: This page contains sample records for the topic "neutron tube target" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


21

Neutron production using a pyroelectric driven target coupled with a gated field ionization source  

SciTech Connect (OSTI)

A palm sized, portable neutron source would be useful for widespread implementation of detection systems for shielded, special nuclear material. We present progress towards the development of the components for an ultracompact neutron generator using a pulsed, meso-scale field ionization source, a deuterated (or tritiated) titanium target driven by a negative high voltage lithium tantalate crystal. Neutron production from integrated tests using an ion source with a single, biased tungsten tip and a 3 Multiplication-Sign 1 cm, vacuum insulated crystal with a plastic deuterated target are presented. Component testing of the ion source with a single tip produces up to 3 nA of current. Dielectric insulation of the lithium tantalate crystals appears to reduce flashover, which should improve the robustness. The field emission losses from a 3 cm diameter crystal with a plastic target and 6 cm diameter crystal with a metal target are compared.

Ellsworth, J. L.; Tang, V.; Falabella, S. [Lawrence Livermore National Laboratory, 7000 East Ave., Livermore, CA 94550 (United States); Naranjo, B.; Putterman, S. [University of California Los Angeles, 405 Hilgard Ave., Los Angeles, CA 90095 (United States)

2013-04-19T23:59:59.000Z

22

Parallel computation safety analysis irradiation targets fission product molybdenum in neutronic aspect using the successive over-relaxation algorithm  

SciTech Connect (OSTI)

One of the research activities in support of commercial radioisotope production program is a safety research on target FPM (Fission Product Molybdenum) irradiation. FPM targets form a tube made of stainless steel which contains nuclear-grade high-enrichment uranium. The FPM irradiation tube is intended to obtain fission products. Fission materials such as Mo{sup 99} used widely the form of kits in the medical world. The neutronics problem is solved using first-order perturbation theory derived from the diffusion equation for four groups. In contrast, Mo isotopes have longer half-lives, about 3 days (66 hours), so the delivery of radioisotopes to consumer centers and storage is possible though still limited. The production of this isotope potentially gives significant economic value. The criticality and flux in multigroup diffusion model was calculated for various irradiation positions and uranium contents. This model involves complex computation, with large and sparse matrix system. Several parallel algorithms have been developed for the sparse and large matrix solution. In this paper, a successive over-relaxation (SOR) algorithm was implemented for the calculation of reactivity coefficients which can be done in parallel. Previous works performed reactivity calculations serially with Gauss-Seidel iteratives. The parallel method can be used to solve multigroup diffusion equation system and calculate the criticality and reactivity coefficients. In this research a computer code was developed to exploit parallel processing to perform reactivity calculations which were to be used in safety analysis. The parallel processing in the multicore computer system allows the calculation to be performed more quickly. This code was applied for the safety limits calculation of irradiated FPM targets containing highly enriched uranium. The results of calculations neutron show that for uranium contents of 1.7676 g and 6.1866 g (× 10{sup 6} cm{sup ?1}) in a tube, their delta reactivities are the still within safety limits; however, for 7.9542 g and 8.838 g (× 10{sup 6} cm{sup ?1}) the limits were exceeded.

Susmikanti, Mike, E-mail: mike@batan.go.id [Center for Development of Nuclear Informatics, National Nuclear Energy Agency, PUSPIPTEK, Tangerang (Indonesia); Dewayatna, Winter, E-mail: winter@batan.go.id [Center for Nuclear Fuel Technology, National Nuclear Energy Agency, PUSPIPTEK, Tangerang (Indonesia); Sulistyo, Yos, E-mail: soj@batan.go.id [Center for Nuclear Equipment and Engineering, National Nuclear Energy Agency, PUSPIPTEK, Tangerang (Indonesia)

2014-09-30T23:59:59.000Z

23

Three-dimensional calculations of neutron streaming in the beam tubes of the ORNL HFIR (High Flux Isotope Reactor) Reactor  

SciTech Connect (OSTI)

The streaming of neutrons through the beam tubes in High Flux Isotope Reactor at Oak Ridge National Laboratory has resulted in a reduction of the fracture toughness of the reactor vessel. As a result, an evaluation of vessel integrity was undertaken in order to determine if the reactor can be operated again. As a part of this evaluation, three-dimensional neutron transport calculations were performed to obtain fluxes at points of interest in the wall of the vessel. By comparing the calculated and measured activation of dosimetry specimens from the vessel surveillance program, it was determined that the calculated flux shape was satisfactory to transpose the surveillance data to the locations in the vessel. A bias factor was applied to correct for the average C/E ratio of 0.69. 8 refs., 7 figs., 3 tabs.

Childs, R.L.; Rhoades, W.A.; Williams, L.R.

1988-01-01T23:59:59.000Z

24

Prototype Spallation Neutron Source Rotating Target Assembly Final Test Report  

SciTech Connect (OSTI)

A full-scale prototype of an extended vertical shaft, rotating target assembly based on a conceptual target design for a 1 to 3-MW spallation facility was built and tested. Key elements of the drive/coupling assembly implemented in the prototype include high integrity dynamic face seals, commercially available bearings, realistic manufacturing tolerances, effective monitoring and controls, and fail-safe shutdown features. A representative target disk suspended on a 3.5 meter prototypical shaft was coupled with the drive to complete the mechanical tests. Successful operation for 5400 hours confirmed the overall mechanical feasibility of the extended vertical shaft rotating target concept. The prototype system showed no indications of performance deterioration and the equipment did not require maintenance or relubrication.

McManamy, Thomas J [ORNL; Graves, Van [Oak Ridge National Laboratory (ORNL); Garmendia, Amaia Zarraoa [IDOM Bilbao; Sorda, Fernando [ESS Bilbao; Etxeita, Borja [IDOM Bilbao; Rennich, Mark J [ORNL

2011-01-01T23:59:59.000Z

25

Neutron guide  

DOE Patents [OSTI]

A neutron guide in which lengths of cylindrical glass tubing have rectangular glass plates properly dimensioned to allow insertion into the cylindrical glass tubing so that a sealed geometrically precise polygonal cross-section is formed in the cylindrical glass tubing. The neutron guide provides easier alignment between adjacent sections than do the neutron guides of the prior art.

Greene, Geoffrey L. (Los Alamos, NM)

1999-01-01T23:59:59.000Z

26

High-flux neutron source based on a liquid-lithium target  

SciTech Connect (OSTI)

A prototype compact Liquid Lithium Target (LiLiT), able to constitute an accelerator-based intense neutron source, was built. The neutron source is intended for nuclear astrophysical research, boron neutron capture therapy (BNCT) in hospitals and material studies for fusion reactors. The LiLiT setup is presently being commissioned at Soreq Nuclear research Center (SNRC). The lithium target will produce neutrons through the {sup 7}Li(p,n){sup 7}Be reaction and it will overcome the major problem of removing the thermal power generated by a high-intensity proton beam, necessary for intense neutron flux for the above applications. The liquid-lithium loop of LiLiT is designed to generate a stable lithium jet at high velocity on a concave supporting wall with free surface toward the incident proton beam (up to 10 kW). During off-line tests, liquid lithium was flown through the loop and generated a stable jet at velocity higher than 5 m/s on the concave supporting wall. The target is now under extensive test program using a high-power electron-gun. Up to 2 kW electron beam was applied on the lithium flow at velocity of 4 m/s without any flow instabilities or excessive evaporation. High-intensity proton beam irradiation will take place at SARAF (Soreq Applied Research Accelerator Facility) superconducting linear accelerator currently in commissioning at SNRC.

Halfon, S. [Soreq NRC, Yavne, 81800 (Israel) and Racah Institute of Physics, Hebrew University, Jerusalem, 91904 (Israel); Feinberg, G. [Soreq NRC, Yavne, 81800 (Israel) and Racah Institute of Physics, Hebrew University, Jerusalem, 91904 (Israel); Paul, M. [Racah Institute of Physics, Hebrew University, Jerusalem, 91904 (Israel); Arenshtam, A.; Berkovits, D.; Kijel, D.; Nagler, A.; Eliyahu, I.; Silverman, I. [Soreq NRC, Yavne, 81800 (Israel)

2013-04-19T23:59:59.000Z

27

E-Print Network 3.0 - associated-particle sealed-tube neutron...  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

of low-background 3 He proportional counters Summary: with a mixture of 3 He and CF4 gas capable of detecting the neutrons liberated by the neutrino-deuteron neutral......

28

High-power liquid-lithium jet target for neutron production  

SciTech Connect (OSTI)

A compact liquid-lithium target (LiLiT) was built and tested with a high-power electron gun at the Soreq Nuclear Research Center. The lithium target, to be bombarded by the high-intensity proton beam of the Soreq Applied Research Accelerator Facility (SARAF), will constitute an intense source of neutrons produced by the {sup 7}Li(p,n){sup 7}Be reaction for nuclear astrophysics research and as a pilot setup for accelerator-based Boron Neutron Capture Therapy. The liquid-lithium jet target acts both as neutron-producing target and beam dump by removing the beam thermal power (>5 kW, >1 MW/cm{sup 3}) with fast transport. The target was designed based on a thermal model, accompanied by a detailed calculation of the {sup 7}Li(p,n) neutron yield, energy distribution, and angular distribution. Liquid lithium is circulated through the target loop at ?200 °C and generates a stable 1.5 mm-thick film flowing at a velocity up to 7 m/s onto a concave supporting wall. Electron beam irradiation demonstrated that the liquid-lithium target can dissipate electron power areal densities of >4 kW/cm{sup 2} and volume power density of ?2 MW/cm{sup 3} at a lithium flow of ?4 m/s while maintaining stable temperature and vacuum conditions. The LiLiT setup is presently in online commissioning stage for high-intensity proton beam irradiation (1.91–2.5 MeV, 1–2 mA) at SARAF.

Halfon, S.; Feinberg, G. [Soreq NRC, Yavne 81800 (Israel) [Soreq NRC, Yavne 81800 (Israel); Racah Institute of Physics, Hebrew University, Jerusalem 91904 (Israel); Arenshtam, A.; Kijel, D.; Berkovits, D.; Eliyahu, I.; Hazenshprung, N.; Mardor, I.; Nagler, A.; Shimel, G.; Silverman, I. [Soreq NRC, Yavne 81800 (Israel)] [Soreq NRC, Yavne 81800 (Israel); Paul, M.; Friedman, M.; Tessler, M. [Racah Institute of Physics, Hebrew University, Jerusalem 91904 (Israel)] [Racah Institute of Physics, Hebrew University, Jerusalem 91904 (Israel)

2013-12-15T23:59:59.000Z

29

Compact neutron generator  

DOE Patents [OSTI]

A compact neutron generator has at its outer circumference a toroidal shaped plasma chamber in which a tritium (or other) plasma is generated. A RF antenna is wrapped around the plasma chamber. A plurality of tritium ion beamlets are extracted through spaced extraction apertures of a plasma electrode on the inner surface of the toroidal plasma chamber and directed inwardly toward the center of neutron generator. The beamlets pass through spaced acceleration and focusing electrodes to a neutron generating target at the center of neutron generator. The target is typically made of titanium tubing. Water is flowed through the tubing for cooling. The beam can be pulsed rapidly to achieve ultrashort neutron bursts. The target may be moved rapidly up and down so that the average power deposited on the surface of the target may be kept at a reasonable level. The neutron generator can produce fast neutrons from a T-T reaction which can be used for luggage and cargo interrogation applications. A luggage or cargo inspection system has a pulsed T-T neutron generator or source at the center, surrounded by associated gamma detectors and other components for identifying explosives or other contraband.

Leung, Ka-Ngo; Lou, Tak Pui

2005-03-22T23:59:59.000Z

30

HEATING DISTRIBUTIONS IN THE TARGET OF THE SPALLATION NEUTRON SOURCE  

Office of Scientific and Technical Information (OSTI)

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr May Jun Jul(Summary)morphinan antagonist Journal Article: Crystal structureComposite--FORRemarksHEATING DISTRIBUTIONS IN THE TARGET

31

Study on collimation and shielding of the back-streaming neutrons at the CSNS target  

E-Print Network [OSTI]

The back-streaming neutrons from the spallation target at CSNS are very intense, and can pose serious damage problems for the devices in the accelerator-target interface region. To tackle the problems, a possible scheme for this region was studied, namely a specially designed optics for the proton beam line produces two beam waists, and two collimators are placed at the two waist positions to maximize the collimation effect of the back-streaming neutrons. Detailed Monte Carlo simulations with the beams in the two different CSNS phases show the effectiveness of the collimation system, and the radiation dose rate decreases largely in the interface section. This can ensure the use of epoxy coils for the last magnets and other devices in the beam transport line with reasonable lifetimes, e.g. thirty years. The design philosophy for such an accelerator-target interface region can also be applicable to other high-power proton beam applications.

Han-Tao, Jing; Zheng, Yang

2013-01-01T23:59:59.000Z

32

The study of neutron spectra in water bath from Pb target irradiated by 250MeV/u protons  

E-Print Network [OSTI]

The spallation neutrons were produced by the irradiation of Pb with 250 MeV protons. The Pb target was surrounded by water which was used to slow down the emitted neutrons. The moderated neutrons in the water bath were measured by using the resonance detectors of Au, Mn and In with Cd cover. According to the measured activities of the foils, the neutron flux at different resonance energy were deduced and the epithermal neutron spectra were proposed. Corresponding results calculated with the Monte Carlo code MCNPX were compared with the experimental data to check the validity of the code.

Yanyan Li; Xueying Zhang; Yongqin Ju; Fei Ma; Hongbin Zhang; Liang Chen; Honglin Ge; Peng Luo; Bin Zhou; Yanbin Zhang; Jianyang Li; Junkui Xu; Songlin Wang; Yongwei Yang; Lei Yang

2014-09-05T23:59:59.000Z

33

Fast neutron scattering on Gallium target at 14.8 MeV  

E-Print Network [OSTI]

Benchmarking of evaluated nuclear data libraries was performed for $\\sim 14.8$ MeV neutrons on Gallium targets. The experiments were performed at China Institute of Atomic Energy(CIAE). Solid samples of natural Gallium (3.2 cm and 6.4 cm thick) were bombarded by $\\sim 14.8$ MeV neutrons and leakage neutron energy spectra were measured at 60$^{\\circ}$ and 120$^{\\circ}$. The measured spectra are rather well reproduced by MCNP-4C simulations with the CENDL-3.1, ENDF/B-VII and JENDL-4.0 evaluated nuclear data libraries, except for the inelastic contributions around $E_{n} = 10-13$ MeV. All three libraries significantly underestimate the inelastic contributions. The inelastic contributions are further studied, using the Talys simulation code and the experimental spectra are reproduced reasonably well in the whole energy range by the Talys calculation, including the inelastic contributions.

R. Han; R. Wada; Z. Chen; Y. Nie; X. Liu; S. Zhang; P. Ren; B. Jia; G. Tian; F. Luo; W. Lin; J. Liu; F. Shi; M. Huang; X. Ruan; J. Ren; Z. Zhou; H. Huang; J. Bao; K. Zhang; B. Hu

2014-11-03T23:59:59.000Z

34

Fast neutron scattering on Gallium target at 14.8 MeV  

E-Print Network [OSTI]

Benchmarking of evaluated nuclear data libraries was performed for $\\sim 14.8$ MeV neutrons on Gallium targets. The experiments were performed at China Institute of Atomic Energy(CIAE). Solid samples of natural Gallium (3.2 cm and 6.4 cm thick) were bombarded by $\\sim 14.8$ MeV neutrons and leakage neutron energy spectra were measured at 60$^{\\circ}$ and 120$^{\\circ}$. The measured spectra are rather well reproduced by MCNP-4C simulations with the CENDL-3.1, ENDF/B-VII and JENDL-4.0 evaluated nuclear data libraries, except for the inelastic contributions around $E_{n} = 10-13$ MeV. All three libraries significantly underestimate the inelastic contributions. The inelastic contributions are further studied, using the Talys simulation code and the experimental spectra are reproduced reasonably well in the whole energy range by the Talys calculation, including the inelastic contributions.

Han, R; Chen, Z; Nie, Y; Liu, X; Zhang, S; Ren, P; Jia, B; Tian, G; Luo, F; Lin, W; Liu, J; Shi, F; Huang, M; Ruan, X; Ren, J; Zhou, Z; Huang, H; Bao, J; Zhang, K; Hu, B

2014-01-01T23:59:59.000Z

35

Nuclear Simulation and Radiation Physics Investigations of the Target Station of the European Spallation Neutron Source  

SciTech Connect (OSTI)

The European Spallation Neutron Source (ESS) delivers high-intensity pulsed particle beams with 5-MW average beam power at 1.3-GeV incident proton energy. This causes sophisticated demands on material and geometry choices and a very careful optimization of the whole target system. Therefore, complex and detailed particle transport models and computer code systems have been developed and used to study the nuclear assessment of the ESS target system. The purpose here is to describe the methods of calculation mainly based on the Monte Carlo code to show the performance of the ESS target station. The interesting results of the simulations of the mercury target system are as follows: time-dependent neutron flux densities, energy deposition and heating, radioactivity and afterheat, materials damage by radiation, and high-energy source shielding. The results are discussed in great detail. The validity of codes and models, further requirements to improve the methods of calculation, and the status of running and planned experiments are given also.

Filges, Detlef; Neef, Ralf-Dieter; Schaal, Hartwig [Forschungszentrum Juelich GmbH (Germany)

2000-10-15T23:59:59.000Z

36

Neutronic Assessment of Transmutation Target Compositions in Heterogeneous Sodium Fast Reactor Geometries  

SciTech Connect (OSTI)

The sodium fast reactor is under consideration for consuming the transuranic waste in the spent nuclear fuel generated by light water reactors. This work is concerned with specialized target assemblies for an oxide-fueled sodium fast reactor that are designed exclusively for burning the americium and higher mass actinide component of light water reactor spent nuclear fuel (SNF). The associated gamma and neutron radioactivity, as well as thermal heat, associated with decay of these actinides may significantly complicate fuel handling and fabrication of recycled fast reactor fuel. The objective of using targets is to isolate in a smaller number of assemblies these concentrations of higher actinides, thus reducing the volume of fuel having more rigorous handling requirements or a more complicated fabrication process. This is in contrast to homogeneous recycle where all recycled actinides are distributed among all fuel assemblies. Several heterogeneous core geometries were evaluated to determine the fewest target assemblies required to burn these actinides without violating a set of established fuel performance criteria. The DIF3D/REBUS code from Argonne National Laboratory was used to perform the core physics and accompanying fuel cycle calculations in support of this work. Using the REBUS code, each core design was evaluated at the equilibrium cycle condition.

Samuel E. Bays; Rodolfo M. Ferrer; Michael A. Pope; Benoit Forget; Mehdi Asgari

2008-02-01T23:59:59.000Z

37

Instrument performance study on the short and long pulse options of the second Spallation Neutron Source target station  

SciTech Connect (OSTI)

The Spallation Neutron Source (SNS) facility at the Oak Ridge National Laboratory is designed with an upgrade option for a future low repetition rate, long wavelength second target station. This second target station is intended to complement the scientific capabilities of the 1.4 MW, 60 Hz high power first target station. Two upgrade possibilities have been considered, the short and the long pulse options. In the short pulse mode, proton extraction occurs after the pulse compression in the accumulator ring. The proton pulse structure is thus the same as that for the first target station with a pulse width of ?0.7 ?s. In the long pulse mode, protons are extracted as they are produced by the linac, with no compression in the accumulator ring. The time width of the uncompressed proton pulse is ?1 ms. This difference in proton pulse structure means that neutron pulses will also be different. Neutron scattering instruments thus have to be designed and optimized very differently for these two source options which will directly impact the overall scientific capabilities of the SNS facility. In order to assess the merits of the short and long pulse target stations, we investigated a representative suit of neutron scattering instruments and evaluated their performance under each option. Our results indicate that the short pulse option will offer significantly better performance for the instruments and is the preferred choice for the SNS facility.

Zhao, J. K.; Herwig, Kenneth W.; Robertson, J. L.; Gallmeier, Franz X.; Riemer, Bernard W. [Instrument and Source Division, Spallation Neutron Source, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831 (United States)] [Instrument and Source Division, Spallation Neutron Source, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831 (United States)

2013-10-15T23:59:59.000Z

38

Note: Proton irradiation at kilowatt-power and neutron production from a free-surface liquid-lithium target  

SciTech Connect (OSTI)

The free-surface Liquid-Lithium Target, recently developed at Soreq Applied Research Accelerator Facility (SARAF), was successfully used with a 1.9 MeV, 1.2 mA (2.3 kW) continuous-wave proton beam. Neutrons (?2 × 10{sup 10} n/s having a peak energy of ?27 keV) from the {sup 7}Li(p,n){sup 7}Be reaction were detected with a fission-chamber detector and by gold activation targets positioned in the forward direction. The setup is being used for nuclear astrophysics experiments to study neutron-induced reactions at stellar energies and to demonstrate the feasibility of accelerator-based boron neutron capture therapy.

Halfon, S.; Feinberg, G. [Soreq NRC, Yavne 81800 (Israel); Racah Institute of Physics, Hebrew University, Jerusalem 91904 (Israel); Arenshtam, A.; Kijel, D.; Weissman, L.; Aviv, O.; Berkovits, D.; Dudovitch, O.; Eisen, Y.; Eliyahu, I.; Haquin, G.; Hazenshprung, N.; Kreisel, A.; Mardor, I.; Shimel, G.; Shor, A.; Silverman, I.; Yungrais, Z. [Soreq NRC, Yavne 81800 (Israel); Paul, M., E-mail: paul@vms.huji.ac.il; Tessler, M. [Racah Institute of Physics, Hebrew University, Jerusalem 91904 (Israel)

2014-05-15T23:59:59.000Z

39

IPNS enriched uranium booster target  

SciTech Connect (OSTI)

Since startup in 1981, IPNS has operated on a fully depleted /sup 238/U target. With the booster as in the present system, high energy protons accelerated to 450 MeV by the Rapid Cycling Synchrotron are directed at the target and by mechanisms of spallation and fission of the uranium, produce fast neutrons. The neutrons from the target pass into adjacent moderator where they slow down to energies useful for spectroscopy. The target cooling systems and monitoring systems have operated very reliably and safely during this period. To provide higher neutron intensity, we have developed plans for an enriched uranium (booster) target. HETC-VIM calculations indicate that the target will produce approx.90 kW of heat, with a nominal x5 gain (k/sub eff/ = 0.80). The neutron beam intensity gain will be a factor of approx.3. Thermal-hydraulic and heat transport calculations indicate that approx.1/2 in. thick /sup 235/U discs are subject to about the same temperatures as the present /sup 238/U 1 in. thick discs. The coolant will be light demineralized water (H/sub 2/O) and the coolant flow rate must be doubled. The broadening of the fast neutron pulse width should not seriously affect the neutron scattering experiments. Delayed neutrons will appear at a level about 3% of the total (currently approx.0.5%). This may affect backgrounds in some experiments, so that we are assessing measures to control and correct for this (e.g., beam tube choppers). Safety analyses and neutronic calculations are nearing completion. Construction of the /sup 235/U discs at the ORNL Y-12 facility is scheduled to begin late 1985. The completion of the booster target and operation are scheduled for late 1986. No enriched uranium target assembly operating at the projected power level now exists in the world. This effort thus represents an important technological experiment as well as being a ''flux enhancer''.

Schulke, A.W. Jr.

1985-01-01T23:59:59.000Z

40

Testing of T-odd, P-even interactions by nonpolarized neutron transmission through a nonpolarized nuclear target placed into electric field  

E-Print Network [OSTI]

A new possibility for the study of time-reversal violation is described. It consists in measurement of nonpolarized neutron transmission through nonpolarized nuclear target placed into electric field

V. G. Baryshevsky

2003-12-01T23:59:59.000Z

Note: This page contains sample records for the topic "neutron tube target" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


41

Design of a TOF-SANS instrument for the proposed Long Wavelength Target Station at the Spallation Neutron Source.  

SciTech Connect (OSTI)

We have designed a versatile high-throughput SANS instrument [Broad Range Intense Multipurpose SANS (BRIMS)] for the proposed Long Wavelength Target Station at the SNS by using acceptance diagrams and the Los Alamos NISP Monte Carlo simulation package. This instrument has been fully optimized to take advantage of the 10 Hz source frequency (broad wavelength bandwidth) and the cold neutron spectrum from a tall coupled solid methane moderator (12 cm x 20 cm). BRIMS has been designed to produce data in a Q range spanning from 0.001 to 0.7 {angstrom}{sup {minus}1} in a single measurement by simultaneously using neutrons with wavelengths ranging from 1 to 14.5 {angstrom} in a time of flight mode. A supermirror guide and bender assembly is employed to separate and redirect the useful portion of the neutron spectrum with {lambda} > 1 {angstrom}, by 2.3{degree} away from the direct beam containing high energy neutrons and {gamma} rays. The effects of the supermirror coating of the guide, the location of the bender assembly with respect to the source, the bend angle, and various collimation choices on the flux, resolution and Q{sub min} have been characterized using spherical particle and delta function scatterers. The overall performance of BRIMS has been compared with that of the best existing reactor-based SANS instrument D22 at ILL.

Thiyagarajan, P.; Littrell, K.; Seeger, P. A.

2000-11-28T23:59:59.000Z

42

Thermal-hydraulic performance of a water-cooled tungsten-rod target for a spallation neutron source  

SciTech Connect (OSTI)

A thermal-hydraulic (T-H) analysis is conducted to determine the feasibility and limitations of a water-cooled tungsten-rod target at powers of 1 MW and above. The target evaluated has a 10-cm x 10-cm cross section perpendicular to the beam axis, which is typical of an experimental spallation neutron source - both for a short-pulse spallation source and long-pulse spallation source. This report describes the T-H model and assumptions that are used to evaluate the target. A 1-MW baseline target is examined, and the results indicate that this target should easily handle the T-H requirements. The possibility of operating at powers >1 MW is also examined. The T-H design is limited by the condition that the coolant does not boil (actual limits are on surface subcooling and wall heat flux); material temperature limits are not approached. Three possible methods of enhancing the target power capability are presented: reducing peak power density, altering pin dimensions, and improving coolant conditions (pressure and temperature). Based on simple calculations, it appears that this target concept should have little trouble reaching the 2-MW range (from a purely T-H standpoint), and possibly much higher powers. However, one must keep in mind that these conclusions are based solely on thermal-hydraulics. It is possible, and perhaps likely, that target performance could be limited by structural issues at higher powers, particularly for a short-pulse spallation source because of thermal shock issues.

Poston, D.I.

1997-08-01T23:59:59.000Z

43

Status of R&D on Mitigating the Effects of Pressure Waves for the Spallation Neutron Source Mercury Target  

SciTech Connect (OSTI)

The Spallation Neutron Source (SNS) at the Oak Ridge National Laboratory has been conducting R&D on mitigating the effects of pressure waves in mercury spallation targets since 2001. More precisely, cavitation damage of the target vessel caused by the short beam pulse threatens to limit its lifetime more severely than radiation damage as well as limit its ultimate power capacity and hence its neutron intensity performance. The R&D program has moved from verification of the beam-induced damage phenomena to study of material and surface treatments for damage resistance to the current emphasis on gas injection techniques for damage mitigation. Two techniques are being worked on: injection of small dispersed gas bubbles that mitigate the pressure waves volumetrically; and protective gas walls that isolate the vessel from the damaging effects of collapsing cavitation bubbles. The latter has demonstrated good damage mitigation during in-beam testing with limited pulses, and adequate gas wall coverage at the beam entrance window has been demonstrated with the SNS mercury target flow configuration using a full scale mercury test loop. A question on the required area coverage remains which depends on results from SNS target post irradiation examination. The small gas bubble technique has been less effective during past in-beam tests but those results were with un-optimized and un-verified bubble populations. Another round of in-beam tests with small gas bubbles is planned for 2011. The first SNS target was removed from service in mid 2009 and samples were cut from two locations at the target s beam entrance window. Through-wall damage was observed at the innermost mercury vessel wall (not a containment wall). The damage pattern suggested correlation with the local mercury flow condition which is nearly stagnant at the peak damage location. Detailed post irradiation examination of the samples is under way that will assess the erosion and measure irradiation-induced changes in mechanical properties. Similar samples were cut from the second SNS target after it was removed from service in mid 2010. More extensive damage was observed on the target inner wall but damage to the containment wall was minimal.

Riemer, Bernie [ORNL] [ORNL; Wendel, Mark W [ORNL] [ORNL; Felde, David K [ORNL] [ORNL; Abdou, Ashraf A [ORNL] [ORNL; McClintock, David A [ORNL] [ORNL

2012-01-01T23:59:59.000Z

44

Measuring the Neutron Lifetime Using Magnetically Trapped Neutrons  

E-Print Network [OSTI]

The neutron beta-decay lifetime plays an important role both in understanding weak interactions within the framework of the Standard Model and in theoretical predictions of the primordial abundance of 4He in Big Bang Nucleosynthesis. In previous work, we successfully demonstrated the trapping of ultracold neutrons (UCN) in a conservative potential magnetic trap. A major upgrade of the apparatus is nearing completion at the National Institute of Standards and Technology Center for Neutron Research (NCNR). In our approach, a beam of 0.89 nm neutrons is incident on a superfluid 4He target within the minimum field region of an Ioffe-type magnetic trap. A fraction of the neutrons is downscattered in the helium to energies <200 neV, and those in the appropriate spin state become trapped. The inverse process is suppressed by the low phonon density of helium at temperatures less than 200 mK, allowing the neutron to travel undisturbed. When the neutron decays the energetic electron ionizes the helium, producing scintillation light that is detected using photomultiplier tubes. Statistical limitations of the previous apparatus will be alleviated by significant increases in field strength and trap volume resulting in twenty times more trapped neutrons.

C. M. O'Shaughnessy; R. Golub; K. W. Schelhammer; C. M. Swank; P. -N. Seo; P. R. Huffman; S. N. Dzhosyuk; C. E. H. Mattoni; L. Yang; J. M. Doyle; K. J. Coakley; A. K. Thompson; H. P. Mumm; S. K. Lamoreaux; G. Yang

2009-03-31T23:59:59.000Z

45

The thick-target {sup 9}Be(d,n) neutron spectra for deuteron energies between 2.6 and 7.0-MeV  

SciTech Connect (OSTI)

The measurement of the zero deg. neutron spectra and yields from deuterons incident on thick beryllium metal targets is described. {sup 235}U and {sup 238}U fission ion chambers were used as neutron detectors to span the neutron energy range above 0.05-MeV with a time resolution of {le} 3 nanosec. Measurements were made for incident deuteron energies from 2.6 to 7.0-MeV, at 0.4-MeV intervals, using time-of-flight techniques with flight paths of 2.7 and 6.8 meters. The results are presented in graphical form and in tables.

Meadows, J.W.

1991-11-01T23:59:59.000Z

46

The thick-target sup 9 Be(d,n) neutron spectra for deuteron energies between 2. 6 and 7. 0-MeV  

SciTech Connect (OSTI)

The measurement of the zero deg. neutron spectra and yields from deuterons incident on thick beryllium metal targets is described. {sup 235}U and {sup 238}U fission ion chambers were used as neutron detectors to span the neutron energy range above 0.05-MeV with a time resolution of {le} 3 nanosec. Measurements were made for incident deuteron energies from 2.6 to 7.0-MeV, at 0.4-MeV intervals, using time-of-flight techniques with flight paths of 2.7 and 6.8 meters. The results are presented in graphical form and in tables.

Meadows, J.W.

1991-11-01T23:59:59.000Z

47

Measurements of delayed neutrons yields and time spectra from 1 GeV protons interacting with thick {sup nat}Pb targets  

SciTech Connect (OSTI)

This paper presents the preliminary results on measured delayed neutron (DN) yields and time spectra from 1 GeV protons interacting with thick {sup nat}Pb targets. In parallel, the MCNPX and PHTTS codes were used to predict the DN precursors and construct the theoretical DN tables. Different model parameters are examined and show significant dependence on the choice of the intra-nuclear cascade and fission-evaporation models used. These data and modeling are of great importance for the new generation spallation neutron sources based on liquid metal technologies where a significant amount of the DN precursor activity can be accumulated in the target fluid. (authors)

Ridikas, D. [CEA Saclay, DSM/DAPNIA, 91191 Gif-sur-Yvette (France); Barzakh, A. [Petersburg Nuclear Physics Inst., Leningrad district, 188350 Gatchina (Russian Federation); Blideanu, V.; David, J. C.; Dore, D. [CEA Saclay, DSM/DAPNIA, 91191 Gif-sur-Yvette (France); Fedorov, D. [Petersburg Nuclear Physics Inst., Leningrad district, 188350 Gatchina (Russian Federation); Ledoux, X. [CEA Bruyeres, DIF/DPTA, 91680 Bruyeres-le-Chatel (France); Moroz, F.; Panteleev, V. [Petersburg Nuclear Physics Inst., Leningrad district, 188350 Gatchina (Russian Federation); Plukis, A.; Plukiene, R. [Inst. of Physics, Savanoriu pr. 231, 02300 Vilnius (Lithuania); Prevost, A. [CEA Saclay, DSM/DAPNIA, 91191 Gif-sur-Yvette (France); Shcherbakov, O.; Vorobyev, A. [Petersburg Nuclear Physics Inst., Leningrad district, 188350 Gatchina (Russian Federation)

2006-07-01T23:59:59.000Z

48

Design and Testing of a Prototype Spallation Neutron Source Rotating Target Assembly  

SciTech Connect (OSTI)

The mechanical aspects of an extended vertical shaft rotating target have been evaluated in a full-scale mockup test. A prototype assembly based on a conceptual target design for a 1 to 3-MW spallation facility was built and tested. Key elements of the drive/coupling assembly implemented in the prototype include high integrity dynamic face seals, commercially available bearings, realistic manufacturing tolerances, effective monitoring and controls, and fail-safe shutdown features. A representative target disk suspended on a 3.5 meter prototypical shaft was coupled with the drive to complete the mechanical tests. After1800 hours of operation the test program has confirmed the overall mechanical feasibility of the extended vertical shaft rotating target concept. Precision alignment of the suspended target disk; successful containment of the water and verification of operational stability over the full speed range of 30 to 60 rpm were primary indications the proposed mechanical design is valid for use in a high power target station.

Rennich, Mark J [ORNL; McManamy, Thomas J [ORNL; Graves, Van [Oak Ridge National Laboratory (ORNL); Garmendia, Amaia Zarraoa [IDOM Bilbao; Sorda, Fernando [ESS Bilbao

2010-01-01T23:59:59.000Z

49

Neutron-Rich Isotope Production Using a Uranium Carbide Carbon Nanotubes SPES Target Prototype  

SciTech Connect (OSTI)

The SPES (Selective Production of Exotic Species) project, under development at the Istituto Nazionale di Fisica Nucleare - Laboratori Nazionali di Legnaro (INFN-LNL), is a new-generation Isotope Separation On-Line (ISOL) facility for the production of radioactive ion beams by means of the proton-induced fission of uranium. In the framework of the research on the SPES target, seven uranium carbide discs, obtained by reacting uranium oxide with graphite and carbon nanotubes, were irradiated with protons at the Holifield Radioactive Ion Beam Facility (HRIBF) of Oak Ridge National Laboratory (ORNL). In the following, the yields of several fission products obtained during the experiment are presented and discussed. The experimental results are then compared to those obtained using a standard uranium carbide target. The reported data highlights the capability of the new type of SPES target to produce and release isotopes of interest for the nuclear physics community.

Corradetti, Stefano [ORNL; Biasetto, Lisa [INFN, Laboratori Nazionali di Legnaro, Italy; Manzolaro, Mattia [INFN, Laboratori Nazionali di Legnaro, Italy; Scarpa, Daniele [ORNL; Carturan, S. [INFN, Laboratori Nazionali di Legnaro, Italy; Andrighetto, Alberto [INFN, Laboratori Nazionali di Legnaro, Italy; Prete, Gianfranco [ORNL; Vasquez, Jose L [ORNL; Zanonato, P. [Dipartimento di Scienze Chimiche, Padova, Italy; Colombo, P. [Dipartimento di Ingegneria Meccanica, Padova, Italy; Jost, Carola [University of Tennessee, Knoxville (UTK); Stracener, Daniel W [ORNL

2013-01-01T23:59:59.000Z

50

The Susceptibility of Materials in Spallation Neutron Source Target and Blanket Cooling Loops to Corrosion  

E-Print Network [OSTI]

to Corrosion R. Scott Lillard, Darryl P. Butt Materials Corrosion and Environmental Effects Lab MST-6 cooling loops to corrosion. To simulate the environment that materials may be exposed to in a target of exposing corrosion samples to an 800 MeV proton beam at currents upwards of 1 mA was constructed. This loop

51

Progress on Neutron-Target Multipoles above 1 GeV  

SciTech Connect (OSTI)

We report a new extraction of nucleon resonance couplings using ?{sup ?} photo-production cross sections on the neutron. The world database for the process ?n ? ?{sup ?}p above 1 GeV has quadrupled with the addition of new differential cross sections from the CEBAF Large Acceptance Spectrometer (CLAS) at Jefferson Lab in Hall B. Differential cross sections from CLAS have been improved with a new final-state interaction determination using a diagrammatic technique taking into account the SAID phenomenological NN and ?N final-state interaction amplitudes. Resonance couplings have been extracted and compared to previous determinations. With the addition of these new cross sections, significant changes are seen in the high-energy behavior of the SAID cross sections and amplitudes.

Strakovsky, I I; Gao, H; Briscoe, W J; Dutta, D; Kudryavtsev, A E; Mirazite, M; Paris, M; Rossi, P; Stepanyan, S; Tarasov, V E

2012-12-01T23:59:59.000Z

52

A Measurement of the neutron electric form factor at very large momentum transfer using polaried electrions scattering from a polarized helium-3 target  

SciTech Connect (OSTI)

Knowledge of the electric and magnetic elastic form factors of the nucleon is essential for an understanding of nucleon structure. Of the form factors, the electric form factor of the neutron has been measured over the smallest range in Q{sup 2} and with the lowest precision. Jefferson Lab experiment 02-013 used a novel new polarized {sup 3}He target to nearly double the range of momentum transfer in which the neutron form factor has been studied and to measure it with much higher precision. Polarized electrons were scattered off this target, and both the scattered electron and neutron were detected. G{sup n}{sub E} was measured to be 0.0242 ± 0.0020(stat) ± 0.0061(sys) and 0.0247 ± 0.0029(stat) ± 0.0031(sys) at Q{sup 2} = 1.7 and 2.5 GeV{sup 2}, respectively.

Aidan Kelleher

2010-10-01T23:59:59.000Z

53

Summary of Mercury Compatibility Issues for the Spallation Neutron Source Target Containment and Ancillary Equipment  

SciTech Connect (OSTI)

The purpose of this document is to summarize the primary results of the Hg compatibility research in support of the SNS target. In the absence of possible synergisms resulting from beam/irradiation effects, wetting of 316L/316LN stainless steel under SNS conditions by the Hg target is expected to be very limited. As a result, significant interactions such as dissolution, mass transfer, and embrittlement affecting general compatibility are not anticipated. A wide range of experiments on 316L/316LN stainless steel, including thermal convection and pumped loops, confirmed low corrosion/penetration rates in Hg up to 305 C and little or no wetting or mass transfer below about 250 C. A variety of standard mechanical tests comparing behavior of 316L in air and Hg revealed limited wetting and no degradation of mechanical properties such as reduced elongation or development of brittle fracture features. Preliminary fatigue tests indicated a negative effect (reduced cycles to failure and intergranular cracking) at very high loads for 316LN, but little or no effect at more modest loading. Annealed 316LN was found to be somewhat susceptible to cavitation-erosion damage, but significant improvement was realized with a kolsterizing surface treatment or coldworking the material. Within the scope of these test conditions, no compatibility-limited operations were identified for type 316L/316LN stainless steel (and variations thereof) as the Hg target containment material. More limited compatibility data on other materials are also reported.

Pawel, SJ

2003-04-08T23:59:59.000Z

54

Thermal-hydraulic design of the target/blanket for the accelerator production of tritium conceptual design  

SciTech Connect (OSTI)

A conceptual design was developed for the target/blanket system of an accelerator-based system to produce tritium. The target/blanket system uses clad tungsten rods for a spallation target and clad lead rods as a neutron multiplier in a blanket surrounding the target. The neutrons produce tritium in {sup 3}He, which is contained in aluminum tubes located in the decoupler and blanket regions. This paper presents the thermal-hydraulic design of the target, decoupler, and blanket developed for the conceptual design of the Accelerator Production of Tritium Project, and demonstrates there is adequate margin in the design at full power operation.

Willcutt, G.J.E. Jr.; Kapernick, R.J.

1997-11-01T23:59:59.000Z

55

Correlation between simulations and cavitation-induced erosion damage in Spallation Neutron Source target modules after operation  

SciTech Connect (OSTI)

An explicit finite element (FE) technique developed for estimating dynamic strain in the Spallation Neutron Source (SNS) mercury target module vessel is now providing insight into cavitation damage patterns observed in used targets. The technique uses an empirically developed material model for the mercury that describes liquid-like volumetric stiffness combined with a tensile pressure cut-off limit that approximates cavitation. The longest period each point in the mercury is at the tensile cut-off threshold is denoted its saturation time. Now, the pattern of saturation time can be obtained from these simulations and is being positively correlated with observed damage patterns and is interpreted as a qualitative measure of damage potential. Saturation time has been advocated by collaborators at J-Parc as a factor in predicting bubble nuclei growth and collapse intensity. The larger the ratio of maximum bubble size to nucleus, the greater the bubble collapse intensity to be expected; longer saturation times result in greater ratios. With the recent development of a user subroutine for the FE solver saturation time is now provided over the entire mercury domain. Its pattern agrees with spots of damage seen above and below the beam axis on the SNS inner vessel beam window and elsewhere. The other simulation result being compared to observed damage patterns is mercury velocity at the wall. Related R&D has provided evidence for the damage mitigation that higher wall velocity provides. In comparison to observations in SNS targets, inverse correlation of high velocity to damage is seen. In effect, it is the combination of the patterns of saturation time and low velocity that seems to match actual damage patterns.

Riemer, Bernie [ORNL] [ORNL; McClintock, David A [ORNL] [ORNL; Kaminskas, Saulius [ORNL] [ORNL; Abdou, Ashraf A [ORNL] [ORNL

2014-01-01T23:59:59.000Z

56

ACHIEVING THE REQUIRED COOLANT FLOW DISTRIBUTION FOR THE ACCELERATOR PRODUCTION OF TRITIUM (APT) TUNGSTEN NEUTRON SOURCE  

SciTech Connect (OSTI)

The Accelerator Production of Tritium neutron source consists of clad tungsten targets, which are concentric cylinders with a center rod. These targets are arranged in a matrix of tubes, producing a large number of parallel coolant paths. The coolant flow required to meet thermal-hydraulic design criteria varies with location. This paper describes the work performed to ensure an adequate coolant flow for each target for normal operation and residual heat-removal conditions.

D. SIEBE; K. PASAMEHMETOGLU

2000-11-01T23:59:59.000Z

57

Shielding Experiments Under JASMIN Collaboration at Fermilab(IV) - Measurement and Analyses of High-Energy Neutron Spectra in the Anti-Proton Target Station  

E-Print Network [OSTI]

Neutron spectra in high-energy region between 1 and 100-MeV in the shield configuration of the anti-proton target station and a 120-GeV proton beam at Fermi National Accelerator Laboratory (Fermilab) were determined using the reaction rate data obtained with the multi-foil activation method. Two kinds of methods were employed for the determination of neutron spectra: one is the fitting method which is newly developed in this work, another is the unfolding method with SAND-II code. The calculations were performed using the PHITS. From the comparison between the calculated and experimental neutron spectra, it concluded that the PHITS can be used for shielding design of high-energy proton accelerators.

JASMIN Collaboration

2012-04-27T23:59:59.000Z

58

Systematics of 0-Degrees Neutron-Production by 800 Mev Protons on Targets with 27 Less-Than-Or-Equal-to a Less-Than-Or-Equal-to 238  

E-Print Network [OSTI]

associated cross sections. I. INTRODUCTION We report here absolute measurements of the 0' neutron spectra produced by 800 MeV proton col- lisions with targets of Al, Ti, Cu, W, Pb, and U. The resolution attained in the measurement of the neutron... SYSTEMATICS OF 0 NEUTRON PBODUCTION BY 800 MeV. . . FIG. 1. Plan view of the experimental setup used for the present measurements. The targets were mounted at the location indicated by LD2 in the figure. rotateble target wheel which was used to position...

Bonner, BE; Simmons, J. E.; Newsom, C. R.; Riley, P. J.; Glass, G.; Hiebert, John C.; Jain, M.; Northcliffe, L. C.

1978-01-01T23:59:59.000Z

59

Proton recoil scintillator neutron rem meter  

DOE Patents [OSTI]

A neutron rem meter utilizing proton recoil and thermal neutron scintillators to provide neutron detection and dose measurement. In using both fast scintillators and a thermal neutron scintillator the meter provides a wide range of sensitivity, uniform directional response, and uniform dose response. The scintillators output light to a photomultiplier tube that produces an electrical signal to an external neutron counter.

Olsher, Richard H. (Los Alamos, NM); Seagraves, David T. (Los Alamos, NM)

2003-01-01T23:59:59.000Z

60

Neutron source, linear-accelerator fuel enricher and regenerator and associated methods  

DOE Patents [OSTI]

A device for producing fissile material inside of fabricated nuclear elements so that they can be used to produce power in nuclear power reactors. Fuel elements, for example, of a LWR are placed in pressure tubes in a vessel surrounding a liquid lead-bismuth flowing columnar target. A linear-accelerator proton beam enters the side of the vessel and impinges on the dispersed liquid lead-bismuth columns and produces neutrons which radiate through the surrounding pressure tube assembly or blanket containing the nuclear fuel elements. These neutrons are absorbed by the natural fertile uranium-238 elements and are transformed to fissile plutonium-239. The fertile fuel is thus enriched in fissile material to a concentration whereby they can be used in power reactors. After use in the power reactors, dispensed depleted fuel elements can be reinserted into the pressure tubes surrounding the target and the nuclear fuel regenerated for further burning in the power reactor.

Steinberg, Meyer (Huntington Station, NY); Powell, James R. (Shoreham, NY); Takahashi, Hiroshi (Setauket, NY); Grand, Pierre (Blue Point, NY); Kouts, Herbert (Brookhaven, NY)

1982-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "neutron tube target" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


61

Neutron capture therapy with deep tissue penetration using capillary neutron focusing  

DOE Patents [OSTI]

An improved method for delivering thermal neutrons to a subsurface cancer or tumor which has been first doped with a dopant having a high cross section for neutron capture. The improvement is the use of a guide tube in cooperation with a capillary neutron focusing apparatus, or neutron focusing lens, for directing neutrons to the tumor, and thereby avoiding damage to surrounding tissue.

Peurrung, Anthony J. (Richland, WA)

1997-01-01T23:59:59.000Z

62

Multiple tube premixing device  

DOE Patents [OSTI]

The present application provides a premixer for a combustor. The premixer may include a fuel plenum with a number of fuel tubes and a burner tube with a number of air tubes. The fuel tubes extend about the air tubes.

Uhm, Jong Ho; Naidu, Balachandar; Ziminksy, Willy Steve; Kraemer, Gilbert Otto; Yilmaz, Ertan; Lacy, Benjamin; Stevenson, Christian; Felling, David

2013-08-13T23:59:59.000Z

63

Multiple tube premixing device  

DOE Patents [OSTI]

The present application provides a premixer for a combustor. The premixer may include a fuel plenum with a number of fuel tubes and a burner tube with a number of air tubes. The fuel tubes extend about the air tubes.

Uhm, Jong Ho; Varatharajan, Balachandar; Ziminsky, Willy Steve; Kraemer, Gilbert Otto; Yilmaz, Ertan; Lacy, Benjamin; Stevenson, Christian; Felling, David

2012-12-11T23:59:59.000Z

64

Neutron dose equivalent meter  

DOE Patents [OSTI]

A neutron dose equivalent detector for measuring neutron dose capable of accurately responding to neutron energies according to published fluence to dose curves. The neutron dose equivalent meter has an inner sphere of polyethylene, with a middle shell overlying the inner sphere, the middle shell comprising RTV.RTM. silicone (organosiloxane) loaded with boron. An outer shell overlies the middle shell and comprises polyethylene loaded with tungsten. The neutron dose equivalent meter defines a channel through the outer shell, the middle shell, and the inner sphere for accepting a neutron counter tube. The outer shell is loaded with tungsten to provide neutron generation, increasing the neutron dose equivalent meter's response sensitivity above 8 MeV.

Olsher, Richard H. (Los Alamos, NM); Hsu, Hsiao-Hua (Los Alamos, NM); Casson, William H. (Los Alamos, NM); Vasilik, Dennis G. (Los Alamos, NM); Kleck, Jeffrey H. (Menlo Park, CA); Beverding, Anthony (Foster City, CA)

1996-01-01T23:59:59.000Z

65

Downhole pulse tube refrigerators  

SciTech Connect (OSTI)

This report summarizes a preliminary design study to explore the plausibility of using pulse tube refrigeration to cool instruments in a hot down-hole environment. The original motivation was to maintain Dave Reagor`s high-temperature superconducting electronics at 75 K, but the study has evolved to include three target design criteria: cooling at 30 C in a 300 C environment, cooling at 75 K in a 50 C environment, cooling at both 75 K and 30 C in a 250 C environment. These specific temperatures were chosen arbitrarily, as representative of what is possible. The primary goals are low cost, reliability, and small package diameter. Pulse-tube refrigeration is a rapidly growing sub-field of cryogenic refrigeration. The pulse tube refrigerator has recently become the simplest, cheapest, most rugged and reliable low-power cryocooler. The authors expect this technology will be applicable downhole because of the ratio of hot to cold temperatures (in absolute units, such as Kelvin) of interest in deep drilling is comparable to the ratios routinely achieved with cryogenic pulse-tube refrigerators.

Swift, G.; Gardner, D. [Los Alamos National Lab., NM (United States). Condensed Matter and Thermal Physics Group

1997-12-01T23:59:59.000Z

66

Neutron spectral and angular distribution measurements for 113 and 256 MeV protons on range-thick Al and sup 238 U targets using the foil activation techniques  

SciTech Connect (OSTI)

Second neutron yields, energy spectra, and angular distributions have been measured at seven angles from 0 to 150{degree} for 113 and 256 MeV protons stopped in range-thick targets of aluminum and depleted uranium ({sup 238}U). Thin foil stacks of ten different materials were activated by secondary neutrons at distances of 20--30 cm from the targets. Following each irradiation, 30--40 different activation products were measured by gamma-ray spectroscopy. These activation rates were then used to adjust neutron energy spectra calculated by the HETC computer code. Activation cross sections were taken from ENDF/BV below 20 MeV, from literature values tested in Be(d,n) fields up to 50 MeV, and from proton spallation data and calculations from 50--250 MeV. Spectral adjustments were made with the STAY'SL computer code using a least-squares technique to minimize {chi}{sup 2} for a covariance matrix determined from uncertainties in the measured activities, cross sections, and calculated flux spectra. Neutron scattering effects were estimated from foil packets irradiated at different distances from the target. Proton effects were measured with (p,n) reactions. Systematic differences were found between the adjusted and calculated neutron spectra, namely, that HETC underpredicts the neutron flux at back angles by a factor of 2--3 and slightly overpredicts the flux at forward angles. 19 refs., 23 figs., 13 tabs.

Greenwood, L.R.; Intasorn, A.

1989-07-01T23:59:59.000Z

67

Shielding Experiments Under JASMIN Collaboration at Fermilab(III) - Measurement of High-Energy Neutrons Penetrating a Thick Iron Shield from the Antiproton Production Target by AU Activation Method  

E-Print Network [OSTI]

In an antiproton production (Pbar) target station of the Fermi National Accelerator Laboratory (FNAL), the secondary particles produced by bombarding a target with 120-GeV protons are shielded by a thick iron shield. In order to obtain experimental data on high-energy neutron transport at more than 100-GeV-proton accelerator facilities, we indirectly measured more than 100-MeV neutrons at the outside of the iron shield at an angle of 50{\\deg} in the Pbar target station. The measurement was performed by using the Au activation method coupled with a low-background {\\gamma}-ray counting system. As an indicator for the neutron flux, we determined the production rates of 8 spallation nuclides (196-Au, 188-Pt, 189-Ir, 185-Os, 175-Hf, 173-Lu, 171-Lu, and 169-Yb) in the Au activation detector. The measured production rates were compared with the theoretical production rates calculated using PHITS. We proved that the Au activation method can serve as a powerful tool for indirect measurements of more than 100-MeV neutrons that play a vital role in neutron transport. These results will be important for clarifying the problems in theoretical calculations of high-energy neutron transport.

H. Matsumura; N. Kinoshita; H. Iwase; A. Toyoda; Y. Kasugai; N. Matsuda; Y. Sakamoto; H. Nakashima; H. Yashima; N. Mokhov; A. Leveling; D. Boehlein; K. Vaziri; G. Lautenschlager; W. Schmitt; K. Oishi

2012-05-01T23:59:59.000Z

68

Source Terms for HFIR Beam Tube Shielding Analyses, and a Complete Shielding Analysis of the HB-3 Tube  

SciTech Connect (OSTI)

The High Flux Isotope Reactor (HFIR) at the Oak Ridge National Laboratory is in the midst of a massive upgrade program to enhance experimental facilities. The reactor presently has four horizontal experimental beam tubes, all of which will be replaced or redesigned. The HB-2 beam tube will be enlarged to support more guide tubes, while the HB-4 beam tube will soon include a cold neutron source.

Bucholz, J.A.

2000-07-01T23:59:59.000Z

69

Pulsed-neutron monochromator  

DOE Patents [OSTI]

In one aspect, the invention is an improved pulsed-neutron monochromator of the vibrated-crystal type. The monochromator is designed to provide neutron pulses which are characterized both by short duration and high density. A row of neutron-reflecting crystals is disposed in a neutron beam to reflect neutrons onto a common target. The crystals in the row define progressively larger neutron-scattering angles and are vibrated sequentially in descending order with respect to the size of their scattering angles, thus generating neutron pulses which arrive simultaneously at the target. Transducers are coupled to one end of the crystals to vibrate them in an essentially non-resonant mode. The transducers propagate transverse waves in the crystal which progress longitudinally therein. The waves are absorbed at the undriven ends of the crystals by damping material mounted thereon. In another aspect, the invention is a method for generating neutron pulses characterized by high intensity and short duration.

Mook, H.A. Jr.

1984-01-01T23:59:59.000Z

70

Pulsed-neutron monochromator  

DOE Patents [OSTI]

In one aspect, the invention is an improved pulsed-neutron monochromator of the vibrated-crystal type. The monochromator is designed to provide neutron pulses which are characterized both by short duration and high density. A row of neutron-reflecting crystals is disposed in a neutron beam to reflect neutrons onto a common target. The crystals in the row define progressively larger neutron-scattering angles and are vibrated sequentially in descending order with respect to the size of their scattering angles, thus generating neutron pulses which arrive simultaneously at the target. Transducers are coupled to one end of the crystals to vibrate them in an essentially non-resonant mode. The transducers propagate transverse waves in the crystal which progress longitudinally therein. The wave are absorbed at the undriven ends of the crystals by damping material mounted thereon. In another aspect, the invention is a method for generating neutron pulses characterized by high intensity and short duration.

Mook, Jr., Herbert A. (Oak Ridge, TN)

1985-01-01T23:59:59.000Z

71

Cylindrical neutron generator  

DOE Patents [OSTI]

A cylindrical neutron generator is formed with a coaxial RF-driven plasma ion source and target. A deuterium (or deuterium and tritium) plasma is produced by RF excitation in a cylindrical plasma ion generator using an RF antenna. A cylindrical neutron generating target is coaxial with the ion generator, separated by plasma and extraction electrodes which contain many slots. The plasma generator emanates ions radially over 360.degree. and the cylindrical target is thus irradiated by ions over its entire circumference. The plasma generator and target may be as long as desired. The plasma generator may be in the center and the neutron target on the outside, or the plasma generator may be on the outside and the target on the inside. In a nested configuration, several concentric targets and plasma generating regions are nested to increase the neutron flux.

Leung, Ka-Ngo

2005-06-14T23:59:59.000Z

72

Cylindrical neutron generator  

DOE Patents [OSTI]

A cylindrical neutron generator is formed with a coaxial RF-driven plasma ion source and target. A deuterium (or deuterium and tritium) plasma is produced by RF excitation in a cylindrical plasma ion generator using an RF antenna. A cylindrical neutron generating target is coaxial with the ion generator, separated by plasma and extraction electrodes which contain many slots. The plasma generator emanates ions radially over 360.degree. and the cylindrical target is thus irradiated by ions over its entire circumference. The plasma generator and target may be as long as desired. The plasma generator may be in the center and the neutron target on the outside, or the plasma generator may be on the outside and the target on the inside. In a nested configuration, several concentric targets and plasma generating regions are nested to increase the neutron flux.

Leung, Ka-Ngo (Hercules, CA)

2008-04-22T23:59:59.000Z

73

Cylindrical neutron generator  

DOE Patents [OSTI]

A cylindrical neutron generator is formed with a coaxial RF-driven plasma ion source and target. A deuterium (or deuterium and tritium) plasma is produced by RF excitation in a cylindrical plasma ion generator using an RF antenna. A cylindrical neutron generating target is coaxial with the ion generator, separated by plasma and extraction electrodes which contain many slots. The plasma generator emanates ions radially over 360.degree. and the cylindrical target is thus irradiated by ions over its entire circumference. The plasma generator and target may be as long as desired. The plasma generator may be in the center and the neutron target on the outside, or the plasma generator may be on the outside and the target on the inside. In a nested configuration, several concentric targets and plasma generating regions are nested to increase the neutron flux.

Leung, Ka-Ngo (Hercules, CA)

2009-12-29T23:59:59.000Z

74

Tapered pulse tube for pulse tube refrigerators  

DOE Patents [OSTI]

Thermal insulation of the pulse tube in a pulse-tube refrigerator is maintained by optimally varying the radius of the pulse tube to suppress convective heat loss from mass flux streaming in the pulse tube. A simple cone with an optimum taper angle will often provide sufficient improvement. Alternatively, the pulse tube radius r as a function of axial position x can be shaped with r(x) such that streaming is optimally suppressed at each x.

Swift, Gregory W. (Sante Fe, NM); Olson, Jeffrey R. (San Mateo, CA)

1999-01-01T23:59:59.000Z

75

Neutron-deuteron breakup and quasielastic scattering  

E-Print Network [OSTI]

Quasielastic scattering and deuteron breakup in the 200 MeV region is studied by impinging a pulsed neutron beam on a deuterium target at the Weapons Neutron Research facility at the Los Alamos Neutron Science Center. The ...

Ohlson, Alice Elisabeth

2009-01-01T23:59:59.000Z

76

Tube-in-tube thermophotovoltaic generator  

DOE Patents [OSTI]

A thermophotovoltaic device includes at least one thermal radiator tube, a cooling tube concentrically disposed within each thermal radiator tube and an array of thermophotovoltaic cells disposed on the exterior surface of the cooling tube. A shell having a first end and a second end surrounds the thermal radiator tube. Inner and outer tubesheets, each having an aperture corresponding to each cooling tube, are located at each end of the shell. The thermal radiator tube extends within the shell between the inner tubesheets. The cooling tube extends within the shell through the corresponding apertures of the two inner tubesheets to the corresponding apertures of the two outer tubesheets. A plurality of the thermal radiator tubes can be arranged in a staggered or an in-line configuration within the shell. 8 figs.

Ashcroft, J.; Campbell, B.; DePoy, D.

1998-06-30T23:59:59.000Z

77

A new neutron time-of-flight detector for fuel-areal-density measurements on OMEGA  

SciTech Connect (OSTI)

A new neutron time-of-flight (nTOF) detector for fuel-areal-density measurements in cryogenic DT implosions was installed on the OMEGA Laser System. The nTOF detector has a cylindrical thin-wall, stainless-steel, 8-in.-diam, 4-in.-thick cavity filled with an oxygenated liquid xylene scintillator. Four gated photomultiplier tubes (PMTs) with different gains are used to measure primary DT and D{sub 2} neutrons, down-scattered neutrons in nT and nD kinematic edge regions, and to study tertiary neutrons in the same detector. The nTOF detector is located 13.4 m from target chamber center in a well-collimated line of sight. The design details of the nTOF detector, PMT optimization, and test results on OMEGA will be presented.

Glebov, V. Yu., E-mail: vgle@lle.rochester.edu; Forrest, C. J.; Marshall, K. L.; Romanofsky, M.; Sangster, T. C.; Shoup, M. J.; Stoeckl, C. [Laboratory for Laser Energetics, University of Rochester, Rochester, New York 14623 (United States)

2014-11-15T23:59:59.000Z

78

Switchable radioactive neutron source device  

DOE Patents [OSTI]

This invention is a switchable neutron generating apparatus comprised of a pair of plates, the first plate having an alpha emitter section on it and the second plate having a target material portion on it which generates neutrons when its nuclei absorb an alpha particle. In operation, the alpha portion of the first plate is aligned with the neutron portion of the second plate to produce neutrons and brought out of alignment to cease production of neutrons. 3 figs.

Stanford, G.S.; Rhodes, E.A.; Devolpi, A.; Boyar, R.E.

1987-11-06T23:59:59.000Z

79

Neutron capture therapy with deep tissue penetration using capillary neutron focusing  

DOE Patents [OSTI]

An improved method is disclosed for delivering thermal neutrons to a subsurface cancer or tumor which has been first doped with a dopant having a high cross section for neutron capture. The improvement is the use of a guide tube in cooperation with a capillary neutron focusing apparatus, or neutron focusing lens, for directing neutrons to the tumor, and thereby avoiding damage to surrounding tissue. 1 fig.

Peurrung, A.J.

1997-08-19T23:59:59.000Z

80

Postirradiation evaluations of capsules HANS-1 and HANS-2 irradiated in the HFIR target region in support of fuel development for the advanced neutron source  

SciTech Connect (OSTI)

This report describes the design, fabrication, irradiation, and evaluation of two capsule tests containing U{sub 3}Si{sub 2} fuel particles in contact with aluminum. The tests were in support of fuel qualification for the Advanced Neutron Source (ANS) reactor, a high-powered research reactor that was planned for the Oak Ridge National Laboratory. At the time of these tests, the fuel consisted of U{sub 3}Si{sub 2}, containing highly enriched uranium dispersed in aluminum at a volume fraction of {approximately}0.15. The extremely high thermal flux in the target region of the High Flux Isotope Reactor provided up to 90% burnup in one 23-d cycle. Temperatures up to 450{degrees}C were maintained by gamma heating. Passive SiC temperature monitors were employed. The very small specimen size allowed only microstructural examination of the fuel particles but also allowed many specimens to be tested at a range of temperatures. The determination of fission gas bubble morphology by microstructural examination has been beneficial in developing a fuel performance model that allows prediction of fuel performance under these extreme conditions. The results indicate that performance of the reference fuel would be satisfactory under the ANS conditions. In addition to U{sub 3}Si{sub 2}, particles of U{sub 3}Si, UAl{sub 2}, UAl{sub x}, and U{sub 3}O{sub 8} were tested.

Hofman, G.L.; Snelgrove, J.L. [Argonne National Lab., IL (United States); Copeland, G.L. [Oak Ridge National Lab., TN (United States)

1995-08-01T23:59:59.000Z

Note: This page contains sample records for the topic "neutron tube target" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


81

Neutron-induced background by an alpha-beam incident on a deuterium gas target and its implications for the study of the 2H(alpha,gamma)6Li reaction at LUNA  

E-Print Network [OSTI]

The production of the stable isotope Li-6 in standard Big Bang nucleosynthesis has recently attracted much interest. Recent observations in metal-poor stars suggest that a cosmological Li-6 plateau may exist. If true, this plateau would come in addition to the well-known Spite plateau of Li-7 abundances and would point to a predominantly primordial origin of Li-6, contrary to the results of standard Big Bang nucleosynthesis calculations. Therefore, the nuclear physics underlying Big Bang Li-6 production must be revisited. The main production channel for Li-6 in the Big Bang is the 2H(alpha,gamma)6Li reaction. The present work reports on neutron-induced effects in a high-purity germanium detector that were encountered in a new study of this reaction. In the experiment, an {\\alpha}-beam from the underground accelerator LUNA in Gran Sasso, Italy, and a windowless deuterium gas target are used. A low neutron flux is induced by energetic deuterons from elastic scattering and, subsequently, the 2H(d,n)3He reaction. Due to the ultra-low laboratory neutron background at LUNA, the effect of this weak flux of 2-3 MeV neutrons on well-shielded high-purity germanium detectors has been studied in detail. Data have been taken at 280 and 400 keV alpha-beam energy and for comparison also using an americium-beryllium neutron source.

M. Anders; D. Trezzi; A. Bellini; M. Aliotta; D. Bemmerer; C. Broggini; A. Caciolli; H. Costantini; P. Corvisiero; T. Davinson; Z. Elekes; M. Erhard; A. Formicola; Zs. Fülöp; G. Gervino; A. Guglielmetti; C. Gustavino; Gy. Gyürky; M. Junker; A. Lemut; M. Marta; C. Mazzocchi; R. Menegazzo; P. Prati; C. Rossi Alvarez; D. Scott; E. Somorjai; O. Straniero; T. Szücs

2013-01-30T23:59:59.000Z

82

First neutron generation in the BINP accelerator based neutron source B. Bayanova  

E-Print Network [OSTI]

First neutron generation in the BINP accelerator based neutron source B. Bayanova , A. Burdakova c l e i n f o Keywords: Epithermal neutrons Lithium target Neutron capture therapy Tandem accelerator a b s t r a c t Pilot innovative facility for neutron capture therapy was built at Budker

Taskaev, Sergey Yur'evich

83

NEUTRON AND NON-NEUTRON NUCLEAR DATA FOR RADIATION DOSIMETRY  

SciTech Connect (OSTI)

NEUTRON NUCLEAR DATA THAT IS USED IN REACTOR DOSIMETRY INCLUDE THERMAL NEUTRON CROSS SECTIONS AND NEUTRON RESONANCE INTEGRALS, FISSION SPECTRUM AVERAGED CROSS SECTIONS FOR REACTIONS ON A TARGET NUCLEUS. NON-NEUTRON NUCLEAR DATA USED IN REACTOR DOSIMETRY INCLUDE ISOTOPIC COMPOSITIONS OF TARGET NUCLIDES AND RADIOACTIVE HALF-LIVES, GAMMA-RAY ENERGIES AND INTENSITIES OF REACTION PRODUCT NUCLIDES. ALL OF THESE DATA ARE PERIODICALLY EVALUATED AND RECOMMENDED VALUES ARE PROVIDED IN THE HANDBOOK OF CHEMISTRY AND PHYSICS. THE LATEST RECOMMENDED VALUES ARE DISCUSSED AND THEY ARE CONTRASTED WITH SOME EARLIER NUCLEAR DATA, WHICH WAS PROVIDED WITH NEUTRON DETECTOR FOILS.

HOLDEN,N.E.

1999-09-10T23:59:59.000Z

84

Fracture analysis of HFIR beam tube caused by radiation embrittlement  

SciTech Connect (OSTI)

With an attempt to estimate the neutron beam tube embrittlement condition for the Oak Ridge High Flux Isotope Reactor (HFIR), fracture mechanics calculations are carried out in this paper. The analysis provides some numerical result on how the tube has been structurally weakened. In this calculation, a lateral impact force is assumed. Numerical result is obtained on how much the critical crack size should be reduced if the beam tube has been subjected to an extended period of irradiation. It is also calculated that buckling strength of the tube is increased, not decreased, with irradiation.

Chang, S.J. [Oak Ridge National Lab., TN (United States). Research Reactors Div.

1994-12-31T23:59:59.000Z

85

Microhole Tubing Bending Report  

SciTech Connect (OSTI)

A downhole tubing bending study was made and is reported herein. IT contains a report and 2 excel spreadsheets to calculate tubing bending and to estimate contact points of the tubing to the drilled hole wall (creating a new support point).

Oglesby, Ken

2012-01-01T23:59:59.000Z

86

Microhole Tubing Bending Report  

DOE Data Explorer [Office of Scientific and Technical Information (OSTI)]

A downhole tubing bending study was made and is reported herein. IT contains a report and 2 excel spreadsheets to calculate tubing bending and to estimate contact points of the tubing to the drilled hole wall (creating a new support point).

Oglesby, Ken

87

Shifting scintillator neutron detector  

DOE Patents [OSTI]

Provided are sensors and methods for detecting thermal neutrons. Provided is an apparatus having a scintillator for absorbing a neutron, the scintillator having a back side for discharging a scintillation light of a first wavelength in response to the absorbed neutron, an array of wavelength-shifting fibers proximate to the back side of the scintillator for shifting the scintillation light of the first wavelength to light of a second wavelength, the wavelength-shifting fibers being disposed in a two-dimensional pattern and defining a plurality of scattering plane pixels where the wavelength-shifting fibers overlap, a plurality of photomultiplier tubes, in coded optical communication with the wavelength-shifting fibers, for converting the light of the second wavelength to an electronic signal, and a processor for processing the electronic signal to identify one of the plurality of scattering plane pixels as indicative of a position within the scintillator where the neutron was absorbed.

Clonts, Lloyd G; Cooper, Ronald G; Crow, Jr., Morris Lowell; Hannah, Bruce W; Hodges, Jason P; Richards, John D; Riedel, Richard A

2014-03-04T23:59:59.000Z

88

Neutron-deuteron breakup reaction as a tool for studying neutron-neutron interactions  

SciTech Connect (OSTI)

An analysis of the most recent data on the reaction nd {yields} pnn revealed a serious discrepancy between theoretical predictions and cross sections measured for this reaction in various configurations where the role of neutron-neutron interactions is important. In view of this, it seems necessary both to develop theoretical approaches and to obtain new experimental data. For this purpose, a setup for studying the neutron-deuteron breakup reaction was created at the Institute for Nuclear Research on the basis of the neutron beam in the RADEX channel and deuterium targets. This facility makes it possible to perform experiments over a broad region of primary-neutron energies (10-60 MeV) and in various (final-state interaction, quasifree scattering, and spatial-star) configurations. Preliminary results of the respective experiment were obtained for configurations of final-state neutron-neutron interaction and quasifree neutron-neutron scattering.

Konobeevski, E. S., E-mail: konobeev@inr.ru; Zuyev, S. V.; Mordovskoy, M. V.; Potashev, S. I.; Sharapov, I. M. [Russian Academy of Sciences, Institute for Nuclear Research (Russian Federation)] [Russian Academy of Sciences, Institute for Nuclear Research (Russian Federation)

2013-11-15T23:59:59.000Z

89

Spherical neutron generator  

DOE Patents [OSTI]

A spherical neutron generator is formed with a small spherical target and a spherical shell RF-driven plasma ion source surrounding the target. A deuterium (or deuterium and tritium) ion plasma is produced by RF excitation in the plasma ion source using an RF antenna. The plasma generation region is a spherical shell between an outer chamber and an inner extraction electrode. A spherical neutron generating target is at the center of the chamber and is biased negatively with respect to the extraction electrode which contains many holes. Ions passing through the holes in the extraction electrode are focused onto the target which produces neutrons by D-D or D-T reactions.

Leung, Ka-Ngo

2006-11-21T23:59:59.000Z

90

Spallation-Driven Cold Neutron Sources Dr. Bradley J. Micklich  

E-Print Network [OSTI]

Neutrons were produced by spallation/fission by 450MeV protons striking depleted uranium target Proton

McDonald, Kirk

91

Conduction cooled tube supports  

DOE Patents [OSTI]

In boilers, process tubes are suspended by means of support studs that are in thermal contact with and attached to the metal roof casing of the boiler and the upper bend portions of the process tubes. The support studs are sufficiently short that when the boiler is in use, the support studs are cooled by conduction of heat to the process tubes and the roof casing thereby maintaining the temperature of the stud so that it does not exceed 1400.degree. F.

Worley, Arthur C. (Mt. Tabor, NJ); Becht, IV, Charles (Morristown, NJ)

1984-01-01T23:59:59.000Z

92

Coiled Tubing Safety Manual  

SciTech Connect (OSTI)

This document addresses safety concerns regarding the use of coiled tubing as it pertains to the preservation of personnel, environment and the wellbore.

Crow, W.

1999-04-06T23:59:59.000Z

93

Sapphire tube pressure vessel  

DOE Patents [OSTI]

A pressure vessel is provided for observing corrosive fluids at high temperatures and pressures. A transparent Teflon bag contains the corrosive fluid and provides an inert barrier. The Teflon bag is placed within a sapphire tube, which forms a pressure boundary. The tube is received within a pipe including a viewing window. The combination of the Teflon bag, sapphire tube and pipe provides a strong and inert pressure vessel. In an alternative embodiment, tie rods connect together compression fittings at opposite ends of the sapphire tube.

Outwater, John O. (Cambridge, MA)

2000-01-01T23:59:59.000Z

94

Steam generator tube failures  

SciTech Connect (OSTI)

A review and summary of the available information on steam generator tubing failures and the impact of these failures on plant safety is presented. The following topics are covered: pressurized water reactor (PWR), Canadian deuterium uranium (CANDU) reactor, and Russian water moderated, water cooled energy reactor (VVER) steam generator degradation, PWR steam generator tube ruptures, the thermal-hydraulic response of a PWR plant with a faulted steam generator, the risk significance of steam generator tube rupture accidents, tubing inspection requirements and fitness-for-service criteria in various countries, and defect detection reliability and sizing accuracy. A significant number of steam generator tubes are defective and are removed from service or repaired each year. This wide spread damage has been caused by many diverse degradation mechanisms, some of which are difficult to detect and predict. In addition, spontaneous tube ruptures have occurred at the rate of about one every 2 years over the last 20 years, and incipient tube ruptures (tube failures usually identified with leak detection monitors just before rupture) have been occurring at the rate of about one per year. These ruptures have caused complex plant transients which have not always been easy for the reactor operators to control. Our analysis shows that if more than 15 tubes rupture during a main steam line break, the system response could lead to core melting. Although spontaneous and induced steam generator tube ruptures are small contributors to the total core damage frequency calculated in probabilistic risk assessments, they are risk significant because the radionuclides are likely to bypass the reactor containment building. The frequency of steam generator tube ruptures can be significantly reduced through appropriate and timely inspections and repairs or removal from service.

MacDonald, P.E.; Shah, V.N.; Ward, L.W.; Ellison, P.G.

1996-04-01T23:59:59.000Z

95

THERMAL NEUTRON BACKSCATTER IMAGING.  

SciTech Connect (OSTI)

Objects of various shapes, with some appreciable hydrogen content, were exposed to fast neutrons from a pulsed D-T generator, resulting in a partially-moderated spectrum of backscattered neutrons. The thermal component of the backscatter was used to form images of the objects by means of a coded aperture thermal neutron imaging system. Timing signals from the neutron generator were used to gate the detection system so as to record only events consistent with thermal neutrons traveling the distance between the target and the detector. It was shown that this time-of-flight method provided a significant improvement in image contrast compared to counting all events detected by the position-sensitive {sup 3}He proportional chamber used in the imager. The technique may have application in the detection and shape-determination of land mines, particularly non-metallic types.

VANIER,P.; FORMAN,L.; HUNTER,S.; HARRIS,E.; SMITH,G.

2004-10-16T23:59:59.000Z

96

Neutronic reactor  

DOE Patents [OSTI]

A nuclear reactor includes an active portion with fissionable fuel and neutron moderating material surrounded by neutron reflecting material. A control element in the active portion includes a group of movable rods constructed of neutron-absorbing material. Each rod is movable with respect to the other rods to vary the absorption of neutrons and effect control over neutron flux.

Wende, Charles W. J. (Augusta, GA); Babcock, Dale F. (Wilmington, DE); Menegus, Robert L. (Wilmington, DE)

1983-01-01T23:59:59.000Z

97

Target design optimization for an electron accelerator driven subcritical facility with circular and square beam profiles.  

SciTech Connect (OSTI)

A subcritical facility driven by an electron accelerator is planned at the Kharkov Institute of Physics and Technology (KIPT) in Ukraine for medical isotope production, materials research, training, and education. The conceptual design of the facility is being pursued through collaborations between ANL and KIPT. As part of the design effort, the high-fidelity analyses of various target options are performed with formulations to reflect the realistic configuration and the three dimensional geometry of each design. This report summarizes the results of target design optimization studies for electron beams with two different beam profiles. The target design optimization is performed via the sequential neutronic, thermal-hydraulic, and structural analyses for a comprehensive assessment of each configuration. First, a target CAD model is developed with proper emphasis on manufacturability to provide a basis for separate but consistent models for subsequent neutronic, thermal-hydraulic, and structural analyses. The optimizations are pursued for maximizing the neutron yield, streamlining the flow field to avoid hotspots, and minimizing the thermal stresses to increase the durability. In addition to general geometric modifications, the inlet/outlet channel configurations, target plate partitioning schemes, flow manipulations and rates, electron beam diameter/width options, and cladding material choices are included in the design optimizations. The electron beam interactions with the target assembly and the neutronic response of the subcritical facility are evaluated using the MCNPX code. the results for the electron beam energy deposition, neutron generation, and utilization in the subcritical pile are then used to characterize the axisymmetric heat generation profiles in the target assembly with explicit simulations of the beam tube, the coolant, the clad, and the target materials. Both tungsten and uranium are considered as target materials. Neutron spectra from tungsten and uranium are very similar allowing the use of either material in the subcritical assembly without changing its characteristics. However, the uranium target has a higher neutron yield, which increases the neutron flux of the subcritical assembly. Based on the considered dimensions and heat generation profiles, the commercial CFD software Star-CD is used for the thermal-hydraulic analysis of each target design to satisfy a set of thermal criteria, the most limiting of which being to maintain the water temperature 50 below the boiling point. It is found that the turbulence in the inlet channels dissipates quickly in narrow gaps between the target plates and, as a result, the heat transfer is limited by the laminar flow conditions. On average, 3-D CFD analyses of target assemblies agree well with 1-D calculations using RELAP (performed by KIPT). However, the recirculation and stagnation zones predicted with the CFD models prove the importance of a 3-D analysis to avoid the resulting hotspots. The calculated temperatures are subsequently used for the structural analysis of each target configuration to satisfy the other engineering design requirements. The thermo-structural calculations are performed mostly with NASTRAN and the results occasionally compared with the results from MARC. Both, NASTRAN and MARC are commercially available structural-mechanics analysis software. Although, a significant thermal gradient forms in target elements along the beam direction, the high thermal stresses are generally observed peripherally around the edge of thin target disks/plates. Due to its high thermal conductivity, temperatures and thermal stresses in tungsten target are estimated to be significantly lower than in uranium target. The deformations of the target disks/plates are found to be insignificant, which eliminate concerns for flow blockages in narrow coolant channels. Consistent with the specifications of the KIPT accelerator to be used in this facility, the electron beam power is 100-kW with electron energy in the range of 100 to 200 MeV. As expected, the 100 MeV el

Gohar, M. Y. A; Sofu, T.; Zhong, Z.; Belch, H.; Naberezhnev, D.; Nuclear Engineering Division

2008-10-30T23:59:59.000Z

98

Neutron-deuteron breakup and quasielastic scattering .  

E-Print Network [OSTI]

??Quasielastic scattering and deuteron breakup in the 200 MeV region is studied by impinging a pulsed neutron beam on a deuterium target at the Weapons… (more)

Ohlson, Alice Elisabeth

2009-01-01T23:59:59.000Z

99

The CNGS Target Station Presented by L.Bruno  

E-Print Network [OSTI]

sealed system filled with 0.5 bar of He. The tube has annular fins to enhance convective heat transfer enclosure Inlet target Inlet fixed shielding Outlet Beam #12;The target Assembly The CNGS Target Station as

McDonald, Kirk

100

Neutronic fuel element fabrication  

DOE Patents [OSTI]

This disclosure describes a method for metallurgically bonding a complete leak-tight enclosure to a matrix-type fuel element penetrated longitudinally by a multiplicity of coolant channels. Coolant tubes containing solid filler pins are disposed in the coolant channels. A leak-tight metal enclosure is then formed about the entire assembly of fuel matrix, coolant tubes and pins. The completely enclosed and sealed assembly is exposed to a high temperature and pressure gas environment to effect a metallurgical bond between all contacting surfaces therein. The ends of the assembly are then machined away to expose the pin ends which are chemically leached from the coolant tubes to leave the coolant tubes with internal coolant passageways. The invention described herein was made in the course of, or under, a contract with the U.S. Atomic Energy Commission. It relates generally to fuel elements for neutronic reactors and more particularly to a method for providing a leak-tight metal enclosure for a high-performance matrix-type fuel element penetrated longitudinally by a multiplicity of coolant tubes. The planned utilization of nuclear energy in high-performance, compact-propulsion and mobile power-generation systems has necessitated the development of fuel elements capable of operating at high power densities. High power densities in turn require fuel elements having high thermal conductivities and good fuel retention capabilities at high temperatures. A metal clad fuel element containing a ceramic phase of fuel intimately mixed with and bonded to a continuous refractory metal matrix has been found to satisfy the above requirements. Metal coolant tubes penetrate the matrix to afford internal cooling to the fuel element while providing positive fuel retention and containment of fission products generated within the fuel matrix. Metal header plates are bonded to the coolant tubes at each end of the fuel element and a metal cladding or can completes the fuel-matrix enclosure by encompassing the sides of the fuel element between the header plates.

Korton, George (Cincinnati, OH)

2004-02-24T23:59:59.000Z

Note: This page contains sample records for the topic "neutron tube target" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


101

How the Spallation Neutron Source Works | ORNL Neutron Sciences  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

high-energy proton pulses strike a heavy-metal target, which is a container of liquid mercury. Corresponding pulses of neutrons freed by the spallation process are slowed down in...

102

Neutron capture therapies  

DOE Patents [OSTI]

In one embodiment there is provided an application of the .sup.10 B(n,.alpha.).sup.7 Li nuclear reaction or other neutron capture reactions for the treatment of rheumatoid arthritis. This application, called Boron Neutron Capture Synovectomy (BNCS), requires substantially altered demands on neutron beam design than for instance treatment of deep seated tumors. Considerations for neutron beam design for the treatment of arthritic joints via BNCS are provided for, and comparisons with the design requirements for Boron Neutron Capture Therapy (BNCT) of tumors are made. In addition, exemplary moderator/reflector assemblies are provided which produce intense, high-quality neutron beams based on (p,n) accelerator-based reactions. In another embodiment there is provided the use of deuteron-based charged particle reactions to be used as sources for epithermal or thermal neutron beams for neutron capture therapies. Many d,n reactions (e.g. using deuterium, tritium or beryllium targets) are very prolific at relatively low deuteron energies.

Yanch, Jacquelyn C. (Cambridge, MA); Shefer, Ruth E. (Newton, MA); Klinkowstein, Robert E. (Winchester, MA)

1999-01-01T23:59:59.000Z

103

Protons hog the momentum in neutron-rich nuclei | Argonne National...  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

a greater fraction of the protons than neutrons to have high momentum in relatively neutron-rich nuclei. The CLAS detector completely surrounds an experimental target and is...

104

E-Print Network 3.0 - advanced pulsed-neutron research Sample...  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

Fuels ; Geosciences 13 Major Facilities for Materials Research Summary: Neutron Source: upgrading of the National Magnet Laboratory: and enriched pulsed neutron targets... and...

105

A neutron transmission study of environmental Gd  

E-Print Network [OSTI]

A new method for the determination of environmental Gd by neutron transmission (NT) experiments is proposed. The NT method is based on the measurements of neutron spectra passing through a target. From the attenuation neutron spectra new data as concentration, width, resonance energies and cross section have been obtained.

Cristiana Oprea; Ioan Alexandru Oprea; Alexandru Mihul

2014-06-02T23:59:59.000Z

106

Neutron Scattering Stiudies  

SciTech Connect (OSTI)

This project covers four principal areas of research: Elastic and inelastic neutron scattering studies in odd-A terbium, thulium and other highly deformed nuclei near A=160 with special regard to interband transitions and to the investigation of the direct-interaction versus the compound-nucleus excitation process in these nuclei. Examination of new, fast photomultiplier tubes suitable for use in a miniaturized neutron-time-of-flight spectrometer. Measurement of certain inelastic cross sections of 238U. Determination of the multiplicity of prompt fission gamma rays in even-A fissile actinides. Energies and mean lives of fission isomers produced by fast fission of even-Z, even-A actinides. Study of the mean life of 7Be in different host matrices and its possible astro-physical significance.

Kegel, Gunter H.R.; Egan, James J

2007-04-18T23:59:59.000Z

107

The Advanced Neutron Source (ANS) project: A world-class research reactor facility  

SciTech Connect (OSTI)

This paper provides an overview of the Advanced Neutron Source (ANS), a new research facility being designed at Oak Ridge National Laboratory. The facility is based on a 330 MW, heavy-water cooled and reflected reactor as the neutron source, with a thermal neutron flux of about 7.5{times}10{sup 19}m{sup {minus}2}{center_dot}sec{sup {minus}1}. Within the reflector region will be one hot source which will serve 2 hot neutron beam tubes, two cryogenic cold sources serving fourteen cold neutron beam tubes, two very cold beam tubes, and seven thermal neutron beam tubes. In addition there will be ten positions for materials irradiation experiments, five of them instrumented. The paper touches on the project status, safety concerns, cost estimates and scheduling, a description of the site, the reactor, and the arrangements of the facilities.

Thompson, P.B. [Martin Marietta Energy Systems, Inc., Oak Ridge, TN (US); Meek, W.E. [Gilbert/Commonwealth, Inc., Pittsburgh, PA (US)

1993-07-01T23:59:59.000Z

108

Neutron skins and neutron stars  

SciTech Connect (OSTI)

The neutron-skin thickness of heavy nuclei provides a fundamental link to the equation of state of neutron-rich matter, and hence to the properties of neutron stars. The Lead Radius Experiment ('PREX') at Jefferson Laboratory has recently provided the first model-independence evidence on the existence of a neutron-rich skin in {sup 208}Pb. In this contribution we examine how the increased accuracy in the determination of neutron skins expected from the commissioning of intense polarized electron beams may impact the physics of neutron stars.

Piekarewicz, J. [Department of Physics, Florida State University, Tallahassee, FL 32306-4350 (United States)

2013-11-07T23:59:59.000Z

109

Fluorescent Tube Lamps  

Broader source: Energy.gov [DOE]

FEMP temporarily suspended its energy efficiency requirements for fluorescent tube lamps as it evaluates the market impact of the pending 2012 minimum efficiency standards for fluorescent lamps. The program will issue updated energy efficiency requirements when the market distribution of this product category stabilizes and when doing so has the potential to result in significant Federal energy savings.

110

High efficiency proportional neutron detector with solid liner internal structures  

DOE Patents [OSTI]

A tube-style neutron detector, a panel-style neutron detector incorporating a plurality of tube-style neutron detectors, and a panel-style neutron detector including a plurality of anode wires are provided. A plurality of channels is provided in a neutron detector such that each channel has an inner surface of a coating layer including a neutron-absorbing material. A wire anode is provided at end of each channel so that electrons generated by a charged daughter particle generated by a neutron are collected to detect a neutron-matter interaction. Moderator units can be incorporated into a neutron detector to provide improved detection efficiencies and/or to determine neutron energy spectrum. Gas-based proportional response from the neutron detectors can be employed for special nuclear material (SNM) detection. This neutron detector can provide similar performance to .sup.3He-based detectors without requiring .sup.3He and without containing toxic, flammable, or high-pressure materials.

Kisner, Roger Allen; Holcomb, David Eugene; Brown, Gilbert M.

2014-08-05T23:59:59.000Z

111

Induction plasma tube  

DOE Patents [OSTI]

An induction plasma tube having a segmented, fluid-cooled internal radiation shield is disclosed. The individual segments are thick in cross-section such that the shield occupies a substantial fraction of the internal volume of the plasma enclosure, resulting in improved performance and higher sustainable plasma temperatures. The individual segments of the shield are preferably cooled by means of a counterflow fluid cooling system wherein each segment includes a central bore and a fluid supply tube extending into the bore. The counterflow cooling system results in improved cooling of the individual segments and also permits use of relatively larger shield segments which permit improved electromagnetic coupling between the induction coil and a plasma located inside the shield. Four embodiments of the invention, each having particular advantages, are disclosed.

Hull, D.E.

1982-07-02T23:59:59.000Z

112

Induction plasma tube  

DOE Patents [OSTI]

An induction plasma tube having a segmented, fluid-cooled internal radiation shield is disclosed. The individual segments are thick in cross-section such that the shield occupies a substantial fraction of the internal volume of the plasma enclosure, resulting in improved performance and higher sustainable plasma temperatures. The individual segments of the shield are preferably cooled by means of a counterflow fluid cooling system wherein each segment includes a central bore and a fluid supply tube extending into the bore. The counterflow cooling system results in improved cooling of the individual segments and also permits use of relatively larger shield segments which permit improved electromagnetic coupling between the induction coil and a plasma located inside the shield. Four embodiments of the invention, each having particular advantages, are disclosed.

Hull, Donald E. (Los Alamos, NM)

1984-01-01T23:59:59.000Z

113

Joined concentric tubes  

DOE Patents [OSTI]

Tubular objects having two or more concentric layers that have different properties are joined to one another during their manufacture primarily by compressive and friction forces generated by shrinkage during sintering and possibly mechanical interlocking. It is not necessary for the concentric tubes to display adhesive-, chemical- or sinter-bonding to each other in order to achieve a strong bond. This facilitates joining of dissimilar materials, such as ceramics and metals.

DeJonghe, Lutgard; Jacobson, Craig; Tucker, Michael; Visco, Steven

2013-01-01T23:59:59.000Z

114

Inspecting the minefield and residual explosives by fast neutron activation method  

SciTech Connect (OSTI)

As an upgrade of a robotic mobile system for antipersonnel land-mine clearance, a fast neutron probe has been considered for the detection of mines and explosive residues. Laboratory tests were made by using the 14 MeV 6 x 10{sup 7} neutrons/sec beam with the associated alpha particle detection and with a LaBr{sub 3} gamma ray detector. Simulant of the anti-personal mine was used as a target. Several measurements were made with the target buried into the soil at different depths. For each depth minimal time measurement was estimated for false negative 0.4 % and false positive equal to 10 %. Tests showed that is possible to detect buried land-mine as well as residual explosives; however, in order to reach the optimal speed of 10 cm/s for de-mining vehicle it is necessarily to use several sealed tube neutron generators and few tens of LaBr{sub 3} gamma ray detectors. (authors)

Sudac, D. [Rudjer Boskovic Inst., Bijenicka c. 54, 10000 Zagreb (Croatia); Majetic, S. [DOK-ING Ltd., Kanalski put 1, 10000 Zagreb (Croatia); Kollar, R. [A.C.T. D.o.o., Prilesje 4, 10000 Zagreb (Croatia); Nad, K.; Obhodas, J. [Rudjer Boskovic Inst., Bijenicka c. 54, 10000 Zagreb (Croatia); Valkovic, V. [A.C.T. D.o.o., Prilesje 4, 10000 Zagreb (Croatia)

2011-07-01T23:59:59.000Z

115

Concentric tube support assembly  

SciTech Connect (OSTI)

An assembly (45) includes a plurality of separate pie-shaped segments (72) forming a disk (70) around a central region (48) for retaining a plurality of tubes (46) in a concentrically spaced apart configuration. Each segment includes a support member (94) radially extending along an upstream face (96) of the segment and a plurality of annularly curved support arms (98) transversely attached to the support member and radially spaced apart from one another away from the central region for receiving respective upstream end portions of the tubes in arc-shaped spaces (100) between the arms. Each segment also includes a radial passageway (102) formed in the support member for receiving a fluid segment portion (106) and a plurality of annular passageways (104) formed in the support arms for receiving respective arm portions (108) of the fluid segment portion from the radial passageway and for conducting the respective arm portions into corresponding annular spaces (47) formed between the tubes retained by the disk.

Rubio, Mark F.; Glessner, John C.

2012-09-04T23:59:59.000Z

116

DEVELOPMENT AND ON-LINE TESTS OF DIFFERENT TARGET-ION SOURCE UNITS FOR PRODUCTION OF NUCLIDES FAR FROM STABILITY  

E-Print Network [OSTI]

of the element chosen for the investigation, a special selection of a metal carbide target material is required as a general goal the development of a massive (up to 1 kg) uranium carbide target prototype for the third of neutron-rich and neutron-deficient heavy nuclei. The main line of uranium carbide target development

Titov, Anatoly

117

Neutron detector  

DOE Patents [OSTI]

A neutron detector has a volume of neutron moderating material and a plurality of individual neutron sensing elements dispersed at selected locations throughout the moderator, and particularly arranged so that some of the detecting elements are closer to the surface of the moderator assembly and others are more deeply embedded. The arrangement captures some thermalized neutrons that might otherwise be scattered away from a single, centrally located detector element. Different geometrical arrangements may be used while preserving its fundamental characteristics. Different types of neutron sensing elements may be used, which may operate on any of a number of physical principles to perform the function of sensing a neutron, either by a capture or a scattering reaction, and converting that reaction to a detectable signal. High detection efficiency, an ability to acquire spectral information, and directional sensitivity may be obtained.

Stephan, Andrew C. (Knoxville, TN); Jardret; Vincent D. (Powell, TN)

2011-04-05T23:59:59.000Z

118

Review of High Power Proton Target Challenges Heat Removal and Thermal `Shock'  

E-Print Network [OSTI]

body Graphite (ToyoTanso IG-43) Helium cooling Graphite to titanium diffusion bond Ti-6Al-4V tube Peripherally cooled cylinder Water cooled gold target Radiation cooled tungsten target ~940 mm Titanium target

McDonald, Kirk

119

Slow neutron leakage spectra from spallation neutron sources  

SciTech Connect (OSTI)

An efficient technique is described for Monte Carlo simulation of neutron beam spectra from target-moderator-reflector assemblies typical of pulsed spallation neutron sources. The technique involves the scoring of the transport-theoretical probability that a neutron will emerge from the moderator surface in the direction of interest, at each collision. An angle-biasing probability is also introduced which further enhances efficiency in simple problems. These modifications were introduced into the VIM low energy neutron transport code, representing the spatial and energy distributions of the source neutrons approximately as those of evaporation neutrons generated through the spallation process by protons of various energies. The intensity of slow neutrons leaking from various reflected moderators was studied for various neutron source arrangements. These include computations relating to early measurements on a mockup-assembly, a brief survey of moderator materials and sizes, and a survey of the effects of varying source and moderator configurations with a practical, liquid metal cooled uranium source Wing and slab, i.e., tangential and radial moderator arrangements, and Be vs CH/sub 2/ reflectors are compared. Results are also presented for several complicated geometries which more closely represent realistic arrangements for a practical source, and for a subcritical fission multiplier such as might be driven by an electron linac. An adaptation of the code was developed to enable time dependent calculations, and investigated the effects of the reflector, decoupling and void liner materials on the pulse shape.

Das, S.G.; Carpenter, J.M.; Prael, R.E.

1980-02-01T23:59:59.000Z

120

Measuring the Neutron's Mean Square Charge Radius Using Neutron Interferometry  

E-Print Network [OSTI]

The neutron is electrically neutral, but its substructure consists of charged quarks so it may have an internal charge distribution. In fact it is known to have a negative mean square charge radius (MSCR), the second moment of the radial charge density. In other words the neutron has a positive core and negative skin. In the first Born approximation the neutron MSCR can be simply related to the neutron-electron scattering length b_ne. In the past this important quantity has been extracted from the energy dependence of the total transmission cross-section of neutrons on high-Z targets, a very difficult and complicated process. A few years ago S.A. Werner proposed a novel approach to measuring b_ne from the neutron's dynamical phase shift in a perfect crystal close to the Bragg condition. We are conducting an experiment based on this method at the NIST neutron interferometer which may lead to a five-fold improvement in precision of b_ne and hence the neutron MSCR.

F. E. Wietfeldt; M. Huber; T. C. Black; H. Kaiser; M. Arif; D. L. Jacobson; S. A. Werner

2005-09-14T23:59:59.000Z

Note: This page contains sample records for the topic "neutron tube target" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


121

Neutron production enhancements for the Intense Pulsed Neutron Source.  

SciTech Connect (OSTI)

The Intense Pulsed Neutron Source (IPNS) was the first high energy spallation neutron source in the US dedicated to materials research. It has operated for sixteen years, and in that time has had a very prolific record concerning the development of new target and moderator systems for pulsed spallation sources. IPNS supports a very productive user program on its thirteen instruments, which are oversubscribed by more than two times, meanwhile having an excellent overall reliability of 95%. Although the proton beam power is relatively low at 7 kW, the target and moderator systems are very efficient. The typical beam power which gives an equivalent flux for long-wavelength neutrons is about 60 kW, due to the use of a uranium target and liquid and solid methane moderators, precluded at some sources due to a higher accelerator power. The development of new target and moderator systems is by no means stagnant at IPNS. They are presently considering numerous enhancements to the target and moderators that offer prospects for increasing the useful neutron production by substantial factors. Many of these enhancements could be combined, although their combined benefit has not yet been well established. Meanwhile, IPNS is embarking on a coherent program of study concerning these improvements and their possible combination and implementation. Moreover, any improvements accomplished at IPNS would immediately increase the performance of IPNS instruments.

Iverson, E. B.

1999-01-04T23:59:59.000Z

122

Neutron Transversity at Jefferson Lab  

SciTech Connect (OSTI)

Nucleon transversity and single transverse spin asymmetries have been the recent focus of large efforts by both theorists and experimentalists. On-going and planned experiments from HERMES, COMPASS and RHIC are mostly on the proton or the deuteron. Presented here is a planned measurement of the neutron transversity and single target spin asymmetries at Jefferson Lab in Hall A using a transversely polarized {sup 3}He target. Also presented are the results and plans of other neutron transverse spin experiments at Jefferson Lab. Finally, the factorization for semi-inclusive DIS studies at Jefferson Lab is discussed.

Jian-Ping Chen; Xiaodong Jiang; Jen-chieh Peng; Lingyan Zhu

2005-09-07T23:59:59.000Z

123

Alternative Neutron Detection Testing Summary  

SciTech Connect (OSTI)

Radiation portal monitors used for interdiction of illicit materials at borders include highly sensitive neutron detection systems. The main reason for having neutron detection capability is to detect fission neutrons from plutonium. Most currently deployed radiation portal monitors (RPMs) use neutron detectors based upon 3He-filled gas proportional counters, which are the most common large area neutron detector. This type of neutron detector is used in the TSA and other RPMs installed in international locations and in the Ludlum and Science Applications International Corporation RPMs deployed primarily for domestic applications. There is a declining supply of 3He in the world and, thus, methods to reduce the use of this gas in RPMs with minimal changes to the current system designs and sensitivity to cargo-borne neutrons are being investigated. Four technologies have been identified as being currently commercially available, potential alternative neutron detectors to replace the use of 3He in RPMs. These technologies are: 1) Boron trifluoride-filled proportional counters, 2) Boron-lined proportional counters, 3) Lithium-loaded glass fibers, and 4) Coated wavelength-shifting plastic fibers. Reported here is a summary of the testing carried out at Pacific Northwest National Laboratory on these technologies to date, as well as measurements on 3He tubes at various pressures. Details on these measurements are available in the referenced reports. Sponsors of these tests include the Department of Energy (DOE), Department of Homeland Security (DHS), and the Department of Defense (DoD), as well as internal Pacific Northwest National Laboratory funds.

Kouzes, Richard T.; Ely, James H.; Erikson, Luke E.; Kernan, Warnick J.; Lintereur, Azaree T.; Siciliano, Edward R.; Stromswold, David C.; Woodring, Mitchell L.

2010-04-08T23:59:59.000Z

124

A Permanent-Magnet Microwave Ion Source for a Compact High-Yield Neutron Generator  

SciTech Connect (OSTI)

We present recent work on the development of a microwave ion source that will be used in a high-yield compact neutron generator for active interrogation applications. The sealed tube generator will be capable of producing high neutron yields, 5x1011 n/s for D-T and ~;;1x1010 n/s for D-D reactions, while remaining transportable. We constructed a microwave ion source (2.45 GHz) with permanent magnets to provide the magnetic field strength of 87.5 mT necessary for satisfying the electron cyclotron resonance (ECR) condition. Microwave ion sources can produce high extracted beam currents at the low gas pressures required for sealed tube operation and at lower power levels than previously used RF-driven ion sources. A 100 mA deuterium/tritium beam will be extracted through a large slit (60x6 mm2) to spread the beam power over a larger target area. This paper describes the design of the permanent-magnet microwave ion source and discusses the impact of the magnetic field design on the source performance. The required equivalent proton beam current density of 40 mA/cm2 was extracted at a moderate microwave power of 400 W with an optimized magnetic field.

Waldmann, Ole; Ludewigt, Bernhard

2010-10-11T23:59:59.000Z

125

Study on neutron emission from 2.2?kJ plasma focus device  

SciTech Connect (OSTI)

The neutron emission from a low energy (2.2?kJ) plasma focus device operated in deuterium medium has been investigated by employing photo-multiplier tube (PMT) and bubble dosimeter. The neutron emission is found to be pressure dependent and anisotropic in nature. In most cases of plasma focus shots, the PMT signal shows double pulses of neutron emission with different intensities and widths. An interesting relation between intensity of hard X-ray and neutron emission is also observed.

Talukdar, N.; Neog, N. K.; Borthakur, T. K., E-mail: tkborthakur@yahoo.co.uk [Centre of Plasma Physics, Institute for Plasma Research, Sonapur 782402, Kamrup, Assam (India)

2014-06-15T23:59:59.000Z

126

Aspects of a high intensity neutron source  

E-Print Network [OSTI]

A unique methodology for creating a neutron source model was developed for deuterons and protons incident on solid phase beryllium and lithium targets. This model was then validated against experimental results already ...

Chapman, Peter H. (Peter Henry)

2010-01-01T23:59:59.000Z

127

Neutron sources: Present practice and future potential  

SciTech Connect (OSTI)

The present capability and future potential of accelerator-based monoenergetic and white neutron sources are outlined in the context of fundamental and applied neutron-nuclear research. The neutron energy range extends from thermal to 500 MeV, and the time domain from steady-state to pico-second pulsed sources. Accelerator technology is summarized, including the production of intense light-ion, heavy-ion and electron beams. Target capabilities are discussed with attention to neutron-producing efficiency and power-handling capabilities. The status of underlying neutron-producing reactions is summarized. The present and future use of neutron sources in: fundamental neutron-nuclear research, nuclear data acquisition, materials damage studies, engineering tests, and biomedical applications are discussed. Emphasis is given to current status, near-term advances well within current technology, and to long-range projections. 90 refs., 4 figs.

Cierjacks, S.; Smith, A.B.

1988-01-01T23:59:59.000Z

128

Nuclear reactor with internal thimble-type delayed neutron detection system  

SciTech Connect (OSTI)

This paper describes a liquid-metal cooled nuclear reactor. It comprises: a housing having a core containing nuclear material, a shell and tube heat exchanger positioned within the housing. The shell and tube heat exchanger have the tubes thereof arranged in parallel, a primary coolant within the shell and tube heat exchanger, means for detecting positioned within a tube in the shell and tube heat exchanger for generating a signal in response to a reaction detected by the means for detecting, the means for detecting including signal detectors D-1, D-2, and D-3 selectively spaced from one another along the coolant flow within the shell and tube heat exchanger so that the total time lapsed after the occurrence of the reaction and a delayed-neutron is detected is: TOTAL = T{sub h} + T{sub t} + T{sub d}. Where: T{sub h} = isotopic holdup time for the delayed-neutron traveling from the reaction spot to the coolant T{sub t} = transit time for the delayed-neutron traveling from the coolant to the heat exchanger inlet T{sub d} = constant transit time for the delayed-neutrons to reach each of the delayed-neutron detectors D-1, D-2, and D-3, which is dependent upon the position of the delayed-neutron detector; and a mechanism remotely connected to the signal detectors to record the reaction detected thereby.

Gross, K.C.; Poloncsik, J.; Lambert, J.D.B.

1990-07-03T23:59:59.000Z

129

SANS -Small Angle Neutron Scattering Tcnica de difrao  

E-Print Network [OSTI]

SANS - Small Angle Neutron Scattering Técnica de difração informações sobre tamanho e forma de- Neutrons are created in the centre of the target station when the beam of high energy protons collides by evaporating nuclear particles, mainly neutrons, in all directions. Each proton produces approximately 15

Loh, Watson

130

SNS Target R&D Presented by  

E-Print Network [OSTI]

since been resolved ­ QA program would have to be very stringent for long lifetime Second target station implemented #12;11 Managed by UT-Battelle for the U.S. Department of Energy Spallation Neutron Source

McDonald, Kirk

131

Measuring the Neutron Lifetime Using Magnetically Trapped Neutrons  

E-Print Network [OSTI]

The neutron beta-decay lifetime plays an important role both in understanding weak interactions within the framework of the Standard Model and in theoretical predictions of the primordial abundance of 4He in Big Bang Nucleosynthesis. In previous work, we successfully demonstrated the trapping of ultracold neutrons (UCN) in a conservative potential magnetic trap. A major upgrade of the apparatus is nearing completion at the National Institute of Standards and Technology Center for Neutron Research (NCNR). In our approach, a beam of 0.89 nm neutrons is incident on a superfluid 4He target within the minimum field region of an Ioffe-type magnetic trap. A fraction of the neutrons is downscattered in the helium to energies <200 neV, and those in the appropriate spin state become trapped. The inverse process is suppressed by the low phonon density of helium at temperatures less than 200 mK, allowing the neutron to travel undisturbed. When the neutron decays the energetic electron ionizes the helium, producing sci...

O'Shaughnessy, C M; Schelhammer, K W; Swank, C M; Seo, P -N; Huffman, P R; Dzhosyuk, S N; Mattoni, C E H; Yang, L; Doyle, J M; Coakley, K J; Thompson, A K; Mumm, H P; Lamoreaux, S K; Yang, G

2009-01-01T23:59:59.000Z

132

SHORT-TUBE SUBCRITICAL FLOW Enerag Division  

E-Print Network [OSTI]

#12;SHORT-TUBE SUBCRITICAL FLOW Y. C. Mei Enerag Division Oak Ridge National Laboratory Oak Ridge-tube subcritical flow. For short tubes used as refrigerant expansion devices, the orifice model is found inadequate-TUBE SUBCRITICAL FLOW INTRODUCTION Much theoretical and experimental work regarding short tube fluid flow has

Oak Ridge National Laboratory

133

Solid Targets for Neutron Spallation Sources  

E-Print Network [OSTI]

can be cooled by water · For single-phase D2O: ­ 10 m/s bulk velocity in 1mm gap ­ 70 A/cm2 beam Channel Cartridge Heaters Copper Test Section Channel Flow Rate 10 m/s Cartridge heaters in tapered copper using water coolant confirm heat-transfer correlations #12;AHIPA Workshop, Fermilab, October 20, 2009 6

McDonald, Kirk

134

Thermal neutron detection system  

DOE Patents [OSTI]

According to the present invention, a system for measuring a thermal neutron emission from a neutron source, has a reflector/moderator proximate the neutron source that reflects and moderates neutrons from the neutron source. The reflector/moderator further directs thermal neutrons toward an unmoderated thermal neutron detector.

Peurrung, Anthony J. (Richland, WA); Stromswold, David C. (West Richland, WA)

2000-01-01T23:59:59.000Z

135

2014 Tube -1 STANDING WAVES  

E-Print Network [OSTI]

2014 Tube - 1 STANDING WAVES IN AN AIR COLUMN The objective of the experiment is: · To study the harmonic structure of standing waves in an air column. APPARATUS: Computer, FFTScope software, PC speaker, meterstick, sound tube apparatus, thermometer, microphone INTRODUCTION traveling wave of sinusoidal shape

Glashausser, Charles

136

The aligned nuclear targets for investigation of time reversal invariance violation: thermal heating and optimization of target dimension  

E-Print Network [OSTI]

The thermal heating of aligned nuclear targets of HIO_3, LiIO_3 ans Sb target materials under neutron irradiation at JSNS is considered. It is shown that presently the targets of large volumes (several tens of cm^3) can be used in experiment. The optimal target dimensions are recommended for investigation with resonance neutrons. The use of proposed aligned targets at the new neutron spallation source JSNS (Japan) will make p[ossible to discover TRIV or decrease the present limit on the intensity of parity conserving time violating interaction by two-three order of magnitude.

A. G. Beda; A. S. Gerasimov

2007-06-18T23:59:59.000Z

137

Tubing pressurized firing apparatus for a tubing conveyed perforating gun  

SciTech Connect (OSTI)

A tubing pressurized firing apparatus is shown for use with a tubing conveyed perforating gun of the type used to perforate a cased well bore. The firing apparatus has a tubular body with an upper end for connection in the well tubing string and with a lower end for connection to a well perforating gun. An inner mandrel is slidably mounted within the tubular body and has a ball seat formed in the interior bore thereof for receiving a ball dropped through the well tubing string. The ball and ball seat together form a pressure tight seal whereby tubing pressure in the well tubing string acts on the inner mandrel to slide the mandrel downwardly within the tubular body. A cocking mechanism located below the inner mandrel within the body includes a lockout member which is initially positioned between a detonating pin and a percussion detonator. The cocking mechanism is actuated by downward sliding movement of the inner mandrel to move the lockout member from between the detonating pin and percussion detonator whereby a subsequent release of tubing pressure and upward sliding movement of the inner mandrel exposes the detonating pin to the percussion detonator to actuate the detonator and fire the perforating gun.

Davies, D. L.

1985-11-26T23:59:59.000Z

138

Neutron Tomography and Space  

E-Print Network [OSTI]

Kevin Shields, “Optimization of neutron tomography for rapidNEUTRON TOMOGRAPHY AND SPACE Hal Egbert, Ronald Walker, R.industrial applications[1]. Neutron Computed Tomography was

Egbert, Hal; Walker, Ronald; Flocchini, R.

2007-01-01T23:59:59.000Z

139

Neutron range spectrometer  

DOE Patents [OSTI]

A neutron range spectrometer and method for determining the neutron energy spectrum of a neutron emitting source are disclosed. Neutrons from the source are colliminated along a collimation axis and a position sensitive neutron counter is disposed in the path of the collimated neutron beam. The counter determines positions along the collimation axis of interactions between the neutrons in the neutron beam and a neutron-absorbing material in the counter. From the interaction positions, a computer analyzes the data and determines the neutron energy spectrum of the neutron beam. The counter is preferably shielded and a suitable neutron-absorbing material is He-3. 1 fig.

Manglos, S.H.

1988-03-10T23:59:59.000Z

140

Compact, energy EFFICIENT neutron source: enabling technology for various applications  

SciTech Connect (OSTI)

A novel neutron source comprising of a deuterium beam (energy of about 100 KeV) injected into a tube filled with tritium gas and/or tritium plasma that generates D-T fusion reactions, whose products are 14.06 MeV neutrons and 3.52 MeV alpha particles, is described. At the opposite end of the tube, the energy of deuterium ions that did not interact is recovered. Beryllium walls of proper thickness can be utilized to absorb 14 MeV neutrons and release 2-3 low energy neutrons. Each ion source and tube forms a module. Larger systems can be formed from multiple units. Unlike currently proposed methods, where accelerator-based neutron sources are very expensive, large, and require large amounts of power for operation, this neutron source is compact, inexpensive, easy to test and to scale up. Among possible applications for this neutron source concept are sub-critical nuclear breeder reactors and transmutation of radioactive waste.

Hershcovitch, A.; Roser, T.

2009-12-01T23:59:59.000Z

Note: This page contains sample records for the topic "neutron tube target" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


141

Inspection of the objects on the sea floor by using 14 MeV tagged neutrons  

SciTech Connect (OSTI)

Variety of objects found on the sea floor needs to be inspected for the presence of materials which represent the threat to the environment and to the safety of humans. We have demonstrated that the sealed tube 14 MeV neutron generator with the detection of associated alpha particles can be used underwater when mounted inside ROV equipped with the hydraulic legs and variety of sensors for the inspection of such objects for the presence of threat materials. Such a system is performing the measurement by using the NaI gamma detector and an API-120 neutron generator which could be rotated in order to maximize the inspected target volume. The neutron beam intensity during the 10-30 min. measurements is usually 1 x 10{sup 7} n/s in 4{pi}. In this report the experimental results for some of commonly found objects containing TNT explosive or its simulant are presented. The measured gamma spectra are dominant by C, O and Fe peaks enabling the determination of the presence of explosives inside the ammunition shell. Parameters influencing the C/O ratio are discussed in some details. (authors)

Valkovic, V. [A.C.T.d.o.o., Prilesje 4, Zagreb (Croatia); Sudac, D.; Obhodas, J. [Dept. of Experimental Physics, Inst. Ruder Boskovic, Zagreb (Croatia); Matika, D. [Inst. for Researches and Development of Defense Systems, Zagreb (Croatia); Kollar, R. [A.C.T.d.o.o., Prilesje 4, Zagreb (Croatia); Nad, K.; Orlic, Z. [Dept. of Experimental Physics, Inst. Ruder Boskovic, Zagreb (Croatia)

2011-07-01T23:59:59.000Z

142

Method of making straight fuel cell tubes  

DOE Patents [OSTI]

A method and an apparatus for making straight fuel cell tubes are disclosed. Extruded tubes comprising powders of fuel cell material and a solvent are dried by rotating the extruded tubes. The rotation process provides uniform circumferential drying which results in uniform linear shrinkage of the tubes. The resultant dried tubes are very straight, thereby eliminating subsequent straightening steps required with conventional processes. The method is particularly useful for forming inner air electrode tubes of solid oxide fuel cells.

Borglum, Brian P. (Edgewood, PA)

2001-01-01T23:59:59.000Z

143

Subcritical Neutron Multiplication Measurements of HEU Using Delayed Neutrons as the Driving Source  

SciTech Connect (OSTI)

A new method for the determination of the multiplication of highly enriched uranium systems is presented. The method uses delayed neutrons to drive the HEU system. These delayed neutrons are from fission events induced by a pulsed 14-MeV neutron source. Between pulses, neutrons are detected within a medium efficiency neutron detector using {sup 3}He ionization tubes within polyethylene enclosures. The neutron detection times are recorded relative to the initiation of the 14-MeV neutron pulse, and subsequently analyzed with the Feynman reduced variance method to extract singles, doubles and triples neutron counting rates. Measurements have been made on a set of nested hollow spheres of 93% enriched uranium, with mass values from 3.86 kg to 21.48 kg. The singles, doubles and triples counting rates for each uranium system are compared to calculations from point kinetics models of neutron multiplicity to assign multiplication values. These multiplication values are compared to those from MC NP K-Code calculations.

Hollas, C.L.; Goulding, C.A.; Myers, W.L.

1999-09-20T23:59:59.000Z

144

Combustion-thermoelectric tube  

SciTech Connect (OSTI)

In direct combustion-thermoelectric energy conversion, direct fuel injection and reciprocation of the air flowing in a solid matrix are combined with the solid conduction to allow for obtaining super-adiabatic temperatures at the hot junctions. While the solid conductivity is necessary, the relatively large thermal conductivity of the available high-temperature thermoelectric materials (e.g., Si-Ge alloys) results in a large conduction loss from the hot junctions and deteriorates the performance. Here a combustion-thermoelectric tube is introduced and analyzed. Radially averaged temperatures are used for the fluid and solid phases. A combination of external cooling of the cold junctions, and direct injection of the fuel, has been used to increase the energy conversion efficiency for low thermal conductivity, high-melting temperature thermoelectric materials. The parametric study (geometry, flow, stoichiometry, materials) shows that with the current high figure of merit, high temperature Si{sub 0.7}Ge{sub 0.3} properties, a conversion efficiency of about 11% is achievable. With lower thermal conductivities for these high-temperature materials, efficiencies about 25% appear possible. This places this energy conversion in line with the other high efficiency, direct electric power generation methods.

Park, C.W.; Kaviany, M.

1999-07-01T23:59:59.000Z

145

Accelerator-based neutron source for boron neutron capture therapy (BNCT) and method  

DOE Patents [OSTI]

A source for boron neutron capture therapy (BNCT) comprises a body of photoneutron emitter that includes heavy water and is closely surrounded in heat-imparting relationship by target material; one or more electron linear accelerators for supplying electron radiation having energy of substantially 2 to 10 MeV and for impinging such radiation on the target material, whereby photoneutrons are produced and heat is absorbed from the target material by the body of photoneutron emitter. The heavy water is circulated through a cooling arrangement to remove heat. A tank, desirably cylindrical or spherical, contains the heavy water, and a desired number of the electron accelerators circumferentially surround the tank and the target material as preferably made up of thin plates of metallic tungsten. Neutrons generated within the tank are passed through a surrounding region containing neutron filtering and moderating materials and through neutron delimiting structure to produce a beam or beams of epithermal neutrons normally having a minimum flux intensity level of 1.0{times}10{sup 9} neutrons per square centimeter per second. Such beam or beams of epithermal neutrons are passed through gamma ray attenuating material to provide the required epithermal neutrons for BNCT use. 3 figs.

Yoon, W.Y.; Jones, J.L.; Nigg, D.W.; Harker, Y.D.

1999-05-11T23:59:59.000Z

146

Accelerator-based neutron source for boron neutron capture therapy (BNCT) and method  

DOE Patents [OSTI]

A source for boron neutron capture therapy (BNCT) comprises a body of photoneutron emitter that includes heavy water and is closely surrounded in heat-imparting relationship by target material; one or more electron linear accelerators for supplying electron radiation having energy of substantially 2 to 10 MeV and for impinging such radiation on the target material, whereby photoneutrons are produced and heat is absorbed from the target material by the body of photoneutron emitter. The heavy water is circulated through a cooling arrangement to remove heat. A tank, desirably cylindrical or spherical, contains the heavy water, and a desired number of the electron accelerators circumferentially surround the tank and the target material as preferably made up of thin plates of metallic tungsten. Neutrons generated within the tank are passed through a surrounding region containing neutron filtering and moderating materials and through neutron delimiting structure to produce a beam or beams of epithermal neutrons normally having a minimum flux intensity level of 1.0.times.10.sup.9 neutrons per square centimeter per second. Such beam or beams of epithermal neutrons are passed through gamma ray attenuating material to provide the required epithermal neutrons for BNCT use.

Yoon, Woo Y. (Idaho Falls, ID); Jones, James L. (Idaho Falls, ID); Nigg, David W. (Idaho Falls, ID); Harker, Yale D. (Idaho Falls, ID)

1999-01-01T23:59:59.000Z

147

Neutron Repulsion  

E-Print Network [OSTI]

Earth is connected gravitationally, magnetically and electrically to its heat source - a neutron star that is obscured from view by waste products in the photosphere. Neutron repulsion is like the hot filament in an incandescent light bulb. Excited neutrons are emitted from the solar core and decay into hydrogen that glows in the photosphere like a frosted light bulb. Neutron repulsion was recognized in nuclear rest mass data in 2000 as the overlooked source of energy, the keystone of an arch that locked together these puzzling space-age observations: 1.) Excess 136Xe accompanied primordial helium in the stellar debris that formed the solar system (Fig. 1); 2.) The Sun formed on the supernova core (Fig. 2); 3.) Waste products from the core pass through an iron-rich mantle, selectively carrying lighter elements and lighter isotopes of each element into the photosphere (Figs. 3-4); and 4.) Neutron repulsion powers the Sun and sustains life (Figs. 5-7). Together these findings offer a framework for understanding how: a.) The Sun generates and releases neutrinos, energy and solar-wind hydrogen and helium; b.) An inhabitable planet formed and life evolved around an ordinary-looking star; c.) Continuous climate change - induced by cyclic changes in gravitational interactions of the Sun's energetic core with planets - has favored survival by adaptation.

Oliver K. Manuel

2011-02-08T23:59:59.000Z

148

Secondary electron ion source neutron generator  

DOE Patents [OSTI]

A neutron generator employing an electron emitter, an ion source bombarded by the electrons from the electron emitter, a plasma containment zone, and a target situated between the plasma containment zone and the electron emitter is disclosed. The target contains occluded deuterium, tritium, or a mixture thereof. 4 figs.

Brainard, J.P.; McCollister, D.R.

1998-04-28T23:59:59.000Z

149

Secondary electron ion source neutron generator  

DOE Patents [OSTI]

A neutron generator employing an electron emitter, an ion source bombarded by the electrons from the electron emitter, a plasma containment zone, and a target situated between the plasma containment zone and the electron emitter. The target contains occluded deuterium, tritium, or a mixture thereof

Brainard, John P. (Albuquerque, NM); McCollister, Daryl R. (Albuquerque, NM)

1998-01-01T23:59:59.000Z

150

Tube-wave seismic imaging  

DOE Patents [OSTI]

The detailed analysis of cross well seismic data for a gas reservoir in Texas revealed two newly detected seismic wave effects, recorded approximately 2000 feet above the reservoir. A tube-wave (150) is initiated in a source well (110) by a source (111), travels in the source well (110), is coupled to a geological feature (140), propagates (151) through the geological feature (140), is coupled back to a tube-wave (152) at a receiver well (120), and is and received by receiver(s) (121) in either the same (110) or a different receiving well (120). The tube-wave has been shown to be extremely sensitive to changes in reservoir characteristics. Tube-waves appear to couple most effectively to reservoirs where the well casing is perforated, allowing direct fluid contact from the interior of a well case to the reservoir.

Korneev, Valeri A. (Lafayette, CA); Bakulin, Andrey (Houston, TX)

2009-10-13T23:59:59.000Z

151

Tube-wave seismic imaging  

DOE Patents [OSTI]

The detailed analysis of cross well seismic data for a gas reservoir in Texas revealed two newly detected seismic wave effects, recorded approximately 2000 feet above the reservoir. A tube-wave (150) is initiated in a source well (110) by a source (111), travels in the source well (110), is coupled to a geological feature (140), propagates (151) through the geological feature (140), is coupled back to a tube-wave (152) at a receiver well (120), and is and received by receiver(s) (121) in either the same (110) or a different receiving well (120). The tube-wave has been shown to be extremely sensitive to changes in reservoir characteristics. Tube-waves appear to couple most effectively to reservoirs where the well casing is perforated, allowing direct fluid contact from the interior of a well case to the reservoir.

Korneev, Valeri A [LaFayette, CA

2009-05-05T23:59:59.000Z

152

Steam generator tube rupture study  

E-Print Network [OSTI]

This report describes our investigation of steam generator behavior during a postulated tube rupture accident. Our study was performed using the steam generator, thermal-hydraulic analysis code THERMIT-UTSG. The purpose ...

Free, Scott Thomas

1986-01-01T23:59:59.000Z

153

Cyclotron-based neutron source for BNCT  

SciTech Connect (OSTI)

Kyoto University Research Reactor Institute (KURRI) and Sumitomo Heavy Industries, Ltd. (SHI) have developed a cyclotron-based neutron source for Boron Neutron Capture Therapy (BNCT). It was installed at KURRI in Osaka prefecture. The neutron source consists of a proton cyclotron named HM-30, a beam transport system and an irradiation and treatment system. In the cyclotron, H- ions are accelerated and extracted as 30 MeV proton beams of 1 mA. The proton beams is transported to the neutron production target made by a beryllium plate. Emitted neutrons are moderated by lead, iron, aluminum and calcium fluoride. The aperture diameter of neutron collimator is in the range from 100 mm to 250 mm. The peak neutron flux in the water phantom is 1.8 Multiplication-Sign 109 neutrons/cm{sup 2}/sec at 20 mm from the surface at 1 mA proton beam. The neutron source have been stably operated for 3 years with 30 kW proton beam. Various pre-clinical tests including animal tests have been done by using the cyclotron-based neutron source with {sup 10}B-p-Borono-phenylalanine. Clinical trials of malignant brain tumors will be started in this year.

Mitsumoto, T.; Yajima, S.; Tsutsui, H.; Ogasawara, T.; Fujita, K. [Sumitomo Heavy Industries, Ltd (Japan); Tanaka, H.; Sakurai, Y.; Maruhashi, A. [Kyoto University Research Reactor Institute (Japan)

2013-04-19T23:59:59.000Z

154

Rotating Target Development for SNS Second Target Station  

SciTech Connect (OSTI)

A rotating target for the second target station (STS) at SNS has been identified as an option along with a mercury target. Evaluation of the rotating target alternative for STS has started at 1.5 MW which is considered an upper bound for the power. Previous preconceptual design work for a 3 MW rotating target is being modified for the lower power level. Transient thermal analysis for a total loss of active water cooling has been done for a simplified 2D model of the target and shielding monolith which shows that peak temperatures are well below the level at which tungsten vaporization by steam could exceed site boundary dose limits. Design analysis and integration configuration studies have been done for the target-moderator-reflector assembly which maximizes the number of neutron beam lines and provides for replacement of the target and moderators. Target building hot cell arrangement for this option will be described. An option for operation in rough vacuum without a proton beam window using Ferro fluid seals on a vertical shaft is being developed. A full scale prototypic drive module based on the 3 MW preconceptual design has been fabricated and successfully tested with a shaft and mock up target supplied by the ESS-Bilbao team. Overall planning leading to decision between mercury and the rotating target in 2011 will be discussed

McManamy, Thomas J [ORNL; Rennich, Mark J [ORNL; Crawford, Roy K [ORNL; Geoghegan, Patrick J [ORNL; Janney, Jim G [ORNL

2010-01-01T23:59:59.000Z

155

Advanced Neutron Source (ANS) Project Progress report, FY 1991  

SciTech Connect (OSTI)

This report discusses the following about the Advanced Neutron Source: Project Management; Research and Development; Fuel Development; Corrosion Loop Tests and Analyses; Thermal-Hydraulic Loop Tests; Reactor Control and Shutdown Concepts; Critical and Subcritical Experiments; Material Data, Structural Tests, and Analysis; Cold-Source Development; Beam Tube, Guide, and Instrument Development; Hot-Source Development; Neutron Transport and Shielding; I & C Research and Development; Design; and Safety.

Campbell, J.H. [ed.] [Oak Ridge National Lab., TN (United States); Selby, D.L.; Harrington, R.M. [Oak Ridge National Lab., TN (United States); Thompson, P.B. [Martin Marietta Energy Systems, Inc., (United States). Engineering Division

1992-01-01T23:59:59.000Z

156

Advanced Neutron Source (ANS) Project Progress report, FY 1991  

SciTech Connect (OSTI)

This report discusses the following about the Advanced Neutron Source: Project Management; Research and Development; Fuel Development; Corrosion Loop Tests and Analyses; Thermal-Hydraulic Loop Tests; Reactor Control and Shutdown Concepts; Critical and Subcritical Experiments; Material Data, Structural Tests, and Analysis; Cold-Source Development; Beam Tube, Guide, and Instrument Development; Hot-Source Development; Neutron Transport and Shielding; I C Research and Development; Design; and Safety.

Campbell, J.H. (ed.) (Oak Ridge National Lab., TN (United States)); Selby, D.L.; Harrington, R.M. (Oak Ridge National Lab., TN (United States)); Thompson, P.B. (Martin Marietta Energy Systems, Inc., (United States). Engineering Division)

1992-01-01T23:59:59.000Z

157

Introduction to Neutron Coincidence Counter Design Based on Boron-10  

SciTech Connect (OSTI)

The Department of Energy Office of Nonproliferation Policy (NA-241) is supporting the project 'Coincidence Counting With Boron-Based Alternative Neutron Detection Technology' at Pacific Northwest National Laboratory (PNNL) for development of an alternative neutron coincidence counter. The goal of this project is ultimately to design, build and demonstrate a boron-lined proportional tube based alternative system in the configuration of a coincidence counter. This report, providing background information for this project, is the deliverable under Task 1 of the project.

Kouzes, Richard T.; Ely, James H.; Lintereur, Azaree T.; Siciliano, Edward R.

2012-01-22T23:59:59.000Z

158

CHINA SPALLATION NEUTRON SOURCE DESIGN.  

SciTech Connect (OSTI)

The China Spallation Neutron Source (CSNS) is an accelerator-based high-power project currently in preparation under the direction of the Chinese Academy of Sciences (CAS). The complex is based on an H- linear accelerator, a rapid cycling proton synchrotron accelerating the beam to 1.6 GeV, a solid tungsten target station, and five initial instruments for spallation neutron applications. The facility will operate at 25 Hz repetition rate with a phase-I beam power of about 120 kW. The major challenge is to build a robust and reliable user's facility with upgrade potential at a fractional of ''world standard'' cost.

WEI,J.

2007-01-29T23:59:59.000Z

159

A determination of the effective thickness of a liquid deuterium target for a quasielastic scattering experiment  

E-Print Network [OSTI]

The effective thickness of a liquid deuterium target was determined by measuring the yield of the neutron-deuteron elastic scattering cross section. The flux of incident neutrons was determined by a fission ionization ...

Turkewitz, Jared Ripley

2010-01-01T23:59:59.000Z

160

Thermal Neutron Imaging in an Active Interrogation Environment  

SciTech Connect (OSTI)

We have developed a thermal-neutron coded-aperture imager that reveals the locations of hydrogenous materials from which thermal neutrons are being emitted. This imaging detector can be combined with an accelerator to form an active interrogation system in which fast neutrons are produced in a heavy metal target by means of excitation by high energy photons. The photo-induced neutrons can be either prompt or delayed, depending on whether neutron-emitting fission products are generated. Provided that there are hydrogenous materials close to the target, some of the photo-induced neutrons slow down and emerge from the surface at thermal energies. These neutrons can be used to create images that show the location and shape of the thermalizing materials. Analysis of the temporal response of the neutron flux provides information about delayed neutrons from induced fission if there are fissionable materials in the target. The combination of imaging and time-of-flight discrimination helps to improve the signal-to-background ratio. It is also possible to interrogate the target with neutrons, for example using a D-T generator. In this case, an image can be obtained from hydrogenous material in a target without the presence of heavy metal. In addition, if fissionable material is present in the target, probing with fast neutrons can stimulate delayed neutrons from fission, and the imager can detect and locate the object of interest, using appropriate time gating. Operation of this sensitive detection equipment in the vicinity of an accelerator presents a number of challenges, because the accelerator emits electromagnetic interference as well as stray ionizing radiation, which can mask the signals of interest.

Vanier, Peter E. [Brookhaven National Laboratory, Upton, NY 11973 (United States); Forman, Leon [Ion Focus Technology, Inc., Miller Place, NY 11764 (United States); Norman, Daren R. [Idaho National Laboratory, Idaho Falls, ID 83415 (United States)

2009-03-10T23:59:59.000Z

Note: This page contains sample records for the topic "neutron tube target" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


161

assays targeting formyltetrahydrofolate: Topics by E-print Network  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

Tovesson, F; Towell, D; Towell, R S; Watson, S; Wendt, B; Wood, L 2013-01-01 34 MECO Production Target Developments Physics Websites Summary: channel & thin containment tube costs...

162

Methods for absorbing neutrons  

DOE Patents [OSTI]

A conduction cooled neutron absorber may include a metal matrix composite that comprises a metal having a thermal neutron cross-section of at least about 50 barns and a metal having a thermal conductivity of at least about 1 W/cmK. Apparatus for providing a neutron flux having a high fast-to-thermal neutron ratio may include a source of neutrons that produces fast neutrons and thermal neutrons. A neutron absorber positioned adjacent the neutron source absorbs at least some of the thermal neutrons so that a region adjacent the neutron absorber has a fast-to-thermal neutron ratio of at least about 15. A coolant in thermal contact with the neutron absorber removes heat from the neutron absorber.

Guillen, Donna P. (Idaho Falls, ID); Longhurst, Glen R. (Idaho Falls, ID); Porter, Douglas L. (Idaho Falls, ID); Parry, James R. (Idaho Falls, ID)

2012-07-24T23:59:59.000Z

163

NEUTRON ELECTRIC-DIPOLE MOMENT, ULTRACOLD NEUTRONS  

E-Print Network [OSTI]

NEUTRON ELECTRIC-DIPOLE MOMENT, ULTRACOLD NEUTRONS AND POLARIZED 3He R. GOLUB~and Steve K REPORTS (Review Section of Physics Letters) 237, No. 1(1994)1--62. PHYSICS REPORTS North-Holland Neutron electric-dipole moment, ultracold neutrons and polarized 3He R. Goluba and Steve K. Lamoreauxb a

164

Neutron reflecting supermirror structure  

DOE Patents [OSTI]

An improved neutron reflecting supermirror structure comprising a plurality of stacked sets of bilayers of neutron reflecting materials. The improved neutron reflecting supermirror structure is adapted to provide extremely good performance at high incidence angles, i.e. up to four time the critical angle of standard neutron mirror structures. The reflection of neutrons striking the supermirror structure at a high critical angle provides enhanced neutron throughput, and hence more efficient and economical use of neutron sources.

Wood, James L. (Drayton Plains, MI)

1992-01-01T23:59:59.000Z

165

Neutron reflecting supermirror structure  

DOE Patents [OSTI]

An improved neutron reflecting supermirror structure comprising a plurality of stacked sets of bilayers of neutron reflecting materials. The improved neutron reflecting supermirror structure is adapted to provide extremely good performance at high incidence angles, i.e. up to four time the critical angle of standard neutron mirror structures. The reflection of neutrons striking the supermirror structure at a high critical angle provides enhanced neutron throughput, and hence more efficient and economical use of neutron sources. 2 figs.

Wood, J.L.

1992-12-01T23:59:59.000Z

166

Core-tube data logger  

SciTech Connect (OSTI)

Wireline core drilling, increasingly used for geothermal exploration, employs a core-tube to capture a rock core sample during drilling. Three types of core-tube data loggers (CTDL) have been built and tested to date by Sandia national Laboratories. They are: (1) temperature-only logger, (2) temperature/inclinometer logger and (3) heat-shielded temperature/inclinometer logger. All were tested during core drilling operations using standard wireline diamond core drilling equipment. While these tools are designed for core-tube deployment, the tool lends itself to be adapted to other drilling modes and equipment. Topics covered in this paper include: (1) description on how the CTDLs are implemented, (2) the components of the system, (3) the type of data one can expect from this type of tool, (4) lessons learned, (5) comparison to its counterpart and (6) future work.

Henfling, J.A.; Normann, R.A.; Knudsen, S.; Drumheller, D.

1997-01-01T23:59:59.000Z

167

Mechanical Design of Steel Tubing for Use in Black Liquor Recovery Boilers  

SciTech Connect (OSTI)

Finite element models were developed for thermal-mechanical analysis of black liquor recovery boiler floor tubes. Residual stresses in boiler floors due to various manufacturing processes were analyzed. The modeling results were verified by X-ray and neutron diffraction measurements at room temperature on as-manufactured tubes as well as tubes after service. The established finite element models were then used to evaluate stress conditions during boiler operation. Using these finite element models, a parametric response surface study was performed to investigate the influence of material properties of the clad layer on stresses in the floor tubes during various boiler operating conditions, which yielded a generalized solution of stresses in the composite tube floors. The results of the study are useful for identifying the mechanisms of cracking experienced by recovery boilers. Based on the results of the response surface study, a recommendation was made for more suitable materials in terms of the analyzed mechanical properties. Alternative materials and manufacturing processes are being considered to improve the resistance to cracking and the in-service life of composite tubes. To avoid numerous FE stress-strain analyses of composite tubes made of different material combinations, a response surface study was performed that considered two essential mechanical properties of the clad material - coefficient of thermal expansion and yield stress - as independent variables. The response surface study provided a generalized solution of stresses in the floor in terms of the two selected parameters.

Taljat, B.; Zacharaia, T.; Wang, X.; Kesier, J.; Swindeman, R.; Hubbard, C.

1999-05-26T23:59:59.000Z

168

Thermal neutron imaging in an active interrogation environment  

SciTech Connect (OSTI)

We have developed a thermal-neutron coded-aperture imager that reveals the locations of hydrogenous materials from which thermal neutrons are being emitted. This imaging detector can be combined with an accelerator to form an active interrogation system in which fast neutrons are produced in a heavy metal target by means of xcitation by high energy photons. The photo-induced neutrons can be either prompt or delayed, depending on whether neutronemitting fission products are generated. Provided that there are hydrogenous materials close to the target, some of the photo-induced neutrons slow down and emerge from the surface at thermal energies. These neutrons can be used to create images that show the location and shape of the thermalizing materials. Analysis of the temporal response of the neutron flux provides information about delayed neutrons from induced fission if there are fissionable materials in the target. The combination of imaging and time-of-flight discrimination helps to improve the signal-to-background ratio. It is also possible to interrogate the target with neutrons, for example using a D-T generator. In this case, an image can be obtained from hydrogenous material in a target without the presence of heavy metal. In addition, if fissionable material is present in the target, probing with fast neutrons can stimulate delayed neutrons from fission, and the imager can detect and locate the object of interest, using appropriate time gating. Operation of this sensitive detection equipment in the vicinity of an accelerator presents a number of challenges, because the accelerator emits electromagnetic interference as well as stray ionizing radiation, which can mask the signals of interest.

Vanier,P.E.; Forman, L., and Norman, D.R.

2009-03-10T23:59:59.000Z

169

An Accelerator Neutron Source for BNCT  

SciTech Connect (OSTI)

The overall goal of this project was to develop an accelerator-based neutron source (ABNS) for Boron Neutron Capture Therapy (BNCT). Specifically, our goals were to design, and confirm by measurement, a target assembly and a moderator assembly that would fulfill the design requirements of the ABNS. These design requirements were 1) that the neutron field quality be as good as the neutron field quality for the reactor-based neutron sources for BNCT, 2) that the patient treatment time be reasonable, 3) that the proton current required to treat patients in reasonable times be technologially achievable at reasonable cost with good reliability, and accelerator space requirements which can be met in a hospital, and finally 4) that the treatment be safe for the patients.

Blue, Thomas, E

2006-03-14T23:59:59.000Z

170

Compact neutron imaging system using axisymmetric mirrors  

DOE Patents [OSTI]

A dispersed release of neutrons is generated from a source. A portion of this dispersed neutron release is reflected by surfaces of a plurality of nested, axisymmetric mirrors in at least an inner mirror layer and an outer mirror layer, wherein the neutrons reflected by the inner mirror layer are incident on at least one mirror surface of the inner mirror layer N times, wherein N is an integer, and wherein neutrons reflected by the outer mirror are incident on a plurality of mirror surfaces of the outer layer N+i times, where i is a positive integer, to redirect the neutrons toward a target. The mirrors can be formed by a periodically reversed pulsed-plating process.

Khaykovich, Boris; Moncton, David E; Gubarev, Mikhail V; Ramsey, Brian D; Engelhaupt, Darell E

2014-05-27T23:59:59.000Z

171

E-Print Network 3.0 - advanced spallation neutron Sample Search...  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

40 Lead-Bismuth Spallation Target Design Yousry Gohar Summary: . Protect the subcritical multiplier from the high-energy protons and neutrons. Contain the spallation... of...

172

New measurement of the scattering cross section of slow neutrons on liquid parahydrogen from neutron transmission  

E-Print Network [OSTI]

Slow neutron scattering provides quantitative information on the structure and dynamics of materials of interest in physics, chemistry, materials science, biology, geology, and other fields. Liquid hydrogen is a widely-used neutron moderator medium, and an accurate knowledge of its slow neutron cross section is essential for the design and optimization of intense slow neutron sources. In particular the rapid drop of the slow neutron scattering cross section of liquid parahydrogen below 14.5~meV is especially interesting and important. We have measured the total cross section and the scattering cross section for slow neutrons with energies between 0.43~meV and 16.1~meV on liquid hydrogen at 15.6~K using neutron transmission measurements on the hydrogen target of the NPDGamma collaboration at the Spallation Neutron Source at Oak Ridge National Laboratory. At 1~meV this measurement is a factor of 3 below the data from previous work which has been used in the design of liquid hydrogen moderators at slow neutron sources. We describe our measurements, compare them with previous work, and discuss the implications for designing more intense slow neutron sources.

K. B. Grammer; R. Alarcon; L. Barrón-Palos; D. Blyth; J. D. Bowman; J. Calarco; C. Crawford; K. Craycraft; D. Evans; N. Fomin; J. Fry; M. Gericke; R. C. Gillis; G. L. Greene; J. Hamblen; C. Hayes; S. Kucuker; R. Mahurin; M. Maldonado-Velázquez; E. Martin; M. McCrea; P. E. Mueller; M. Musgrave; H. Nann; S. I. Penttilä; W. M. Snow; Z. Tang; W. S. Wilburn

2014-12-12T23:59:59.000Z

173

Cold neutron scattering in imperfect deuterium crystals  

E-Print Network [OSTI]

The differential cross sections for cold neutron scattering in mosaic deuterium crystals have been calculated for various target temperatures. The theoretical results are compared with the recent experimental data for the neutron wavelengths $\\lambda\\approx$~1--9~\\AA. It is shown that the structures of observed Bragg peaks can be explained by the mosaic spread of about $3^{\\circ}$ and contributions from a~limited number of crystal orientations. Such a~crystal structure should be also taken into account in ultracold neutron upscattering due to the coherent phonon annihilation in solid deuterium.

Andrzej Adamczak

2010-12-10T23:59:59.000Z

174

Apparatus for connecting aligned abutted tubes  

DOE Patents [OSTI]

An apparatus for connecting abutted tubes and for maintaining their rotary alignment during connection. The apparatus comprises first and second tubes, a rotation prevention element, a collar and a retainer. Each tube has inside and outside walls, and first and second ends, each end having an inside and outside edge. The first tube has portions defining a first plurality of cavities located at the outside edge of its first end. An external threaded portion is on the outside wall of the first tube and next to the first plurality of cavities. The second tube has portions defining a second plurality of cavities located at the outside edge of its first end. The first plurality has a different number than the second plurality. The first ends of the first and second tubes have substantially the same outside diameter and are abutted during connection so that an orifice is formed whenever first and second tube cavities substantially overlap. A rotation prevension element is placed in the orifice to prevent rotation of the first and second tubes. A collar with an internal threaded portion is slidably disposed about the second tube. The internal threaded portion engages the external threaded portion of the first tube to connect the tubes. A lip connected to the collar prevents separation of the collar from the second tube.

Williams, R.E.

1984-11-29T23:59:59.000Z

175

Publications | Neutron Science | ORNL  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

Publications SHARE Publications The Neutron Science publications system contains peer-reviewed publications based on research conducted at ORNL's Neutron Science facilities or...

176

SHARP Neutronics Expanded  

Broader source: Energy.gov [DOE]

The SHARP neutronics module, PROTEUS, includes neutron and gamma transport solvers and cross-section processing tools as well as the capability for depletion and fuel cycle analysis.

177

Fracture compliance estimation using borehole tube waves  

E-Print Network [OSTI]

We tested two models, one for tube-wave generation and the other for tube-wave attenuation at a fracture intersecting a borehole that can be used to estimate fracture compliance, fracture aperture, and lateral extent. In ...

Bakku, Sudhish Kumar

178

Performance of drift tubes under high radiation  

E-Print Network [OSTI]

In this thesis, the aging and the rejuvenation of an ATLAS proportional drift tube are described. Firstly, the Diethorn model of gain is tested using pressure and sense-wire voltage measurements. The drift tube was then ...

Shi, Yue, S.B. Massachusetts Institute of Technology

2005-01-01T23:59:59.000Z

179

Neutron Interactions: Q-Equation, Elastic Scattering  

E-Print Network [OSTI]

Since a neutron has no charge it can easily enter into a nucleus and cause a reaction. Neutrons interact primarily with the nucleus of an atom, except in the special case of magnetic scattering where the interaction involves the neutron spin and the magnetic moment of the atom. Because magnetic scattering is of no interest in this class, we can neglect the interaction between neutrons and electrons and think of atoms and nuclei interchangeably. Neutron reactions can take place at any energy, so one has to pay particular attention to the energy variation of the interaction cross section. In a nuclear reactor neutrons can have energies ranging from 10-3 ev (1 mev) to 10 7 ev (10 Mev). This means our study of neutron interactions, in principle, will have to cover an energy range of 10 ten orders of magnitude. In practice we will limit ourselves to two energy ranges, the slowing down region (ev to Kev) and the thermal region (around 0.025 ev). For a given energy region – thermal, epithermal, resonance, fast – not all the possible reactions are equally important. Which reaction is important depends on the target nucleus and the neutron energy. Generally speaking the important types of interactions, in the order of increasing complexity from the standpoint of theoretical

unknown authors

180

Stability of tube rows in crossflow. [LMFBR  

SciTech Connect (OSTI)

A mathematical model for the instability of tube rows subjected to crossflow is examined. The theoretical model, based on the fluid-force data for a pitch-to-diameter ratio of 1.33, provides additional insight into the instability phenomenon. Tests are also conducted for three sets of tube rows. The effects of mass ratio, tube pitch, damping, detuning and finned tubes are investigated. Theoretical results and experimental data are in good agreement.

Chen, S.S.; Jendrzejczyk, J.A.

1982-10-01T23:59:59.000Z

Note: This page contains sample records for the topic "neutron tube target" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


181

Manual tube-to-tubesheet welding torch  

DOE Patents [OSTI]

A welding torch made of a high temperature plastic which fits over a tube intermediate the ends thereof for welding the juncture between the tube and the back side of a tube plate and has a ballooned end in which an electrode, filler wire guide, fiber optic bundle, and blanketing gas duct are disposed.

Kiefer, Joseph H. (Tampa, FL); Smith, Danny J. (Tampa, FL)

1982-01-01T23:59:59.000Z

182

Studies of Degraded Smelt Spout Opening Tubes  

SciTech Connect (OSTI)

Co-extruded type 304L stainless steel/SA210 carbon steel tubes have been used on the floors and lower walls of many black liquor recovery boilers to address the wall thinning problem that had been an issue for boiler owners and operators. Use of these tubes greatly reduced the corrosion issue, but corrosion was still sometimes observed and cracking was discovered in some tubes, particularly those that are bent to form the openings for smelt spouts. Because cracks in the opening tubes were sometimes observed to extend a significant distance into the tube wall and because these cracks were found fairly frequently, tubes made from a number of alternate cladding materials were tried in place of the 304L clad opening tubes. This paper describes the results of examinations of spout opening tubes of the standard 304L/carbon steel and of several of the alternate materials that have been tried. In addition to the corrosion and cracking seen in the spout opening tubes, another issue associated with these tubes has been observed. Preferential corrosion of the cap welds is sometimes seen on butt welds attaching the spout opening tubes made with alternate cladding materials to the standard 304L/carbon steel co-extruded wall tubes. Some information on the observations of this corrosion is also included in this paper.

Keiser, James R [ORNL; Kish, Joseph R. [Paprican; Willoughby, Adam W [ORNL; Longmire, Hu Foster [ORNL; Singbeil, Douglas [Paprican

2007-01-01T23:59:59.000Z

183

Radiobiology of normal rat lung in Boron Neutron Capture Therapy  

E-Print Network [OSTI]

Boron Neutron Capture Therapy (BNCT) is a binary cancer radiation therapy that utilizes biochemical tumor cell targeting and provides a mixed field of high and low Linear Energy Transfer (LET) radiation with differing ...

Kiger, Jingli Liu

2006-01-01T23:59:59.000Z

184

Computational aspects of treatment planning for neutron capture therapy  

E-Print Network [OSTI]

Boron Neutron Capture Therapy (BNCT) is a biochemically targeted form of binary radiation therapy that has the potential to deliver radiation to cancers with cellular dose selectivity. Accurate and efficient treatment ...

Albritton, James Raymond, 1977-

2010-01-01T23:59:59.000Z

185

Real-Time Active Cosmic Neutron Background Reduction Methods  

SciTech Connect (OSTI)

Neutron counting using large arrays of pressurized 3He proportional counters from an aerial system or in a maritime environment suffers from the background counts from the primary cosmic neutrons and secondary neutrons caused by cosmic ray?induced mechanisms like spallation and charge-exchange reaction. This paper reports the work performed at the Remote Sensing Laboratory–Andrews (RSL-A) and results obtained when using two different methods to reduce the cosmic neutron background in real time. Both methods used shielding materials with a high concentration (up to 30% by weight) of neutron-absorbing materials, such as natural boron, to remove the low-energy neutron flux from the cosmic background as the first step of the background reduction process. Our first method was to design, prototype, and test an up-looking plastic scintillator (BC-400, manufactured by Saint Gobain Corporation) to tag the cosmic neutrons and then create a logic pulse of a fixed time duration (~120 ?s) to block the data taken by the neutron counter (pressurized 3He tubes running in a proportional counter mode). The second method examined the time correlation between the arrival of two successive neutron signals to the counting array and calculated the excess of variance (Feynman variance Y2F)1 in the neutron count distribution from Poisson distribution. The dilution of this variance from cosmic background values ideally would signal the presence of man-made neutrons.2 The first method has been technically successful in tagging the neutrons in the cosmic-ray flux and preventing them from being counted in the 3He tube array by electronic veto—field measurement work shows the efficiency of the electronic veto counter to be about 87%. The second method has successfully derived an empirical relationship between the percentile non-cosmic component in a neutron flux and the Y2F of the measured neutron count distribution. By using shielding materials alone, approximately 55% of the neutron flux from man-made sources like 252Cf or Am-Be was removed.

Mukhopadhyay, Sanjoy; Maurer, Richard; Wolff, Ronald; Mitchell, Stephen; Guss, Paul

2013-09-01T23:59:59.000Z

186

Neutron capture and neutron-induced fission experiments on americium isotopes with DANCE  

SciTech Connect (OSTI)

Neutron capture cross section data on Am isotopes were measured using the Detector for Advanced Neutron Capture Experiments (DANCE) at Los Alamos National Laboratory. The neutron capture cross section was determined for {sup 241}Am for neutron energies between thermal and 320 keV. Preliminary results were also obtained for {sup 243}Am for neutron energies between 35 eV and 200 keV. The results on concurrent neutron-induced fission and neutron-capture measurements on {sup 242m}Am will be presented, where the fission events were actively triggered during the experiments. In these experiments, the Parallel-Plate Avalanche Counter (PPAC) detector that surrounds the target located in the center of the DANCE array was used as a fission-tagging detector to separate (n,{gamma}) from (n,f) events. The first evidence of neutron capture on {sup 242m}Am in the resonance region in between 2 and 9 eV of the neutron energy was obtained.

Jandel, Marian [Los Alamos National Laboratory

2008-01-01T23:59:59.000Z

187

Neutron capture and neutron-induced fission experiments on americium isotopes with DANCE  

SciTech Connect (OSTI)

Neutron capture cross section data on Am isotopes were measured using the Detector for Advanced Neutron Capture Experiments (DANCE) at Los Alamos National Laboratory. The neutron capture cross section was determined for {sup 241}Am for neutron energies between thermal and 320 keV. Preliminary results were also obtained for {sup 243}Am for neutron energies between 10 eV and 250 keV. The results on concurrent neutron-induced fission and neutron-capture measurements on {sup 242m}Am will be presented where the fission events were actively triggered during the experiments. In these experiments, a Parallel-Plate Avalanche Counter (PPAC) detector that surrounds the target located in the center of the DANCE array was used as a fission-tagging detector to separate (n,{gamma}) events from (n,f) events. The first direct observation of neutron capture on {sup 242m}Am in the resonance region in between 2 and 9 eV of the neutron energy was obtained.

Jandel, M.; Bredeweg, T. A.; Fowler, M. M.; Bond, E. M.; Couture, A.; Haight, R. C.; Keksis, A. L.; O'Donnell, J. M.; Rundberg, R. S.; Ullmann, J. L.; Vieira, D. J.; Wilhelmy, J. B.; Wouters, J. M. [Los Alamos National Laboratory, Los Alamos, NM, 87545 (United States); Stoyer, M. A.; Wu, C. Y.; Becker, J. A.; Haslett, R. J.; Henderson, R. A. [Lawrence Livermore National Laboratory, Livermore, CA, 94550 (United States)

2009-01-28T23:59:59.000Z

188

A Neutron Multiplicity Meter for Deep Underground Muon-Induced High Energy Neutron Measurements  

E-Print Network [OSTI]

We present the design of an instrument capable of measuring the high energy ($>$60 MeV) muon-induced neutron flux deep underground. The instrument is based on applying the Gd-loaded liquid-scintillator technique to measure the rate of high-energy neutrons underground based on the neutron multiplicity induced in a Pb target. We present design studies based on Monte Carlo simulations that show that an apparatus consisting of a Pb target of 200 cm by 200 cm area by 60 cm thickness covered by a 60 cm thick Gd-loaded liquid scintillator (0.5% Gd content) detector could measure, at a depth of 2000 meters of water equivalent, a rate of $70\\pm8$ (stat) events/year. Based on these studies, we also discuss the benefits of using a neutron multiplicity meter as a component of active shielding in such experiments.

R. Hennings-Yeomans; D. S. Akerib

2007-01-24T23:59:59.000Z

189

Ionization tube simmer current circuit  

DOE Patents [OSTI]

A highly efficient flash lamp simmer current circuit utilizes a fifty percent duty cycle square wave pulse generator to pass a current over a current limiting inductor to a full wave rectifier. The DC output of the rectifier is then passed over a voltage smoothing capacitor through a reverse current blocking diode to a flash lamp tube to sustain ionization in the tube between discharges via a small simmer current. An alternate embodiment of the circuit combines the pulse generator and inductor in the form of an FET off line square wave generator with an impedance limited step up output transformer which is then applied to the full wave rectifier as before to yield a similar simmer current.

Steinkraus, Jr., Robert F. (Livermore, CA)

1994-01-01T23:59:59.000Z

190

Ionization tube simmer current circuit  

DOE Patents [OSTI]

A highly efficient flash lamp simmer current circuit utilizes a fifty percent duty cycle square wave pulse generator to pass a current over a current limiting inductor to a full wave rectifier. The DC output of the rectifier is then passed over a voltage smoothing capacitor through a reverse current blocking diode to a flash lamp tube to sustain ionization in the tube between discharges via a small simmer current. An alternate embodiment of the circuit combines the pulse generator and inductor in the form of an FET off line square wave generator with an impedance limited step up output transformer which is then applied to the full wave rectifier as before to yield a similar simmer current. 6 figures.

Steinkraus, R.F. Jr.

1994-12-13T23:59:59.000Z

191

Conceptual design of a pressure tube light water reactor with variable moderator control  

SciTech Connect (OSTI)

This paper presents the development of innovative pressure tube light water reactor with variable moderator control. The core layout is derived from a CANDU line of reactors in general, and advanced ACR-1000 design in particular. It should be stressed however, that while some of the ACR-1000 mechanical design features are adopted, the core design basics of the reactor proposed here are completely different. First, the inter fuel channels spacing, surrounded by the calandria tank, contains a low pressure gas instead of heavy water moderator. Second, the fuel channel design features an additional/external tube (designated as moderator tube) connected to a separate moderator management system. The moderator management system is design to vary the moderator tube content from 'dry' (gas) to 'flooded' (light water filled). The dynamic variation of the moderator is a unique and very important feature of the proposed design. The moderator variation allows an implementation of the 'breed and burn' mode of operation. The 'breed and burn' mode of operation is implemented by keeping the moderator tube empty ('dry' filled with gas) during the breed part of the fuel depletion and subsequently introducing the moderator by 'flooding' the moderator tube for the 'burn' part. This paper assesses the conceptual feasibility of the proposed concept from a neutronics point of view. (authors)

Rachamin, R.; Fridman, E. [Reactor Safety Div., Inst. of Resource Ecology, Helmholtz-Zentrum Dresden-Rossendorf, POB 51 01 19, 01314 Dresden (Germany); Galperin, A. [Dept. of Nuclear Engineering, Ben-Gurion Univ. of the Negev, POB 653, Beer Sheva 84105 (Israel)

2012-07-01T23:59:59.000Z

192

Tomsk Polytechnic University cyclotron as a source for neutron based cancer treatment  

SciTech Connect (OSTI)

In this paper we present our cyclotron based neutron source with average energy 6.3 MeV generated during the 13.6 MeV deuterons interactions with beryllium target, neutron field dosimetry, and dosimetry of attendant gamma fields. We also present application of our neutron source for cancer treatment.

Lisin, V. A. [Cancer Research Institute, 5 Kooperativny St., Tomsk 634050 (Russian Federation) [Cancer Research Institute, 5 Kooperativny St., Tomsk 634050 (Russian Federation); Tomsk Polytechnic University, 30 Lenina av., Tomsk 634050 (Russian Federation); Bogdanov, A. V.; Golovkov, V. M.; Sukhikh, L. G.; Verigin, D. A., E-mail: verigin@tpu.ru [Tomsk Polytechnic University, 30 Lenina av., Tomsk 634050 (Russian Federation); Musabaeva, L. I. [Cancer Research Institute, 5 Kooperativny St., Tomsk 634050 (Russian Federation)] [Cancer Research Institute, 5 Kooperativny St., Tomsk 634050 (Russian Federation)

2014-02-15T23:59:59.000Z

193

ESS liquid-metal target design using computational fluid dynamics  

SciTech Connect (OSTI)

The thermal-hydraulic performance of a spallation neutron source target limits the highest neutron fluxes that can be generated. The current design for the European spallation source consists of a liquid metal encased within a containing shell, wedge-shaped in the direction of the incoming proton beam, with rounded sides in a cross section through a plane normal to the beam.

Dury, T.V. [Paul Scherrer Institute, Villigen (Switzerland)

1997-12-01T23:59:59.000Z

194

Turbine nozzle stage having thermocouple guide tube  

DOE Patents [OSTI]

A guide tube is fixed adjacent opposite ends in outer and inner covers of a nozzle stage segment. The guide tube is serpentine in shape between the outer and inner covers and extends through a nozzle vane. An insert is disposed in the nozzle vane and has apertures to accommodate serpentine portions of the guide tube. Cooling steam is also supplied through chambers of the insert on opposite sides of a central insert chamber containing the guide tube. The opposite ends of the guide tube are fixed to sleeves, in turn fixed to the outer and inner covers.

Schotsch, Margaret Jones (Greer, SC); Kirkpatrick, Francis Lawrence (late of Galway, NY); Lapine, Eric Michael (Northwood, NH)

2002-01-01T23:59:59.000Z

195

Methodology for the use of proportional counters in pulsed fast neutron yield measurements  

E-Print Network [OSTI]

This paper introduces in full detail a methodology for the measurement of neutron yield and the necessary efficiency calibration, to be applied to the intensity measurement of neutron bursts where individual neutrons are not resolved in time, for any given moderated neutron proportional counter array. The method allows efficiency calibration employing the detection neutrons arising from an isotopic neutron source. Full statistical study of the procedure is descripted, taking into account contributions arising from counting statistics, piling-up statistics of real detector pulse-height spectra and background fluctuations. The useful information is extracted from the net waveform area of the signal arising from the electric charge accumulated inside the detector tube. Improvement of detection limit is gained, therefore this detection system can be used in detection of low emission neutron pulsed sources with pulses of duration from nanoseconds to up. The application of the methodology to detection systems to be...

Tarifeńo-Saldivia, Ariel; Pavez, Cristian; Soto, Leopoldo

2011-01-01T23:59:59.000Z

196

A High Density Polarized Hydrogen Gas Target for Storage Rings  

E-Print Network [OSTI]

A High Density Polarized Hydrogen Gas Target for Storage Rings K. Zapfe \\Lambday , B. Braun z , H of gaseous polarized hydrogen was formed by injecting polarized H atoms (produced by Stern­Gerlach spin separation) into a storage cell consisting of a cylindrical tube open at both ends. The target was placed

197

Neutron reflecting supermirror structure  

DOE Patents [OSTI]

An improved neutron reflecting supermirror structure comprising a plurality of stacked sets of bilayers of neutron reflecting materials. The improved neutron reflecting supermirror structure is adapted to provide extremely good performance at high incidence angles, i.e. up to four time the critical angle of standard neutron mirror structures. The reflection of neutrons striking the supermirror structure at a high critical angle provides enhanced neutron throughput, and hence more efficient and economical use of neutron sources. One layer of each set of bilayers consist of titanium, and the second layer of each set of bilayers consist of an alloy of nickel with carbon interstitially present in the nickel alloy.

Wood, James L. (Drayton Plains, MI)

1992-01-01T23:59:59.000Z

198

Neutron-Mirror-Neutron Oscillations in a Trap  

E-Print Network [OSTI]

We calculate the rate of neutron-mirror-neutron oscillations for ultracold neutrons trapped in a storage vessel. Recent experimental bounds on the oscillation time are discussed.

B. Kerbikov; O. Lychkovskiy

2008-04-03T23:59:59.000Z

199

Imaging with Scattered Neutrons  

E-Print Network [OSTI]

We describe a novel experimental technique for neutron imaging with scattered neutrons. These scattered neutrons are of interest for condensed matter physics, because they permit to reveal the local distribution of incoherent and coherent scattering within a sample. In contrast to standard attenuation based imaging, scattered neutron imaging distinguishes between the scattering cross section and the total attenuation cross section including absorption. First successful low-noise millimeter-resolution images by scattered neutron radiography and tomography are presented.

H. Ballhausen; H. Abele; R. Gaehler; M. Trapp; A. Van Overberghe

2006-10-30T23:59:59.000Z

200

Qualification tests of materials for spallation neutron sources  

SciTech Connect (OSTI)

Several existing and planned facilities, worldwide, use protons at 650-2000 MeV to produce neutrons by spallation reactions. In the advanced spallation neutron sources, materials in the target and blanket structures will be exposed to high-energy proton fluences at 10{sup 25}-10{sup 26}/m{sup 2} per year. Information obtained in fusion reactor studies are being applied to the design of spallation neutron sources. The APT project is sponsoring a materials qualification program including irradiations in the proton beam and neutron field at the Los Alamos Spallation Radiation Damage Facility.

Sommer, W.F.

1996-12-31T23:59:59.000Z

Note: This page contains sample records for the topic "neutron tube target" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


201

Bubble masks for time-encoded imaging of fast neutrons.  

SciTech Connect (OSTI)

Time-encoded imaging is an approach to directional radiation detection that is being developed at SNL with a focus on fast neutron directional detection. In this technique, a time modulation of a detected neutron signal is induced-typically, a moving mask that attenuates neutrons with a time structure that depends on the source position. An important challenge in time-encoded imaging is to develop high-resolution two-dimensional imaging capabilities; building a mechanically moving high-resolution mask presents challenges both theoretical and technical. We have investigated an alternative to mechanical masks that replaces the solid mask with a liquid such as mineral oil. Instead of fixed blocks of solid material that move in pre-defined patterns, the oil is contained in tubing structures, and carefully introduced air gaps-bubbles-propagate through the tubing, generating moving patterns of oil mask elements and air apertures. Compared to current moving-mask techniques, the bubble mask is simple, since mechanical motion is replaced by gravity-driven bubble propagation; it is flexible, since arbitrary bubble patterns can be generated by a software-controlled valve actuator; and it is potentially high performance, since the tubing and bubble size can be tuned for high-resolution imaging requirements. We have built and tested various single-tube mask elements, and will present results on bubble introduction and propagation as a function of tubing size and cross-sectional shape; real-time bubble position tracking; neutron source imaging tests; and reconstruction techniques demonstrated on simple test data as well as a simulated full detector system.

Brubaker, Erik; Brennan, James S.; Marleau, Peter; Nowack, Aaron B.; Steele, John; Sweany, Melinda; Throckmorton, Daniel J.

2013-09-01T23:59:59.000Z

202

Multi-tube arrangement for combustor and method of making the multi-tube arrangement  

DOE Patents [OSTI]

A fuel injector tube includes a one piece, unitary, polygonal tube having an inlet end and an outlet end. The fuel injector tube further includes a fuel passage extending from the inlet end to the outlet end along a longitudinal axis of the polygonal tube, a plurality of air passages extending from the inlet end to the outlet end and surrounding the fuel passage, and a plurality of fuel holes. Each fuel hole connects an air passage with the fuel passage. The inlet end of the polygonal tube is formed into a fuel tube. A fuel injector includes a plurality of fuel injector tubes and a plate. The plurality of fuel tubes are connected to the plate adjacent the inlet ends of the plurality of fuel injector tubes.

Ziminsky, Willy Steve (Simpsonville, SC)

2012-07-31T23:59:59.000Z

203

A pulsed eddy current probe for inspection of support plates from within Alloy-800 steam generator tubes  

SciTech Connect (OSTI)

Support plate degradation and fouling in nuclear steam generators (SGs) can lead to SG tube corrosion and loss of efficiency. Inspection and monitoring of these conditions can be integrated with preventive maintenance programs, thereby advancing station-life management processes. A prototype pulsed eddy current (PEC) probe, targeting inspection issues associated with SG tubes in SS410 tube support plate structures, has been developed using commercial finite element (FE) software. FE modeling was used to identify appropriate driver and pickup coil configurations for optimum sensitivity to changes in gap and offset for Alloy-800 SG tubes passing through 25 mm thick SS410 support plates. Experimental measurements using a probe that was manufactured based on the modeled configuration, were used to confirm the sensitivity of differential PEC signals to changes in relative position of the tube within the tube support plate holes. Models investigated the effect of shift and tilt of tube with respect to hole centers. Near hole centers and for small shifts, modeled signal amplitudes from the differentially connected coil pairs were observed to change linearly with tube shift. This was in agreement with experimentally measured TEC coil response. The work paves the way for development of a system targeting the inspection and evaluation of support plate structures in steam generators.

Krause, T. W.; Babbar, V. K.; Underhill, P. R. [Department of Physics, Royal Military College of Canada, Kingston, ON (Canada)

2014-02-18T23:59:59.000Z

204

Optimizing Moderator Dimensions for Neutron Scattering at the Spallation Neutron Source  

SciTech Connect (OSTI)

In this work, we investigate the effect of neutron moderator dimensions on the performance of neutron scattering instruments at the Spallation Neutron Source. In a recent study of the planned second target station at the Spallation Neutron Source (SNS) facility [1,2], we have found that the dimensions of a moderator play a significant role in determining its surface brightness. A smaller moderator may be significantly brighter for a smaller viewing area [4]. One of the immediate implications of this finding is that for modern neutron scattering instrument designs, moderator dimensions and brightness have to be incorporated as an integrated optimization parameter. Here, we establish a strategy of matching neutron scattering instruments with moderators using analytical and Monte Carlo techniques. In order to simplify our treatment, we group the instruments into two broad categories, those with natural collimation and those that use neutron guide systems. We found that the cross-sections of the sample and the neutron guide, respectively, are the deciding factors for choosing the moderator. Beam divergence plays no role as long as it is within the reach of practical constraints. Namely, the required divergence is not too large for the guide or sample to be located close enough to the moderator on an actual spallation source.

Zhao, Jinkui [ORNL] [ORNL; Robertson, Lee [ORNL] [ORNL; Herwig, Kenneth W [ORNL] [ORNL; Gallmeier, Franz X [ORNL] [ORNL; Riemer, Bernie [ORNL] [ORNL

2013-01-01T23:59:59.000Z

205

Electro-optic Laser-Sampled Neutron Detector  

SciTech Connect (OSTI)

A new method of detecting radiation which can allow for long distance measurements is being investigated. The device is primarily for neutrons detection althought it could, in principle, be used for gamma ray detection. The neutron detection medium is a solid, transparent, electro-optical material, such as lithium niobate, lithium tantalite, or barium borate. Crystals of these materials act as optical gates to laser light, allowing light to pass through only when a neutron interaction occurs in the crystal. Typical light detection devices, such as CCD cameras or photomultiplier tubes, can be used to signal when light passes through the crystal. The overall goal of the project is to investigate the feasibility of such devices for the detection of neutron radiation and to quantify their capabilities and limitations.

J. Kenneth Shultis; Douglas McGregor

2009-11-30T23:59:59.000Z

206

Neutron range spectrometer  

DOE Patents [OSTI]

A neutron range spectrometer and method for determining the neutron energy spectrum of a neutron emitting source are disclosed. Neutrons from the source are collimnated along a collimation axis and a position sensitive neutron counter is disposed in the path of the collimated neutron beam. The counter determines positions along the collimation axis of interactions between the neutrons in the neutron beam and a neutron-absorbing material in the counter. From the interaction positions, a computer analyzes the data and determines the neutron energy spectrum of the neutron beam. The counter is preferably shielded and a suitable neutron-absorbing material is He-3. The computer solves the following equation in the analysis: ##EQU1## where: N(x).DELTA.x=the number of neutron interactions measured between a position x and x+.DELTA.x, A.sub.i (E.sub.i).DELTA.E.sub.i =the number of incident neutrons with energy between E.sub.i and E.sub.i +.DELTA.E.sub.i, and C=C(E.sub.i)=N .sigma.(E.sub.i) where N=the number density of absorbing atoms in the position sensitive counter means and .sigma. (E.sub.i)=the average cross section of the absorbing interaction between E.sub.i and E.sub.i +.DELTA.E.sub.i.

Manglos, Stephen H. (East Syracuse, NY)

1989-06-06T23:59:59.000Z

207

Monte Carlo modeling of spallation targets containing uranium and americium  

E-Print Network [OSTI]

Neutron production and transport in spallation targets made of uranium and americium are studied with a Geant4-based code MCADS (Monte Carlo model for Accelerator Driven Systems). A good agreement of MCADS results with experimental data on neutron- and proton-induced reactions on $^{241}$Am and $^{243}$Am nuclei allows to use this model for simulations with extended Am targets. Several geometry options and material compositions (U, U+Am, Am, Am$_2$O$_3$) are considered for spallation targets to be used in Accelerator Driven Systems. It was demonstrated that MCADS model can be reliably used for calculating critical masses of fissile materials. All considered options operate as deep subcritical targets having neutron multiplication factor of $k \\sim 0.5$. It is found that more than 4 kg of Am can be burned in one spallation target during the first year of operation.

Malyshkin, Yury; Mishustin, Igor; Greiner, Walter

2013-01-01T23:59:59.000Z

208

Monte Carlo modeling of spallation targets containing uranium and americium  

E-Print Network [OSTI]

Neutron production and transport in spallation targets made of uranium and americium are studied with a Geant4-based code MCADS (Monte Carlo model for Accelerator Driven Systems). A good agreement of MCADS results with experimental data on neutron- and proton-induced reactions on $^{241}$Am and $^{243}$Am nuclei allows to use this model for simulations with extended Am targets. It was demonstrated that MCADS model can be used for calculating the values of critical mass for $^{233,235}$U, $^{237}$Np, $^{239}$Pu and $^{241}$Am. Several geometry options and material compositions (U, U+Am, Am, Am$_2$O$_3$) are considered for spallation targets to be used in Accelerator Driven Systems. All considered options operate as deep subcritical targets having neutron multiplication factor of $k \\sim 0.5$. It is found that more than 4 kg of Am can be burned in one spallation target during the first year of operation.

Yury Malyshkin; Igor Pshenichnov; Igor Mishustin; Walter Greiner

2014-05-02T23:59:59.000Z

209

Large Diameter Lasing Tube Cooling Arrangement  

DOE Patents [OSTI]

A cooling structure (16) for use inside a ceramic cylindrical tube (11) of a metal vapor laser (10) to cool the plasma in the tube (11), the cooling structure (16) comprising a plurality of circular metal members (17,31) and mounting members (18, 34) that position the metal members (17,31) coaxially in the tube (11) to form an annular lasing volume, with the metal members (17, 31) being axially spaced from each other along the length of the tube (11) to prevent the metal members from shorting out the current flow through the plasma in the tube (11) and to provide spaces through which the heat from localized hot spots in the plasma may radiate to the other side of the tube (11).

Hall, Jerome P.; Alger, Terry W.; Anderson, Andrew T.; Arnold, Philip A.

2004-05-18T23:59:59.000Z

210

Tube support grid and spacer therefor  

DOE Patents [OSTI]

A tube support grid and spacers therefor provide radially inward preloading of heat exchange tubes to minimize stress upon base welds due to differential thermal expansion. The grid comprises a concentric series of rings and spacers with opposing concave sides for conforming to the tubes and V-shaped ends to provide resilient flexibility. The flexibility aids in assembly and in transmitting seismic vibrations from the tubes to a shroud. The tube support grid may be assembled in place to achieve the desired inwardly radial preloading of the heat exchange tubes. Tab and slot assembly further minimizes stresses in the system. The radii of the grid rings may be preselected to effect the desired radially inward preloading.

Ringsmuth, Richard J. (Solano Beach, CA); Kaufman, Jay S. (Del Mar, CA)

1986-01-01T23:59:59.000Z

211

Layered semiconductor neutron detectors  

DOE Patents [OSTI]

Room temperature operating solid state hand held neutron detectors integrate one or more relatively thin layers of a high neutron interaction cross-section element or materials with semiconductor detectors. The high neutron interaction cross-section element (e.g., Gd, B or Li) or materials comprising at least one high neutron interaction cross-section element can be in the form of unstructured layers or micro- or nano-structured arrays. Such architecture provides high efficiency neutron detector devices by capturing substantially more carriers produced from high energy .alpha.-particles or .gamma.-photons generated by neutron interaction.

Mao, Samuel S; Perry, Dale L

2013-12-10T23:59:59.000Z

212

Neutron streak camera  

DOE Patents [OSTI]

Apparatus for improved sensitivity and time resolution of a neutron measurement. The detector is provided with an electrode assembly having a neutron sensitive cathode which emits relatively low energy secondary electrons. The neutron sensitive cathode has a large surface area which provides increased sensitivity by intercepting a greater number of neutrons. The cathode is also curved to compensate for differences in transit time of the neutrons emanating from the point source. The slower speeds of the secondary electrons emitted from a certain portion of the cathode are matched to the transit times of the neutrons impinging thereupon.

Wang, C.L.

1981-05-14T23:59:59.000Z

213

Study on neutron radiation field of carbon ions therapy  

E-Print Network [OSTI]

Carbon ions offer significant advantages for deep-seated local tumors therapy due to their physical and biological properties. Secondary particles, especially neutrons caused by heavy ion reactions should be carefully considered in treatment process and radiation protection. For radiation protection purposes, the FLUKA Code was used in order to evaluate the radiation field at deep tumor therapy room of HIRFL in this paper. The neutron energy spectra, neutron dose and energy deposition of carbon ion and neutron in tissue-like media was studied for bombardment of solid water target by 430MeV/u C ions. It is found that the calculated neutron dose have a good agreement with the experimental date, and the secondary neutron dose may not exceed one in a thousand of the carbon ions dose at Bragg peak area in tissue-like media.

Xu, Jun-Kui; Li, Wu-Yuan; Yan, Wei-Wei; Chen, Xi-Meng; Mao, Wang; Pang, Cheng-Guo

2015-01-01T23:59:59.000Z

214

Focused Ion Beam Production Using a Pyroelectric Crystal and a Resistive Glass Tube  

E-Print Network [OSTI]

Focused Ion Beam Production Using a Pyroelectric Crystal and a Resistive Glass Tube T. Z. Fullem, A to accelerate electrons into a metal target has led to the production of compact X-Ray generators [4], [5], [6 tungsten tip (marketed for use in a scanning electron microscope) with an apex radius of 70 nm was mounted

Danon, Yaron

215

Eddy current measurement of tube element spacing  

DOE Patents [OSTI]

A method of electromagnetically measuring the distance between adjacent tube elements in a heat exchanger. A cylindrical, high magnetic permeability ferrite slug is placed in the tube adjacent the spacing to be measured. A bobbin or annular coil type probe operated in the absolute mode is inserted into a second tube adjacent the spacing to be measured. From prior calibrations on the response of the eddy current coil, the signals from the coil, when sensing the presence of the ferrite slug, are used to determine the spacing between the tubes.

Latham, Wayne Meredith (Forest, VA); Hancock, Jimmy Wade (Lynchburg, VA); Grut, Jayne Marie (Madison Heights, VA)

1998-01-01T23:59:59.000Z

216

ORNL Neutron Sciences Annual Report for 2007  

SciTech Connect (OSTI)

This is the first annual report of the Oak Ridge National Laboratory Neutron Sciences Directorate for calendar year 2007. It describes the neutron science facilities, current developments, and future plans; highlights of the year's activities and scientific research; and information on the user program. It also contains information about education and outreach activities and about the organization and staff. The Neutron Sciences Directorate is responsible for operation of the High Flux Isotope Reactor and the Spallation Neutron Source. The main highlights of 2007 were highly successful operation and instrument commissioning at both facilities. At HFIR, the year began with the reactor in shutdown mode and work on the new cold source progressing as planned. The restart on May 16, with the cold source operating, was a significant achievement. Furthermore, measurements of the cold source showed that the performance exceeded expectations, making it one of the world's most brilliant sources of cold neutrons. HFIR finished the year having completed five run cycles and 5,880 MWd of operation. At SNS, the year began with 20 kW of beam power on target; and thanks to a highly motivated staff, we reached a record-breaking power level of 183 kW by the end of the year. Integrated beam power delivered to the target was 160 MWh. Although this is a substantial accomplishment, the next year will bring the challenge of increasing the integrated beam power delivered to 887 MWh as we chart our path toward 5,350 MWh by 2011.

Anderson, Ian S [ORNL; Horak, Charlie M [ORNL; Counce, Deborah Melinda [ORNL; Ekkebus, Allen E [ORNL

2008-07-01T23:59:59.000Z

217

Ultrafast neutron detector  

DOE Patents [OSTI]

A neutron detector of very high temporal resolution is described. It may be used to measure distributions of neutrons produced by fusion reactions that persist for times as short as about 50 picoseconds.

Wang, C.L.

1985-06-19T23:59:59.000Z

218

The determination of phosphorus by fast neutron activation analysis  

E-Print Network [OSTI]

SCALER POWER SUPPLY NAI(TlJ CRYSTAL NAIPL) CRYSTAL PIN LIGHT SOL. SYSTEM CONTROL CHASSIS PRE AMP VACUUM NEUTRON DETECTOR AIR VALVE I50 KV COCKCROFT- WALTON ACCELERA LIGHT Figure 4. Block Diagram of the Nark III System 21 3, When.... At the center of the irradiation position, the neutron flux varies from 10 - 106 n/cm /sec. depending on the str'ength 2 of the tritium target, beam current, and the target life time. Targets are commercially available from Texas Nuclear Corporation...

To-On, Maen

2012-06-07T23:59:59.000Z

219

Leakage-flow-induced vibration of a tube-in-tube slip joint. [LMFBR  

SciTech Connect (OSTI)

The susceptibility of a cantilevered tube conveying water to self-excitation by leakage flow through a slip joint is assessed experimentally. The slip joint is formed by inserting a smaller, rigid tube into the free end of the cantilevered tube. Variations of the slip joint annular gaps and engagement lengths are tested, and several mechanisms for self-excitation are described.

Mulcahy, T.M.

1983-06-01T23:59:59.000Z

220

Neutron computed tomography  

E-Print Network [OSTI]

to make the Donner Algorithms run. TABLE OF CONTEliiTS CHAPTF. . R I NEI. TRON RADIOGRAPHY . I. 1 Background . I. 2 Theory . l. 3 Neutron Beam Characterization I. 4 Image Detectors . COMPI'TED TOMOGRAPHY . Il I Background . II. 2 Notation II. 3... data which is generated by rays traveling (and being attenuated) in straight lines. However in neutron radiography, what is measured is, to most extents, the levels of neutrons which are not attenuated. Neutrons are particles. They scatter...

Russell, Clifford Marlow

2012-06-07T23:59:59.000Z

Note: This page contains sample records for the topic "neutron tube target" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


221

EA-1131: Final Environmental Assessment | Department of Energy  

Broader source: Energy.gov (indexed) [DOE]

of Neutron Tube Target Loading Operation, Los Alamos Laboratory, Los Alamos, New Mexico This EA evaluates the environmental impacts of the proposal to relocate the Neutron...

222

Advanced neutron absorber materials  

DOE Patents [OSTI]

A neutron absorbing material and method utilizing rare earth elements such as gadolinium, europium and samarium to form metallic glasses and/or noble base nano/microcrystalline materials, the neutron absorbing material having a combination of superior neutron capture cross sections coupled with enhanced resistance to corrosion, oxidation and leaching.

Branagan, Daniel J. (Idaho Falls, ID); Smolik, Galen R. (Idaho Falls, ID)

2000-01-01T23:59:59.000Z

223

Accelerator target  

DOE Patents [OSTI]

A target includes a body having a depression in a front side for holding a sample for irradiation by a particle beam to produce a radioisotope. Cooling fins are disposed on a backside of the body opposite the depression. A foil is joined to the body front side to cover the depression and sample therein. A perforate grid is joined to the body atop the foil for supporting the foil and for transmitting the particle beam therethrough. A coolant is circulated over the fins to cool the body during the particle beam irradiation of the sample in the depression. 5 figs.

Schlyer, D.J.; Ferrieri, R.A.; Koehler, C.

1999-06-29T23:59:59.000Z

224

Accelerator target  

DOE Patents [OSTI]

A target includes a body having a depression in a front side for holding a sample for irradiation by a particle beam to produce a radioisotope. Cooling fins are disposed on a backside of the body opposite the depression. A foil is joined to the body front side to cover the depression and sample therein. A perforate grid is joined to the body atop the foil for supporting the foil and for transmitting the particle beam therethrough. A coolant is circulated over the fins to cool the body during the particle beam irradiation of the sample in the depression.

Schlyer, David J. (Bellport, NY); Ferrieri, Richard A. (Patchogue, NY); Koehler, Conrad (Miller Place, NY)

1999-01-01T23:59:59.000Z

225

Characterization of stainless steel 304 tubing  

SciTech Connect (OSTI)

Earlier studies have shown that stainless steel 304 (SS304) containing martensite is susceptible to hydrogen embrittlement. This generated concern regarding the structural integrity of SS304 tubing we use in the W87 pit tube. During surveillance operations, the pit tube undergoes a series of bending and straightening as it goes through a number of surveillance cycles. This motivated the study to characterize austenitic SS304 tubing obtained from Rocky Flats. The tubes continued to display structural soundness even after numerous repeated bending and straightening cycles. The minimum and maximum number of bends to failure occurred after 13 and 16 cycles, respectively. After 5 bends, both the inner and outer surfaces of the tubing showed no microcracks. When the bent tubing samples were pressurized and tested using deuterium at 74{degrees}C and at {approximately}78{degrees}C, they failed away from the bent area. Thus deuterium embrittlement of the bent SS304 tubing should not be a problem. Moreover, to increase our 95% confidence level to 5 bends, we are planning to perform at least four additional bends to failure tests.

Sunwoo, A.J.; Brooks, M.A.; Kervin, J.E.

1995-10-16T23:59:59.000Z

226

Sampling Artifacts from Conductive Silicone Tubing  

SciTech Connect (OSTI)

We report evidence that carbon impregnated conductive silicone tubing used in aerosol sampling systems can introduce two types of experimental artifacts: 1) silicon tubing dynamically absorbs carbon dioxide gas, requiring greater than 5 minutes to reach equilibrium and 2) silicone tubing emits organic contaminants containing siloxane that adsorb onto particles traveling through it and onto downstream quartz fiber filters. The consequence can be substantial for engine exhaust measurements as both artifacts directly impact calculations of particulate mass-based emission indices. The emission of contaminants from the silicone tubing can result in overestimation of organic particle mass concentrations based on real-time aerosol mass spectrometry and the off-line thermal analysis of quartz filters. The adsorption of siloxane contaminants can affect the surface properties of aerosol particles; we observed a marked reduction in the water-affinity of soot particles passed through conductive silicone tubing. These combined observations suggest that the silicone tubing artifacts may have wide consequence for the aerosol community and should, therefore, be used with caution. Gentle heating, physical and chemical properties of the particle carriers, exposure to solvents, and tubing age may influence siloxane uptake. The amount of contamination is expected to increase as the tubing surface area increases and as the particle surface area increases. The effect is observed at ambient temperature and enhanced by mild heating (<100 oC). Further evaluation is warranted.

Timko, Michael T.; Yu, Zhenhong; Kroll, Jesse; Jayne, John T.; Worsnop, Douglas R.; Miake-Lye, Richard C.; Onasch, Timothy B.; Liscinsky, David; Kirchstetter, Thomas W.; Destaillats, Hugo; Holder, Amara L.; Smith, Jared D.; Wilson, Kevin R.

2009-05-15T23:59:59.000Z

227

Optimizing moderator dimensions for neutron scattering at the spallation neutron source  

SciTech Connect (OSTI)

In this work, we investigate the effect of neutron moderator dimensions on the performance of neutron scattering instruments at the Spallation Neutron Source (SNS). In a recent study of the planned second target station at the SNS facility, we have found that the dimensions of a moderator play a significant role in determining its surface brightness. A smaller moderator may be significantly brighter over a smaller viewing area. One of the immediate implications of this finding is that for modern neutron scattering instrument designs, moderator dimensions and brightness have to be incorporated as an integrated optimization parameter. Here, we establish a strategy of matching neutron scattering instruments with moderators using analytical and Monte Carlo techniques. In order to simplify our treatment, we group the instruments into two broad categories: those with natural collimation and those that use neutron guide systems. For instruments using natural collimation, the optimal moderator selection depends on the size of the moderator, the sample, and the moderator brightness. The desired beam divergence only plays a role in determining the distance between sample and moderator. For instruments using neutron optical systems, the smallest moderator available that is larger than the entrance dimension of the closest optical element will perform the best (assuming, as is the case here that smaller moderators are brighter)

Zhao, J. K.; Robertson, J. L.; Herwig, Kenneth W.; Gallmeier, Franz X.; Riemer, Bernard W. [Instrument and Source Division, Spallation Neutron Source, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831 (United States)] [Instrument and Source Division, Spallation Neutron Source, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831 (United States)

2013-12-15T23:59:59.000Z

228

High heat flux testing of a two-tube copper panel specimen for LLNL at ASURF  

SciTech Connect (OSTI)

This letter documents the results of the test program conducted for Lawrence Livermore National Laboratory (LLNL) by Westinghouse Advanced Energy Systems Division (AESD) in fulfillment of the Third Amendment to Subcontract 9125401. The original test matrix of 20,000 heating cycles on two test articles called for in the contract was not technically feasible due to the inability of the test articles supplied by LLNL to perform successfully at the required test conditions. Burnout occurred in one of the tubes of a two-tube target during the first series of tests. As a result, the work scope was changed by LLNL such that the tests on the milled copper plate panel specimen were replaced by a second set of heating tests on the second tube of the two-tube copper panel specimen to confirm the conditions for burnout failure. The testing requirements were completed following failure of the second tube at nominally identical conditions under which the first tube failed, and verification of these conditions. This letter completes all contractual obligations by serving as the final report on the test program.

Easoz, J.R.; Sink, D.A.

1984-12-01T23:59:59.000Z

229

Target Diagnostics Supports NIF's Path to Ignition  

SciTech Connect (OSTI)

The physics requirements derived from the National Ignition Facility (NIF) experimental campaigns are leading to a wide variety of target diagnostics. Software development for the control and analysis of these diagnostics is included in the NIF Integrated Computer Control System, Diagnostic Control System and Data Visualization. These projects implement the configuration, controls, data analysis and visual representation of most of these diagnostics. To date, over 40 target diagnostics have been developed to support NIF experiments. In 2011 diagnostics were developed or enhanced to measure Ignition performance in a high neutron yield environment. Performance is optimized around four key variables: Adiabat (a) which is the strength and timing of four shocks delivered to the target, Velocity (V) of the imploding target, Mix (M) is the uniformity of the burn, and the Shape (S) of the imploding Deuterium Tritium (DT) hot spot. The diagnostics used to measure each of these parameters is shown in figure 1. Adiabat is measured using the Velocity Interferometer System for Any Reflector (VISAR) diagnostic consisting of three streak cameras. To provide for more accurate adiabat measurements the VISAR streak cameras were enhanced in FY11 with a ten comb fiducial signal controller to allow for post shot correction of the streak camera sweep non-linearity. Mix is measured by the Neutron Time of Flight (NTOF) and Radiochemical Analysis of Gaseous Samples (RAGS) diagnostics. To accommodate high neutron yield shots, NTOF diagnostic controls are being modified to use Mach Zehnder interferometer signals to allow the digitizers to be moved from near the target chamber to the neutron shielded diagnostic mezzanine. In December 2011 the first phase of RAGS diagnostic commissioning will be completed. This diagnostic will analyze the tracers that are added to NIF target capsules that undergo nuclear reactions during the shot. These gases are collected and purified for nuclear counting by the RAGS system. Three new instrument controllers were developed and commissioned to support this diagnostic. A residual-gas analyzer (RGA) instrument measures the gas content at various points in the system. The Digital Gamma Spectrometer instrument measures the radiological spectrum of the decaying gas isotopes. A final instrument controller was developed to interface to a PLC based Gas collection system. In order to support the implosion velocity measurements an additional Gated X-ray Detector (GXD) diagnostic was tested and commissioned. This third GXD views the target through a slit contained in its snout and allows the other GXD diagnostics to be used for measuring the shape on the same shot. In order to measure the implosion shape in a high neutron environment, Actide Readout In A Neutron Environment (ARIANE) and Neutron Imaging (NI) diagnostics were commissioned. The controls for ARIANE, a fixed port gated x-ray imager, contain a neutron shielded camera and micro channel plate pulser with its neutron sensitive electronics located in the diagnostic mezzanine. The NI diagnostic is composed of two Spectral Instruments SI-1000 cameras located 20M from the target and provides neutron images of the DT hot spot for high yield shots. The development and commissioning of these new or enhanced diagnostics in FY11 have provided meaningful insight that facilitates the optimization of the four key Ignition variables. In FY12 they will be adding three new diagnostics and enhancing four existing diagnostics in support of the continuing optimization series of campaigns.

Shelton, R

2011-12-07T23:59:59.000Z

230

Semiconductor neutron detector  

DOE Patents [OSTI]

A neutron detector has a compound of lithium in a single crystal form as a neutron sensor element. The lithium compound, containing improved charge transport properties, is either lithium niobate or lithium tantalate. The sensor element is in direct contact with a monitor that detects an electric current. A signal proportional to the electric current is produced and is calibrated to indicate the neutrons sensed. The neutron detector is particularly useful for detecting neutrons in a radiation environment. Such radiation environment may, e.g. include gamma radiation and noise.

Ianakiev, Kiril D. (Los Alamos, NM); Littlewood, Peter B. (Cambridge, GB); Blagoev, Krastan B. (Arlington, VA); Swinhoe, Martyn T. (Los Alamos, NM); Smith, James L. (Los Alamos, NM); Sullivan, Clair J. (Los Alamos, NM); Alexandrov, Boian S. (Los Alamos, NM); Lashley, Jason Charles (Santa Fe, NM)

2011-03-08T23:59:59.000Z

231

High energy neutron dosimeter  

DOE Patents [OSTI]

A device for measuring dose equivalents in neutron radiation fields is described. The device includes nested symmetrical hemispheres (forming spheres) of different neutron moderating materials that allow the measurement of dose equivalents from 0.025 eV to past 1 GeV. The layers of moderating material surround a spherical neutron counter. The neutron counter is connected by an electrical cable to an electrical sensing means which interprets the signal from the neutron counter in the center of the moderating spheres. The spherical shape of the device allows for accurate measurement of dose equivalents regardless of its positioning. 2 figures.

Rai, K.S.F.

1994-01-11T23:59:59.000Z

232

High energy neutron dosimeter  

DOE Patents [OSTI]

A device for measuring dose equivalents in neutron radiation fields. The device includes nested symmetrical hemispheres (forming spheres) of different neutron moderating materials that allow the measurement of dose equivalents from 0.025 eV to past 1 GeV. The layers of moderating material surround a spherical neutron counter. The neutron counter is connected by an electrical cable to an electrical sensing means which interprets the signal from the neutron counter in the center of the moderating spheres. The spherical shape of the device allows for accurate measurement of dose equivalents regardless of its positioning.

Sun, Rai Ko S.F. (Albany, CA)

1994-01-01T23:59:59.000Z

233

The Neutron Lifetime  

E-Print Network [OSTI]

The decay of the free neutron into a proton, electron, and antineutrino is the prototype semileptonic weak decay and the simplest example of nuclear beta decay. The nucleon vector and axial vector weak coupling constants G_V and G_A determine the neutron lifetime as well as the strengths of weak interaction processes involving free neutrons and protons that are important in astrophysics, cosmology, solar physics and neutrino detection. In combination with a neutron decay angular correlation measurement, the neutron lifetime can be used to determine the first element of the CKM matrix Vud. Unfortunately the two main experimental methods for measuring the neutron lifetime currently disagree by almost 4 sigma. I will present a brief review of the status of the neutron lifetime and prospects for the future.

F. E. Wietfeldt

2014-11-13T23:59:59.000Z

234

High Flux Isotope Reactor cold neutron source reference design concept  

SciTech Connect (OSTI)

In February 1995, Oak Ridge National Laboratory`s (ORNL`s) deputy director formed a group to examine the need for upgrades to the High Flux Isotope Reactor (HFIR) system in light of the cancellation of the Advanced neutron Source Project. One of the major findings of this study was that there was an immediate need for the installation of a cold neutron source facility in the HFIR complex. In May 1995, a team was formed to examine the feasibility of retrofitting a liquid hydrogen (LH{sub 2}) cold source facility into an existing HFIR beam tube. The results of this feasibility study indicated that the most practical location for such a cold source was the HB-4 beam tube. This location provides a potential flux environment higher than the Institut Laue-Langevin (ILL) vertical cold source and maximizes the space available for a future cold neutron guide hall expansion. It was determined that this cold neutron beam would be comparable, in cold neutron brightness, to the best facilities in the world, and a decision was made to complete a preconceptual design study with the intention of proceeding with an activity to install a working LH{sub 2} cold source in the HFIR HB-4 beam tube. During the development of the reference design the liquid hydrogen concept was changed to a supercritical hydrogen system for a number of reasons. This report documents the reference supercritical hydrogen design and its performance. The cold source project has been divided into four phases: (1) preconceptual, (2) conceptual design and testing, (3) detailed design and procurement, and (4) installation and operation. This report marks the conclusion of the conceptual design phase and establishes the baseline reference concept.

Selby, D.L.; Lucas, A.T.; Hyman, C.R. [and others

1998-05-01T23:59:59.000Z

235

Delayed neutron detection with an integrated differential die-away and delayed neutron instrument  

SciTech Connect (OSTI)

The Next Generation Safeguards Initiative (NGSI) of the U.S. Department of Energy (DOE) has funded a multilab/university collaboration to quantify the plutonium (Pu) mass and detect the diversion of pins from spent nuclear fuel. The first two years of this NGSI effort was focused on quantifying the capability of a range of nondestructive assay (NDA) techniques with Monte Carlo (MCNPX) modeling and the second current phase involves measuring Spent Fuel. One of the techniques of interest in this paper involves measuring delayed neutrons. A delayed neutron instrument using 36 fission chambers and a 14 MeV neutron generator so called DT generator (Deuterium + Tritium) surrounding the fuel was previously studied as part of the NGSI effort. This paper will quantify the capability of a standalone delayed neutron instrument using 4 {sup 3}He gas filled tubes and a DT generator with significant spectrum tailoring, located far from the fuel. So that future research can assess how well a delayed neutron instrument will function as part of an integrated NDA system. A new design is going to be used to respond to the need of the techniques. This design has been modeled for a water media and is currently being optimized for borated water and air media as part of ongoing research. This new design was selected in order to minimize the fission of {sup 238}U, to use a more realistic neutron generator design in the model, to reduce cost and facilitate the integration of a delayed neutron (DN) with a differential die-away (DDA) instrument. Since this paper will focus on delayed neutron detection, the goal is to quantify the signal from {sup 235}U, {sup 239}Pu and {sup 241}Pu, which are the isotopes present in Spent Fuel that respond significantly to a neutron interrogation. This report will quantify the capability of this new delayed neutron design to measure the combined mass of {sup 235}U, {sup 239}Pu and {sup 241}Pu for 16 of the 64 assemblies of the NGSI Spent Fuel library in one of the three media, water.

Blanc, Pauline [Los Alamos National Laboratory; Tobin, Stephen J [Los Alamos National Laboratory; Lee, Taehoon [Los Alamos National Laboratory; Hu, Jianwei S [Los Alamos National Laboratory; Hendricks, John [Los Alamos National Laboratory; Croft, Stephen [Los Alamos National Laboratory

2010-01-01T23:59:59.000Z

236

Multi-tube fuel nozzle with mixing features  

DOE Patents [OSTI]

A system includes a multi-tube fuel nozzle having an inlet plate and a plurality of tubes adjacent the inlet plate. The inlet plate includes a plurality of apertures, and each aperture includes an inlet feature. Each tube of the plurality of tubes is coupled to an aperture of the plurality of apertures. The multi-tube fuel nozzle includes a differential configuration of inlet features among the plurality of tubes.

Hughes, Michael John

2014-04-22T23:59:59.000Z

237

Nuclear-spectroscopy problems studied with neutrons  

SciTech Connect (OSTI)

Nuclear spectroscopy with neutrons continues to have a major impact on the progress of nuclear science. Neutrons, being uncharged, are particularly useful for the study of low energy reactions. Recent advances in time-of-flight spectroscopy, as well as in the gamma ray spectroscopy following neutron capture, have permitted precision studies of unbound and bound nuclear levels and related phenomena. By going to new energy domains, by using polarized beams and targets, through the invention of new kinds of detectors, and through the general improvement in beam quantity and quality, new features of nuclear structure and reactions have been obtained that are not ony interesting per se but are also grist for old and new theory mills. The above technical advances have opened up new opportunities for further discoveries.

Raman, S.

1982-01-01T23:59:59.000Z

238

Method and apparatus for optimized sampling of volatilizable target substances  

DOE Patents [OSTI]

An apparatus for capturing, from gases such as soil gas, target analytes. Target analytes may include emanations from explosive materials or from residues of explosive materials. The apparatus employs principles of sorption common to solid phase microextraction, and is best used in conjunction with analysis means such as a gas chromatograph. To sorb target analytes, the apparatus functions using various sorptive structures to capture target analyte. Depending upon the embodiment, those structures may include 1) a conventional solid-phase microextraction (SPME) fiber, 2) a SPME fiber suspended in a capillary tube (with means provided for moving gases through the capillary tube so that the gases come into close proximity to the suspended fiber), and 3) a capillary tube including an interior surface on which sorptive material (similar to that on the surface of a SPME fiber) is supported (along with means for moving gases through the capillary tube so that the gases come into close proximity to the sorptive material). In one disclosed embodiment, at least one such sorptive structure is associated with an enclosure including an opening in communication with the surface of a soil region potentially contaminated with buried explosive material such as unexploded ordnance. Emanations from explosive materials can pass into and accumulate in the enclosure where they are sorbed by the sorptive structures. Also disclosed is the use of heating means such as microwave horns to drive target analytes into the soil gas from solid and liquid phase components of the soil.

Lindgren, Eric R. (Albuquerque, NM); Phelan, James M. (Bosque Farms, NM)

2002-01-01T23:59:59.000Z

239

Precision Measurement of the n-3He Incoherent Scattering Length Using Neutron Interferometry  

E-Print Network [OSTI]

We report the first measurement of the low-energy neutron-$^3$He incoherent scattering length using neutron interferometry: $b_i' = (-2.512\\pm 0.012{statistical}\\pm0.014{systematic})$ fm. This is in good agreement with a recent calculation using the AV18+3N potential. The neutron-$^3$He scattering lengths are important for testing and developing nuclear potential models that include three nucleon forces, effective field theories for few-body nuclear systems, and neutron scattering measurements of quantum excitations in liquid helium. This work demonstrates the first use of a polarized nuclear target in a neutron interferometer.

M. G. Huber; M. Arif; T. C. Black; W. C. Chen; T. R. Gentile; D. S. Hussey; D. Pushin; F. E. Wietfeldt; L. Yang

2009-05-12T23:59:59.000Z

240

Photomultiplier Tubes: Calibration and Neutrino Physics  

SciTech Connect (OSTI)

Photomultiplier Tubes are devices designed to amplify very small light signals, on the order of single photons, to levels that are detectable by conventional electronics. Such a high level of amplification, however, comes with a quite a few potential problems, as the relationship between a light signal in and the current out- the response of the system- can be difficult to determine, meaning that photomultiplier tubes' use in scientific research requires a great deal of sensitive calibration. Once calibrated, the photomultiplier tube is a tool that can be used on a number of interesting problems, including the field of neutrino physics. This work deals with the use of photomultiplier tubes' use in the upcoming Double Chooz experiment to determine the mixing angle theta{sub 13}, between different neutrino mass eigenstates. Calibration of the tubes requires measurement of the charge characteristics, most notably, the gain, pedestal, and the dark rate of a tube. Moreover, for all modern tubes, there is an additional feature which can be used to calibrate the system, the single photo electron peak, which describes the response of the tube to a single photon. Some theories predict higher order effects, in addition to the single photoelectron peak, including things like incomplete multiplication of a single photon electron, features which are theoretically able to be determined by a detailed examination of the single photoelectron peak. This paper goes through the methods of calibrating a phototubes both with and without a single photoelectron peak, and is unable to determine conclusively whether or not partial multiplication is able to explain certain features of photomultiplier tubes with a single photoelectron peak.

Damon, Edward; Maricic, Jelena [Drexel University, Philadelphia, PA 19104 (United States)

2010-03-30T23:59:59.000Z

Note: This page contains sample records for the topic "neutron tube target" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


241

Scintillation probe with photomultiplier tube saturation indicator  

DOE Patents [OSTI]

A photomultiplier tube saturation indicator is formed by supplying a supplemental light source, typically an light emitting diode (LED), adjacent to the photomultiplier tube. A switch allows the light source to be activated. The light is forwarded to the photomultiplier tube by an optical fiber. If the probe is properly light tight, then a meter attached to the indicator will register the light from the LED. If the probe is no longer light tight, and the saturation indicator is saturated, no signal will be registered when the LED is activated.

Ruch, Jeffrey F. (Bethel Park, PA); Urban, David J. (Glassport, PA)

1996-01-01T23:59:59.000Z

242

Progress with developing a target for magnetized target fusion  

SciTech Connect (OSTI)

Magnetized Target Fusion (MTF) is an approach to fusion where a preheated and magnetized plasma is adiabatically compressed to fusion conditions. Successful MTF requires a suitable initial target plasma with an embedded magnetic field of at least 5 T in a closed-field-line topology, a density of roughly 10{sup 18} cm{sup {minus}3}, a temperature of at least 50 eV, and must be free of impurities which would raise radiation losses. Target plasma generation experiments are underway at Los Alamos National Laboratory using the Colt facility; a 0.25 MJ, 2--3 {micro}s rise-time capacitor bank. The goal of these experiments is to demonstrate plasma conditions meeting the minimum requirements for a MTF initial target plasma. In the first experiments, a Z-pinch is produced in a 2 cm radius by 2 cm high conducting wall using a static gas-fill of hydrogen or deuterium gas in the range of 0.5 to 2 torr. Thus far, the diagnostics include an array of 12 B-dot probes, framing camera, gated OMA visible spectrometer, time-resolved monochrometer, filtered silicon photodiodes, neutron yield, and plasma-density interferometer. These diagnostics show that a plasma is produced in the containment region that lasts roughly 10 to 20 {micro}s with a maximum plasma density exceeding 10{sup 18} cm{sup {minus}3}. The experimental design and data are presented.

Wysocki, F.J.; Chrien, R.E.; Idzorek, G.; Oona, H.; Whiteson, D.O.; Kirkpatrick, R.C.; Lindemuth, I.R.; Sheehey, P.T.

1997-09-01T23:59:59.000Z

243

Halogenated sulfidohydroboranes for nuclear medicine and boron neutron capture therapy  

DOE Patents [OSTI]

A method for performing boron neutron capture therapy for the treatment of tumors is disclosed. The method includes administering to a patient an iodinated sulfidohydroborane, a boron-10-containing compound. The site of the tumor is localized by visualizing the increased concentration of the iodine labelled compound at the tumor. The targeted tumor is then irradiated with a beam of neutrons having an energy distribution effective for neutron capture. Destruction of the tumor occurs due to high LET particle irradiation of the tissue secondary to the incident neutrons being captured by the boron-10 nuclei. Iodinated sulfidohydroboranes are disclosed which are especially suitable for the method of the invention. In a preferred embodiment, a compound having the formula Na.sub.4 B.sub.12 I.sub.11 SSB.sub.12 I.sub.11, or another pharmaceutically acceptable salt of the compound, may be administered to a cancer patient for boron neutron capture therapy.

Miura, Michiko (Hampton Bays, NY); Slatkin, Daniel N. (Southold, NY)

1997-03-18T23:59:59.000Z

244

Halogenated sulfidohydroboranes for nuclear medicine and boron neutron capture therapy  

DOE Patents [OSTI]

A method for performing boron neutron capture therapy for the treatment of tumors is disclosed. The method includes administering to a patient an iodinated sulfidohydroborane, a boron-10-containing compound. The site of the tumor is localized by visualizing the increased concentration of the iodine labelled compound at the tumor. The targeted tumor is then irradiated with a beam of neutrons having an energy distribution effective for neutron capture. Destruction of the tumor occurs due to high LET particle irradiation of the tissue secondary to the incident neutrons being captured by the boron-10 nuclei. Iodinated sulfidohydroboranes are disclosed which are especially suitable for the method of the invention. In a preferred embodiment, a compound having the formula Na{sub 4}B{sub 12}I{sub 11}SSB{sub 12}I{sub 11}, or another pharmaceutically acceptable salt of the compound, may be administered to a cancer patient for boron neutron capture therapy. 1 fig.

Miura, M.; Slatkin, D.N.

1997-03-18T23:59:59.000Z

245

Halogenated sulfidohydroboranes for nuclear medicine and boron neutron capture therapy  

DOE Patents [OSTI]

A method for performing boron neutron capture therapy for the treatment of tumors is disclosed. The method includes administering to a patient an iodinated sulfidohydroborane, a boron-10-containing compound. The site of the tumor is localized by visualizing the increased concentration of the iodine labelled compound at the tumor. The targeted tumor is then irradiated with a beam of neutrons having an energy distribution effective for neutron capture. Destruction of the tumor occurs due to high LET particle irradiation of the tissue secondary to the incident neutrons being captured by the boron-10 nuclei. Iodinated sulfidohydroboranes are disclosed which are especially suitable for the method of the invention. In a preferred embodiment, a compound having the formula Na.sub.4 B.sub.12 I.sub.11 SSB.sub.12 I.sub.11, or another pharmaceutically acceptable salt of the compound, may be administered to a cancer patient for boron neutron capture therapy.

Miura, Michiko (Hampton Bays, NY); Slatkin, Daniel N. (Southold, NY)

1995-10-03T23:59:59.000Z

246

Halogenated sulfidohydroboranes for nuclear medicine and boron neutron capture therapy  

DOE Patents [OSTI]

A method for performing boron neutron capture therapy for the treatment of tumors is disclosed. The method includes administering to a patient an iodinated sulfidohydroborane, a boron-10-containing compound. The site of the tumor is localized by visualizing the increased concentration of the iodine labelled compound at the tumor. The targeted tumor is then irradiated with a beam of neutrons having an energy distribution effective for neutron capture. Destruction of the tumor occurs due to high LET particle irradiation of the tissue secondary to the incident neutrons being captured by the boron-10 nuclei. Iodinated sulfidohydroboranes are disclosed which are especially suitable for the method of the invention. In a preferred embodiment, a compound having the formula Na{sub 4}B{sub 12}I{sub 11}SSB{sub 12}I{sub 11}, or another pharmaceutically acceptable salt of the compound, may be administered to a cancer patient for boron neutron capture therapy. 1 fig.

Miura, M.; Slatkin, D.N.

1997-08-05T23:59:59.000Z

247

Halogenated sulfidohydroboranes for nuclear medicine and boron neutron capture therapy  

DOE Patents [OSTI]

A method for performing boron neutron capture therapy for the treatment of tumors is disclosed. The method includes administering to a patient an iodinated sulfidohydroborane, a boron-10-containing compound. The site of the tumor is localized. by visualizing the increased concentration of the iodine labelled compound at the tumor. The targeted tumor is then irradiated with a beam of neutrons having an energy distribution effective for neutron capture. Destruction of the tumor occurs due to high LET particle irradiation of the tissue secondary to the incident neutrons being captured by the boron-10 nuclei. Iodinated sulfidohydroboranes are disclosed which are especially suitable for the method of the invention. In a preferred embodiment, a compound having the formula Na.sub.4 B.sub.12 I.sub.11 SSB.sub.12 I.sub.11, or another pharmaceutically acceptable salt of the compound, may be administered to a cancer patient for boron neutron capture therapy.

Miura, Michiko (Hampton Bays, NY); Slatkin, Daniel N. (Southold, NY)

1997-08-05T23:59:59.000Z

248

FB-line neutron multiplicity counter operation manual  

SciTech Connect (OSTI)

This manual describes the design features, performance, and operating characteristics for the FB-Line Neutron Multiplicity counter (FBLNMC). The FBLNMC counts neutron multiplicities to quantitatively assay plutonium in many forms, including impure scrap and waste. Monte Carlo neutronic calculations were used to design the high-efficiency (57%) detector that has 113 {sup 3}He tubes in a high-density polyethylene body. The new derandomizer circuit is included in the design to reduce deadtime. The FBLNMC can be applied to plutonium masses in the range from a few tens of grams to 5 kg; both conventional coincidence counting and multiplicity counting can be used as appropriate. This manual gives the performance data and preliminary calibration parameters for the FBLNMC.

Langner, D.G.; Sweet, M.R.; Salazar, S.D.; Kroncke, K.E.

1997-12-31T23:59:59.000Z

249

Neutron sources and applications  

SciTech Connect (OSTI)

Review of Neutron Sources and Applications was held at Oak Brook, Illinois, during September 8--10, 1992. This review involved some 70 national and international experts in different areas of neutron research, sources, and applications. Separate working groups were asked to (1) review the current status of advanced research reactors and spallation sources; and (2) provide an update on scientific, technological, and medical applications, including neutron scattering research in a number of disciplines, isotope production, materials irradiation, and other important uses of neutron sources such as materials analysis and fundamental neutron physics. This report summarizes the findings and conclusions of the different working groups involved in the review, and contains some of the best current expertise on neutron sources and applications.

Price, D.L. [ed.] [Argonne National Lab., IL (United States); Rush, J.J. [ed.] [National Inst. of Standards and Technology, Gaithersburg, MD (United States)

1994-01-01T23:59:59.000Z

250

Staged multi-tube premixing injector  

DOE Patents [OSTI]

A fuel injection nozzle includes a body member having an upstream wall opposing a downstream wall, and an internal wall disposed between the upstream wall and the downstream wall, a first chamber partially defined by the an inner surface of the upstream wall and a surface of the internal wall, a second chamber partially defined by an inner surface of the downstream wall and a surface of the internal wall a first gas inlet communicative with the first chamber operative to emit a first gas into the first chamber, a second gas inlet communicative with the second chamber operative to emit a second gas into the second chamber, and a plurality of mixing tubes, each of the mixing tubes having a tube inner surface, a tube outer surface, a first inlet communicative with an aperture in the upstream wall operative to receive a third gas.

Zuo, Baifang; Khan, Abdul Rafey; York, William David; Ziminsky, Willy Steve

2012-10-02T23:59:59.000Z

251

Sample inlet tube for ion source  

DOE Patents [OSTI]

An improved inlet tube is positioned within an aperture through the device to allow the passage of ions from the ion source, through the improved inlet tube, and into the interior of the device. The inlet tube is designed with a larger end and a smaller end wherein the larger end has a larger interior diameter than the interior diameter of the smaller end. The inlet tube is positioned within the aperture such that the larger end is pointed towards the ion source, to receive ions therefrom, and the smaller end is directed towards the interior of the device, to deliver the ions thereto. Preferably, the ion source utilized in the operation of the present invention is a standard electrospray ionization source. Similarly, the present invention finds particular utility in conjunction with analytical devices such as mass spectrometers.

Prior, David [Hermiston, OR; Price, John [Richland, WA; Bruce, Jim [Oceanside, CA

2002-09-24T23:59:59.000Z

252

Electric and Gas Fired Radiant Tubes 'ERT'  

E-Print Network [OSTI]

The paper covers a unique development by the Surface Division of Midland Ross of a radiant tube heating element which will heat an industrial furnace with either gas or electric without any down time or physical conversion required...

Nilsen, E. K.

1981-01-01T23:59:59.000Z

253

Forced-convection condensation inside tubes  

E-Print Network [OSTI]

High vapor velocity condensation inside a tube was studied analytically. The von Karman universal velocity distribution was applied to the condensate flow, pressure drops were calculated using the Lockhart- Martinelli ...

Traviss, Donald P.

1971-01-01T23:59:59.000Z

254

Time dependence of delayed neutron emission for fissionable isotope identification  

SciTech Connect (OSTI)

The time dependence of delayed neutron emission was examined as a method of fissionable isotope identification. A pulsed bremsstrahlung photon beam was used to induce photofission reactions in {sup 238}U, {sup 232}Th, and {sup 239}Pu targets. The resulting delayed neutron emission was recorded between irradiating pulses and is a well-known technique for fissionable material detection. Monitoring the decay of delayed neutron emission between irradiating pulses demonstrates the ability to not only detect the presence of fissionable materials, but also to identify which fissionable isotope is present.

Kinlaw, M.T.; Hunt, A.W. [Idaho Accelerator Center, Idaho State University, Pocatello, Idaho 83209-8263 (United States); Department of Physics, Idaho State University, Pocatello, Idaho 83209-8106 (United States)

2005-06-20T23:59:59.000Z

255

Computational Benchmark Calculations Relevant to the Neutronic Design of the Spallation Neutron Source (SNS)  

SciTech Connect (OSTI)

The Spallation Neutron Source (SNS) will provide an intense source of low-energy neutrons for experimental use. The low-energy neutrons are produced by the interaction of a high-energy (1.0 GeV) proton beam on a mercury (Hg) target and slowed down in liquid hydrogen or light water moderators. Computer codes and computational techniques are being benchmarked against relevant experimental data to validate and verify the tools being used to predict the performance of the SNS. The LAHET Code System (LCS), which includes LAHET, HTAPE ad HMCNP (a modified version of MCNP version 3b), have been applied to the analysis of experiments that were conducted in the Alternating Gradient Synchrotron (AGS) facility at Brookhaven National Laboratory (BNL). In the AGS experiments, foils of various materials were placed around a mercury-filled stainless steel cylinder, which was bombarded with protons at 1.6 GeV. Neutrons created in the mercury target, activated the foils. Activities of the relevant isotopes were accurately measured and compared with calculated predictions. Measurements at BNL were provided in part by collaborating scientists from JAERI as part of the AGS Spallation Target Experiment (ASTE) collaboration. To date, calculations have shown good agreement with measurements.

Gallmeier, F.X.; Glasgow, D.C.; Jerde, E.A.; Johnson, J.O.; Yugo, J.J.

1999-11-14T23:59:59.000Z

256

Soft pion emission from fat flux tubes  

SciTech Connect (OSTI)

The emission of pions from multiquark flux tubes is examined as an explanation of the soft pion puzzle. Although the soft pion spectra from the decay of fat flux tubes can account for some low {ital p}{sub {perpendicular}} enhancement, the dependence on the number of involved quarks is too weak to provide a plausible explanation of the observed enhancement in the pion spectrum at low transverse momenta.

Kusnezov, D.; Danielewicz, P. (National Superconducting Cyclotron Laboratory and Department of Physics Astronomy, Michigan State University, East Lansing, Michigan (USA))

1991-08-01T23:59:59.000Z

257

Neutron Science Forum | ORNL  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

environment for discussion, innovation, and dissemination of information within the neutron scattering community as well as engaging closely related disciplines through...

258

Neutron wave packet tomography  

E-Print Network [OSTI]

A tomographic technique is introduced in order to determine the quantum state of the center of mass motion of neutrons. An experiment is proposed and numerically analyzed.

G. Badurek; P. Facchi; Y. Hasegawa; Z. Hradil; S. Pascazio; H. Rauch; J. Rehacek; T. Yoneda

2005-03-29T23:59:59.000Z

259

Lujan Neutron Scattering Center  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

the inadvertent spread of Technetium 99 by employees and contractors at the Lujan Neutron Scattering Center August 27, 2012-The Laboratory is investigating the inadvertent...

260

Tube construction for fluidized bed combustor  

DOE Patents [OSTI]

A fluidized bed combustor comprises a reactor or a housing which has a windbox distributor plate adjacent the lower end thereof which contains a multiplicity of hole and air discharge nozzles for discharging air and coal into a fluidized bed which is maintained above the distributor plate and below a take-off connection or flue to a cyclone separator in which some of the products of combustion are treated to remove the dust which is returned into the fluidized bed. A windbox is spaced below the fluidized bed and it has a plurality of tubes passing therethrough with the passage of combustion air and fluidizing air which passes through an air space so that fluidizing air is discharged into the reaction chamber fluidized bed at the bottom thereof to maintain the bed in a fluidized condition. A fluid, such as air, is passed through the tubes which extend through the windbox and provide a preheating of the combustion air and into an annular space between telescoped inner and outer tubes which comprise heat exchanger tubes or cooling tubes which extend upwardly through the distributor plate into the fluidized bed. The heat exchanger tubes are advantageously arranged so that they may be exposed in groups within the reactor in a cluster which is arranged within holding rings.

De Feo, Angelo (Totowa, NJ); Hosek, William (Mt. Tabor, NJ)

1984-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "neutron tube target" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


261

Fluidized bed combustor and tube construction therefor  

DOE Patents [OSTI]

A fluidized bed combustor comprises a reactor or a housing which has a windbox distributor plate adjacent the lower end thereof which contains a multiplicity of hole and air discharge nozzles for discharging air and coal into a fluidized bed which is maintained above the distributor plate and below a take-off connection or flue to a cyclone separator in which some of the products of combustion are treated to remove the dust which is returned into the fluidized bed. A windbox is spaced below the fluidized bed and it has a plurality of tubes passing therethrough with the passage of combustion air and fluidizing air which passes through an air space so that fluidizing air is discharged into the reaction chamber fluidized bed at the bottom thereof to maintain the bed in a fluidized condition. A fluid, such as air, is passed through the tubes which extend through the windbox and provide a preheating of the combustion air and into an annular space between telescoped inner and outer tubes which comprise heat exchanger tubes or cooling tubes which extend upwardly through the distributor plate into the fluidized bed. The heat exchanger tubes are advantageously arranged so that they may be exposed in groups within the reactor in a cluster which is arranged within holding rings.

De Feo, Angelo (Passaic, NJ); Hosek, William (Morris, NJ)

1981-01-01T23:59:59.000Z

262

Fast neutron production from lithium converters and laser driven protons  

SciTech Connect (OSTI)

Experiments to generate neutrons from the {sup 7}Li(p,n){sup 7}Be reaction with 60 J, 180 fs laser pulses have been performed at the Texas Petawatt Laser Facility at the University of Texas at Austin. The protons were accelerated from the rear surface of a thin target membrane using the target-normal-sheath-acceleration mechanism. The neutrons were generated in nuclear reactions caused by the subsequent proton bombardment of a pure lithium foil of natural isotopic abundance. The neutron energy ranged up to 2.9 MeV. The total yield was estimated to be 1.6 × 10{sup 7} neutrons per steradian. An extreme ultra-violet light camera, used to image the target rear surface, correlated variations in the proton yield and peak energy to target rear surface ablation. Calculations using the hydrodynamics code FLASH indicated that the ablation resulted from a laser pre-pulse of prolonged intensity. The ablation severely limited the proton acceleration and neutron yield.

Storm, M.; Jiang, S.; Wertepny, D.; Orban, C.; Morrison, J.; Willis, C.; McCary, E.; Balencourt, P.; Snyder, J.; Chowdhury, E.; Freeman, R. R.; Akli, K. [Department of Physics, The Ohio State University, 191 West Woodruff Avenue, Columbus, Ohio 43210 (United States)] [Department of Physics, The Ohio State University, 191 West Woodruff Avenue, Columbus, Ohio 43210 (United States); Bang, W.; Gaul, E.; Dyer, G.; Ditmire, T. [Department of Physics, Center for High Energy Density Science, C1510, University of Texas at Austin, Austin, Texas 78712 (United States)] [Department of Physics, Center for High Energy Density Science, C1510, University of Texas at Austin, Austin, Texas 78712 (United States)

2013-05-15T23:59:59.000Z

263

Neutron Coincidence Counting Studies  

SciTech Connect (OSTI)

The efficiency comparison for measured and simulated responses of a 10B-lined proportional counter and a 3He proportional counter in a close, symmetrical geometry are presented. The measurement geometry was modeled in MCNPX to validate the methods used for simulating the response of both the 3He and 10B-lined tubes. The MCNPX models agree within 1% with the 3He tube measurements and within 3% for the 10B-lined tubes when a 0.75-µm boron-metal lining is used.

Rogers, Jeremy L.; Ely, James H.; Kouzes, Richard T.; Lintereur, Azaree T.; Siciliano, Edward R.

2012-08-31T23:59:59.000Z

264

Physics design of a cold neutron source for KIPT neutron source facility.  

SciTech Connect (OSTI)

Argonne National Laboratory (ANL) of USA and Kharkov Institute of Physics and Technology (KIPT) of Ukraine have been collaborating on the conceptual design development of a neutron source facility. It is based on the use of an electron accelerator driven subcritical (ADS) facility with low enriched uranium fuel, using the existing electron accelerators at KIPT of Ukraine [1]. The neutron source of the subcritical assembly is generated from the interaction of 100-KW electron beam, which has a uniform spatial distribution and the electron energy in the range of 100 to 200 MeV, with a natural uranium target [2]. The main functions of the facility are the production of medical isotopes and the support of the Ukraine nuclear power industry. Neutron beam experiments and material studies are also included. Over the past two-three decades, structures with characteristic lengths of 100 {angstrom} and correspondingly smaller vibrational energies have become increasingly important for both science and technology [3]. The characteristic dimensions of the microstructures can be well matched by neutrons with longer vibrational wavelength and lower energy. In the accelerator-driven subcritical facility, most of the neutrons are generated from fission reactions with energy in the MeV range. They are slowed down to the meV energy range through scattering reactions in the moderator and reflector materials. However, the fraction of neutrons with energies less than 5 meV in a normal moderator spectrum is very low because of up-scattering caused by the thermal motion of moderator or reflector molecules. In order to obtain neutrons with energy less than 5 meV, cryogenically cooled moderators 'cold neutron sources' should be used to slow down the neutrons. These cold moderators shift the neutron energy spectrum down because the thermal motion of moderator molecules as well as the up-scattering is very small, which provides large gains in intensity of low energy neutrons, E < 5 meV. The accelerator driven subcritical facility is designed with a provision to add a cryogenically cooled moderator system. This cold neutron source could provide the neutrons beams with lower energy, which could be utilized in scattering experiment and material structures analysis. This study describes the performed physics analyses to define and characterize the cold neutron source of the KIPT neutron source facility. The cold neutron source is designed to optimize the cold neutron brightness to the experimental instruments outside the radial heavy concrete shield of the facility. Liquid hydrogen or solid methane with 20 K temperature is used as a cold moderator. Monte Carlo computer code MCNPX [4], with ENDF/B-VI nuclear data libraries, is utilized to calculate the cold neutron source performance and estimate the nuclear heat load to the cold moderator. The surface source generation capability of MCNPX code has been used to provide the possibility of analyzing different design configurations and perform design optimization analyses with reasonable computer resources. Several design configurations were analyzed and their performance were characterized and optimized.

Zhong, Z.; Gohar, Y.; Kellogg, R.; Nuclear Engineering Division

2009-02-17T23:59:59.000Z

265

Improved di-neutron cluster model for 6He scattering  

E-Print Network [OSTI]

The structure of the three-body Borromean nucleus 6He is approximated by a two-body di-neutron cluster model. The binding energy of the 2n-\\alpha system is determined to obtain a correct description of the 2n-\\alpha coordinate, as given by a realistic three-body model calculation. The model is applied to describe the break-up effects in elastic scattering of 6He on several targets, for which experimental data exist. We show that an adequate description of the di-neutron-core degree of freedom permits a fairly accurate description of the elastic scattering of 6He on different targets.

A. M. Moro; K. Rusek; J. M. Arias; J. Gomez-Camacho; M. Rodriguez-Gallardo

2007-03-01T23:59:59.000Z

266

HFIR History - ORNL Neutron Sciences  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

has grown to include materials irradiation, neutron activation, and, most recently, neutron scattering. In 2007, HFIR completed the most dramatic transformation in its...

267

Neutron Stars and Fractal Dimensionality  

E-Print Network [OSTI]

We argue that the material inside Neutron stars behaves anomalously with fractal statistics and that in principle, we could induce mini Neutron stars, with the release of energy.

Burra G. Sidharth

2008-05-06T23:59:59.000Z

268

Ultrasonic liquid-in-line detector for tubes  

DOE Patents [OSTI]

An apparatus and method for detecting the presence of liquid in pipes or tubes using ultrasonic techniques A first piezoelectric crystal is coupled to the outside of the pipe or tube at the location where liquid in the tube is to be detected. A second piezoelectric crystal is coupled to the outside of the pipe or tube at the same location along the tube but circumferentially displaced from the first crystal by an angle around the pipe or tube of less than 180.degree.. Liquid in the pipe or tube is detected by measuring the attenuation of an ultrasonic signal sent by the first piezoelectric crystal and received by the second piezoelectric crystal.

Piper, Thomas C. (Idaho Falls, ID)

1991-01-01T23:59:59.000Z

269

Measurements of delayed neutron parameters for U-235 and Np-237  

SciTech Connect (OSTI)

Delayed neutrons are emitted by excited nuclei formed in beta decay of fission products called delayed neutron precursors. About 1% of the total neutrons released in fission are delayed neutrons; however, this small fraction plays an important role in nuclear reactor control. The delayed neutrons determine the time-dependent behavior of reactors, and knowledge of parameters used to predict neutron emission rate is essential for establishing reactivity worths. The delayed neutron yields, decay constants, and the absolute yield for the six-group delayed neutrons have been measured for U-235 and Np-237. This experiment has been called for in the forecast of experiments needed to support operations in the US. The bare U-235 metal assembly Godiva IV at the Los Alamos Critical Experiment Facility (LACEF) provided the source of neutrons. Godiva IV generated about 10{sup 7} total fissions in the samples for the infinite and instantaneous irradiation needed to accentuate the shorter and longer-lived groups of delayed neutrons. The detection system used in the experiment consisted of 20 He-3 tubes embedded in a polyethylene cylinder. The delayed neutron activity resulting from the fast neutron-induced fission has been measured. The measured absolute yield for U-235 was determined to be 0.0163 {+-} 0.009 neutrons/fission. This value compares very well with the well-established Keepin absolute yield of 0.0165 {+-} 0.0005. The newly measured absolute yield value for Np-237 was 0.0126 {+-} 0.0007, which compares well to the recently reported value of 0.0129 {+-} 0.0004 by Saleh and Parish. The measured values for U-235 are corroborated with period (e-folding time) versus reactivity calculations.

Loaiza, D.

1997-07-01T23:59:59.000Z

270

Fireside carburization of stainless steel furnace tubes  

SciTech Connect (OSTI)

Most heavy Venezuelan crudes are recognized for having a high total acid number (TAN) that is usually associated with a high tendency to produce naphthenic acid corrosion. To resist this type of corrosion in vacuum heaters, 9Cr-1Mo steel and stainless steels containing molybdenum are usually recommended. In 1993 the original 5Cr-1/2Mo roof tubes of the furnace in a vacuum unit were replaced by stainless steel 316Ti to minimize tube replacement and increase heater reliability. Unexpectedly, some of the new tubes failed after only three years of service, and just one year after undergoing the last turnaround inspection. The damage occurred in the form of deep holes and perforations, starting from the outside tube surface on the fireside. Coke build-up occurred due to severe operating conditions, overheating the tubes on the fireside, above 675 C (1250 F). Metallographic and Scanning Electron Microscopic (SEM) examination revealed internal and external carburization of the material due to the presence of coke and combustion ashes, respectively. The increase in the skin metal temperature facilitated the diffusion of carbon from these carbon-rich deposits into the low carbon content material (0.023 O/O).Depletion of chromium at the grain boundaries due to the massive formation of chromium carbides, resulted in a severe intergranular corrosion attack by molten salts rich in vanadium and sulfur due to asphalt burning. Normal operating practice demands the use of steam for the heater tubes to control coke build-up. This practice had been first reduced and then eliminated, during the past two years prior to the failure, because of economic incentives. This paper describes the root cause analysis conducted to account for these premature tube failures.

Mirabal, E.; Molina, C. [PDVSA-Refineria Isla, Curayao (Netherlands); Mayorga, A.; Hau, J.L. [PDVSA-Intevep, Caracas (Venezuela)

1999-11-01T23:59:59.000Z

271

Measurements of prompt gamma-rays from fast-neutron induced fission with the LICORNE directional neutron source  

E-Print Network [OSTI]

At the IPN Orsay we have developed a unique, directional, fast neutron source called LICORNE, intended initially to facilitate prompt fission gamma measurements. The ability of the IPN Orsay tandem accelerator to produce intense beams of $^7$Li is exploited to produce quasi-monoenergetic neutrons between 0.5 - 4 MeV using the p($^7$Li,$^7$Be)n inverse reaction. The available fluxes of up to 7 × 10$^7$ neutrons/second/steradian for the thickest hydrogen-rich targets are comparable to similar installations, but with two added advantages: (i) The kinematic focusing produces a natural neutron beam collimation which allows placement of gamma detectors adjacent to the irradiated sample unimpeded by source neutrons. (ii) The background of scattered neutrons in the experimental hall is drastically reduced. The dedicated neutron converter was commissioned in June 2013. Some preliminary results from the first experiment using the LICORNE neutron source at the IPN Orsay are presented. Prompt fission gamma rays from fas...

Wilson, J N; Halipre, P; Oberstedt, S; Oberstedt, A

2014-01-01T23:59:59.000Z

272

Pocked surface neutron detector  

DOE Patents [OSTI]

The detection efficiency, or sensitivity, of a neutron detector material such as of Si, SiC, amorphous Si, GaAs, or diamond is substantially increased by forming one or more cavities, or holes, in its surface. A neutron reactive material such as of elemental, or any compound of, .sup.10 B, .sup.6 Li, .sup.6 LiF, U, or Gd is deposited on the surface of the detector material so as to be disposed within the cavities therein. The portions of the neutron reactive material extending into the detector material substantially increase the probability of an energetic neutron reaction product in the form of a charged particle being directed into and detected by the neutron detector material.

McGregor, Douglas (Whitmore Lake, MI); Klann, Raymond (Bolingbrook, IL)

2003-04-08T23:59:59.000Z

273

Pulsed neutron detector  

DOE Patents [OSTI]

A pulsed neutron detector and system for detecting low intensity fast neutron pulses has a body of beryllium adjacent a body of hydrogenous material the latter of which acts as a beta particle detector, scintillator, and moderator. The fast neutrons (defined as having En>1.5 MeV) react in the beryllium and the hydrogenous material to produce larger numbers of slow neutrons than would be generated in the beryllium itself and which in the beryllium generate hellium-6 which decays and yields beta particles. The beta particles reach the hydrogenous material which scintillates to yield light of intensity related to the number of fast neutrons. A photomultiplier adjacent the hydrogenous material (scintillator) senses the light emission from the scintillator. Utilization means, such as a summing device, sums the pulses from the photo-multiplier for monitoring or other purposes.

Robertson, deceased, J. Craig (late of Albuquerque, NM); Rowland, Mark S. (Livermore, CA)

1989-03-21T23:59:59.000Z

274

Proceedings of the 10th meeting of the international collaboration on advanced neutron sources  

SciTech Connect (OSTI)

This report contains papers from the 10th meeting of the International Collaboration on Advanced Neutron Sources. Two general types of workshops are discussed, instrument and target-station. Individual papers are indexed separately elsewhere. (LSP)

Hyer, D.K. (comp. and ed.)

1989-03-01T23:59:59.000Z

275

A Superluminal Subway: The Krasnikov Tube  

E-Print Network [OSTI]

The ``warp drive'' metric recently presented by Alcubierre has the problem that an observer at the center of the warp bubble is causally separated from the outer edge of the bubble wall. Hence such an observer can neither create a warp bubble on demand nor control one once it has been created. In addition, such a bubble requires negative energy densities. One might hope that elimination of the first problem might ameliorate the second as well. We analyze and generalize a metric, originally proposed by Krasnikov for two spacetime dimensions, which does not suffer from the first difficulty. As a consequence, the Krasnikov metric has the interesting property that although the time for a one-way trip to a distant star cannot be shortened, the time for a round trip, as measured by clocks on Earth, can be made arbitrarily short. In our four dimensional extension of this metric, a ``tube'' is constructed along the path of an outbound spaceship, which connects the Earth and the star. Inside the tube spacetime is flat, but the light cones are opened out so as to allow superluminal travel in one direction. We show that, although a single Krasnikov tube does not involve closed timelike curves, a time machine can be constructed with a system of two non-overlapping tubes. Furthermore, it is demonstrated that Krasnikov tubes, like warp bubbles and traversable wormholes, also involve unphysically thin layers of negative energy density, as well as large total negative energies, and therefore probably cannot be realized in practice.

Allen E. Everett; Thomas A. Roman

1997-02-25T23:59:59.000Z

276

Circumferential cracking of steam generator tubes  

SciTech Connect (OSTI)

On April 28, 1995, the U.S. Nuclear Regulatory Commission (NRC) issued Generic Letter (GL) 95-03, {open_quote}Circumferential Cracking of Steam Generator Tubes.{close_quote} GL 95-03 was issued to obtain information needed to verify licensee compliance with existing regulatory requirements regarding the integrity of steam generator tubes in domestic pressurized-water reactors (PWRs). This report briefly describes the design and function of domestic steam generators and summarizes the staff`s assessment of the responses to GL 95-03. The report concludes with several observations related to steam generator operating experience. This report is intended to be representative of significant operating experience pertaining to circumferential cracking of steam generator tubes from April 1995 through December 1996. Operating experience prior to April 1995 is discussed throughout the report, as necessary, for completeness.

Karwoski, K.J.

1997-04-01T23:59:59.000Z

277

Alternate Materials for Recovery Boiler Superheater Tubes  

SciTech Connect (OSTI)

The ever escalating demands for increased efficiency of all types of boilers would most sensibly be realized by an increase in the steam parameters of temperature and pressure. However, materials and corrosion limitations in the steam generating components, particularly the superheater tubes, present major obstacles to boiler designers in achieving systems that can operate under the more severe conditions. This paper will address the issues associated with superheater tube selection for many types of boilers; particularly chemical recovery boilers, but also addressing the similarities in issues for biomass and coal fired boilers. It will also review our recent study of materials for recovery boiler superheaters. Additional, more extensive studies, both laboratory and field, are needed to gain a better understanding of the variables that affect superheater tube corrosion and to better determine the best means to control this corrosion to ultimately permit operation of recovery boilers at higher temperatures and pressures.

Keiser, James R [ORNL; Kish, Joseph [McMaster University; Singbeil, Douglas [FPInnovations

2009-01-01T23:59:59.000Z

278

Neutron LifetimeNeutron Lifetime IUCF Colloquium April 13,  

E-Print Network [OSTI]

Neutron LifetimeNeutron Lifetime IUCF Colloquium April 13, 2007 Albert Steyerl Department 940 878.5±0.8 885.7±0.8 new result neutronlifetime(),s year world average Neutron lifetime data #12 world average Neutron lifetime data A. Serebrov et al. 2005Storage of ultra-cold neutrons878.5 ±±±± 0

Steyerl, Albert

279

A Flexural Mode Tuning Technique for Membraned Boiler Tubing  

SciTech Connect (OSTI)

Corrosion of tubing used in black-liquor recovery boilers is a major concern in all pulp and paper mills. Extensive corrosion in recovery boiler tubes can result in a significant safety and environmental hazard. Considerable plant resources are expended to inspect recovery boiler tubing. Currently, visual and ultrasonic inspections are primarily used during the annual maintenance shutdown to monitor corrosion rates and cracking of tubing. This project is developing guided acoustic waves for use on recovery boiler tubing. The feature of this acoustic technique is its cost-effectiveness in inspecting long lengths of tubes from a single inspection point. A piezoelectric or electromagnetic transducer induces guided waves into the tubes. The transducer detects fireside defects from the cold side or fireside of the tube. Cracking and thinning on recovery boiler tubes have been detected with this technique in both laboratory and field applications.

Quarry, M J; Chinn, D J; Rose, J L

2005-03-21T23:59:59.000Z

280

Hyperons in neutron stars  

E-Print Network [OSTI]

Using the Dirac-Brueckner-Hartree-Fock approach, the properties of neutron-star matter including hyperons are investigated. In the calculation, we consider both time and space components of the vector self-energies of baryons as well as the scalar ones. Furthermore, the effect of negative-energy states of baryons is partly taken into account. We obtain the maximum neutron-star mass of $2.08\\,M_{\\odot}$, which is consistent with the recently observed, massive neutron stars. We discuss a universal, repulsive three-body force for hyperons in matter.

Katayama, Tetsuya

2015-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "neutron tube target" from the National Library of EnergyBeta (NLEBeta).
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281

In the Target Area  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

8 22 | Next | Last Back to Index NIF Target Chamber The interior of the NIF target chamber. The service module carrying technicians can be seen on the left. The target...

282

Calibration of a Neutron Hydroprobe for Moisture Measurements in Small-Diameter Steel-Cased Boreholes  

SciTech Connect (OSTI)

Computation of soil moisture content from thermalized neutron counts for the T-Farm Interim cover requires a calibration relationship but none exists for 2-in tubes. A number of calibration options are available for the neutron probe, including vendor calibration, field calibration, but none of these methods were deemed appropriate for the configuration of interest. The objective of this work was to develop a calibration relation for converting neutron counts measured in 2-in access tubes to soil water content. The calibration method chosen for this study was a computational approach using the Monte Carlo N-Particle Transport Code (MCNP). Model calibration was performed using field measurements in the Hanford calibration models with 6-in access tubes, in air and in the probe shield. The bet-fit model relating known water content to measured neutron counts was an exponential model that was essentially equivalent to that currently being used for 6-in steel cased wells. The MCNP simulations successfully predicted the neutron count rate for the neutron shield and the three calibration models for which data were collected in the field. However, predictions for air were about 65% lower than the measured counts . This discrepancy can be attributed to uncertainties in the configuration used for the air measurements. MCNP-simulated counts for the physical models were essentially equal to the measured counts with values. Accurate prediction of the response in 6-in casings in the three calibration models was motivation to predict the response in 2-in access tubes. Simulations were performed for six of the seven calibration models as well as 4 virtual models with the entire set covering a moisture range of 0 to 40%. Predicted counts for the calibration models with 2-in access tubes were 40 to 50% higher than in the 6-inch tubes. Predicted counts for water were about 60% higher in the 2-in tube than in the 6-in tube. The discrepancy between the 2-in and 6-in tube can be attributed to the smaller air gap between the probe and the 2-in access tube. The best-fit model relating volumetric water content to count ratio (CR) is of the form e^A x CR^B with A=0.3596 ± 0.0216 and B=0.4629 ± 0.0629 and r^2= 0.9998. It is recommended that the calibration function based on the count ratio, rather than raw counts, be used to avoid the effects of electronic noise in the probe that may arise due to the conditions at the time of measurement. These results suggest that the MCNP code can be used to extend calibrations for the neutron probe to different conditions including access tube size as well as composition without the need to construct additional physical models.

Ward, Anderson L.; Wittman, Richard S.

2009-08-01T23:59:59.000Z

283

In the Target Area  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

6 22 | Next | Last Back to Index NIF Target Chamber A service system lift allows technicians to access the target chamber interior for inspection and maintenance. Photo Number:...

284

Proceedings of the first international symposium on neutron capture therapy  

SciTech Connect (OSTI)

This meeting was arranged jointly by MIT and BNL in order to illuminate progress in the synthesis and targeting of boron compounds and to evaluate and document progress in radiobiological and dosimetric aspects of neutron capture therapy. It is hoped that this meeting will facilitate transfer of information between groups working in these fields, and encourage synergistic collaboration.

Fairchild, R.G.; Brownell, G.L. (eds.)

1982-01-01T23:59:59.000Z

285

Strangeness in Neutron Stars  

E-Print Network [OSTI]

It is generally agreed on that the tremendous densities reached in the centers of neutron stars provide a high-pressure environment in which several intriguing particles processes may compete with each other. These range from the generation of hyperons to quark deconfinement to the formation of kaon condensates and H-matter. There are theoretical suggestions of even more exotic processes inside neutron stars, such as the formation of absolutely stable strange quark matter. In the latter event, neutron stars would be largely composed of strange quark matter possibly enveloped in a thin nuclear crust. This paper gives a brief overview of these striking physical possibilities with an emphasis on the role played by strangeness in neutron star matter, which constitutes compressed baryonic matter at ultra-high baryon number density but low temperature which is no accessible to relativistic heavy ion collision experiments.

Fridolin Weber; Alexander Ho; Rodrigo P. Negreiros; Philip Rosenfield

2006-04-20T23:59:59.000Z

286

Delayed neutron emission probabilities of Li-F nuclides  

SciTech Connect (OSTI)

Delayed neutron emission probabilities (P{sub n}) have been measured for 18 nuclides ranging from {sup 9}Li to {sup 25}F. Neutron-rich nuclides were produced by reaction of 800 MeV p on a {sup 232}Th target at the LAMPF accelerator at Los Alamos National Laboratory. Recoil nuclides were individually identified as to their mass, nuclear charged, and ionic charge by use of the Time-of-Flight Isochronous (TOFI) spectrometer. The distribution of time intervals between the arrival of a specific ion and the subsequent detection of a neutron was determined. The P{sub n} was calculated from the total number of ions observed, the initial neutron count rate, the neutron counting efficiency, and the half-life. The technique is shown to be valid for half-lives ranging from 10 ms ({sup 15}B) to 4 s ({sup 17}N) and for P{sub n} values as low as 0.3% ({sup 13}B). Delayed neutron emission has been measured for {sup 12}Be, {sup 14}B, {sup 17}C, {sup 18}N, {sup 21}N, and {sup 25}F for the first time. A small branch for beta-delayed two-neutron emission was observed in {sup 15}B (P{sub 2n} = 0.4 {plus minus} 0.2%). 14 refs., 6 figs., 1 tab.

Reeder, P.L.; Warner, R.A.; Hensley, W.K. (Pacific Northwest Lab., Richland, WA (USA)); Vieira, D.J.; Wouters, J.M. (Los Alamos National Lab., NM (USA))

1989-09-01T23:59:59.000Z

287

2010 American Conference on Neutron Scattering (ACNS 2010)  

SciTech Connect (OSTI)

The ACNS provides a focal point for the national neutron user community to strengthen ties within this diverse group, while at the same time promoting neutron research among colleagues in related disciplines identified as “would-be” neutron users. The American Conference on Neutron Scattering thus serves a dual role as a national user meeting and a scientific meeting. As a venue for scientific exchange, the ACNS showcases recent results and provides forums for scientific discussion of neutron research in diverse fields such as hard and soft condensed matter, liquids, biology, magnetism, engineering materials, chemical spectroscopy, crystal structure, and elementary excitations, fundamental physics and development of neutron instrumentation through a combination of invited talks, contributed talks and poster sessions. As a “super-user” meeting, the ACNS fulfills the main objectives of users' meetings previously held periodically at individual national neutron facilities, with the advantage of a larger and more diverse audience. To this end, each of the major national neutron facilities (NIST, LANSCE, HFIR and SNS) have an opportunity to exchange information and update users, and potential users, of their facility. This is also an appropriate forum for users to raise issues that relate to the facilities. For many of the national facilities, this super-user meeting should obviate the need for separate user meetings that tax the time, energy and budgets of facility staff and the users alike, at least in years when the ACNS is held. We rely upon strong participation from the national facilities. The NSSA intends that the American Conference on Neutron Scattering (ACNS) will occur approximately every two years, but not in years that coincide with the International or European Conferences on Neutron Scattering. The ACNS is to be held in association with one of the national neutron centers in a rotating sequence, with the host facility providing local organization and planning assistance. Additional logistical support is being provided this year through a partnership with the conferencing office of the Materials Research Society (MRS). The ACNS, targeting the entire potential neutron North American user community, complements the annual NIST, ANL and LANSCE neutron and scattering schools which give hands-on experience primarily to graduate students who anticipate using neutron scattering in their thesis research. The summer schools are promoted at the ACNS and represent a natural path for students to take after being inspired by the activities of the ACNS.

Billinge, Simon

2011-06-17T23:59:59.000Z

288

Analyzing the Effects of Neutron Polarizabilities in Elastic Compton Scattering off ${}^3He$  

E-Print Network [OSTI]

Motivated by the fact that a polarized ${}^3He$ nucleus behaves as an `effective' neutron target, we examine manifestations of neutron electromagnetic polarizabilities in elastic Compton scattering from the Helium-3 nucleus. We calculate both unpolarized and double-polarization observables using chiral perturbation theory to next-to-leading order (${\\mathcal O}(e^2 Q)$) at energies, $\\omega \\lsim m_{\\pi}$, where $m_{\\pi}$ is the pion mass. Our results show that the unpolarized differential cross section can be used to measure neutron electric and magnetic polarizabilities, while two double-polarization observables are sensitive to different linear combinations of the four neutron spin polarizabilities.

Deepshikha Shukla; Andreas Nogga; Daniel R. Phillips

2008-12-01T23:59:59.000Z

289

Wave guides: vacuum w/ tube of conductor  

E-Print Network [OSTI]

Wave guides: vacuum w/ tube of conductor boundary conditions for conductor Properties: non-transverse waves except TEM mode in coaxial cable speed normal modes (from Liouville problem) TE or TM TEM for coaxial cable cuto frequency otherwise evanescent waves separation into and components with 1 #12;B

Hart, Gus

290

Stress-Assisted Corrosion in Boiler Tubes  

SciTech Connect (OSTI)

A number of industrial boilers, including in the pulp and paper industry, needed to replace their lower furnace tubes or decommission many recovery boilers due to stress-assisted corrosion (SAC) on the waterside of boiler tubes. More than half of the power and recovery boilers that have been inspected reveal SAC damage, which portends significant energy and economic impacts. The goal of this project was to clarify the mechanism of stress-assisted corrosion (SAC) of boiler tubes for the purpose of determining key parameters in its mitigation and control. To accomplish this in-situ strain measurements on boiler tubes were made. Boiler water environment was simulated in the laboratory and effects of water chemistry on SAC initiation and growth were evaluated in terms of industrial operations. Results from this project have shown that the dissolved oxygen is single most important factor in SAC initiation on carbon steel samples. Control of dissolved oxygen can be used to mitigate SAC in industrial boilers. Results have also shown that sharp corrosion fatigue and bulbous SAC cracks have similar mechanism but the morphology is different due to availability of oxygen during boiler shutdown conditions. Results are described in the final technical report.

Preet M Singh; Steven J Pawel

2006-05-27T23:59:59.000Z

291

Composite Tube Trailer Design/Manufacturing Needs  

E-Print Network [OSTI]

composite tube trailers and can, therefore, address issues with: ­ Design ­ Materials ­ Manufacturing in the system ­ Lower cost of carbon fiber ($/strength) ­ Identify material with lower net cost ($/strength) ­ Identify lower cost resin system (raw material & manufacture) ­ Reduce carbon fiber safety factor

292

Digital radiographic systems detect boiler tube cracks  

SciTech Connect (OSTI)

Boiler water wall leaks have been a major cause of steam plant forced outages. But conventional nondestructive evaluation techniques have a poor track record of detecting corrosion fatigue cracking on the inside surface of the cold side of waterwall tubing. EPRI is performing field trials of a prototype direct-digital radiographic system that promises to be a game changer. 8 figs.

Walker, S. [EPRI, Charlotte, NC (United States)

2008-06-15T23:59:59.000Z

293

High-efficiency scintillation detector for combined detection of thermal and fast neutrons and gamma radiation  

DOE Patents [OSTI]

A scintillation based radiation detector for the combined detection of thermal neutrons, high-energy neutrons and gamma rays in a single detecting unit. The detector consists of a pair of scintillators sandwiched together and optically coupled to the light sensitive face of a photomultiplier tube. A light tight radiation pervious housing is disposed about the scintillators and a portion of the photomultiplier tube to hold the arrangement in assembly and provides a radiation window adjacent the outer scintillator through which the radiation to be detected enters the detector. The outer scintillator is formed of a material in which scintillations are produced by thermal-neutrons and the inner scintillator is formed of a material in which scintillations are produced by high-energy neutrons and gamma rays. The light pulses produced by events detected in both scintillators are coupled to the photomultiplier tube which produces a current pulse in response to each detected event. These current pulses may be processed in a conventional manner to produce a count rate output indicative of the total detected radiation event count rate. Pulse discrimination techniques may be used to distinguish the different radiations and their energy distribution.

Chiles, M.M.; Mihalczo, J.T.; Blakeman, E.D.

1987-02-27T23:59:59.000Z

294

Half-lives and delayed neutron emission probabilities of neutron-rich Li--Al nuclides (US)  

SciTech Connect (OSTI)

Beta-decay half-lives and delayed neutron emission probabilities of very neutron-rich nuclides from Li to Al have been measured by a delayed coincidence technique. Neutron-rich nuclides were produced by reaction of 800-MeV protons on a {sup 232}Th target and were individually identified by use of the time-of-flight isochronous spectrometer. For 16 previously measured nucides, the half-lives determined here agree with literature values within the uncertainties. The previously unmeasured half-lives for {sup 25}F (59{plus minus}40 ms) and {sup 28}Ne (14{plus minus}10 ms) have been determined. Delayed neutron emission has been measured for {sup 12}Be, {sup 14}B, {sup 17}C, {sup 18}N, {sup 25}F, and {sup 28}Ne. Emission probabilities are reported for 19 precursors and upper limits are reported for 12 other nuclides. These data are compared with predictions of several beta-decay models.

Reeder, P.L.; Warner, R.A.; Hensley, W.K. (Pacific Northwest Laboratory, Richland, Washington (USA)); Vieira, D.J.; Wouters, J.M. (Los Alamos National Laboratory, Los Alamos, New Mexico (USA))

1991-10-01T23:59:59.000Z

295

Condensation in horizontal heat exchanger tubes  

SciTech Connect (OSTI)

Many innovative reactor concepts for Generation III nuclear power plants use passive safety equipment for residual heat removal. These systems use two phase natural circulation. Heat transfer to the coolant results in a density difference providing the driving head for the required mass flow. By balancing the pressure drop the system finds its operational mode. Therefore the systems depend on a strong link between heat transfer and pressure drop determining the mass flow through the system. In order to be able to analyze these kind of systems with the help of state of the art computer codes the implemented numerical models for heat transfer, pressure drop or two phase flow structure must be able to predict the system performance in a wide parameter range. Goal of the program is to optimize the numerical models and therefore the performance of computer codes analyzing passive systems. Within the project the heat transfer capacity of a heat exchanger tube will be investigated. Therefore the tube will be equipped with detectors, both temperature and pressure, in several directions perpendicular to the tube axis to be able to resolve the angular heat transfer. In parallel the flow structure of a two phase flow inside and along the tube will be detected with the help of x-ray tomography. The water cooling outside of the tube will be realized by forced convection. It will be possible to combine the flow structure measurement with an angular resolved heat transfer for a wide parameter range. The test rig is set up at the TOPLFOW facility at the Helmholtz-Zentrum Dresden-Rossendorf (HZDR), so that it will be possible to vary the pressure between 5 and 70 bar. The steam mass content will be varied between 0 and 100 percent. The results will be compared to the large scaled Emergency Condenser Tests performed at the INKA test facility in Karlstein (Germany). The paper will explain the test setup and the status of the project will be presented. (authors)

Leyer, S.; Zacharias, T.; Maisberger, F.; Lamm, M. [AREVA NP GmbH, Paul-Gossen-Strasse 100, Erlangen, 91052 (Germany); Vallee, C.; Beyer, M.; Hampel, U. [Helmholtz-Zentrum Dresden-Rossendorf e.V., Bautzner Landstrasse 400, Dresden, 01328 (Germany)

2012-07-01T23:59:59.000Z

296

MAGNETIC NEUTRON SCATTERING  

SciTech Connect (OSTI)

Much of our understanding of the atomic-scale magnetic structure and the dynamical properties of solids and liquids was gained from neutron-scattering studies. Elastic and inelastic neutron spectroscopy provided physicists with an unprecedented, detailed access to spin structures, magnetic-excitation spectra, soft-modes and critical dynamics at magnetic-phase transitions, which is unrivaled by other experimental techniques. Because the neutron has no electric charge, it is an ideal weakly interacting and highly penetrating probe of matter's inner structure and dynamics. Unlike techniques using photon electric fields or charged particles (e.g., electrons, muons) that significantly modify the local electronic environment, neutron spectroscopy allows determination of a material's intrinsic, unperturbed physical properties. The method is not sensitive to extraneous charges, electric fields, and the imperfection of surface layers. Because the neutron is a highly penetrating and non-destructive probe, neutron spectroscopy can probe the microscopic properties of bulk materials (not just their surface layers) and study samples embedded in complex environments, such as cryostats, magnets, and pressure cells, which are essential for understanding the physical origins of magnetic phenomena. Neutron scattering is arguably the most powerful and versatile experimental tool for studying the microscopic properties of the magnetic materials. The magnitude of the cross-section of the neutron magnetic scattering is similar to the cross-section of nuclear scattering by short-range nuclear forces, and is large enough to provide measurable scattering by the ordered magnetic structures and electron spin fluctuations. In the half-a-century or so that has passed since neutron beams with sufficient intensity for scattering applications became available with the advent of the nuclear reactors, they have became indispensable tools for studying a variety of important areas of modern science, ranging from large-scale structures and dynamics of polymers and biological systems, to electronic properties of today's technological materials. Neutron scattering developed into a vast field, encompassing many different experimental techniques aimed at exploring different aspects of matter's atomic structure and dynamics. Modern magnetic neutron scattering includes several specialized techniques designed for specific studies and/or particular classes of materials. Among these are magnetic reflectometry aimed at investigating surfaces, interfaces, and multilayers, small-angle scattering for the large-scale structures, such as a vortex lattice in a superconductor, and neutron spin-echo spectroscopy for glasses and polymers. Each of these techniques and many others offer exciting opportunities for examining magnetism and warrant extensive reviews, but the aim of this chapter is not to survey how different neutron-scattering methods are used to examine magnetic properties of different materials. Here, we concentrate on reviewing the basics of the magnetic neutron scattering, and on the recent developments in applying one of the oldest methods, the triple axis spectroscopy, that still is among the most extensively used ones. The developments discussed here are new and have not been coherently reviewed. Chapter 2 of this book reviews magnetic small-angle scattering, and modern techniques of neutron magnetic reflectometry are discussed in Chapter 3.

ZALIZNYAK,I.A.; LEE,S.H.

2004-07-30T23:59:59.000Z

297

Math 13900 YouTube Quiz 2013 Find a video on YouTube that ...  

E-Print Network [OSTI]

Find a video on YouTube that addresses the idea of symmetry – either for 2 dimensions or 3 as we have been studying in lessons 9 and 10. The video should be ...

Roames, Renee S

2013-01-02T23:59:59.000Z

298

Characterization of Friction Stir Welded Tubes by Means of Tube Bulge Test  

SciTech Connect (OSTI)

Mechanical properties of friction stir welded joints are generally evaluated by means of conventional tensile test. This testing method might provide insufficient information because maximum strain obtained in tensile test before necking is small; moreover, the application of tensile test is limited when the joint path is not linear or even when the welds are executed on curved surfaces. Therefore, in some cases, it would be preferable to obtain the joints properties from other testing methods. Tube bulge test can be a valid solution for testing circumferential or longitudinal welds executed on tubular workpieces. The present work investigates the mechanical properties and the formability of friction stir welded tubes by means of tube bulge tests. The experimental campaign was performed on tubular specimens having a thickness of 3 mm and an external diameter of 40 mm, obtained starting from two semi-tubes longitudinally friction stir welded. The first step, regarding the fabrication of tubes, was performed combining a conventional forming process and friction stir welding. Sheets in Al-Mg-Si-Cu alloy AA6060 T6 were adopted for this purpose. Plates having a dimension of 225x60 mm were bent (with a bending axis parallel to the main dimension) in order to obtain semi-tubes. A particular care was devoted to the fabrication of forming devices (punch and die) in order to minimize the springback effects. Semi-tubes were then friction stir welded by means of a CNC machine tool. Some preliminary tests were carried out by varying the welding parameters, namely feed rate and rotational speed. A very simple tool having flat shoulder and cylindrical pin was used. The second step of the research was based on testing the welded tubes by means of tube bulge test. A specific equipment having axial actuators with a conical shape was adopted for this study. Some analyses were carried out on the tubes bulged up to a certain pressure level. In particular, the burst pressure and the wall thickness were measured for each tested tube.

D'Urso, G.; Longo, M.; Giardini, C. [University of Bergamo-Dept. of Design and Technologies-Italy-Viale Marconi 5, 24044 Dalmine (Italy)

2011-05-04T23:59:59.000Z

299

Investigation of target in C-ADS and IAEA ADS benchmark  

E-Print Network [OSTI]

The spatial and energy distribution of spallation neutrons have an effect on the performance of Accelerator Driven Subcritical systems. In this work, the spatial, energy distribution of spallation neutrons and the effect of these factors on proton efficiency was studied. When the radius of spallation region increases, backward neutrons were found to have a rather big ratio and have a positive effect on proton efficiency. By making better use of these neutrons, we may increase the radius of target to satisfy some other requirements in the design of subcritical core.

Guojun Hu; Hongli Wu; Tian Jing; Xiangqi Wang; Jingyu Tang

2012-11-01T23:59:59.000Z

300

First SNS Target Replacement  

E-Print Network [OSTI]

First SNS Target Replacement Experience M. Dayton, M. Rennich, Van Graves, J. DeVore Presented by T.S. Department of Energy AHIP Workshop Oct. 2009 Overview · Initial Target Replacement · Target Maintenance-Battelle for the U.S. Department of Energy AHIP Workshop Oct. 2009 First SNS Target Replacement · Replacement

McDonald, Kirk

Note: This page contains sample records for the topic "neutron tube target" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


301

MECO Production Target Developments  

E-Print Network [OSTI]

be reoptimized Tungsten target Simulations of design parameters with GEANT3 indicate that both production targetMECO Production Target Developments James L. Popp University of California, Irvine NuFact'03 Columbia, June, 2003 #12;June, 2003J.L.Popp, UCI MECO Production Target 2 MECO Collaboration Institute

McDonald, Kirk

302

Refrigerant forced-convection condensation inside horizontal tubes  

E-Print Network [OSTI]

Condensing heat transfer rates inside a horizontal tube were investigated -for large quality changes across the tube. The proposed correlation is a modification of the work of Rohsenow, Webber and Ling [29]. The result of ...

Bae, Soonhoon

1968-01-01T23:59:59.000Z

303

Fouling of HVAC fin and tube heat exchangers  

E-Print Network [OSTI]

air ? air ? part ? part FPI HVAC REFERENCES Anonymous, 1987,LBNL-47668 Fouling of HVAC Fin and Tube Heat ExchangersCIEE SPONSOR. FOULING OF HVAC FIN AND TUBE HEAT EXCHANGERS

Siegel, Jeffrey; Carey, Van P.

2001-01-01T23:59:59.000Z

304

Insulated laser tube structure and method of making same  

DOE Patents [OSTI]

An insulated high temperature ceramic laser tube having substantially uniform insulation along the length of the tube is disclosed having particulate ceramic insulation positioned between the outer wall of the ceramic laser tube and the inner surface of tubular ceramic fiber insulation which surrounds the ceramic laser tube. The particulate ceramic insulation is preferably a ceramic capable of sintering to the outer surface of the ceramic laser tube and to the inner surface of the tubular ceramic fiber insulation. The addition of the particulate ceramic insulation to fill all the voids between the ceramic laser tube and the fibrous ceramic insulation permits the laser tube to be operated at a substantially uniform temperature throughout the length of the laser tube.

Dittbenner, Gerald R. (4353 Findlay Way, Livermore, CA 94550)

1999-01-01T23:59:59.000Z

305

Automatic Tube Cleaning Systems for Condensers and Heat Exchangers  

E-Print Network [OSTI]

AUTOMATIC TUBE CLEANING SYSTEMS FOR CONDENSERS AND HEAT EXCHANGERS Kaveh Someah/V.P. Sales & Mktg. WSA Engineered Systems, Milwaukee, WI (414) 354-6470 ABSTRACT The on-line Automatic Tube Cleaning Systems (ATCS) for condensers and heat... exchangers provide a positive means for automatic cleaning on a continuous basis, while the exchanger or condenser remains "on stream" and at its full operating potential. Condenser tube fouling contributes up to 50% of the total condenser tube heat...

Someah, K.

306

Polarized internal target apparatus  

DOE Patents [OSTI]

A polarized internal target apparatus with a polarized gas target of improved polarization and density achieved by mixing target gas atoms with a small amount of alkali metal gas atoms, and passing a high intensity polarized light source into the mixture to cause the alkali metal gas atoms to become polarized which interact in spin exchange collisions with target gas atoms yielding polarized target gas atoms.

Holt, Roy J. (Downers Grove, IL)

1986-01-01T23:59:59.000Z

307

Polarized internal target apparatus  

DOE Patents [OSTI]

A polarized internal target apparatus with a polarized gas target of improved polarization and density (achieved by mixing target gas atoms with a small amount of alkali metal gas atoms, and passing a high intensity polarized light source into the mixture to cause the alkali metal gas atoms to become polarized which interact in spin exchange collisions with target gas atoms yielding polarized target gas atoms) is described.

Holt, R.J.

1984-10-10T23:59:59.000Z

308

Department of Mechanical Engineering Spring 2010 Wellbore Coil Tubing  

E-Print Network [OSTI]

PENNSTATE Department of Mechanical Engineering Spring 2010 Wellbore Coil Tubing Overview In BP reaching the bottom of the wellbore utilizing a pre- loaded constant force spring. The coiled tubing's North American Gas Division, there are approximately 800 wellbores with coiled tubing installed

Demirel, Melik C.

309

ACCELERATOR TUBES H. R. McK. HYDER  

E-Print Network [OSTI]

ACCELERATOR TUBES H. R. McK. HYDER Nuclear Physics Laboratory, University of Oxford, Oxford OX1 3RH The characteristics and performance of accelerator tubes required by the new generation of large tandem accelerators conclusions are drawn about future progress and developments. ACCELERATOR TUBES AND INSULATORS. 1

Paris-Sud XI, Université de

310

Instability characteristics of fluidelastic instability of tube rows in crossflow  

SciTech Connect (OSTI)

An experimental study is reported to investigate the jump phenomenon in critical flow velocities for tube rows with different pitch-to-diameter ratios and the excited and intrinsic instabilities for a tube row with a pitch-to-diameter ratio of 1.75. The experimental data provide additional insights into the instability phenomena of tube arrays in crossflow. 9 refs., 10 figs.

Chen, S.S.; Jendrzejczyk, J.A.

1986-04-01T23:59:59.000Z

311

Finned Tube With Vortex Generators For A Heat Exchanger.  

DOE Patents [OSTI]

A system for and method of manufacturing a finned tube for a heat exchanger is disclosed herein. A continuous fin strip is provided with at one pair of vortex generators. A tube is rotated and linearly displaced while the continuous fin strip with vortex generators is spirally wrapped around the tube.

Sohal, Manohar S. (Idaho Falls, ID); O'Brien, James E. (Idaho Falls, ID)

2005-12-20T23:59:59.000Z

312

ORIGINAL ARTICLE Yield prediction for seamless tubing processes  

E-Print Network [OSTI]

tubing process 1 Introduction Pipe products made from carbon and alloy steel are commonly used in oil and natural gas exploration and production, fluid transmission, and the construction indus- try. A market an increasing demand for seamless tubing for gas and oil production [1]. Steel tubes are made by several

Huang, Samuel H.

313

Characterization of a novel, short pulse laser-driven neutron source  

SciTech Connect (OSTI)

We present a full characterization of a short pulse laser-driven neutron source. Neutrons are produced by nuclear reactions of laser-driven ions deposited in a secondary target. The emission of neutrons is a superposition of an isotropic component into 4? and a forward directed, jet-like contribution, with energies ranging up to 80 MeV. A maximum flux of 4.4 × 10{sup 9} neutrons/sr has been observed and used for fast neutron radiography. On-shot characterization of the ion driver and neutron beam has been done with a variety of different diagnostics, including particle detectors, nuclear reaction, and time-of-flight methods. The results are of great value for future optimization of this novel technique and implementation in advanced applications.

Jung, D.; Falk, K.; Guler, N.; Devlin, M.; Favalli, A.; Fernandez, J. C.; Gautier, D. C.; Haight, R.; Hamilton, C. E.; Hegelich, B. M.; Johnson, R. P.; Merrill, F.; Schoenberg, K.; Shimada, T.; Taddeucci, T.; Tybo, J. L.; Wender, S. A.; Wilde, C. H.; Wurden, G. A. [Los Alamos National Laboratory, Los Alamos, New Mexico 87545 (United States)] [Los Alamos National Laboratory, Los Alamos, New Mexico 87545 (United States); Deppert, O. [Technische Universität Darmstadt, 64289 Darmstadt (Germany)] [Technische Universität Darmstadt, 64289 Darmstadt (Germany); and others

2013-05-15T23:59:59.000Z

314

NEUTRON RADIOGRAPHY (NRAD) REACTOR 64-ELEMENT CORE UPGRADE  

SciTech Connect (OSTI)

The neutron radiography (NRAD) reactor is a 250 kW TRIGA (registered) (Training, Research, Isotopes, General Atomics) Mark II , tank-type research reactor currently located in the basement, below the main hot cell, of the Hot Fuel Examination Facility (HFEF) at the Idaho National Laboratory (INL). It is equipped with two beam tubes with separate radiography stations for the performance of neutron radiography irradiation on small test components. The interim critical configuration developed during the core upgrade, which contains only 62 fuel elements, has been evaluated as an acceptable benchmark experiment. The final 64-fuel-element operational core configuration of the NRAD LEU TRIGA reactor has also been evaluated as an acceptable benchmark experiment. Calculated eigenvalues differ significantly (approximately +/-1%) from the benchmark eigenvalue and have demonstrated sensitivity to the thermal scattering treatment of hydrogen in the U-Er-Zr-H fuel.

John D. Bess

2014-03-01T23:59:59.000Z

315

Investigation of pressure-tube and calandria-tube deformation following a single channel blockage event in ACR-700  

E-Print Network [OSTI]

The ACR-700 is an advanced pressure-tube (PT) reactor being developed by Atomic Energy of Canada Limited (AECL). As in conventional CANDU reactors, the PTs are horizontal. Each PT is surrounded by a calandria tube (CT), ...

Gerardi, Craig Douglas

2006-01-01T23:59:59.000Z

316

Investigation of Pressure-Tube and Calandria-Tube Deformation Following a Single Channel Blockage Event in ACR-700  

E-Print Network [OSTI]

The ACR-700 is an advanced pressure-tube (PT) reactor being developed by Atomic Energy of Canada Limited (AECL). As in conventional CANDU reactors, the PTs are horizontal. Each PT is surrounded by a calandria tube (CT), ...

Buongiorno, Jacopo

317

Electron-neutron scattering and transport properties of neutron stars  

E-Print Network [OSTI]

We show that electrons can couple to the neutron excitations in neutron stars and find that this can limit their contribution to the transport properties of dense matter, especially the shear viscosity. The coupling between electrons and neutrons is induced by protons in the core, and by ions in the crust. We calculate the effective electron-neutron interaction for the kinematics of relevance to the scattering of degenerate electrons at high density. We use this interaction to calculate the electron thermal conductivity, electrical conductivity, and shear viscosity in the neutron star inner crust, and in the core where we consider both normal and superfluid phases of neutron-rich matter. In some cases, particularly when protons are superconducting and neutrons are in their normal phase, we find that electron-neutron scattering can be more important than the other scattering mechanisms considered previously.

Bertoni, Bridget; Rrapaj, Ermal

2014-01-01T23:59:59.000Z

318

Novel neutron focusing mirrors for compact neutron sources  

E-Print Network [OSTI]

We demonstrated neutron beam focusing and neutron imaging using axisymmetric optics, based on pairs of confocal ellipsoid and hyperboloid mirrors. Such systems, known as Wolter mirrors, are commonly used in x-ray telescopes. ...

Gubarev, M.V.

319

Neutron lifetime measurements using gravitationally trapped ultracold neutrons  

SciTech Connect (OSTI)

Our experiment using gravitationally trapped ultracold neutrons (UCN) to measure the neutron lifetime is reviewed. Ultracold neutrons were trapped in a material bottle covered with perfluoropolyether. The neutron lifetime was deduced from comparison of UCN losses in the traps with different surface-to-volume ratios. The precise value of the neutron lifetime is of fundamental importance to particle physics and cosmology. In this experiment, the UCN storage time is brought closer to the neutron lifetime than in any experiments before: the probability of UCN losses from the trap was only 1% of that for neutron {beta} decay. The neutron lifetime obtained, 878.5{+-}0.7{sub stat}{+-}0.3{sub sys} s, is the most accurate experimental measurement to date.

Serebrov, A. P.; Varlamov, V. E.; Kharitonov, A. G.; Fomin, A. K.; Krasnoschekova, I. A.; Lasakov, M. S.; Taldaev, R. R.; Vassiljev, A. V.; Zherebtsov, O. M. [Petersburg Nuclear Physics Institute, Russian Academy of Sciences, RU-188300 Gatchina, Leningrad District (Russian Federation); Pokotilovski, Yu. N. [Joint Institute for Nuclear Research, RU-141980 Dubna, Moscow Region (Russian Federation); Geltenbort, P. [Institut Max von Laue Paul Langevin, Boite Postal 156, F-38042 Grenoble Cedex 9 (France)

2008-09-15T23:59:59.000Z

320

Neutron lifetime measurements using gravitationally trapped ultracold neutrons  

E-Print Network [OSTI]

Our experiment using gravitationally trapped ultracold neutrons (UCN) to measure the neutron lifetime is reviewed. Ultracold neutrons were trapped in a material bottle covered with perfluoropolyether. The neutron lifetime was deduced from comparison of UCN losses in the traps with different surface-to-volume ratios. The precise value of the neutron lifetime is of fundamental importance to particle physics and cosmology. In this experiment, the UCN storage time is brought closer to the neutron lifetime than in any experiments before:the probability of UCN losses from the trap was only 1% of that for neutron beta decay. The neutron lifetime obtained,878.5+/-0.7stat+/-0.3sys s, is the most accurate experimental measurement to date.

A. P. Serebrov; V. E. Varlamov; A. G. Kharitonov; A. K. Fomin; Yu. N. Pokotilovski; P. Geltenbort; I. A. Krasnoschekova; M. S. Lasakov; R. R. Taldaev; A. V. Vassiljev; O. M. Zherebtsov

2007-02-06T23:59:59.000Z

Note: This page contains sample records for the topic "neutron tube target" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


321

Characterization of Dosimetry of the BMRR Horizontal Thimble Tubes and Broad Beam Facility.  

SciTech Connect (OSTI)

The Brookhaven Medical Research Reactor was a 5 mega-watt, light-water cooled and heavy-graphite moderated research facility. It has two shutter-equipped treatment rooms, three horizontally extended thimble tubes, and an ex-core broad beam facility. The three experimental thimbles, or activation ports, external to the reactor tank were designed for several uses, including the investigations on diagnostic and therapeutic methods using radioactive isotopes of very short half-life, the analysis of radiation exposure on tissue-equivalent materials using a collimated neutron beam, and the evaluation of dose effects on biological cells to improve medical treatment. At the broad beam facility where the distribution of thermal neutrons was essential uniform, a wide variety of mammalian whole-body exposures were studied using animals such as burros or mice. Also studied at the broad beam were whole-body phantom experiments, involving the use of a neutron or photon beam streaming through a screen to obtain the flux spectrum suitable for dose analysis on the sugar-urea-water mixture, a tissue-equivalent material. Calculations of the flux and the dose at beam ports based on Monte Carlo particle-transport code were performed, and measurements conducted at the same tally locations were made using bare or cadmium-covered gold foils. Analytical results, which show good agreement with measurement data, are presented in the paper.

Hu,J.P.; Reciniello, R.N.; Holden, N.E.

2008-05-05T23:59:59.000Z

322

Strangeness in Neutron Stars  

E-Print Network [OSTI]

It is generally agreed on that the tremendous densities reached in the centers of neutron stars provide a high-pressure environment in which numerous novel particles processes are likely to compete with each other. These processes range from the generation of hyperons to quark deconfinement to the formation of kaon condensates and H-matter. There are theoretical suggestions of even more exotic processes inside neutron stars, such as the formation of absolutely stable strange quark matter, a configuration of matter even more stable than the most stable atomic nucleus, iron. In the latter event, neutron stars would be largely composed of pure quark matter, eventually enveloped in a thin nuclear crust. No matter which physical processes are actually realized inside neutron stars, each one leads to fingerprints, some more pronounced than others though, in the observable stellar quantities. This feature combined with the unprecedented progress in observational astronomy, which allows us to see vistas with remarkable clarity that previously were only imagined, renders neutron stars to nearly ideal probes for a wide range of physical studies, including the role of strangeness in dense matter.

Fridolin Weber

2000-08-23T23:59:59.000Z

323

ATRC Neutron Detector Testing Quick Look Report  

SciTech Connect (OSTI)

As part of the Advanced Test Reactor (ATR) National Scientific User Facility (NSUF) program, a joint Idaho State University (ISU) / French Alternative Energies and Atomic Energy Commission (CEA) / Idaho National Laboratory (INL) project was initiated in FY-10 to investigate the feasibility of using neutron sensors to provide online measurements of the neutron flux and fission reaction rate in the ATR Critical Facility (ATRC). A second objective was to provide initial neutron spectrum and flux distribution information for physics modeling and code validation using neutron activation based techniques in ATRC as well as ATR during depressurized operations. Detailed activation spectrometry measurements were made in the flux traps and in selected fuel elements, along with standard fission rate distribution measurements at selected core locations. These measurements provide additional calibration data for the real-time sensors of interest as well as provide benchmark neutronics data that will be useful for the ATR Life Extension Program (LEP) Computational Methods and V&V Upgrade project. As part of this effort, techniques developed by Prof. George Imel will be applied by Idaho State University (ISU) for assessing the performance of various flux detectors to develop detailed procedures for initial and follow-on calibrations of these sensors. In addition to comparing data obtained from each type of detector, calculations will be performed to assess the performance of and reduce uncertainties in flux detection sensors and compare data obtained from these sensors with existing integral methods employed at the ATRC. The neutron detectors required for this project were provided to team participants at no cost. Activation detectors (foils and wires) from an existing, well-characterized INL inventory were employed. Furthermore, as part of an on-going ATR NSUF international cooperation, the CEA sent INL three miniature fission chambers (one for detecting fast flux and two for detecting thermal flux) with associated electronics for assessment. In addition, Prof. Imel, ISU, has access to an inventory of Self-Powered Neutron Detectors (SPNDs) with a range of response times as well as Back-to-Back (BTB) fission chambers from prior research he conducted at the Transient REActor Test Facility (TREAT) facility and Neutron RADiography (NRAD) reactors. Finally, SPNDs from the National Atomic Energy Commission of Argentina (CNEA) were provided in connection with the INL effort to upgrade ATR computational methods and V&V protocols that are underway as part of the ATR LEP. Work during fiscal year 2010 (FY10) focussed on design and construction of Experiment Guide Tubes (EGTs) for positioning the flux detectors in the ATRC N-16 locations as well as obtaining ATRC staff concurrence for the detector evaluations. Initial evaluations with CEA researchers were also started in FY10 but were cut short due to reactor reliability issues. Reactor availability issues caused experimental work to be delayed during FY11/12. In FY13, work resumed; and evaluations were completed. The objective of this "Quick Look" report is to summarize experimental activities performed from April 4, 2013 through May 16, 2013.

Troy C. Unruh; Benjamin M. Chase; Joy L. Rempe

2013-08-01T23:59:59.000Z

324

Portable Neutron Sensors for Emergency Response Operations  

SciTech Connect (OSTI)

This slide-show presents neutron measurement work, including design, use and performance of different neutron detection systems.

Mukhopadhyay, S., Maurer, R., Detweiler, R.

2012-06-22T23:59:59.000Z

325

Coupled-cavity drift-tube linac  

DOE Patents [OSTI]

A coupled-cavity drift-tube linac (CCDTL) combines features of the Alvarez drift-tube linac (DTL) and the {pi}-mode coupled-cavity linac (CCL). In one embodiment, each accelerating cavity is a two-cell, 0-mode DTL. The center-to-center distance between accelerating gaps is {beta}{lambda}, where {lambda} is the free-space wavelength of the resonant mode. Adjacent accelerating cavities have oppositely directed electric fields, alternating in phase by 180 degrees. The chain of cavities operates in a {pi}/2 structure mode so the coupling cavities are nominally unexcited. The CCDTL configuration provides an rf structure with high shunt impedance for intermediate velocity charged particles, i.e., particles with energies in the 20-200 MeV range. 5 figs.

Billen, J.H.

1996-11-26T23:59:59.000Z

326

BNL ACTIVITIES IN ADVANCED NEUTRON SOURCE DEVELOPMENT: PAST AND PRESENT  

SciTech Connect (OSTI)

Brookhaven National Laboratory has been involved in advanced neutron sources almost from its inception in 1947. These efforts have mainly focused on steady state reactors beginning with the construction of the first research reactor for neutron beams, the Brookhaven Graphite Research Reactor. This was followed by the High Flux Beam Reactor that has served as the design standard for all the subsequent high flux reactors constructed worldwide. In parallel with the reactor developments BNL has focused on the construction and use of high energy proton accelerators. The first machine to operate over 1 GeV in the world was the Cosmotron. The machine that followed this, the AGS, is still operating and is the highest intensity proton machine in the world and has nucleated an international collaboration investigating liquid metal targets for next generation pulsed spallation sources. Early work using the Cosmotron focused on spallation product studies for both light and heavy elements into the several GeV proton energy region. These original studies are still important today. In the sections below the authors discuss the facilities and activities at BNL focused on advanced neutron sources. BNL is involved in the proton source for the Spallation Neutron source, spectrometer development at LANSCE, target studies using the AGS and state-of-the-art neutron detector development.

HASTINGS,J.B.; LUDEWIG,H.; MONTANEZ,P.; TODOSOW,M.; SMITH,G.C.; LARESE,J.Z.

1998-06-14T23:59:59.000Z

327

BNL Activities in Advanced Neutron Source Development: Past and Present  

SciTech Connect (OSTI)

Brookhaven National Laboratory has been involved in advanced neutron sources almost from its inception in 1947. These efforts have mainly focused on steady state reactors beginning with the construction of the first research reactor for neutron beams, the Brookhaven Graphite Research Reactor. This was followed by the High Flux Beam Reactor that has served as the design standard for all the subsequent high flux reactors constructed worldwide. In parallel with the reactor developments BNL has focused on the construction and use of high energy proton accelerators. The first machine to operate over 1 GeV in the world was the Cosmotron. The machine that followed this, the AGS, is still operating and is the highest intensity proton machine in the world and has nucleated an international collaboration investigating liquid metal targets for next generation pulsed spallation sources. Early work using the Cosmotron focused on spallation product studies for both light and heavy elements into the several GeV proton energy region. These original studies are still important today. In this report we discuss the facilities and activities at BNL focused on advanced neutron sources. BNL is involved in the proton source for the Spallation Neutron source, spectrometer development at LANSCE, target studies using the AGS and state-of-the-art neutron detector development.

Hastings, J.B.; Ludewig, H.; Montanez, P.; Todosow, M.; Smith, G.C.; Larese, J.Z.

1998-06-14T23:59:59.000Z

328

Time-reversal invariance violation measurement using polarized neutron scattering from polarized xenon  

E-Print Network [OSTI]

We proposed to use polarized neutrons scattering from a hyperpolarized 131Xe gaseous target in order to measure time-reversal violation effect in baryon processes with nucleons. This article provides a brief introduction, historical review, and possible methods to construct a hyperpolarized 131Xe gaseous target.

Pinghan Chu

2014-03-06T23:59:59.000Z

329

Production of 239 Pu from a natural Uranium disk and "hot" rock using a neutron howitzer  

E-Print Network [OSTI]

A neutron howitzer was used to produce 239Np from the targets of natural U and a hot rock. An intrinsic Germanium detector enabled the observations of the gamma rays in the decay of 239Np and a determination of its half life of 2.3 days. This shows that 239Pu had been produced in both targets

Joseph Steiner; Aaron Anderson; Michael De Marco

2008-05-23T23:59:59.000Z

330

A silicon photomultiplier readout for time of flight neutron spectroscopy with {gamma}-ray detectors  

SciTech Connect (OSTI)

The silicon photomultiplier (SiPM) is a recently developed photosensor used in particle physics, e.g., for detection of minimum ionizing particles and/or Cherenkov radiation. Its performance is comparable to that of photomultiplier tubes, but with advantages in terms of reduced volume and magnetic field insensitivity. In the present study, the performance of a gamma ray detector made of an yttrium aluminum perovskite scintillation crystal and a SiPM-based readout is assessed for use in time of flight neutron spectroscopy. Measurements performed at the ISIS pulsed neutron source demonstrate the feasibility of {gamma}-detection based on the new device.

Pietropaolo, A.; Gorini, G. [Dipartimento di Fisica ''G. Occhialini'' and CNISM, Universita Degli Studi di Milano-Bicocca, Piazza della Scienza 3, 20126 Milano (Italy); Festa, G.; Andreani, C.; De Pascale, M. P.; Reali, E. [Dipartimento di Fisica and Centro NAST, Universita degli Studi di Roma Tor Vergata, Via della Ricerca Scientifica 1, 00133, Roma (Italy); Grazzi, F. [Istituto dei Sistemi Complessi-Consiglio Nazionale delle Ricerche, Via Madonna del Piano n.10, I-50019 Sesto Fiorentino, Firenze (Italy); Schooneveld, E. M. [ISIS Facility, Rutherford Appleton Laboratory, Chilton, Didcot, Oxfordshire, OX11 0QX (United Kingdom)

2009-09-15T23:59:59.000Z

331

Physics Analyses in the Design of the HFIR Cold Neutron Source  

SciTech Connect (OSTI)

Physics analyses have been performed to characterize the performance of the cold neutron source to be installed in the High Flux Isotope Reactor at the Oak Ridge National Laboratory in the near future. This paper provides a description of the physics models developed, and the resulting analyses that have been performed to support the design of the cold source. These analyses have provided important parametric performance information, such as cold neutron brightness down the beam tube and the various component heat loads, that have been used to develop the reference cold source concept.

Bucholz, J.A.

1999-09-27T23:59:59.000Z

332

Neutron beam characterization at the Neutron Radiography Reactor (NRAD)  

SciTech Connect (OSTI)

The Neutron Radiography Reactor (NRAD) is a 250-kW TRIGA Reactor operated by Argonne National Laboratory and is located near Idaho Falls, Idaho. The reactor and its facilities regarding radiography are detailed in another paper at this conference; this paper summarizes neutron flux measurements and calculations that have been performed to better understand and potentially improve the neutronics characteristics of the reactor.

Imel, G.R.; Urbatsch, T.; Pruett, D.P.; Ross, J.R.

1990-01-01T23:59:59.000Z

333

Measurements Of Spin Observables In Pseudoscalar-Meson Photo-Production Using Polarized Neutrons In Solid HD  

SciTech Connect (OSTI)

Psuedo-scalar meson photo production measurements have been carried out with longitudinally-polarized neutrons using the circularly and linearly polarized photon beams and the CLAS at Thomas Jefferson National Accelerator Facility (Jlab). The experiment aims to obtain a complete set of spin observables on an efficient neutron target. Preliminary E asymmetries for the exclusive reaction, gamma + n(p)--> pi- + p(p), selecting quasi free neutron kinematics are discussed.

Kageya, Tsuneo

2014-01-01T23:59:59.000Z

334

Sulphidation resistance of composite boiler tube materials  

SciTech Connect (OSTI)

A lab-based testing program was undertaken to generate data to better define the sulphidation resistance of composite tubes installed in the lower-furnace section of black liquor recovery boilers. All composite tube cladding alloys tested were observed to have an acceptable corrosion rate at normal operating temperatures (up to 400 C) in the synthetic lower-furnace gaseous environment tested (1% H{sub 2}S-99% N{sub 2}). This acceptable corrosion resistance is due to the expected formation of a relatively protective chromium-rich inner sulphide scale. An increase in temperature up to 560 C was found to significantly increase the corrosion rate. Of the various alloys tested, Alloy HR11N exhibited the lowest corrosion rate at each of the three temperatures tested. Moreover, the corrosion rate was found not to be strongly dependent on the fabrication route (weld overlay versus co-extruded). To minimize corrosion, operating conditions that promote prolonged exposure to elevated temperatures in the lower-furnace section of black liquor recovery boilers should be avoided, regardless of the type of composite tube installed.

Kish, Joseph [McMaster University; Eng, Philip [FPInnovations; Singbeil, Douglas [FPInnovations; Keiser, James R [ORNL

2008-01-01T23:59:59.000Z

335

Tube cutter tool and method of use for coupon removal  

DOE Patents [OSTI]

A tube cutter tool is insertable into a tube for cutting a coupon from a damaged site on the exterior of the tube. Prior to using the tool, the damaged site is first located from the interior of the tube using a multi-coil pancake eddy current test probe. The damaged site is then marked. A fiber optic probe is used to monitor the subsequent cutting procedure which is performed using a hole saw mounted on the tube cutter tool. Prior to completion of the cutting procedure, a drill in the center of the hole saw is drilled into the coupon to hold it in place. 4 figs.

Nachbar, H.D.; Etten, M.P. Jr.; Kurowski, P.A.

1997-05-06T23:59:59.000Z

336

Recirculating wedges for metal-vapor plasma tubes  

DOE Patents [OSTI]

A metal vapor laser is disclosed that recycles condensed metal located at the terminal ends of a plasma tube back toward the center of the tube. A pair of arcuate wedges are incorporated on the bottom of the plasma tube near the terminal ends. The wedges slope downward toward the center so that condensed metal may be transported under the force of gravity away from the terminal ends. The wedges are curved to fit the plasma tube to thereby avoid forming any gaps within the tube interior.

Hall, Jerome P. (Livermore, CA); Sawvel, Robert M. (Modesto, CA); Draggoo, Vaughn G. (Livermore, CA)

1994-01-01T23:59:59.000Z

337

Recirculating wedges for metal-vapor plasma tubes  

DOE Patents [OSTI]

A metal vapor laser is disclosed that recycles condensed metal located at the terminal ends of a plasma tube back toward the center of the tube. A pair of arcuate wedges are incorporated on the bottom of the plasma tube near the terminal ends. The wedges slope downward toward the center so that condensed metal may be transported under the force of gravity away from the terminal ends. The wedges are curved to fit the plasma tube to thereby avoid forming any gaps within the tube interior. 8 figures.

Hall, J.P.; Sawvel, R.M.; Draggoo, V.G.

1994-06-28T23:59:59.000Z

338

Magnetically attached sputter targets  

DOE Patents [OSTI]

An improved method and assembly for attaching sputtering targets to cathode assemblies of sputtering systems which includes a magnetically permeable material is described. The magnetically permeable material is imbedded in a target base that is brazed, welded, or soldered to the sputter target, or is mechanically retained in the target material. Target attachment to the cathode is achieved by virtue of the permanent magnets and/or the pole pieces in the cathode assembly that create magnetic flux lines adjacent to the backing plate, which strongly attract the magnetically permeable material in the target assembly. 11 figures.

Makowiecki, D.M.; McKernan, M.A.

1994-02-15T23:59:59.000Z

339

Personnel electronic neutron dosimeter  

DOE Patents [OSTI]

A personnel electronic dosimeter includes a neutron-proton and neutron-alpha converter for providing an electrical signal having a magnitude proportional to the energy of a detected proton or alpha particle produced from the converter, a pulse generator circuit for generating a pulse having a duration controlled by the weighed effect of the amplitude of the electrical signal, an oscillator enabled by the pulse for generating a train of clock pulses for a time dependent upon the pulse length, a counter for counting the clock pulses, and an indicator for providing a direct reading and aural alarm when the count indicates that the wearer has been exposed to a selected level of neutron dose equivalent.

Falk, Roger B. (Lafayette, CO); Tyree, William H. (Boulder, CO)

1984-12-18T23:59:59.000Z

340

Personnel electronic neutron dosimeter  

DOE Patents [OSTI]

A personnel electronic dosimeter includes a neutron-proton and neutron-alpha converter for providing an electrical signal having a magnitude proportional to the energy of a detected proton or alpha particle produced from the converter, a pulse generator circuit for generating a pulse having a duration controlled by the weighed effect of the amplitude of the electrical signal, an oscillator enabled by the pulse for generating a train of clock pulses for a time dependent upon the pulse length, a counter for counting the clock pulses, and an indicator for providing a direct reading and aural alarm when the count indicates that the wearer has been exposed to a selected level of neutron dose equivalent.

Falk, R.B.; Tyree, W.H.

1982-03-03T23:59:59.000Z

Note: This page contains sample records for the topic "neutron tube target" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


341

Neutron Scattering Tutorials | Neutron Science | ORNL  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr MayAtmosphericNuclear Security Administration the Contributions andDataNational Library of1, 2007Transmission toBeamNDiscoveryNeutron

342

Corrosion resistant neutron absorbing coatings  

DOE Patents [OSTI]

A method of forming a corrosion resistant neutron absorbing coating comprising the steps of spray or deposition or sputtering or welding processing to form a composite material made of a spray or deposition or sputtering or welding material, and a neutron absorbing material. Also a corrosion resistant neutron absorbing coating comprising a composite material made of a spray or deposition or sputtering or welding material, and a neutron absorbing material.

Choi, Jor-Shan; Farmer, Joseph C; Lee, Chuck K; Walker, Jeffrey; Russell, Paige; Kirkwood, Jon; Yang, Nancy; Champagne, Victor

2013-11-12T23:59:59.000Z

343

Corrosion resistant neutron absorbing coatings  

DOE Patents [OSTI]

A method of forming a corrosion resistant neutron absorbing coating comprising the steps of spray or deposition or sputtering or welding processing to form a composite material made of a spray or deposition or sputtering or welding material, and a neutron absorbing material. Also a corrosion resistant neutron absorbing coating comprising a composite material made of a spray or deposition or sputtering or welding material, and a neutron absorbing material.

Choi, Jor-Shan (El Cerrito, CA); Farmer, Joseph C. (Tracy, CA); Lee, Chuck K. (Hayward, CA); Walker, Jeffrey (Gaithersburg, MD); Russell, Paige (Las Vegas, NV); Kirkwood, Jon (Saint Leonard, MD); Yang, Nancy (Lafayette, CA); Champagne, Victor (Oxford, PA)

2012-05-29T23:59:59.000Z

344

Guided wave acoustic monitoring of corrosion in recovery boiler tubing  

SciTech Connect (OSTI)

Corrosion of tubing used in black-liquor recovery boilers is a major concern in all pulp and paper mills. Extensive corrosion in recovery boiler tubes can result in a significant safety and environmental hazard. Considerable plant resources are expended to inspect recovery boiler tubing. Currently, visual and ultrasonic inspections are primarily used during the annual maintenance shutdown to monitor corrosion rates and cracking of tubing. This Department of Energy, Office of Industrial Technologies project is developing guided acoustic waves for use on recovery boiler tubing. The feature of this acoustic technique is its cost-effectiveness in inspecting long lengths of tubes from a single inspection point. A piezoelectric or electromagnetic transducer induces guided waves into the tubes. The transducer detects fireside defects from the coldside or fireside of the tube. Cracking and thinning on recovery boiler tubes have been detected with this technique in both laboratory and field applications. This technique appears very promising for recovery boiler tube application, potentially expediting annual inspection of tube integrity.

Quarry, M J; Chinn, D J

2004-02-19T23:59:59.000Z

345

Fast neutron dosimetry  

SciTech Connect (OSTI)

This progress report concentrates on two major areas of dosimetry research: measurement of fast neutron kerma factors for several elements for monochromatic and white spectrum neutron fields and determination of the response of thermoluminescent phosphors to various ultra-soft X-ray energies and beta-rays. Dr. Zhixin Zhou from the Shanghai Institute of Radiation Medicine, People's Republic of China brought with him special expertise in the fabrication and use of ultra-thin TLD materials. Such materials are not available in the USA. The rather unique properties of these materials were investigated during this grant period.

DeLuca, P.M. Jr.; Pearson, D.W.

1992-01-01T23:59:59.000Z

346

Single-tube thermal and hydraulic tube support test. Volume 2. Appendixes. Final report  

SciTech Connect (OSTI)

The work described in this report (volumes 1 and 2) was an experimental project to measure the inception and extent of dryout or liquid deficient heat transfer and chemical precipitation in presently used steam generator tube-tube support geometries and modified geometries. Since chemical precipitation or concentration may lead to corrosion, this program was planned to find the dependence of dryout and chemical precipitation on geometry, heat flux and fluid conditions. It was found that dryout depended principally on tube support geometry and heat flux. There was little dependence on flow rate, quality and pressure. It was found that certain tube support geometries could produce local dryout which in turn could permit significant chemical concentration. Chemical concentration was not found in the tube support geometries not exhibiting dryout. The interrelationship between the heat and mass transfer processes in the crevices was further demonstrated by comparing the results of an analytic model for predicting the shape of the liquid-vapor interface to the outline of a precipitate pattern resulting from chemical concentration.

Curlee, N.J. Jr.; Baum, A.J.

1981-09-01T23:59:59.000Z

347

Single-tube thermal and hydraulic tube support test. Final report  

SciTech Connect (OSTI)

The work described in this report (volumes 1 and 2) was an experimental project to measure the inception and extent of dryout or liquid deficient heat transfer and chemical precipitation in presently used steam generator tube-tube support geometries and modified geometries. Since chemical precipitation or concentration may lead to corrosion this program was planned to find the dependence of dryout and chemical precipitation on geometry, heat flux and fluid conditions. It was found that dryout depended principally on tube support geometry and heat flux. There was little dependence on flow rate, quality and pressure. It was found that certain tube support geometries could produce local dryout which in turn could permit significant chemical concentration. Chemical concentration was not found in tube support geometries not exhibiting dryout. The interrelationship between the heat and mass transfer processes in the crevices was further demonstrated by comparing the results of an analytic model for predicting the shape of the liquid vapor interface to the outline of a precipitate pattern resulting from chemical concentration.

Curlee, N.J. Jr.; Baum, A.J.

1981-09-01T23:59:59.000Z

348

Synthesis and characterization of Fe(III)-silicate precipitation tubes  

SciTech Connect (OSTI)

Fe(III)-silicate precipitation tubes synthesized through 'silica garden' route have been characterized using a number of analytical techniques including X-ray diffraction, infrared spectroscopy, atomic force microscopy, scanning and transmission electron microscopy. These tubes are brittle and amorphous and are hierarchically built from smaller tubes of 5-10 nm diameters. They remain amorphous at least up to 650 {sup o}C. Crystobalite and hematite are the major phases present in Fe(III)-silicate tubes heated at 850 {sup o}C. Morphology and chemical compositions at the external and internal walls of these tubes are remarkably different. These tubes are porous with high BET surface area of 291.2 m{sup 2}/g. Fe(III)-silicate tubes contain significant amount of physically and chemically bound moisture. They show promise as an adsorbent for Pb(II), Zn(II), and Cr(III) in aqueous medium.

Parmar, K.; Pramanik, A.K. [National Metallurgical Laboratory, Council of Scientific and Industrial Research, Burmamines, Jamshedpur 831007 (India)] [National Metallurgical Laboratory, Council of Scientific and Industrial Research, Burmamines, Jamshedpur 831007 (India); Bandyopadhya, N.R. [Bengal Engineering and Science University, Shibpur, Howrah 711103 (India)] [Bengal Engineering and Science University, Shibpur, Howrah 711103 (India); Bhattacharjee, S., E-mail: santanu@nmlindia.org [National Metallurgical Laboratory, Council of Scientific and Industrial Research, Burmamines, Jamshedpur 831007 (India)

2010-09-15T23:59:59.000Z

349

Optimization of a neutron detector design using adjoint transport simulation  

SciTech Connect (OSTI)

A synthetic aperture approach has been developed and investigated for Special Nuclear Materials (SNM) detection in vehicles passing a checkpoint at highway speeds. SNM is postulated to be stored in a moving vehicle and detector assemblies are placed on the road-side or in chambers embedded below the road surface. Neutron and gamma spectral awareness is important for the detector assembly design besides high efficiencies, so that different SNMs can be detected and identified with various possible shielding settings. The detector assembly design is composed of a CsI gamma-ray detector block and five neutron detector blocks, with peak efficiencies targeting different energy ranges determined by adjoint simulations. In this study, formulations are derived using adjoint transport simulations to estimate detector efficiencies. The formulations is applied to investigate several neutron detector designs for Block IV, which has its peak efficiency in the thermal range, and Block V, designed to maximize the total neutron counts over the entire energy spectrum. Other Blocks detect different neutron energies. All five neutron detector blocks and the gamma-ray block are assembled in both MCNP and deterministic simulation models, with detector responses calculated to validate the fully assembled design using a 30-group library. The simulation results show that the 30-group library, collapsed from an 80-group library using an adjoint-weighting approach with the YGROUP code, significantly reduced the computational cost while maintaining accuracy. (authors)

Yi, C.; Manalo, K.; Huang, M.; Chin, M.; Edgar, C.; Applegate, S.; Sjoden, G. [Georgia Inst. of Technology, Gilhouse Boggs Bldg., 770 State St, Atlanta, GA 30332-0745 (United States)

2012-07-01T23:59:59.000Z

350

Current status of boron neutron capture therapy of high grade gliomas and recurrent head and neck cancer  

E-Print Network [OSTI]

Boron neutron capture therapy (BNCT) is a biochemically targeted radiotherapy based on the nuclear capture and fission reactions that occur when non-radioactive boron-10, which is a constituent of natural elemental boron, ...

Barth, Rolf F

351

In the Target Area  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

8 22 | Next | Last Back to Index NIF Target A NIF target contains a polished capsule about two millimeters in diameter, filled with cryogenic (super-cooled) hydrogen fuel. Photo...

352

In the Target Area  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

5 22 | Next | Last Back to Index NIF Target Chamber This view from the bottom of the chamber shows the target positioner being inserted. Pulses from NIF's high-powered lasers...

353

In the Target Area  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

9 22 | Next | Last Back to Index NIF Hohlraum A metallic case called a hohlraum holds the fuel capsule for NIF experiments. Target handling systems precisely position the target...

354

In the Target Area  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

3 22 | Next | Last Back to Index NIF Target Chamber Temperatures of 100 million degrees and pressures extreme enough to compress the target to densities up to 100 times the...

355

In the Target Area  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

to Index Target Chamber Viewing Window A new viewing window recently installed on the NIF Target Chamber will allow members of the NIF team and visitors to see inside the...

356

Neutron Activation of NIF Final Optics Assemblies  

SciTech Connect (OSTI)

Analyses were performed to characterize the radiation field in the vicinity of the Final Optics Assemblies (FOAs) at the National Ignition Facility (NIF) due to neutron activation following Deuterium-Deuterium (DD), Tritium-Hydrogen-Deuterium (THD), and Deuterium-Tritium (DT) shots associated with different phases of the NIF operations. The activation of the structural components of the FOAs produces one of the larger sources of gamma radiation and is a key factor in determining the stay out time between shots to ensure worker protection. This study provides estimates of effective dose rates in the vicinity of a single FOA and concludes that the DD and THD targets produce acceptable dose rates within 10 minutes following a shot while about 6-days of stay out time is suggested following DT shots. Studies are ongoing to determine the combined effects of multiple FOAs and other components present in the Target Bay on stay-out time and worker dose.

Sitaraman, S; Dauffy, L; Khater, H; Brereton, S

2009-09-29T23:59:59.000Z

357

Thermal Neutron Capture y's (CapGam)  

DOE Data Explorer [Office of Scientific and Technical Information (OSTI)]

The National Nuclear Data Center (NNDC) presents two tables showing energy and photon intensity with uncertainties of gamma rays as seen in thermal-neutron capture.  One table is organized in ascending order of gamma energy, and the second is organized by Z, A of the target. In the energy-ordered table the three strongest transitions are indicated in each case. The nuclide given is the target nucleus in the capture reaction. The gamma energies given are in keV. The gamma intensities given are relative to 100 for the strongest transition. %I? (per 100 n-captures) for the strongest transition is given, where known. All data are taken from the Evaluated Nuclear Structure Data File (ENSDF), a computer file of evaluated nuclear structure data and from the eXperimental Unevaluated Nuclear Data List (XUNDL). (Specialized Interface)

358

Neutrino Factory Target Cryostat  

E-Print Network [OSTI]

SC-2 SC-3 SC-4 SC-5 Window Nozzle Tube Mercury Drains Proton Beam Mercury Pool Water-cooled Tungsten · Remote handling of these modules t t i i lnot trivial · Note slot in shielding module for mercury Aug 2010 #12;Assembled Cryostat · Resistive magnet leads & water cooling for& water cooling

McDonald, Kirk

359

High Power Cryogenic Targets  

SciTech Connect (OSTI)

The development of high power cryogenic targets for use in parity violating electron scattering has been a crucial ingredient in the success of those experiments. As we chase the precision frontier, the demands and requirements for these targets have grown accordingly. We discuss the state of the art, and describe recent developments and strategies in the design of the next generation of these targets.

Gregory Smith

2011-08-01T23:59:59.000Z

360

Neutron Absorbing Alloys  

DOE Patents [OSTI]

The present invention is drawn to new classes of advanced neutron absorbing structural materials for use in spent nuclear fuel applications requiring structural strength, weldability, and long term corrosion resistance. Particularly, an austenitic stainless steel alloy containing gadolinium and less than 5% of a ferrite content is disclosed. Additionally, a nickel-based alloy containing gadolinium and greater than 50% nickel is also disclosed.

Mizia, Ronald E. (Idaho Falls, ID); Shaber, Eric L. (Idaho Falls, ID); DuPont, John N. (Whitehall, PA); Robino, Charles V. (Albuquerque, NM); Williams, David B. (Bethlehem, PA)

2004-05-04T23:59:59.000Z

Note: This page contains sample records for the topic "neutron tube target" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


361

Solid state neutron detector array  

DOE Patents [OSTI]

A neutron detector array is capable of measuring a wide range of neutron fluxes. The array includes multiple semiconductor neutron detectors. Each detector has a semiconductor active region that is resistant to radiation damage. In one embodiment, the array preferably has a relatively small size, making it possible to place the array in confined locations. The ability of the array to detect a wide range of neutron fluxes is highly advantageous for many applications such as detecting neutron flux during start up, ramp up and full power of nuclear reactors. 7 figs.

Seidel, J.G.; Ruddy, F.H.; Brandt, C.D.; Dulloo, A.R.; Lott, R.G.; Sirianni, E.; Wilson, R.O.

1999-08-17T23:59:59.000Z

362

Solid state neutron detector array  

DOE Patents [OSTI]

A neutron detector array is capable of measuring a wide range of neutron fluxes. The array includes multiple semiconductor neutron detectors. Each detector has a semiconductor active region that is resistant to radiation damage. In one embodiment, the array preferably has a relatively small size, making it possible to place the array in confined locations. The ability of the array to detect a wide range of neutron fluxes is highly advantageous for many applications such as detecting neutron flux during start up, ramp up and full power of nuclear reactors.

Seidel, John G. (Pittsburgh, PA); Ruddy, Frank H. (Monroeville, PA); Brandt, Charles D. (Mount Lebanon, PA); Dulloo, Abdul R. (Pittsburgh, PA); Lott, Randy G. (Pittsburgh, PA); Sirianni, Ernest (Monroeville, PA); Wilson, Randall O. (Greensburg, PA)

1999-01-01T23:59:59.000Z

363

Dose-equivalent neutron dosimeter  

DOE Patents [OSTI]

A neutron dosimeter is disclosed which provides a single measurement indicating the amount of potential biological damage resulting from the neutron exposure of the wearer, for a wide range of neutron energies. The dosimeter includes a detecting sheet of track etch detecting material such as a carbonate plastic, for detecting higher energy neutrons, and a radiator layer contaning conversion material such as /sup 6/Li and /sup 10/B lying adjacent to the detecting sheet for converting moderate energy neutrons to alpha particles that produce tracks in the adjacent detecting sheet.

Griffith, R.V.; Hankins, D.E.; Tomasino, L.; Gomaa, M.A.M.

1981-01-07T23:59:59.000Z

364

Breeder-in-tube design for a helium-cooled Li/sub 2/O tokamak blanket  

SciTech Connect (OSTI)

Of the solid breeder designs considered in the Blanket Comparison and Selection Study (BCSS), the lithium oxide breeder with helium coolant and ferritic steel (HT-9) structural material received the highest overall ranking for both tokamak and tandem mirror systems in terms of engineering, economics, safety, and R and D requirements. The BCSS blanket surrounding the fusion plasma consists of a number of thin breeder plates externally cooled by flowing helium and internally purged of tritium by a separate helium stream. A detailed review of this design indicated that significant improvements would be realized in the areas of tritium breeding, blanket thickness, blanket energy multiplication, power-conversion efficiency, breeder temperature window, and geometrical integrity of the coolant and purge paths by using a neutron multiplier (beryllium), a higher temperature structural material (vanadium-based alloy), and a tube geometry. The neutronics, thermal-hydraulics, tritium recovery, and structural performance characteristics of this innovative solid breeder design are discussed in this paper.

Billone, M.C.; Jung, J.; Liu, Y.Y.; Smith, D.L.

1986-01-01T23:59:59.000Z

365

Fuel cell tubes and method of making same  

DOE Patents [OSTI]

A method of manufacturing porous ceramic tubes for fuel cells with improved properties and higher manufacturing yield is disclosed. The method involves extruding a closed end fuel cell tube, such as an air electrode of a solid oxide fuel cell, in which the closed end also functions as the sintering support. The resultant fuel cell tube has a superior porosity distribution which allows improved diffusion of oxygen at the closed end of the tube during operation of the fuel cell. Because this region has the highest current density, performance enhancement and improved reliability of the fuel cell tube result. Furthermore, the higher manufacturing yield associated with the present method decreases the overall fuel cell cost. A method of manufacturing porous ceramic tubes for fuel cells with improved properties and higher manufacturing yield is disclosed. The method involves extruding a closed end fuel cell tube, such as an air electrode of a solid oxide fuel cell, in which the closed end also functions as the sintering support. The resultant fuel cell tube has a superior porosity distribution which allows improved diffusion of oxygen at the closed end of the tube during operation of the fuel cell. Because this region has the highest current density, performance enhancement and improved reliability of the fuel cell tube result. Furthermore, the higher manufacturing yield associated with the present method decreases the overall fuel cell cost.

Borglum, Brian P. (Edgewood, PA)

1999-11-30T23:59:59.000Z

366

Multi-Grid Boron-10 detector for large area applications in neutron scattering science  

E-Print Network [OSTI]

The present supply of 3He can no longer meet the detector demands of the upcoming ESS facility and continued detector upgrades at current neutron sources. Therefore viable alternative technologies are required to support the development of cutting-edge instrumentation for neutron scattering science. In this context, 10B-based detectors are being developed by collaboration between the ESS, ILL, and Link\\"{o}ping University. This paper reports on progress of this technology and the prospects applying it in modern neutron scattering experiments. The detector is made-up of multiple rectangular gas counter tubes coated with B4C, enriched in 10B. An anode wire reads out each tube, thereby giving position of conversion in one of the lateral co-ordinates as well as in depth of the detector. Position resolution in the remaining co-ordinate is obtained by segmenting the cathode tube itself. Boron carbide films have been produced at Link\\"{o}ping University and a detector built at ILL. The characterization study is presented in this paper, including measurement of efficiency, effects of the fill gas species and pressure, coating thickness variation on efficiency and sensitivity to gamma-rays.

Ken Andersen; Thierry Bigault; Jens Birch; Jean-Claude Buffet; Jonathan Correa; Patrick van Esch; Bruno Guerard; Richard Hall-Wilton; Lars Hultman; Carina Höglund; Jens Jensen; Anton Khaplanov; Oliver Kirstein; Francesco Piscitelli; Christian Vettier

2012-09-04T23:59:59.000Z

367

Effects of grids in drift tubes  

SciTech Connect (OSTI)

In 2011, we upgraded a 201 MHz buncher in the proton injector for the alternating gradient synchrotron (AGS) - relativistic heavy ion collider (RHIC) complex. In the buncher we installed four grids made of tungsten to improve the transit time factor. The grid installed drift tubes have 32 mm of inner diameter and the each grid consists of four quadrants. The quadrants were cut out precisely from 1mm thick tungsten plates by a computerized numerically controlled (CNC) wire cutting electrical discharge machining (EDM). The 3D electric field of the grid was simulated.

Okamura M.; Yamauchi, H.

2012-05-20T23:59:59.000Z

368

Sound Coiled-Tubing Drilling Practices  

SciTech Connect (OSTI)

This Coiled-Tubing Drilling (CTD) Sound Practices Manual provides tools needed by CTD engineers and supervisors to plan, design and perform safe, successful CTD operations. As emphasized throughout, both careful planning and attention to detail are mandatory for success. A bibliography of many useful CTD references is presented in Chapter 6. This manual is organized according to three processes: 1) Pre-Job Planning Process, 2) Operations Execution Process, and 3) Post-Job Review Process. Each is discussed in a logical and sequential format.

Williams, Thomas; Deskins, Greg (Maurer Technology Inc.); Ward, Stephen L. (Advantage Energy Services Ltd); Hightower, Mel

2001-09-30T23:59:59.000Z

369

A thermionic tube power change indicator  

E-Print Network [OSTI]

, the a - c component of which Is: =~, P wa~e +82 e+aP z 3 4 (1) Relating Eq. 1 to Fig. 1, the e Is a function of eg and eb, the Instantaneous total anode voltage. The coefficients are various combinations of the tube impedance, its derivat- ives... Is applied to Fig. 1, e is e = )leg + eb Often a d-c gri. d bias voltage, Ecc, is applied to the grid circuit in order to use another portion of the trans- fer curve. Fig. 3 shows such a c ircuit wi th this type of grid bias applied. e~ c~ &cc Fig. 3...

Cook, James Marvin

1952-01-01T23:59:59.000Z

370

YouTube | Department of Energy  

Energy Savers [EERE]

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels Data Center Home Page on Delicious RankCombustion |Energy UsageAUDITVehiclesTankless or Demand-TypeWelcome toFarm Growth ThroughWomenYouTube

371

Drift Tube Linac Conditioning of Tank1  

E-Print Network [OSTI]

Tank1 of the Drift Tube Linac (DTL) of the Linac4 has been conditioned at the Linac4 tunnel. The tank was tuned for resonance at 352.2 MHz, and stable operation has been achieved with 725 µs long RF pulses at a repetition rate of 1 Hz. The maximum RF level that has been reached is 810 kW with a pulse width of 600 µs. Since this was the first RF structure exclusively conditioned in the Linac4 tunnel with the operation and control software of Linac4, some related issues and limitations had to be taken into account.

Shafqat, N; Toor, W A

2014-01-01T23:59:59.000Z

372

Widget:YouTube | Open Energy Information  

Open Energy Info (EERE)

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels Data Center Home5b9fcbce19 NoPublic Utilities Address: 160 East 300 South Place:ReferenceEdit Jump to:UtilityRateFinder JumpVimeo JumpYouTube

373

Flow mapping for an ESS horizontal target  

SciTech Connect (OSTI)

In the target of the European spallation neutron source (ESS), the beam line is horizontal and the mercury is fully forced by a pump in a parallel channel geometry. The top front of the assembly is a hemicylindrical wall, where the beam enters and is thus called a window. The main body is partitioned by a horizontal separation plate into the upper and the lower flow channels. The target liquid flows in the lower channel to the window region, turns there, and flows out in the upper channel. A thermal-hydraulic study is under way to investigate the general behavior of the flow in this configuration. The present experimental work is the first step of an effort to validate computer codes. The model used in this investigation is two-dimensional and uses water.

Takeda, Y.; Kikura, H.; Taishi, T. [Paul Scherrer Institute, Villigen (Switzerland)

1997-12-01T23:59:59.000Z

374

Search for neutron - mirror neutron oscillations in a laboratory experiment with ultracold neutrons  

E-Print Network [OSTI]

Mirror matter is considered as a candidate for dark matter. In connection with this an experimental search for neutron - mirror neutron (nn') transitions has been carried out using storage of ultracold neutrons in a trap with different magnetic fields. As a result, a new limit for the neutron - mirror neutron oscillation time has been obtained, tau_osc >= 448 s (90% C.L.), assuming that there is no mirror magnetic field larger than 100 nT. Besides a first attempt to obtain some restriction for mirror magnetic field has been done.

A. P. Serebrov; E. B. Aleksandrov; N. A. Dovator; S. P. Dmitriev; A. K. Fomin; P. Geltenbort; A. G. Kharitonov; I. A. Krasnoschekova; M. S. Lasakov; A. N. Murashkin; G. E. Shmelev; V. E. Varlamov; A. V. Vassiljev; O. M. Zherebtsov; O. Zimmer

2008-09-29T23:59:59.000Z

375

Method and apparatus for optimized sampling of volatilizable target substances  

DOE Patents [OSTI]

An apparatus for capturing, from gases such as soil gas, target analytes. Target analytes may include emanations from explosive materials or from residues of explosive materials. The apparatus employs principles of sorption common to solid phase microextraction, and is best used in conjunction with analysis means such as a gas chromatograph. To sorb target analytes, the apparatus functions using various sorptive structures to capture target analyte. Depending upon the embodiment, those structures may include a capillary tube including an interior surface on which sorptive material (similar to that on the surface of a SPME fiber) is supported (along with means for moving gases through the capillary tube so that the gases come into close proximity to the sorptive material). In one disclosed embodiment, at least one such sorptive structure is associated with an enclosure including an opening in communication with the surface of a soil region potentially contaminated with buried explosive material such as unexploded ordnance. Emanations from explosive materials can pass into and accumulate in the enclosure where they are sorbed by the sorptive structures. Also disclosed is the use of heating means such as microwave horns to drive target analytes into the soil gas from solid and liquid phase components of the soil.

Lindgren, Eric R.; Phelan, James M.

2004-10-12T23:59:59.000Z

376

Dynamics of Magnetized Vortex Tubes in the Solar Chromosphere  

E-Print Network [OSTI]

We use 3D radiative MHD simulations to investigate the formation and dynamics of small-scale (less than 0.5 Mm in diameter) vortex tubes spontaneously generated by turbulent convection in quiet-Sun regions with initially weak mean magnetic fields. The results show that the vortex tubes penetrate into the chromosphere and substantially affect the structure and dynamics of the solar atmosphere. The vortex tubes are mostly concentrated in intergranular lanes and are characterized by strong (near sonic) downflows and swirling motions that capture and twist magnetic field lines, forming magnetic flux tubes that expand with height and which attain magnetic field strengths ranging from 200 G in the chromosphere to more than 1 kG in the photosphere. We investigate in detail the physical properties of these vortex tubes, including thermodynamic properties, flow dynamics, and kinetic and current helicities, and conclude that magnetized vortex tubes provide an important path for energy and momentum transfer from the con...

Kitiashvili, I N; Mansour, N N; Wray, A A

2012-01-01T23:59:59.000Z

377

Effects On Beam Alignment Due To Neutron-Irradiated CCD Images At The National Ignition Facility  

SciTech Connect (OSTI)

The 192 laser beams in the National Ignition Facility (NIF) are automatically aligned to the target-chamber center using images obtained through charged coupled device (CCD) cameras. Several of these cameras are in and around the target chamber during an experiment. Current experiments for the National Ignition Campaign are attempting to achieve nuclear fusion. Neutron yields from these high energy fusion shots expose the alignment cameras to neutron radiation. The present work explores modeling and predicting laser alignment performance degradation due to neutron radiation effects, and demonstrates techniques to mitigate performance degradation. Camera performance models have been created based on the measured camera noise from the cumulative single-shot fluence at the camera location. We have found that the effect of the neutron-generated noise for all shots to date have been well within the alignment tolerance of half a pixel, and image processing techniques can be utilized to reduce the effect even further on the beam alignment.

Awwal, A; Manuel, A; Datte, P; Burkhart, S

2011-02-28T23:59:59.000Z

378

Production cross sections of neutron rich isotopes from a 82Se beam  

E-Print Network [OSTI]

Production cross sections for neutron-rich nuclei from the fragmentation of a 82Se beam at 139 MeV/u were measured. The longitudinal momentum distributions of 122 neutron-rich isotopes of elements $11 \\le Z \\le 32$ were determined by varying the target thickness. Production cross sections with beryllium and tungsten targets were determined for a large number of nuclei including several isotopes first observed in this work. These are the most neutron-rich nuclides of the elements $22 \\le Z \\le 25$ (64Ti, 67V, 69Cr, 72Mn). One event was registered consistent with 70Cr, and another one with 75Fe. A one-body Qg systematics is used to describe the production cross sections based on thermal evaporation from excited prefragments. The current results confirm those of our previous experiment with a 76Ge beam: enhanced production cross sections for neutron-rich fragments near Z=20.

Tarasov, O B; Amthor, A M; Bandura, L; Baumann, T; Bazin, D; Berryman, J S; Chubarian, G; Fukuda, N; Gade, A; Ginter, T N; Hausmann, M; Inabe, N; Kubo, T; Pereira, J; Portillo, M; Sherrill, B M; Stolz, A; Sumithrarachchi, C; Thoennessen, M; Weisshaar, D

2012-01-01T23:59:59.000Z

379

Production cross sections of neutron rich isotopes from a 82Se beam  

E-Print Network [OSTI]

Production cross sections for neutron-rich nuclei from the fragmentation of a 82Se beam at 139 MeV/u were measured. The longitudinal momentum distributions of 122 neutron-rich isotopes of elements $11 \\le Z \\le 32$ were determined by varying the target thickness. Production cross sections with beryllium and tungsten targets were determined for a large number of nuclei including several isotopes first observed in this work. These are the most neutron-rich nuclides of the elements $22 \\le Z \\le 25$ (64Ti, 67V, 69Cr, 72Mn). One event was registered consistent with 70Cr, and another one with 75Fe. A one-body Qg systematics is used to describe the production cross sections based on thermal evaporation from excited prefragments. The current results confirm those of our previous experiment with a 76Ge beam: enhanced production cross sections for neutron-rich fragments near Z=20.

O. B. Tarasov; D. J. Morrissey; A. M. Amthor; L. Bandura; T. Baumann; D. Bazin; J. S. Berryman; G. Chubarian; N. Fukuda; A. Gade; T. N. Ginter; M. Hausmann; N. Inabe; T. Kubo; J. Pereira; M. Portillo; B. M. Sherrill; A. Stolz; C. Sumithrarachchi; M. Thoennessen; D. Weisshaar

2012-09-06T23:59:59.000Z

380

Preconceptual design of a Long-Pulse Spallation Source (LPSS) at the LANSCE Facility: Target system, facility, and material handling considerations  

SciTech Connect (OSTI)

This report provides a summary of a preconceptual design study for the proposed Long-Pulse Spallation. Source (LPSS) at the Los Alamos Neutron Science Center (LANSCE). The LPSS will use a 0.8-MW proton beam to produce neutrons from a tungsten target. This study focuses on the design of the target station and changes to the existing building that would be made to accommodate the LPSS. The LPSS will provide fifteen flight paths to neutron scattering instruments. In addition, options for generating ultracold neutrons, pions, and muons will be available. Flight-energy, forward-scattered neutrons on the downstream side of the target will also be available for autoradiography studies. A Target Test Bed (TTB) is also proposed for full-beam tests of component materials and advanced spallation neutron sources. The design allows for separation of the experiment hall from the beam line, target, and flight paths. The target and moderator systems and the systems/components to be tested in the TTB will be emplaced and removed separately by remotely operated, shielded equipment. Irradiated materials will be transported to a hot cell adjacent to the target chamber for testing by remotely operated instruments. These tests will provide information about how materials properties are affected by proton and neutron beams.

Sommer, W.F. [comp.

1995-12-01T23:59:59.000Z

Note: This page contains sample records for the topic "neutron tube target" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


381

Casimir effect in hemisphere capped tubes  

E-Print Network [OSTI]

In this paper we investigate the vacuum densities for a massive scalar field with general curvature coupling in background of a (2+1)-dimensional spacetime corresponding to a cylindrical tube with a hemispherical cap. A complete set of mode functions is constructed and the positive-frequency Wightman function is evaluated for both the cylindrical and hemispherical subspaces. On the base of this, the vacuum expectation values of the field squared and energy-momentum tensor are investigated. The mean field squared and the normal stress are finite on the boundary separating two subspaces, whereas the energy density and the parallel stress diverge as the inverse power of the distance from the boundary. For a conformally coupled field, the vacuum energy density is negative on the cylindrical part of the space. On the hemisphere, it is negative near the top and positive close to the boundary. In the case of minimal coupling the energy density on the cup is negative. On the tube it is positive near the boundary and negative at large distances. Though the geometries of the subspaces are different, the Casimir pressures on the separate sides of the boundary are equal and the net Casimir force vanishes. The results obtained may be applied to capped carbon nanotubes described by an effective field theory in the long-wavelength approximation.

E. R. Bezerra de Mello; A. A. Saharian

2014-08-27T23:59:59.000Z

382

A Superluminal Subway The Krasnikov Tube  

E-Print Network [OSTI]

The ``warp drive'' metric recently presented by Alcubierre has the problem that an observer at the center of the warp bubble is causally separated from the outer edge of the bubble wall. Hence such an observer can neither create a warp bubble on demand nor control one once it has been created. In addition, such a bubble requires negative energy densities. One might hope that elimination of the first problem might ameliorate the second as well. We analyze and generalize a metric, originally proposed by Krasnikov for two spacetime dimensions, which does not suffer from the first difficulty. As a consequence, the Krasnikov metric has the interesting property that although the time for a one-way trip to a distant star cannot be shortened, the time for a round trip, as measured by clocks on Earth, can be made arbitrarily short. In our four dimensional extension of this metric, a ``tube'' is constructed along the path of an outbound spaceship, which connects the Earth and the star. Inside the tube spacetime is flat...

Everett, A E; Everett, Allen E.; Roman, Thomas A.

1997-01-01T23:59:59.000Z

383

Fast neutron spectra produced by a 49 MeV deuteron-beryllium reaction and its modification by selected absorbers  

E-Print Network [OSTI]

. ' ' The determination of 7, 11, 12 neutron energies by time-of-flight techniques fundamentally consists of measuring the elapsed time between production of a neutron in the target and i, ts arrival at the detector location. The straight line distance the neutron... through the collimator, and 2. 73 m from the collimator exit to the detector. 2 2 4 Measurements Neutron energy spectra were measured both on and off the central beam axis using different radiation field sizes A straight bore research collimator...

Hertel, Nolan Elmer

2012-06-07T23:59:59.000Z

384

Local Heat Transfer for Finned-Tube Heat Exchangers using Oval Tubes  

SciTech Connect (OSTI)

This paper presents the results of an experimental study of forced convection heat transfer in a narrow rectangular duct fitted with either a circular tube or an elliptical tube in crossflow. The duct was designed to simulate a single passage in a fin-tube heat exchanger. Heat transfer measurements were obtained using a transient technique in which a heated airflow is suddenly introduced to the test section. High-resolution local fin-surface temperature distributions were obtained at several times after initiation of the transient using an imaging infrared camera. Corresponding local fin-surface heat transfer coefficient distributions were then calculated from a locally applied one-dimensional semi-infinite inverse heat conduction model. Heat transfer results were obtained over an airflow rate ranging from 1.56 x 10-3 to 15.6 x 10-3 kg/s. These flow rates correspond to a duct-height Reynolds number range of 630 – 6300 with a duct height of 1.106 cm and a duct width-toheight ratio, W/H, of 11.25. The test cylinder was sized such that the diameter-to-duct height ratio, D/H is 5. The elliptical tube had an aspect ratio of 3:1 and a/H equal to 4.33. Results presented in this paper reveal visual and quantitative details of local fin-surface heat transfer distributions in the vicinity of circular and oval tubes and their relationship to the complex horseshoe vortex system that forms in the flow stagnation region. Fin surface stagnation-region Nusselt numbers are shown to be proportional to the square-root of Reynolds number.

O'Brien, James Edward; Sohal, Manohar Singh

2000-08-01T23:59:59.000Z

385

Penetrameter positioner for bore-side radiography of tubes  

DOE Patents [OSTI]

A positioner is provided for placing plaque or wire penetrameters, as used in radiographic inspection, in close proximity with the inner wall of tubing at any desired location along the tubing. The positioner head carrying the penetrameter is inflatable whereby it is positioned in tte deflated condition, inflated to place the penetrameter against a weld to be inspected in the tubing wall, and then deflated during removal. If desired, the penetrameter holder may be used to center the radiographic source on the axis of the tube.

Davis, E.V.; Foster, B.E.

1980-02-05T23:59:59.000Z

386

Method Of Making Closed End Ceramic Fuel Cell Tubes  

DOE Patents [OSTI]

A method of manufacturing closed end ceramic fuel cell tubes with improved properties and higher manufacturing yield is disclosed. The method involves bonding an unfired cap to a hollow unfired tube to form a compound joint. The assembly is then fired to net shape without subsequent machining. The resultant closed end tube is superior in that it provides a leak-tight seal and its porosity is substantially identical to that of the tube wall. The higher manufacturing yield associated with the present method decreases overall fuel cell cost significantly.

Borglum, Brian P. (Edgewood, PA)

2002-04-30T23:59:59.000Z

387

Failure of extruded magnesium alloy tubes during hydroforming.  

E-Print Network [OSTI]

??Research is currently being conducted on the feasibility of hydroforming extruded magnesium tubes to integrate multiple parts into a single hydroformed section. Among other advantages,… (more)

Hiscocks, Jessica.

2006-01-01T23:59:59.000Z

388

Energy Separation And Lox Separation Studies In Vortex Tubes.  

E-Print Network [OSTI]

??Vortex Tube (VT) is a simple device having no moving mechanical parts, in which compressed gas at high pressure is injected through one or more… (more)

Behera, Upendra

2011-01-01T23:59:59.000Z

389

AB Electronic Tubes and Quasi-Superconductivity at Room Temperature  

E-Print Network [OSTI]

Author offers and researches a new idea - filling tubes by electronic gases. He shows: If the insulating envelope (cover) of the tube is charged positively, the electrons within the tube are not attracted to covering. Tube (as a whole) remains a neutral (uncharged) body. The electron gas in the tube has very low density and very high conductivity, close to superconductivity. If we take the density (pressure) of electron gas as equal to atmospheric pressure, the thickness of insulator film may be very small and the resulting tube is very light. Author shows the offered tubes can be applied to many technical fields. For example: (1) Transfer of energy over very long distance with very small electric losses. (2) Design of cheap high altitude electric lines without masts. (3) Transfer of energy from one continent to another continent through the ionosphere. (4) Transfer of a plasma beam (which can convey thrust and energy) from Earth surface to a space ship. (5) Observation of the sky by telescope without atmospheric hindrances. (6) Dirigibles (air balloons) of the highest lift force. (7) Increasing of gun range severalfold. (8) Transfer of matter. And so on. Key words: AB tubes, electronic tubes, superconductivity, transmission energy.

Alexander Bolonkin

2008-05-02T23:59:59.000Z

390

Bore tube assembly for steam cooling a turbine rotor  

DOE Patents [OSTI]

An axial bore tube assembly for a turbine is provided to supply cooling steam to hot gas components of the turbine wheels and return the spent cooling steam. A pair of inner and outer tubes define a steam supply passage concentric about an inner return passage. The forward ends of the tubes communicate with an end cap assembly having sets of peripheral holes communicating with first and second sets of radial tubes whereby cooling steam from the concentric passage is supplied through the end cap holes to radial tubes for cooling the buckets and return steam from the buckets is provided through the second set of radial tubes through a second set of openings of the end cap into the coaxial return passage. A radial-to-axial flow transitioning device, including anti-swirling vanes is provided in the end cap. A strut ring adjacent the aft end of the bore tube assembly permits axial and radial thermal expansion of the inner tube relative to the outer tube.

DeStefano, Thomas Daniel (Ballston Lake, NY); Wilson, Ian David (Clifton Park, NY)

2002-01-01T23:59:59.000Z

391

Porous material neutron detector  

DOE Patents [OSTI]

A neutron detector employs a porous material layer including pores between nanoparticles. The composition of the nanoparticles is selected to cause emission of electrons upon detection of a neutron. The nanoparticles have a maximum dimension that is in the range from 0.1 micron to 1 millimeter, and can be sintered with pores thereamongst. A passing radiation generates electrons at one or more nanoparticles, some of which are scattered into a pore and directed toward a direction opposite to the applied electrical field. These electrons travel through the pore and collide with additional nanoparticles, which generate more electrons. The electrons are amplified in a cascade reaction that occurs along the pores behind the initial detection point. An electron amplification device may be placed behind the porous material layer to further amplify the electrons exiting the porous material layer.

Diawara, Yacouba (Oak Ridge, TN); Kocsis, Menyhert (Venon, FR)

2012-04-10T23:59:59.000Z

392

Neutron electric polarizability  

E-Print Network [OSTI]

We use the background field method to extract the "connected" piece of the neutron electric polarizability. We present results for quenched simulations using both clover and Wilson fermions and discuss our experience in extracting the mass shifts and the challenges we encountered when we lowered the quark mass. For the neutron we find that as the pion mass is lowered below $500\\MeV$, the polarizability starts rising in agreement with predictions from chiral perturbation theory. For our lowest pion mass, $m_\\pi=320\\MeV$, we find that $\\alpha_n = 3.8(1.3)\\times 10^{-4}\\fm^3$, which is still only one third of the experimental value. We also present results for the neutral pion; we find that its polarizability turns negative for pion masses smaller than $500\\MeV$ which is puzzling.

Andrei Alexandru; Frank X. Lee

2009-11-13T23:59:59.000Z

393

Fast neutron imaging device and method  

DOE Patents [OSTI]

A fast neutron imaging apparatus and method of constructing fast neutron radiography images, the apparatus including a neutron source and a detector that provides event-by-event acquisition of position and energy deposition, and optionally timing and pulse shape for each individual neutron event detected by the detector. The method for constructing fast neutron radiography images utilizes the apparatus of the invention.

Popov, Vladimir; Degtiarenko, Pavel; Musatov, Igor V.

2014-02-11T23:59:59.000Z

394

Spallation Neutron Sources Around the World  

E-Print Network [OSTI]

Spallation Neutron Sources Around the World Bernie Riemer Thanks to others for the many shamelessly Laboratory #12;2 Managed by UT-Battelle for the U.S. Department of Energy Spallation Neutron Source Facilities Spallation Neutron Source Facilities Serve Neutron Science Programs · Neutron beams to suites

McDonald, Kirk

395

Di-neutron correlation in light neutron-rich nuclei  

E-Print Network [OSTI]

Using a three-body model with density-dependent contact interaction, we discuss the root mean square distance between the two valence neutrons in $^{11}$Li nuclues as a function of the center of mass of the neutrons relative to the core nucleus $^9$Li. We show that the mean distance takes a pronounced minimum around the surface of the nucleus, indicating a strong surface di-neutron correlation. We demonstrate that the pairing correlation plays an essential role in this behavior. We also discuss the di-neutron structure in the $^8$He nucleus.

K. Hagino; H. Sagawa; P. Schuck

2008-12-03T23:59:59.000Z

396

REVIEW OF NON-NEUTRON AND NEUTRON NUCLEAR DATA, 2004.  

SciTech Connect (OSTI)

Review articles are in preparation for the 2004 edition of the CRC Handbook of Chemistry and Physics dealing with the evaluation of both non-neutron and neutron nuclear data. Data on the discovery of element 110, Darmstadtium, and element 111 have been officially accepted, while data on element 11 8 have been withdrawn. Data to be presented include revised values for very short-lived nuclides, long-lived nuclides and beta-beta decay measurements. There has been a reassessment of the spontaneous fission (sf) half-lives, which distinguishes between sf decay half-lives and cluster decay half-lives and with cluster-fission decay. New measurements of isotopic abundance values for many elements will be discussed with an emphasis on the minor isotopes of interest for use in neutron activation analysis measurements. Neutron resonance integrals will be discussed emphasizing the differences between the calculated values obtained from the analytical integration over neutron resonances and the measured values in a neutron reactor-spectrum, which does not quite conform to the assumed 1/E neutron energy spectrum. The method used to determine the neutron resonance integral from measurement, using neutron activation analysis, will be discussed.

HOLDEN, N.E.

2004-09-26T23:59:59.000Z

397

Review of Non-Neutron and Neutron Nuclear Data, 2004  

SciTech Connect (OSTI)

Review articles are in preparation for the 2004 edition of the CRC Handbook of Chemistry and Physics dealing with the evaluation of both non-neutron and neutron nuclear data. Data on the discovery of element 110, Darmstadtium, and element 111 have been officially accepted, while data on element 118 have been withdrawn. Data to be presented include revised values for very short-lived nuclides, long-lived nuclides, and beta-beta decay measurements. There has been a reassessment of the spontaneous fission (sf) half-lives, which distinguishes between sf decay half-lives and cluster decay half-lives, and with cluster-fission decay. New measurements of isotopic abundance values for many elements will be discussed with an emphasis on the minor isotopes of interest for use in neutron activation analysis measurements. Neutron resonance integrals will be discussed emphasizing the differences between the calculated values obtained from the analytical integration over neutron resonances and the measured values in a neutron reactor-spectrum, which does not quite conform to the assumed 1/E neutron energy spectrum. The method used to determine the neutron resonance integral from measurement, using neutron activation analysis, will be discussed.

Holden, Norman E. [National Nuclear Data Center, Brookhaven National Laboratory, Upton, NY 11973-5000 (United States)

2005-05-24T23:59:59.000Z

398

Target Cost Management Strategy  

E-Print Network [OSTI]

Target cost management (TCM) is an innovation of Japanese management accounting system and by common sense has been considered with great interest by practitioners. Nowadays, TCM related

Okano, Hiroshi

1996-01-01T23:59:59.000Z

399

APT {sup 3}He target/blanket. Topical report  

SciTech Connect (OSTI)

The {sup 3}He target/blanket (T/B) preconceptual design for the 3/8-Goal facility is based on a 1000-MeV, 200-mA accelerator to produce a high-intensity proton beam that is expanded and then strikes one of two T/B modules. Each module consists of a centralized neutron source made of tungsten and lead, a proton beam backstop region made of zirconium and lead, and a moderator made of D{sub 2}O. Helium-3 gas is circulated through the neutron source region and the blanket to create tritium through neutron capture. The gas is continually processed to extract the tritium with an online separation process.

NONE

1995-03-01T23:59:59.000Z

400

Hubble Sees a Neutron Star Alone in Space Nearest Known Neutron Star  

E-Print Network [OSTI]

Hubble Sees a Neutron Star Alone in Space Nearest Known Neutron Star #12;Birth of a Neutron Star In the core, nuclei are smashed into protons & neutrons; the protons combine with electrons to make neutrons & neutrinos. The birth temperature of a neutron star is ~5Ă?1011 K, but neutrino emission cools it to `only

Barnes, Joshua Edward

Note: This page contains sample records for the topic "neutron tube target" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


401

RECENT RESULTS OF FUSION INDUCED BY NEUTRON-RICH RADIOACTIVE BEAMS STUDIED AT HRIBF  

SciTech Connect (OSTI)

The reaccelerated fission-fragment beams at HRIBF provide a unique opportunity for studying the mechanisms of fusion involving nuclei with large neutron excess. The fusion excitation functions for neutron-rich ra- dioactive 132Sn incident on 40Ca and 58Ni targets have been measured to explore the role of transfer couplings in sub-barrier fusion enhancement. Evaporation residue cross sections for 124,126,127,128Sn+64Ni were measured to study the dependence of fusion probability on neutron excess.

Liang, J Felix [ORNL] [ORNL

2013-01-01T23:59:59.000Z

402

Production of very neutron-rich nuclei with a 76Ge beam  

E-Print Network [OSTI]

Production cross sections for neutron-rich nuclei from the fragmentation of a 76Ge beam at 132 MeV/u were measured. The longitudinal momentum distributions of 34 neutron-rich isotopes of elements 13 Production cross sections with beryllium and tungsten targets were determined for a large number of nuclei including 15 isotopes first observed in this work. These are the most neutron-rich nuclides of the elements 17 production cross sections based on thermal evaporation from excited prefragments. Some of the fragments near 58Ca show anomalously large production cross sections.

O. B. Tarasov; M. Portillo; A. M. Amthor; T. Baumann; D. Bazin; A. Gade; T. N. Ginter; M. Hausmann; N. Inabe; T. Kubo; D. J. Morrissey; A. Nettleton; J. Pereira; B. M. Sherrill; A. Stolz; M. Thoennessen

2009-08-26T23:59:59.000Z

403

Production of very neutron-rich nuclei with a 76Ge beam  

E-Print Network [OSTI]

Production cross sections for neutron-rich nuclei from the fragmentation of a 76Ge beam at 132 MeV/u were measured. The longitudinal momentum distributions of 34 neutron-rich isotopes of elements 13 Production cross sections with beryllium and tungsten targets were determined for a large number of nuclei including 15 isotopes first observed in this work. These are the most neutron-rich nuclides of the elements 17 production cross sections based on thermal evaporation from excited prefragments. Some of the fragments near 58Ca show anomalously large production cross sections.

Tarasov, O B; Amthor, A M; Baumann, T; Bazin, D; Gade, A; Ginter, T N; Hausmann, M; Inabe, N; Kubo, T; Morrissey, D J; Nettleton, A; Pereira, J; Sherrill, B M; Stolz, A; Thoennessen, M

2009-01-01T23:59:59.000Z

404

Design of a magnetic shielding system for the time of flight enhanced diagnostics neutron spectrometer at Experimental Advanced Superconducting Tokamak  

SciTech Connect (OSTI)

The novel neutron spectrometer TOFED (Time of Flight Enhanced Diagnostics), comprising 90 individual photomultiplier tubes coupled with 85 plastic scintillation detectors through light guides, has been constructed and installed at Experimental Advanced Superconducting Tokamak. A dedicated magnetic shielding system has been constructed for TOFED, and is designed to guarantee the normal operation of photomultiplier tubes in the stray magnetic field leaking from the tokamak device. Experimental measurements and numerical simulations carried out employing the finite element method are combined to optimize the design of the magnetic shielding system. The system allows detectors to work properly in an external magnetic field of 200 G.

Cui, Z. Q.; Chen, Z. J.; Xie, X. F.; Peng, X. Y.; Hu, Z. M.; Du, T. F.; Ge, L. J.; Zhang, X.; Yuan, X.; Fan, T. S.; Chen, J. X.; Li, X. Q., E-mail: lixq2002@pku.edu.cn, E-mail: guohuizhang@pku.edu.cn; Zhang, G. H., E-mail: lixq2002@pku.edu.cn, E-mail: guohuizhang@pku.edu.cn [School of Physics, State Key Lab of Nuclear Physics and Technology, Peking University, Beijing 100871 (China); Xia, Z. W. [Southwestern Institute of Physics, Chengdu 610225 (China); Hu, L. Q.; Zhong, G. Q.; Lin, S. Y.; Wan, B. N. [Institute of Plasma Physics, CAS, Hefei 230031 (China)

2014-11-15T23:59:59.000Z

405

Iodine-129 separation and determination by neutron activation analysis  

SciTech Connect (OSTI)

A method is described for analysis of /sup 129/I in fission product mixtures originating from fuel reprocessing studies and low-level wastes. The method utilizes conventional iodine valence adjustment and solvent extraction techniques to chemically separate /sup 129/I from most fission products. The /sup 129/I is determined by neutron irradiation and measurement of the 12.4 h /sup 130/I produced by the neutron capture reaction. Special techniques were devised for neutron irradiation of /sup 129/I samples in the pneumatic tube irradiation facilities at the High Flux Isotope (HFIR) and Oak Ridge Research (ORR) Reactors. Chemically separated /sup 129/I is adsorbed on an anion exchange resin column made from an irradiation container. The loaded resin is then irradiated in either of the pneumatic facilities to produce /sup 130/I. Sensitivity of the analysis with the HFIR facility (flux: 5 x 10/sup 14/ n/cm/sup 2//sec) and a 100-second irradiation time is approximately 0.03 nanograms. Samples up to 250 ml in volume can be easily processed.

Bate, L.C.; Stokely, J.R.

1981-01-01T23:59:59.000Z

406

Portable neutron spectrometer and dosimeter  

DOE Patents [OSTI]

The disclosure relates to a battery operated neutron spectrometer/dosimeter utilizing a microprocessor, a built-in tissue equivalent LET neutron detector, and a 128-channel pulse height analyzer with integral liquid crystal display. The apparatus calculates doses and dose rates from neutrons incident on the detector and displays a spectrum of rad or rem as a function of keV per micron of equivalent tissue and also calculates and displays accumulated dose in millirads and millirem as well as neutron dose rates in millirads per hour and millirem per hour.

Waechter, David A. (Los Alamos, NM); Erkkila, Bruce H. (Los Alamos, NM); Vasilik, Dennis G. (Los Alamos, NM)

1985-01-01T23:59:59.000Z

407

CHRPR Neutron Board Replacement Manual  

SciTech Connect (OSTI)

This document will walk through the steps to exchange the neutron channel boards with gamma channel boards in the CHRPR box.

Erikson, Rebecca L.; Myjak, Mitchell J.

2013-03-31T23:59:59.000Z

408

Flash photolysis-shock tube studies  

SciTech Connect (OSTI)

Even though this project in the past has concentrated on the measurement of thermal bimolecular reactions of atomic species with stable molecules by the flash or laser photolysis-shock tube (FP- or LP-ST) method using atomic resonance absorption spectrometry (ARAS) as the diagnostic technique, during the past year the authors have concentrated on studies of the thermal decompositions of selected chlorocarbon molecules. These studies are necessary if the degradation of chlorine containing organic molecules by incineration are to be understood at the molecular level. Clearly, destruction of these molecules will not only involve abstraction reactions, when possible, but also thermal decomposition followed by secondary reactions of the initially formed atoms and radicals. Studies on the thermal decomposition of CH{sub 3}Cl are complete, and the curve-of-growth for Cl-atom atomic resonance absorption has been determined. The new thermal decomposition studies are similar to those already reported for CH{sub 3}Cl.

Michael, J.V. [Argonne National Laboratory, IL (United States)

1993-12-01T23:59:59.000Z

409

Glass heat pipe evacuated tube solar collector  

DOE Patents [OSTI]

A glass heat pipe is adapted for use as a solar energy absorber in an evacuated tube solar collector and for transferring the absorbed solar energy to a working fluid medium or heat sink for storage or practical use. A capillary wick is formed of granular glass particles fused together by heat on the inside surface of the heat pipe with a water glass binder solution to enhance capillary drive distribution of the thermal transfer fluid in the heat pipe throughout the entire inside surface of the evaporator portion of the heat pipe. Selective coatings are used on the heat pipe surface to maximize solar absorption and minimize energy radiation, and the glass wick can alternatively be fabricated with granular particles of black glass or obsidian.

McConnell, Robert D. (Lakewood, CO); Vansant, James H. (Tracy, CA)

1984-01-01T23:59:59.000Z

410

EA-1131: Finding of No Significant Impact | Department of Energy  

Broader source: Energy.gov (indexed) [DOE]

of No Significant Impact EA-1131: Finding of No Significant Impact Relocation of Neutron Tube Target Loading Operation, Los Alamos Laboratory, Los Alamos, New Mexico The...

411

Neutrino Factory Target Vessel  

E-Print Network [OSTI]

by UT-Battelle for the U.S. Department of Energy Target Vessel Update 26 June 2012 Cooling Channel in both walls for draining · Downstream end can be shortened, assuming the window cooling is adequate #12;11 Managed by UT-Battelle for the U.S. Department of Energy Target Vessel Update 26 June 2012 Remote Handling

McDonald, Kirk

412

Neutron detector for fusion reaction-rate measurements  

SciTech Connect (OSTI)

We have developed a fast, sensitive neutron detector for recording the fusion reaction-rate history of inertial-confinement fusion (ICF) experiments. The detector is based on the fast rise-time of a commercial plastic scintillator (BC-422) and has a response < 25-ps FWHM. A thin piece of scintillator material acts as a neutron-to- light converter. A zoom lens images light from the scintillator surface to a high-speed (15 ps) optical streak camera for recording. The zoom lens allows the scintillator to be positioned between 1 and 50 cm from a target. The camera simulaneously records an optical fiducial pulse which allows the camera time base to be calibrated relative to the incident laser power. Bursts of x rays formed by focusing 20-ps, 2.5-TW laser pulses onto gold disk targets demonstrate the detector resolution to be < 25 ps. We have recorded burn histories for deuterium/tritium-filled targets producing as few as 3 {times} 10{sup 7} neutrons.

Lerche, R.A.; Phillion, D.W.; Tietbohl, G.L.

1993-09-03T23:59:59.000Z

413

Analytical estimation of neutron yield in a micro gas-puff X pinch  

SciTech Connect (OSTI)

In this paper, we present the basic concepts for developing a micro x pinch as a small-scale neutron source. For compact sources, these concepts offer repetitive function at higher yields and pulsing rates than competing methods. The uniqueness of these concepts arises from the use of microelectronic technology to reduce the size of the target plasma and to efficiently heat the target gas. The use of repetitive microelectromechanical systems (MEMs) gas puff technology, as compared to cryogenic wires or solid targets (for the beam-target alternatives), has the potential to be robust and have a long lifetime because the plasma is not created from solid surfaces. The modeling suggests that a 50 J at the wall plug pulse could provide >10{sup 5} tritium (DT) neutrons and 10{sup 3} deuterium (DD) neutrons at temperatures of a few keV. At 1 kHz, this would be >10{sup 8} and 10{sup 6} neutrons per second, DT and DD, respectively, with a 250 {mu}m anode-cathode gap. DT gas puff devices may provide >10{sup 12} neutrons/s operating at 1 kHz and requiring 100 kW. The MEMs approach offers potentially high pulse rates and yields.

Derzon, M. S.; Galambos, P. C. [Sandia National Laboratories, Albuquerque, New Mexico 87185 (United States); Hagen, E. C. [NSTec, North Las Vegas, Nevada 89031 (United States)

2012-12-01T23:59:59.000Z

414

Neutron Generators for Spent Fuel Assay  

E-Print Network [OSTI]

of a High Fluence Neutron Source for NondestructiveAugust 8-13, 2010. [11] D-D Neutron Generator Development at2005. [12] High-yield DT Neutron Generator, B.A. Ludewigt et

Ludewigt, Bernhard A

2011-01-01T23:59:59.000Z

415

NEUTRON EMISSION IN RELATIVISTIC NUCLEAR COLLISIONS  

E-Print Network [OSTI]

Figure Captions Figure l. Neutron-to-proton ratio at 30° labapparent anomalies in the neutron-to-proton fragment ratio.3 proton data. Figure 2. Neutron-to-proton ratio R 1 , Solid

Stevenson, J.D.

2013-01-01T23:59:59.000Z

416

NEUTRON PRODUCTION BY NEUTRAL BEAM SOURCES  

E-Print Network [OSTI]

HORSE Code—A Hultigroup Neutron and Gamma-Say Honte CarloR. Smith, "A Tantalus Fast Neutron Integrator," UCRL-17051.FiS- 9 Neutron dose during 3 months of typical TSUI

Berkner, K.H.

2010-01-01T23:59:59.000Z

417

PRACTICAL NEUTRON DOSIMETRY AT HIGH ENERGIES  

E-Print Network [OSTI]

and Chupp, E. L. "Cosmic Ray Neutron Energy Spectrum." Phys.Study of Cosmic-Ray Neutrons." National Aero­ nautics andStudy of Cosmic-Ray Neutrons: Mid-Latitude Flights." Health

McCaslin, J.B.

2010-01-01T23:59:59.000Z

418

Hierarchical Part-Based Detection of 3D Flexible Tubes: Application to CT Colonoscopy  

E-Print Network [OSTI]

operations (region growing). Fig. 1. The rectal tubes are flexible and have variable shape and appearance and tube segments to the whole flexible tube. To increase the speed of the algorithm, can- didate parts are generated using a voting strategy. The detected tube segments are combined into a flexible tube using

Barbu, Adrian

419

Waterside Stress Assisted Corrosion (SAC) of Boiler Tubes  

E-Print Network [OSTI]

Waterside Stress Assisted Corrosion (SAC) of Boiler Tubes School of Materials Science Boiler Areas Susceptible to SAC · Generally SAC initiates near weld joints on cold side of tubes · SAC cracks are difficult to detect inaccessibility · Failures Detected at Various Locations in Boilers

Das, Suman

420

Drift tube suspension for high intensity linear accelerators  

DOE Patents [OSTI]

The disclosure relates to a drift tube suspension for high intensity linear accelerators. The system comprises a series of box-sections girders independently adjustably mounted on a linear accelerator. A plurality of drift tube holding stems are individually adjustably mounted on each girder.

Liska, D.J.; Schamaun, R.G.; Clark, D.C.; Potter, R.C.; Frank, J.A.

1980-03-11T23:59:59.000Z

Note: This page contains sample records for the topic "neutron tube target" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


421

Drift tube suspension for high intensity linear accelerators  

DOE Patents [OSTI]

The disclosure relates to a drift tube suspension for high intensity linear accelerators. The system comprises a series of box-sections girders independently adjustably mounted on a linear accelerator. A plurality of drift tube holding stems are individually adjustably mounted on each girder.

Liska, Donald J. (Los Alamos, NM); Schamaun, Roger G. (Los Alamos, NM); Clark, Donald C. (Los Alamos, NM); Potter, R. Christopher (Los Alamos, NM); Frank, Joseph A. (Los Alamos, NM)

1982-01-01T23:59:59.000Z

422

Analysis of tubes filled with charged electron gas  

E-Print Network [OSTI]

We show that tubes filled with electron gas, as presented by A.Bolonkin, are not possible with current materials. First, the pressure of the charges on the outer surface cancel almost all of the electrostatic pressure of the inner electrons. Second, due to the mutually repulsion most of the electrons are in the outmost shell of the tube and not individually free.

Stefan Karrmann

2011-02-24T23:59:59.000Z

423

ORCHARD BEE NESTING MATERIALS ACE PAPER TUBE CORPORATION  

E-Print Network [OSTI]

ORCHARD BEE NESTING MATERIALS ACE PAPER TUBE CORPORATION Nesting Tubes 4918 Denison Ave., Cleveland, Ohio 44102 Tel: 216-961-0250 Mason Bees and Nesting Supplies 21323 232nd St. SE, Monroe, Washington 98272-8982 Fax: 206-820-8037 E-mail: easugden@msn.com MAXTEK Nest Blocks Chuck McSween Tel: 425

424

Erosion of heat exchanger tubes in fluidized beds  

SciTech Connect (OSTI)

This final report describes the activities of the 3-year project entitled Erosion of Heat Exchanger Tubes In Fluidized Beds.'' which was completed at the end of 1990. Project accomplishments include the collection of a substantial body of wear data In a 24in. [times] 24in. fluidized bed, comparative wear results In a 6in. [times] 6in. fluidized bed, the development of a dragometer and the collection of a comprehensive set of drag force data in the 24in. [times] 24in. bed, Fast Fourier Transform (FFT) analysis of bubble probe data to establish dominant bubble frequencies in the 24in. [times] 24in. bed, the use of a heat flux gauge for measurement of heat transfer coefficients in the 24in. [times] 24in. bed and the modeling of the tube wear in the 24in. [times] 24in. bed. Analysis of the wear data from the 24in. square bed indicates that tube wear increases with increase in superficial velocity, and with increase in tube height. The latter effect is a result of the tubes higher up in the bed seeing greater movement of dense phase than tubes lower down In the bed. In addition, tube wear was found to decrease with increase in particle size, for constant superficial velocity. Three models of tube wear were formulated and provided acceptable prediction of wear when compared with the experimental data.

Johnson, E.K.; Flemmer, R.L.C.

1991-01-01T23:59:59.000Z

425

Thermal Control Techniques for Improved DT Layering of Indirect Drive IFE Targets  

E-Print Network [OSTI]

Thermal Control Techniques for Improved DT Layering of Indirect Drive IFE Targets J. E. Pulsifer, M while they are being staged for feeding to the injection system. Successful layering requires the filled capsule depends upon the thermal properties of the tube material, the capsule material

Tillack, Mark

426

New neutron physics using spallation sources  

SciTech Connect (OSTI)

The extraordinary neutron intensities available from the new spallation pulsed neutron sources open up exciting opportunities for basic and applied research in neutron nuclear physics. The energy range of neutron research which is being explored with these sources extends from thermal energies to almost 800 MeV. The emphasis here is on prospective experiments below 100 keV neutron energy using the intense neutron bursts produced by the Proton Storage Ring (PSR) at Los Alamos. 30 refs., 10 figs.

Bowman, C.D.

1988-01-01T23:59:59.000Z

427

Voluminous D2 source for intense cold neutron beam production at the ESS  

E-Print Network [OSTI]

The development of the flat moderator concept at ESS recently opened up the possibility that a single flat moderator above the target could serve all the scattering instruments, that rely on high brightness. This would allow for the introduction of a fundamentally different moderator below the target for the complementary needs of certain fundamental physics experiments. To facilitate experiments depending on the total number of neutrons in a sizable beam, the option of a voluminous D2 moderator, in a large cross-section extraction guide is discussed and its neutronic performance is assessed.

Klinkby, Esben; Mezei, Ferenc; Schřnfeldt, Troels; Takibayev, Alan; Zanini, Luca

2014-01-01T23:59:59.000Z

428

Voluminous D2 source for intense cold neutron beam production at the ESS  

E-Print Network [OSTI]

The development of the flat moderator concept at ESS recently opened up the possibility that a single flat moderator above the target could serve all the scattering instruments, that rely on high brightness. This would allow for the introduction of a fundamentally different moderator below the target for the complementary needs of certain fundamental physics experiments. To facilitate experiments depending on the total number of neutrons in a sizable beam, the option of a voluminous D2 moderator, in a large cross-section extraction guide is discussed and its neutronic performance is assessed.

Esben Klinkby; Konstantin Batkov; Ferenc Mezei; Troels Schřnfeldt; Alan Takibayev; Luca Zanini

2014-01-23T23:59:59.000Z

429

Neutron structure effects in the deuteron and one neutron halos  

E-Print Network [OSTI]

Although the neutron (n) does not carry a total electric charge, its charge and magnetization distributions represented in momentum space by the electromagnetic form factors, $F_1^{(n)} (q^2)$ and $F_2^{(n)} (q^2)$, lead to an electromagnetic potential of the neutron. Using this fact, we calculate the electromagnetic corrections to the binding energy, $B_d$, of the deuteron and a one neutron halo nucleus (11Be), by evaluating the neutron-proton and the neutron-charged core (10Be) potential, respectively. The correction to $B_d$ (~9 keV) is comparable to that arising due to the inclusion of the $\\Delta$-isobar component in the deuteron wave function. In the case of the more loosely bound halo nucleus, 11Be, the correction is close to about 2 keV.

M. Nowakowski; N. G. Kelkar; T. Mart

2005-11-28T23:59:59.000Z

430

HFIR Experiment Facilities | ORNL Neutron Sciences  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

Scattering Neutron Scattering Facilities at HFIR The fully instrumented HFIR will eventually include 15 state-of-the-art neutron scattering instruments, seven of which will be...

431

Neutron Imaging of Advanced Engine Technologies  

Broader source: Energy.gov (indexed) [DOE]

the development process * Spallation Neutron Source (SNS) - Most intense pulsed neutron beams in the world; energy selective - Multi-laboratory effort funded by DOE Office of...

432

Probing thermonuclear burning on accreting neutron stars.  

E-Print Network [OSTI]

??Neutron stars are the most compact stars that can be directly observed, which makes them ideal laboratories to study physics at extreme densities. Neutron stars… (more)

Keek, L.

2008-01-01T23:59:59.000Z

433

The Neutron EDM Experiment  

E-Print Network [OSTI]

The neutron EDM experiment has played an important part over many decades in shaping and constraining numerous models of CP violation. This review article discusses some of the techniques used to calculate EDMs under various theoretical scenarios, and highlights some of the implications of EDM limits upon such models. A pedagogical introduction is given to the experimental techniques employed in the recently completed ILL experiment, including a brief discussion of the dominant systematic uncertainties. A new and much more sensitive version of the experiment, which is currently under development, is also outlined.

P. G. Harris

2007-09-19T23:59:59.000Z

434

Proceedings: International Conference on Boiler Tube Failures and Heat Recovery Steam Generator (HRSG) Tube Failures and Inspections  

SciTech Connect (OSTI)

Tube failures remain the leading cause of availability loss in conventional fossil plants and combined cycle/heat recovery steam generator (HRSG) plants. These conference proceedings address state-of-the-art practices and techniques worldwide for understanding and reducing tube failures.

None

2002-10-01T23:59:59.000Z

435

Physics of Neutron Star Crusts  

E-Print Network [OSTI]

The physics of neutron star crusts is vast, involving many different research fields, from nuclear and condensed matter physics to general relativity. This review summarizes the progress, which has been achieved over the last few years, in modeling neutron star crusts, both at the microscopic and macroscopic levels. The confrontation of these theoretical models with observations is also briefly discussed.

N. Chamel; P. Haensel

2008-12-20T23:59:59.000Z

436

Condensation of Refrigerant-11 on the outside of horizontal and inclined enhanced tubes  

SciTech Connect (OSTI)

Heat transfer condensation tests with Refrigerant-11 were performed on the outside of a smooth tube and a variety of enhanced tubes oriented horizontally and at various tube inclinations. One smooth tube and seven enhanced (externally fluted, roped, spiraled, and externally finned) tubes of 2.54-cm (1-in.) nominal outside diameter and 1.17-m (4-ft) length were tested. Several of the tested tubes featured internal enhanced geometries, which were caused by the heat transfer enhancing geometry on the tube's external surface. Condensing heat transfer coefficients are reported as composite coefficients, which combine the resistance of the condensing film and the tube wall, and are based on total tube outside surface area. Results show that in the horizontal condensing mode, the rank order (best to worst) of the tube geometries tested was spiral-shaped tubes, rope-shaped tubes, smooth tube, externally finned tube, and externally fluted tube. For a spiral-shaped tube, horizontal composite coefficients were up to 2.0 times the corresponding horizontal smooth tube values. For tilt angles greater than or equal to 60/sup 0/ from the horizontal, the condensing performance of the externally fluted tube was best of all the tubes tested.

Domingo, N.

1982-12-01T23:59:59.000Z

437

Mining data on usage of electronic nicotine delivery systems (ENDS) from YouTube videos  

E-Print Network [OSTI]

systems (ENDS) from YouTube videos My Hua, Henry Yip, PrueENDS) and conventional cigarettes in YouTube videos.Methods Video data from YouTube videos were analysed to

Talbot, Prue

2013-01-01T23:59:59.000Z

438

Microhole Coiled Tubing Bottom Hole Assemblies  

SciTech Connect (OSTI)

The original objective of the project, to deliver an integrated 3 1/8-inch diameter Measurement While Drilling (MWD) and Logging While Drilling (LWD) system for drilling small boreholes using coiled tubing drilling, has been achieved. Two prototype systems have been assembled and tested in the lab. One of the systems has been successfully tested downhole in a conventional rotary drilling environment. Development of the 3 1/8-inch system has also lead to development and commercialization of a slightly larger 3.5-inch diameter system. We are presently filling customer orders for the 3.5-inch system while continuing with commercialization of the 3 1/8-inch system. The equipment developed by this project will be offered for sale to multiple service providers around the world, enabling the more rapid expansion of both coiled tubing drilling and conventional small diameter drilling. The project was based on the reuse of existing technology whenever possible in order to minimize development costs, time, and risks. The project was begun initially by Ultima Labs, at the time a small company ({approx}12 employees) which had successfully developed a number of products for larger oil well service companies. In September, 2006, approximately 20 months after inception of the project, Ultima Labs was acquired by Sondex plc, a worldwide manufacturer of downhole instrumentation for cased hole and drilling applications. The acquisition provided access to proven technology for mud pulse telemetry, downhole directional and natural gamma ray measurements, and surface data acquisition and processing, as well as a global sales and support network. The acquisition accelerated commercialization through existing Sondex customers. Customer demand resulted in changes to the product specification to support hotter (150 C) and deeper drilling (20,000 psi pressure) than originally proposed. The Sondex acquisition resulted in some project delays as the resistivity collar was interfaced to a different MWD system and also as the mechanical design was revised for the new pressure requirements. However, the Sondex acquisition has resulted in a more robust system, secure funding for completion of the project, and more rapid commercialization.

Don Macune

2008-06-30T23:59:59.000Z

439

SINGLE CRYSTAL NIOBIUM TUBES FOR PARTICLE COLLIDERS ACCELERATOR CAVITIES  

SciTech Connect (OSTI)

The objective of this research project is to produce single crystal niobium (Nb) tubes for use as particle accelerator cavities for the Fermi laboratory’s International Linear Collider project. Single crystal Nb tubes may have superior performance compared to a polycrystalline tubes because the absence of grain boundaries may permit the use of higher accelerating voltages. In addition, Nb tubes that are subjected to the high temperature, high vacuum crystallization process are very pure and well annealed. Any impurity with a significantly higher vapor pressure than Nb should be decreased by the relatively long exposure at high temperature to the high vacuum environment. After application of the single crystal process, the surfaces of the Nb tubes are bright and shiny, and the tube resembles an electro polished Nb tube. For these reasons, there is interest in single crystal Nb tubes and in a process that will produce single crystal tubes. To convert a polycrystalline niobium tube into a single crystal, the tube is heated to within a few hundred ?C of the melting temperature of niobium, which is 2477 ?C. RF heating is used to rapidly heat the tube in a narrow zone and after reaching the operating temperature, the hot zone is slowly passed along the length of the tube. For crystallization tests with Nb tubes, the traverse rate was in the range of 1-10 cm per hour. All the crystallization tests in this study were performed in a water-cooled, stainless steel chamber under a vacuum of 5 x10-6 torr or better. In earliest tests of the single crystal growth process, the Nb tubes had an OD of 1.9 cm and a wall thickness of 0.15 mm. With these relatively small Nb tubes, the single crystal process was always successful in producing single crystal tubes. In these early tests, the operating temperature was normally maintained at 2200 ?C, and the traverse rate was 5 cm per hour. In the next test series, the Nb tube size was increased to 3.8 cm OD and the wall thickness was increased 0.18 mm and eventually to 0.21 mm. Again, with these larger tubes, single crystal tubes were usually produced by the crystallization process. The power supply was generally operated at full output during these tests, and the traverse rate was 5 cm per hour. In a few tests, the traverse rate was increased to 10 cm per hour, and at the faster traverse rate, single crystal growth was not achieved. In these tests with a faster traverse rate, it was thought that the tube was not heated to a high enough temperature to achieve single crystal growth. In the next series of tests, the tube OD was unchanged at 3.8 cm and the wall thickness was increased to 0.30 mm. The increased wall thickness made it difficult to reach an operating temperature above 2,000 ?C, and although the single crystal process caused a large increase in the crystal grains, no single crystal tubes were produced. It was assumed that the operating temperature in these tests was not high enough to achieve single crystal growth. In FY 2012, a larger power supply was purchased and installed. With the new power supply, temperatures above the melting point of Nb were easily obtained regardless of the tube thickness. A series of crystallization tests was initiated to determine if indeed the operating temperature of the previous tests was too low to achieve single crystal growth. For these tests, the Nb tube OD remained at 3.8 cm and the wall thickness was 0.30 mm. The first test had an operating temperature of 2,000 ?C. and the operating temperature was increased by 50 ?C increments for each successive test. The final test was very near the Nb melting temperature, and indeed, the Nb tube eventually melted in the center of the tube. These tests showed that higher temperatures did yield larger grain sizes if the traverse rate was held constant at 5 cm per hour, but no single crystal tubes were produced even at the highest operating temperature. In addition, slowing the traverse rate to as low as 1 cm per hour did not yield a single crystal tube regardless of operating temperature. At this time, it

MURPHY, JAMES E [University of Nevada, Reno] [University of Nevada, Reno

2013-02-28T23:59:59.000Z

440

Fast neutron environments.  

SciTech Connect (OSTI)

The goal of this LDRD project is to develop a rapid first-order experimental procedure for the testing of advanced cladding materials that may be considered for generation IV nuclear reactors. In order to investigate this, a technique was developed to expose the coupons of potential materials to high displacement damage at elevated temperatures to simulate the neutron environment expected in Generation IV reactors. This was completed through a high temperature high-energy heavy-ion implantation. The mechanical properties of the ion irradiated region were tested by either micropillar compression or nanoindentation to determine the local properties, as a function of the implantation dose and exposure temperature. In order to directly compare the microstructural evolution and property degradation from the accelerated testing and classical neutron testing, 316L, 409, and 420 stainless steels were tested. In addition, two sets of diffusion couples from 316L and HT9 stainless steels with various refractory metals. This study has shown that if the ion irradiation size scale is taken into consideration when developing and analyzing the mechanical property data, significant insight into the structural properties of the potential cladding materials can be gained in about a week.

Buchheit, Thomas Edward; Kotula, Paul Gabriel; Lu, Ping; Brewer, Luke N. (Naval Postgraduate School, Monterey, CA); Goods, Steven Howard (Sandia National Laboratories, Livermore, CA); Foiles, Stephen Martin; Puskar, Joseph David; Hattar, Khalid Mikhiel; Doyle, Barney Lee; Boyce, Brad Lee; Clark, Blythe G.

2011-10-01T23:59:59.000Z

Note: This page contains sample records for the topic "neutron tube target" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


441

In the Target Area  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

1 22 | Next | Last Back to Index NIF Hohlraum This artist's rendering shows a NIF target pellet inside a hohlraum capsule with laser beams entering through openings on either...

442

In the Target Area  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

1 22 | Next | Last Back to Index NIF Target Chamber On March 10, 2009, at 3:15 a.m., a 192-beam laser shot delivered 1.1 million joules of ultraviolet light to the center of the...

443

SNS Target Systems Operational  

E-Print Network [OSTI]

a failed gas seal on the shaft and leaking oil seals but has operated well since then · The moderator 7.5 k First target replacement · No observed corrosion · Internal Boroscope examination in progress · ~ 50 mm

McDonald, Kirk

444

Instrument performance on the short and long pulse second SNS target stations  

SciTech Connect (OSTI)

In this work, we investigate the effect of neutron moderator dimensions on the performance of neutron scattering instruments at the Spallation Neutron Source. In a recent study of the planned second target station at the Spallation Neutron Source (SNS) facility [1,2], we have found that the dimensions of a moderator play a significant role in determining its surface brightness. A smaller moderator may be significantly brighter for a smaller viewing area [4]. One of the immediate implications of this finding is that for modern neutron scattering instrument designs, moderator dimensions and brightness have to be incorporated as an integrated optimization parameter. Here, we establish a strategy of matching neutron scattering instruments with moderators using analytical and Monte Carlo techniques. In order to simplify our treatment, we group the instruments into two broad categories, those with natural collimation and those that use neutron guide systems. We found that the cross-sections of the sample and the neutron guide, respectively, are the deciding factors for choosing the moderator. Beam divergence plays no role as long as it is within the reach of practical constraints. Namely, the required divergence is not too large for the guide or sample to be located close enough to the moderator on an actual spallation source.

Zhao, Jinkui [ORNL; Herwig, Kenneth W [ORNL; Robertson, Lee [ORNL; Gallmeier, Franz X [ORNL; Riemer, Bernie [ORNL

2013-01-01T23:59:59.000Z

445

Ceramic tube seals cut heat loss, achieve six month payback  

SciTech Connect (OSTI)

The methane reformer at the Celanese Chemical Company's Bishop, TX plant operates at approximately 1900/sup 0/F. The reformer has 32 tubes (9'' diameter) that pass through the firebox. Openings around the tubes measure 11'' in diameter to accommodate horizontal and vertical thermal expansion and movement as well as to facilitate tube removal. The gaps around the tubes permitted cool air to be drawn into the firebox (caused by slight negative pressure) and also allowed radiant heat to escape causing the reformer to operate at a lower than desired level of thermal efficiency. Celanese contracted to retrofit the old rigid firebrick roof in the methane reformer with a 10'' thick ceramic fiber module lining. The gaps around the tubes were sealed by using a special tube seal made from Nextel woven ceramic fiber fabric, a 1984 CHEMICAL PROCESSING Vaaler Award winner (Mid-November 1984, p.52). The Nextel fabric used in this application is a heat resistant textile that has a continuous use temperature of 2200/sup 0/F - well above the 1900/sup 0/F operating temperature of the reformer. The tube seals have been working exactly as intended, verified by observation through inspection ports. Temperatures in the penthouse area above the roof dropped from 240/sup 0/F to 150/sup 0/F. The reduction in heat losses has been attributed to the elimination of the gaps around each tube by the seals and to the improved K-factor of the ceramic module lining. The tube seals have paid for themselves within six months of installation. At that time, the seal boots were inspected and showed no signs of wear. With these results, the improved efficiency of the methane reformer promises to yield additional economic benefits.

Not Available

1985-11-01T23:59:59.000Z

446

Electron Scattering From High-Momentum Neutrons in Deuterium  

SciTech Connect (OSTI)

We report results from an experiment measuring the semi-inclusive reaction D(e,e'p{sub s}) where the proton p{sub s} is moving at a large angle relative to the momentum transfer. If we assume that the proton was a spectator to the reaction taking place on the neutron in deuterium, the initial state of that neutron can be inferred. This method, known as spectator tagging, can be used to study electron scattering from high-momentum (off-shell) neutrons in deuterium. The data were taken with a 5.765 GeV electron beam on a deuterium target in Jefferson Laboratory's Hall B, using the CLAS detector. A reduced cross section was extracted for different values of final-state missing mass W*, backward proton momentum {rvec p}{sub s} and momentum transfer Q{sup 2}. The data are compared to a simple PWIA spectator model. A strong enhancement in the data observed at transverse kinematics is not reproduced by the PWIA model. This enhancement can likely be associated with the contribution of final state interactions (FSI) that were not incorporated into the model. A ''bound neutron structure function'' F{sub 2n}{sup eff} was extracted as a function of W* and the scaling variable x* at extreme backward kinematics, where effects of FSI appear to be smaller. For p{sub s} > 400 MeV/c, where the neutron is far off-shell, the model overestimates the value of F{sub 2n}{sup eff} in the region of x* between 0.25 and 0.6. A modification of the bound neutron structure function is one of possible effects that can cause the observed deviation.

A.V. Klimenko; S.E. Kuhn

2005-10-12T23:59:59.000Z

447

Electron Scattering From High-Momentum Neutrons in Deuterium  

E-Print Network [OSTI]

We report results from an experiment measuring the semi-inclusive reaction $d(e,e'p_s)$ where the proton $p_s$ is moving at a large angle relative to the momentum transfer. If we assume that the proton was a spectator to the reaction taking place on the neutron in deuterium, the initial state of that neutron can be inferred. This method, known as spectator tagging, can be used to study electron scattering from high-momentum (off-shell) neutrons in deuterium. The data were taken with a 5.765 GeV electron beam on a deuterium target in Jefferson Laboratory's Hall B, using the CLAS detector. A reduced cross section was extracted for different values of final-state missing mass $W^{*}$, backward proton momentum $\\vec{p}_{s}$ and momentum transfer $Q^{2}$. The data are compared to a simple PWIA spectator model. A strong enhancement in the data observed at transverse kinematics is not reproduced by the PWIA model. This enhancement can likely be associated with the contribution of final state interactions (FSI) that were not incorporated into the model. A ``bound neutron structure function'' $F_{2n}^{eff}$ was extracted as a function of $W^{*}$ and the scaling variable $x^{*}$ at extreme backward kinematics, where effects of FSI appear to be smaller. For $p_{s}>400$ MeV/c, where the neutron is far off-shell, the model overestimates the value of $F_{2n}^{eff}$ in the region of $x^{*}$ between 0.25 and 0.6. A modification of the bound neutron structure function is one of possible effects that can cause the observed deviation.

A. V. Klimenko; S. E. Kuhn; for the CLAS collaboration

2005-10-12T23:59:59.000Z

448

In-bed tube bank for a fluidized-bed combustor  

DOE Patents [OSTI]

An in-bed tube bank (10) for a fluidized bed combustor. The tube bank (10) of the present invention comprises one or more fluid communicating boiler tubes (30) which define a plurality of selectively spaced boiler tube sections (32). The tube sections (32) are substantially parallel to one another and aligned in a common plane. The tube bank (10) further comprises support members (34) for joining adjacent tube sections (32), the support members (34) engaging and extending along a selected length of the tube sections (32) and spanning the preselected space therebetween.

Hemenway, Jr., Lloyd F. (Morgantown, WV)

1990-01-01T23:59:59.000Z

449

E-Print Network 3.0 - automatic tube compensation Sample Search...  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

REGIONS Summary: to approximately compensate. The magnetic energy density inside a flux tube depends on its evolu- tion during rise... tube emergence from a deep dynamo layer....

450

The Flow of Newtonian Fluids in Axisymmetric Corrugated Tubes  

E-Print Network [OSTI]

This article deals with the flow of Newtonian fluids through axially-symmetric corrugated tubes. An analytical method to derive the relation between volumetric flow rate and pressure drop in laminar flow regimes is presented and applied to a number of simple tube geometries of converging-diverging nature. The method is general in terms of fluid and tube shape within the previous restrictions. Moreover, it can be used as a basis for numerical integration where analytical relations cannot be obtained due to mathematical difficulties.

Taha Sochi

2010-06-08T23:59:59.000Z

451

Why Do Kraft Recovery Boiler Composite Floor Tubes Crack?  

SciTech Connect (OSTI)

Cracks were first reported in 1992 in co-extruded 304L stainless steel/SA210 Gd Al carbon steel floor tubes of North American black liquor recovery boilers. Since then, a considerable amount of information has been collected on the tube environment, crack characteristics, the stress state of the tubes, and the crack initiation and propagation mechanisms. These studies have identified both operating procedures that apparently can greatly lessen the likelihood of crack formation in the stainless steel layer and alternate materials that appear to be much more resistant to cracking than is 304L stainless.

Keiser, J.R.

2001-10-22T23:59:59.000Z

452

Streak tube photocathode development program. Phase 2, Final technical report  

SciTech Connect (OSTI)

This report details the progress made toward developing a streak tube with greater than 1% quantum efficiency at a wavelength of 1300 nm. The achieved performance is the result of approximately three years of effort. The goal of Phase 2 of this contract was to seal a working 1.3 {mu}m streak tube. This effort was focused in two areas. First there was a continuing effort to further develop and demonstrate the cathodes ability to meet the stated requirements. The second effort was aimed at solving the mechanical and process related problems related to sealing this cathode onto a EG&G streak tube.

Not Available

1993-11-20T23:59:59.000Z

453

SNS Target Test Facility: Prototype Hg Operations and Remote Handling Tests P. T. Spampinato, T. W. Burgess, J. B. Chesser, V. B. Graves, and S.L. Schrock  

E-Print Network [OSTI]

SNS Target Test Facility: Prototype Hg Operations and Remote Handling Tests P. T. Spampinato, T. W remote handling techniques and tools for replacing target system components. During the past year and analytical data. These included a welded-tube heat exchanger, an electromagnetic flow meter, a hydraulically

McDonald, Kirk

454

Fast Scintillation Probes For Investigation Of Pulsed Neutron Radiation From Small Fusion Devices  

SciTech Connect (OSTI)

This paper presents the design as well as laboratory/performance tests results taken by means of the fast scintillation probes. The design of each scintillation probe is based on photomultiplier tube hybrid assembly, which--besides photomultiplier itself--also includes high-voltage divider optimized for recording of fast radiation bursts. Plastic scintillators with short-time response are applied as hard X-ray and neutron radiation detectors. Heavy-duty probe's housing provides efficient shielding against electromagnetic interference and allows carrying out pulsed neutron measurements in a harsh electromagnetic environment. The crucial parameters of scintillation probes have been examined during laboratory tests in which our investigations have been aimed mainly to determine: a time response, an anode radiant sensitivity and an electron transit time dependence on high-voltage supply. During the performance tests, the relative calibration of probes set has been done. It allowed to carry out very accurate measurements of neutron emission anisotropy and investigations of neutron radiation scattering by different materials. The usefulness of presented scintillation probes - embedded in the neutron time-of-flight diagnostic system was proven during experimental campaigns conducted on the plasma-focus PF1000 device.

Tomaszewski, Krzysztof J. [ACS Ltd., Advanced Diagnostics Laboratory, Hery 23 St., 01-497 Warsaw (Poland)

2008-04-07T23:59:59.000Z

455

HIGH-POWER TURBODRILL AND DRILL BIT FOR DRILLING WITH COILED TUBING  

SciTech Connect (OSTI)

Commercial introduction of Microhole Technology to the gas and oil drilling industry requires an effective downhole drive mechanism which operates efficiently at relatively high RPM and low bit weight for delivering efficient power to the special high RPM drill bit for ensuring both high penetration rate and long bit life. This project entails developing and testing a more efficient 2-7/8 in. diameter Turbodrill and a novel 4-1/8 in. diameter drill bit for drilling with coiled tubing. The high-power Turbodrill were developed to deliver efficient power, and the more durable drill bit employed high-temperature cutters that can more effectively drill hard and abrasive rock. This project teams Schlumberger Smith Neyrfor and Smith Bits, and NASA AMES Research Center with Technology International, Inc (TII), to deliver a downhole, hydraulically-driven power unit, matched with a custom drill bit designed to drill 4-1/8 in. boreholes with a purpose-built coiled tubing rig. The U.S. Department of Energy National Energy Technology Laboratory has funded Technology International Inc. Houston, Texas to develop a higher power Turbodrill and drill bit for use in drilling with a coiled tubing unit. This project entails developing and testing an effective downhole drive mechanism and a novel drill bit for drilling 'microholes' with coiled tubing. The new higher power Turbodrill is shorter, delivers power more efficiently, operates at relatively high revolutions per minute, and requires low weight on bit. The more durable thermally stable diamond drill bit employs high-temperature TSP (thermally stable) diamond cutters that can more effectively drill hard and abrasive rock. Expectations are that widespread adoption of microhole technology could spawn a wave of 'infill development' drilling of wells spaced between existing wells, which could tap potentially billions of barrels of bypassed oil at shallow depths in mature producing areas. At the same time, microhole coiled tube drilling offers the opportunity to dramatically cut producers' exploration risk to a level comparable to that of drilling development wells. Together, such efforts hold great promise for economically recovering a sizeable portion of the estimated remaining shallow (less than 5,000 feet subsurface) oil resource in the United States. The DOE estimates this U.S. targeted shallow resource at 218 billion barrels. Furthermore, the smaller 'footprint' of the lightweight rigs utilized for microhole drilling and the accompanying reduced drilling waste disposal volumes offer the bonus of added environmental benefits. DOE analysis shows that microhole technology has the potential to cut exploratory drilling costs by at least a third and to slash development drilling costs in half.

Robert Radtke; David Glowka; Man Mohan Rai; David Conroy; Tim Beaton; Rocky Seale; Joseph Hanna; Smith Neyrfor; Homer Robertson

2008-03-31T23:59:59.000Z

456

Research on fusion neutron sources  

SciTech Connect (OSTI)

The use of fusion devices as powerful neutron sources has been discussed for decades. Whereas the successful route to a commercial fusion power reactor demands steady state stable operation combined with the high efficiency required to make electricity production economic, the alternative approach to advancing the use of fusion is free of many of complications connected with the requirements for economic power generation and uses the already achieved knowledge of Fusion physics and developed Fusion technologies. 'Fusion for Neutrons' (F4N), has now been re-visited, inspired by recent progress achieved on comparably compact fusion devices, based on the Spherical Tokamak (ST) concept. Freed from the requirement to produce much more electricity than used to drive it, a fusion neutron source could be efficiently used for many commercial applications, and also to support the goal of producing energy by nuclear power. The possibility to use a small or medium size ST as a powerful or intense steady-state fusion neutron source (FNS) is discussed in this paper in comparison with the use of traditional high aspect ratio tokamaks. An overview of various conceptual designs of compact fusion neutron sources based on the ST concept is given and they are compared with a recently proposed Super Compact Fusion Neutron Source (SCFNS), with major radius as low as 0.5 metres but still able to produce several MW of neutrons in a steady-state regime.

Gryaznevich, M. P. [Tokamak Solutions UK, Culham Science Centre, Abingdon, OXON, OX133DB (United Kingdom)

2012-06-19T23:59:59.000Z

457

The Spectroscopy of Neutron-Rich sdf-Shell Nuclei Using the CLARA-PRISMA Setup  

SciTech Connect (OSTI)

Since the discovery of the breakdown of shell effects in very neutron-rich N=20 and 28 nuclei, studies of the properties of nuclei far from stability have been of intense interest since they provide a unique opportunity to increase our understanding of nuclear interactions in extreme conditions and often challenge our theoretical models.Deep-inelastic processes can be used to populated high spin states of neutron-rich nuclei. In the deep-inelastic processes, an equilibration in N/Z between the target and projectile nuclei is achieved. For most heavy neutron-rich target nuclei, the N/Z ratio is 1.5 - 1.6, while for the possible neutron-rich sdf-shell projectile it is about 1.2. Thus by using deep-inelastic processes one can populate neutron-rich nuclei around N=20 and N=28.New results for the spectroscopy of neutron-rich N=22 36Si and 37P are presented here.

Liang, X.; Hodsdon, A.; Chapman, R.; Burns, M.; Keyes, K.; Ollier, J.; Papenberg, A.; Spohr, K. [School of Engineering and Science, University of Paisley, Paisley, PA1 2BE (United Kingdom); Azaiez, F.; Ibrahim, F.; Stanoiu, M. [IPN, IN2P3-CNRS, F-91406 Orsay Cedex (France); Universite Paris-Sud, F-91406 Orsay Cedex (France); Haas, F.; Caurier, E.; Curien, D.; Nowacki, F.; Salsac, M.-D. [IPHC, UMR 7500, CNRS-IN2P3, 67037 Strasbourg Cedex 2 (France); Universite Louis Pasteur, 67037 Strasbourg Cedex 2 (France); Bazzacco, D.; Beghini, S.; Farnea, E.; Menegazzo, R. [Dipartimento di Fisica, Universita di Padova, I-35131 Padova (Italy); INFN-Sezione di Padova, Universita' di Padova, I-35131 Padova (Italy)] (and others)

2006-08-14T23:59:59.000Z

458

neutron density. The neutron density (nn) of the source was modeled by solving the simul-  

E-Print Network [OSTI]

neutron density. The neutron density (nn) of the source was modeled by solving the simul- taneousT is the thermal neutron velocity, l is the decay constant, Ns is the s-process abun- dance, bsĂ? is the maxwellian-averaged neutron capture cross-section, and t0 is the average neutron exposure (21). The branching decay of 186Re

West, Stuart

459

Neutron Reflectometers -a bibliography Adrian R. Rennie  

E-Print Network [OSTI]

Neutron Reflectometers - a bibliography Adrian R. Rennie Background A short catalogue of neutron on the evolution of the design of neutron reflectometers. The papers listed in the bibliography are restricted "Gravity Diffractometer" for Ultracold-Neutron Optics' Nuclear Instruments and Methods, 179, (1981), 393

Rennie, Adrian

460

Comparison of collimation systems for small-angle neutron scattering  

SciTech Connect (OSTI)

It is shown by simple first-order geometric arguments that for a given resolution, the flux on sample in a small-angle scattering instrument is independent of the form of the collimator or of the length of the instrument. Count rate may be increased by increasing the sample size, through the use of multi-aperture systems. In second order, it is shown to be advantageous to place the beam defining elements as close as possible to the source and the sample. The multiple-pinhole system gives maximum flux on small samples but has non-uniform illumination so that intensity increases only about half as fast as sample area. Soller slits and continuous tubes from source to sample were also considered, but neutron scattering and reflection from surfaces generate a large halo. Monte-Carlo simulations confirm these results, with the conclusion that the optimum collimator configuration is the multiple-pinhole system. 4 refs., 4 figs.

Seeger, P.A.

1985-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "neutron tube target" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


461

The Magnetism of Neutron States  

E-Print Network [OSTI]

The recent measurement by Bignami and co-workers of the magnetic field of a neutron star for the first time gives a value that differs by about two orders of magnitude from the expected value. The speculation has been that the nuclear matter in the neutron stars exhibits some exotic behaviour. In this note we argue that this exotic behaviour is an anomalous statistics obeyed by the neutrons, and moreover these considerations lead to a value of the magnetic field that agrees with the observation. The same considerations also correctly give the magnetic fields of the earth and Jupiter.

B. G. Sidharth

2003-10-01T23:59:59.000Z

462

Scattered neutron tomography based on a neutron transport problem  

E-Print Network [OSTI]

scattering objects because it does not adequately account for the scattering component of the neutron beam intensity exiting the sample. We proposed a new method of computed tomography which employs an inverse problem analysis of both the transmitted...

Scipolo, Vittorio

2005-11-01T23:59:59.000Z

463

X-Ray Measurements Of A Thermo Scientific P385 DD Neutron Generator  

SciTech Connect (OSTI)

Idaho National Laboratory is experimenting with electrical neutron generators, as potential replacements for californium-252 radioisotopic neutron sources in its PINS prompt gamma-ray neutron activation analysis (PGNAA) system for the identification of military chemical warfare agents and explosives. In addition to neutron output, we have recently measured the x-ray output of the Thermo Scientific P385 deuterium-deuterium neutron generator. X rays are a normal byproduct from neutron generators, but depending on their intensity and energy, x rays can interfere with gamma rays from the object under test, increase gamma-spectrometer dead time, and reduce PGNAA system throughput. The P385 x-ray energy spectrum was measured with a high-purity germanium (HPGe) detector, and a broad peak is evident at about 70 keV. To identify the source of the x rays within the neutron generator assembly, it was scanned by collimated scintillation detectors along its long axis. At the strongest x-ray emission points, the generator also was rotated 60 deg. between measurements. The scans show the primary source of x-ray emission from the P385 neutron generator is an area 60 mm from the neutron production target, in the vicinity of the ion source. Rotation of the neutron generator did not significantly alter the x-ray count rate, and its x-ray emission appears to be axially symmetric. A thin lead shield, 3.2 mm (1/8 inch) thick, reduced the 70-keV generator x rays to negligible levels.

Wharton, C. J.; Seabury, E. H.; Chichester, D. L.; Caffrey, A. J. [Idaho National Laboratory, 2525 N. Freemont Avenue, Idaho Falls, Idaho 83415 (United States); Simpson, J.; Lemchak, M. [Thermo-Fisher Scientific/MF Physics, 5074 List Drive, Colorado Springs, Colorado 80919 (United States)

2011-06-01T23:59:59.000Z

464

Coiled tubing drilling with supercritical carbon dioxide  

DOE Patents [OSTI]

A method for increasing the efficiency of drilling operations by using a drilling fluid material that exists as supercritical fluid or a dense gas at temperature and pressure conditions existing at a drill site. The material can be used to reduce mechanical drilling forces, to remove cuttings, or to jet erode a substrate. In one embodiment, carbon dioxide (CO.sub.2) is used as the material for drilling within wells in the earth, where the normal temperature and pressure conditions cause CO.sub.2 to exist as a supercritical fluid. Supercritical carbon dioxide (SC--CO.sub.2) is preferably used with coiled tube (CT) drilling equipment. The very low viscosity SC--CO.sub.2 provides efficient cooling of the drill head, and efficient cuttings removal. Further, the diffusivity of SC--CO.sub.2 within the pores of petroleum formations is significantly higher than that