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1

Beam Time Allocation Committee (BAC)  

NLE Websites -- All DOE Office Websites (Extended Search)

Time Allocation Committee (BAC) Time Allocation Committee (BAC) Charter Purpose: Allocates general user beam time by instrument to promote diverse and high- impact science and a broad-based user community to meet DOE and NSSD goals. Participants: BAC Chair (appointed by NSSD Director), Instrument Group Leaders, User Office Schedule: Tied to proposal calls - expected to meet at least 2 times/year with meetings scheduled about 6 weeks after the proposal call has closed and at least 1 month prior to scheduled operations. Process: 1. Instrument Group Leaders (with group members): a. Confirm feasibility (equipment requirements and instrument capabilities) and safe operations b. Review amount of beam time requested and adjust as needed with consideration for instrument and sample environment availability.

2

Training | Advanced Photon Source  

NLE Websites -- All DOE Office Websites (Extended Search)

Beam Time ESAF Contacts Calendars User Community Scientific Access Site AccessVisit Training See also: Argonne WBT Argonne eJHQ APS Beamline Shielding ASDACIS Training Courses...

3

Training Management System  

NLE Websites -- All DOE Office Websites (Extended Search)

Beam Time ESAF Contacts Calendars User Community Scientific Access Site AccessVisit Training Training Management System Argonne system used to track training requirements and...

4

Training | Advanced Photon Source  

NLE Websites -- All DOE Office Websites (Extended Search)

Beam Time ESAF Contacts Calendars User Community Scientific Access Site AccessVisit Training See also: Argonne WBT Argonne eJHQ ASDACIS Training Courses Training All core...

5

Apply for Beam Time | Advanced Photon Source  

NLE Websites -- All DOE Office Websites (Extended Search)

Apply for Beam Time Apply for Beam Time NEXT PROPOSAL DEADLINE: March 7, 2014 @ 11:59 PM (Chicago time) Submit Proposal » SEE ALSO: Calendar: deadlines, run & review dates Help Page: frequently asked questions, tips for success, common errors, blank forms, instructions Review Criteria Sectors Directory: check CAT websites for info about managed beam time The Run 2014-2 proposal submission deadline is 11:59 p.m. (Chicago time) March 7, 2014. The system will open to accept proposals beginning December 20, 2013. NEW USERS: to avoid delays and to make the most of your time on site, read Become a User. You must register as a user and receive a badge number before submitting a proposal. About the Beam Time Request Process All beam time at the APS must be requested each cycle through the web-based

6

NSLS User Access | Requesting Beam Time  

NLE Websites -- All DOE Office Websites (Extended Search)

Requesting Beam Time Requesting Beam Time Use one of the following options depending on your research: General User Proposal General User proposals are peer reviewed for scientific merit by a Proposal Review Panel (PRP). General User proposals compete for beamtime with other General User Proposals based on scientific merit. Once the original proposal and beam time request is reviewed and rated in the PASS System, additional beam time requests can be submitted against the original proposal for its lifetime, a period of up to six cycles (two years). Data taken during experiments associated with a General User proposal is considered to be in the public domain. There is no charge for General User beamtime. Rapid Access Rapid Access proposals are a subset of General User proposals available for

7

Short rise time intense electron beam generator  

DOE Patents (OSTI)

A generator for producing an intense relativistic electron beam having a subnanosecond current rise time includes a conventional generator of intense relativistic electrons feeding into a short electrically conductive drift tube including a cavity containing a working gas at a low enough pressure to prevent the input beam from significantly ionizing the working gas. Ionizing means such as a laser simultaneously ionize the entire volume of working gas in the cavity to generate an output beam having a rise time less than one nanosecond.

Olson, Craig L. (Albuquerque, NM)

1987-01-01T23:59:59.000Z

8

How to Request & Access Beam Time | Stanford Synchrotron Radiation  

NLE Websites -- All DOE Office Websites (Extended Search)

How to Request & Access Beam Time How to Request & Access Beam Time Step 1: Submit a proposal that summarizes proposed research plans. Step 2: Submit beam time requests. Step 3: Review & accept beam time allocations. Instructions for users allocated beam time on SSRL X-ray/VUV beam lines. Accept Beam Time & Submit Support Request Registration & Assistance User Agreements User Financial Accounts, Supplies, Gases, Domestic & International Shipments User Computer Accounts User Safety Preparing for Arrival/Lodging/Check-In Acknowledgements, Publications, Science Highlights & News Feedback Step 1: Submit a proposal that summarizes proposed research plans. Review the guidelines for proposals and scheduling procedures. Standard proposals can be submitted through the user portal three times each year:

9

TIME DEPENDENCE OF THE BEAM IN THE 86-INCH CYCLOTRON  

SciTech Connect

The study revealed the bunching of protons to produce a short beam burst on each cycle of the l3.4 Mc/sec accelerating voltage. In addition to the l3.4 Mc/sec structure, there was a 360 cps beam pulse modulation. Oscilloscope patterns are given which show: (l) the envelope of the r-f accelerating voltage; (2) 60 cps line voltage with time scale; (3) beam intensity; and (4) beam intensity at faster oscilloscope sweep. Apparently the beam intensity is critically dependent on the accelerating voltage, but is not a monotonic function of that voltage. (B.O.G.)

Goodman, C.D.

1959-07-29T23:59:59.000Z

10

Getting Beam Time at HFIR and SNS | ORNL Neutron Sciences  

NLE Websites -- All DOE Office Websites (Extended Search)

Apply for Beam Time at HFIR and SNS Apply for Beam Time at HFIR and SNS Apply for Beam Time at HFIR and SNS 2014B Call for Proposals Proposal call 2014B All available beam lines will accept proposals through February 26, 2014 Beam time is granted through our general user program, which is open to all. In addition, we have opportunities for extended collaboration through programs such as internships and postdoctoral programs. The instruments at HFIR and SNS can be used free of charge with the understanding that researchers will publish their results, making them available to the scientific community. Our facilities are also available for proprietary research for a fee. ORNL User Portal The ORNL User Portal gives you access to all the resources you need as a new or returning user, such as the proposal system, data access and

11

Fast fall-time ion beam in neutron generators  

Science Conference Proceedings (OSTI)

Ion beam with a fast fall time is useful in building neutron generators for the application of detecting hidden, gamma-shielded SNM using differential die-away (DDA) technique. Typically a fall time of less than 1 {micro}s can't be achieved by just turning off the power to the ion source due to the slow decay of plasma density (partly determined by the fall time of the RF power in the circuit). In this paper, we discuss the method of using an array of mini-apertures (instead of one large aperture beam) such that gating the beamlets can be done with low voltage and a small gap. This geometry minimizes the problem of voltage breakdown as well as reducing the time of flight to produce fast gating. We have designed and fabricated an array of 16 apertures (4 x 4) for a beam extraction experiment. Using a gating voltage of 1400 V and a gap distance of 1 mm, the fall time of extracted ion beam pulses is less than 1 {micro}s at various beam energies ranging between 400 eV to 800 eV. Usually merging an array of beamlets suffers the loss of beam brightness, i.e., emittance growth, but that is not an important issue for neutron source applications.

Ji, Q.; Kwan, J.; Regis, M.; Wu, Y.; Wilde, S.B.; Wallig, J.

2008-08-10T23:59:59.000Z

12

RAPIDD Gives ALS Users a Faster Path to Beam Time  

NLE Websites -- All DOE Office Websites (Extended Search)

RAPIDD Gives ALS Users a Faster RAPIDD Gives ALS Users a Faster Path to Beam Time RAPIDD Gives ALS Users a Faster Path to Beam Time Print Monday, 28 October 2013 08:31 ALS users are invited to check out our web pages detailing our new RAPIDD proposal process. This combined process for Rapid Access Proposals, Industry, and Director's Discretion beam time accommodates users who require limited but rapid access to the ALS. Proposals may be submitted at any time. RAPIDD complements the existing six-month General User Proposal process, which remains the access mechanism of choice for users who require significant beam time for an extended program of research, or for those wanting to perform complex experiments involving setup or reorganization of equipment at a beamline. The ALS structural biology community has been using RAPIDD for a year, with 160 proposals receiving beam time in that period. As of July 2013, RAPIDD access was extended to beamlines 7.3.3 (SAXS/WAXS), 8.3.2 (microtomography) and 11.3.1 (small molecule crystallography) and to users from industrial groups.

13

Radial electron-beam-breakup transit-time oscillator  

DOE Patents (OSTI)

A radial electron-beam-breakup transit-time oscillator (RBTO) provides a compact high power microwave generator. The RBTO includes a coaxial vacuum transmission line having an outer conductor and an inner conductor. The inner conductor defines an annular cavity with dimensions effective to support an electromagnetic field in a TEM.sub.00m mode. A radial field emission cathode is formed on the outer conductor for providing an electron beam directed toward the annular cavity electrode. Microwave energy is then extracted from the annular cavity electrode.

Kwan, Thomas J. T. (Los Alamos, NM); Mostrom, Michael A. (Albuquerque, NM)

1998-01-01T23:59:59.000Z

14

TIME DEPENDENCE OF SPACE CHARGE BEAM LOSSES IN THE COSMOTRON  

SciTech Connect

An investigation was made of Cosmotron intensity versus time through the entire time interval from the beginning of injection to the completion of r-f capture. The induction electrode signal was used for the instartaneous measurement of beam intensity. Oscilloscope displays of the signal were photographed and traced. Base lines were filled in on the tracings and the area of the pulses measured with a polar pianimeter. It was found that the relation losses of beam intensity increase with injection intensity (total injected charge), and that most of the losses take place in the time interval between the end of injection and the completion of the first synchrotron oscillation. (M.C.G.)

Barton, M.Q.; Sacharidis, E.J.

1962-01-01T23:59:59.000Z

15

Characterizing LED with Time-Resolved Photo-Luminescence and Optical Beam Induced Current Imaging.  

E-Print Network (OSTI)

??With rapid development of light emitting device, the detection techniques of semiconductor are more and more important, which include time-resolved photoluminescence (TRPL) and optical beam… (more)

Wu, Shang-jie

2011-01-01T23:59:59.000Z

16

Method and apparatus for real time imaging and monitoring of radiotherapy beams  

Science Conference Proceedings (OSTI)

A method and apparatus for real time imaging and monitoring of radiation therapy beams is designed to preferentially distinguish and image low energy radiation from high energy secondary radiation emitted from a target as the result of therapeutic beam deposition. A detector having low sensitivity to high energy photons combined with a collimator designed to dynamically image in the region of the therapeutic beam target is used.

Majewski, Stanislaw (Yorktown, VA); Proffitt, James (Newport News, VA); Macey, Daniel J. (Birmingham, AL); Weisenberger, Andrew G. (Yorktown, VA)

2011-11-01T23:59:59.000Z

17

Fast fall-time ion beam in neutron generators  

... such that gating the beamlets can be done with low voltage and ... some time to measure the fissile content of nuclear waste ... current level) ...

18

User 'To Do' List as Soon as Beam Time is Assigned | Stanford Synchrotron  

NLE Websites -- All DOE Office Websites (Extended Search)

'To Do' List as Soon as Beam Time is Assigned 'To Do' List as Soon as Beam Time is Assigned Safety Review of Scheduled Experiments Identify potential safety issues on proposals and beam time requests. If there are any potential hazards with your samples, materials you are using, or overall set up you may be contacted by the safety office depending on the degree of the hazard indicated. If you want to bring hazardous equipment or substances to SSRL and have not previously indicated this on either your proposal or beam time request (BTR), contact the safety office immediately. Additionally, any changes you may wish to make to your proposal or BTR must be reviewed and approved by the safety office in advance. Late changes that involve potential hazards may not be possible. The experiment information provided by users is used to generate a Safety

19

Neutron time behavior for deuterium neutral beam injection into a hydrogen plasma in ORMAK  

DOE Green Energy (OSTI)

Neutrons were produced by D-D interactions when a 28-keV deuterium beam was coinjected into a hydrogen plasma in the Oak Ridge Tokamak (ORMAK). Fokker-Planck calculations, which correctly predict the time behavior of the neutron rate after beam turnon, show that the majority of the neutrons are from injected particles interacting with previously injected deuterons that have scattered to pitch angles of approximately 60 to 90/sup 0/ while slowing down.

England, A. C.; Howe, H. C.; Mihalczo, J. T.; Fowler, R. H.

1977-10-01T23:59:59.000Z

20

An algorithm to provide real time neutral beam substitution in the DIII-D tokamak  

Science Conference Proceedings (OSTI)

A key component of the DIII-D tokamak fusion experiment is a flexible and easy to expand digital control system which actively controls a large number of parameters in real-time. These include plasma shape, position, density, and total stored energy. This system, known as the PCS (plasma control system), also has the ability to directly control auxiliary plasma heating systems, such as the 20 MW of neutral beams routinely used on DIII-D. This paper describes the implementation of a real-time algorithm allowing substitution of power from one neutral beam for another, given a fault in the originally scheduled beam. Previously, in the event of a fault in one of the neutral beams, the actual power profile for the shot might be deficient, resulting in a less useful or wasted shot. Using this new real-time algorithm, a stand by neutral beam may substitute within milliseconds for one which has faulted. Since single shots can have substantial value, this is an important advance to DIII-D`s capabilities and utilization. Detailed results are presented, along with a description not only of the algorithm but of the simulation setup required to prove the algorithm without the costs normally associated with using physics operations time.

Phillips, J.C.; Greene, K.L.; Hyatt, A.W.; McHarg, B.B. Jr.; Penaflor, B.G.

1999-06-01T23:59:59.000Z

Note: This page contains sample records for the topic "beam time esaf" 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

Time-Dependent Phase-Space Mapping of Space-Charge-Dominated Beams  

SciTech Connect

In this paper we report on a proof of principle experiment for demonstrating the possibility of reconstructing the time resolved-phase-space distribution of a space-charge dominated beam by a tomographic technique which provides us with far more information than a time-sliced emittance. We emphasize that this work describes and demonstrates a new methodology which can be applicable to any beam pulse using imaging methods with the appropriate time resolution for the pulse duration. The combination of a high precision tomographic diagnostic with fast imaging screens and a gated camera are used to produce phase space maps of two beams: one with a parabolic current profile and another with a short perturbation atop a rectangular pulse. The correlations between longitudinal and transverse phase spaces are apparent and their impact on the dynamics is discussed.

D. Stratakis, R.B. Fiorito, I. Haber, R.A. Kishek, P.G. O'Shea, M. Reiser, J.C.T. Thangaraj, K. Tian

2009-05-01T23:59:59.000Z

22

An FPGA Based Multiprocessing CPU for Beam Synchronous Timing in CERN's SPS and LHC  

E-Print Network (OSTI)

The Beam Synchronous Timing system (BST) will be used around the LHC and its injector, the SPS, to broadcast timing meassages and synchronize actions with the beam in different receivers. To achieve beam synchronization, the BST Master card encodes messages using the bunch clock, with a nominal value of 40.079 MHz for the LHC. These messages are produced by a set of tasks every revolution period, which is every 89 us for the LHC and every 23 us for the SPS, therefore imposing a hard real-time constraint on the system. To achieve determinism, the BST Master uses a dedicated CPU inside its main Field Programmable Gate Array (FPGA) featuring zero-delay hardware task switching and a reduced instruction set. This paper describes the BST Master card, stressing the main FPGA design, as well as the associated software, including the LynxOS driver and the tailor-made assembler.

Ballester, F J; Gras, J J; Lewis, J; Savioz, J J; Serrano, J

2003-01-01T23:59:59.000Z

23

Synchronous timing of multi-energy fast beam extraction during a single AGS cycle  

Science Conference Proceedings (OSTI)

Synchronous triggering of fast beams is required because the field of Kicker Magnets must rise within the open space between one beam bunch and the next. Within the Brookhaven AGS, Fast Extracted Beam (FEB) triggering combines nominal timing, based on beam energy with bunch-to-bunch synchronization, based on the accelerating rf waveform. During beam acceleration, a single bunch is extracted at 22 GeV/c and within the same AGS cycle, the remaining eleven bunches are extracted at 28.4 GeV/c. When the single bunch is extracted, a ''hole'', which is left in the remaining circulating beam, can appear in random locations within the second extraction during successive AGS cycles. To overcome this problem, a synchronous rf/12 counting scheme and logic circuitry are used to keep track of the bunch positions relative to each other, and to place the ''hole'' in any desired location within the second extraction. The rf/12 signal is used also to synchronize experimenters triggers.

Gabusi, J.; Naase, S.

1985-01-01T23:59:59.000Z

24

Telerobotic system concept for real-time soft-tissue imaging during radiotherapy beam delivery  

Science Conference Proceedings (OSTI)

Purpose: The curative potential of external beam radiation therapy is critically dependent on having the ability to accurately aim radiation beams at intended targets while avoiding surrounding healthy tissues. However, existing technologies are incapable of real-time, volumetric, soft-tissue imaging during radiation beam delivery, when accurate target tracking is most critical. The authors address this challenge in the development and evaluation of a novel, minimally interfering, telerobotic ultrasound (U.S.) imaging system that can be integrated with existing medical linear accelerators (LINACs) for therapy guidance. Methods: A customized human-safe robotic manipulator was designed and built to control the pressure and pitch of an abdominal U.S. transducer while avoiding LINAC gantry collisions. A haptic device was integrated to remotely control the robotic manipulator motion and U.S. image acquisition outside the LINAC room. The ability of the system to continuously maintain high quality prostate images was evaluated in volunteers over extended time periods. Treatment feasibility was assessed by comparing a clinically deployed prostate treatment plan to an alternative plan in which beam directions were restricted to sectors that did not interfere with the transabdominal U.S. transducer. To demonstrate imaging capability concurrent with delivery, robot performance and U.S. target tracking in a phantom were tested with a 15 MV radiation beam active. Results: Remote image acquisition and maintenance of image quality with the haptic interface was successfully demonstrated over 10 min periods in representative treatment setups of volunteers. Furthermore, the robot's ability to maintain a constant probe force and desired pitch angle was unaffected by the LINAC beam. For a representative prostate patient, the dose-volume histogram (DVH) for a plan with restricted sectors remained virtually identical to the DVH of a clinically deployed plan. With reduced margins, as would be enabled by real-time imaging, gross tumor volume coverage was identical while notable reductions of bladder and rectal volumes exposed to large doses were possible. The quality of U.S. images obtained during beam operation was not appreciably degraded by radiofrequency interference and 2D tracking of a phantom object in U.S. images obtained with the beam on/off yielded no significant differences. Conclusions: Remotely controlled robotic U.S. imaging is feasible in the radiotherapy environment and for the first time may offer real-time volumetric soft-tissue guidance concurrent with radiotherapy delivery.

Schlosser, Jeffrey; Salisbury, Kenneth; Hristov, Dimitre [Department of Mechanical Engineering, Stanford University, Stanford, California 94305 (United States); Department of Computer Science and Department of Surgery, Stanford University, Stanford, California 94305 (United States); Department of Radiation Oncology, Stanford University, Stanford, California 94305 (United States)

2010-12-15T23:59:59.000Z

25

Advanced time-stamped total data acquisition control front-end for MeV ion beam microscopy and proton beam writing  

Science Conference Proceedings (OSTI)

Many ion-matter interactions exhibit sub-@ms time dependences such as, fluorophore emission quenching and ion beam induced charge (IBIC). Conventional event-mode MeV ion microbeam data acquisition systems discard the time information. Here we describe ... Keywords: Data acquisition, FPGA, Front-end, Microbeam, Time-stamping

Henri Kivistö; Mikko Rossi; Pete Jones; Rattanaporn Norarat; Nitipon Puttaraksa; Timo Sajavaara; Mikko Laitinen; VäInö HäNninen; Kimmo Ranttila; Pauli Heikkinen; Leona Gilbert; Varpu MarjomäKi; Harry J. Whitlow

2013-02-01T23:59:59.000Z

26

Simple and inexpensive time-of-flight charge-to-mass analyzer for ion beam source characterization  

SciTech Connect

We describe the design, electronics, and test results of a simple and low-cost time-of-flight ion charge-to-mass analyzer that is suitable for ion source characterization. The method selects a short-time sample of the beam whose charge-to-mass composition is then separated according to ion velocity and detected by a remote Faraday cup. The analyzer is a detachable device that has been used for rapid analysis of charge-to-mass composition of ion beams accelerated by voltages of up to about 100 kV.

Gushenets, V. I.; Nikolaev, A. G.; Oks, E. M.; Vintizenko, L. G.; Yushkov, G. Yu.; Oztarhan, A.; Brown, I. G. [High Current Electronics Institute, Russian Academy of Sciences, 2/3 Akademichesky Avenue, Tomsk 634055 (Russian Federation); Ege University, Bornova-Izmir 35100 (Turkey); Lawrence Berkeley National Laboratory, Berkeley, California 94720 (United States)

2006-06-15T23:59:59.000Z

27

Gains From Real-Time Tracking of Prostate Motion During External Beam Radiation Therapy  

SciTech Connect

Purpose: To study the gains from real-time tracking of prostate motion and threshold-based intervention and the feasibility of margin reduction for external beam radiation therapy of prostate cancer. Methods and Materials: Prostate intrafractional motion data from 775 randomly selected treatment fractions (105 prostate patients) were analyzed. Statistical distributions of prostate intrafractional displacement from baseline were used for treatment margin calculation together with other geometrical uncertainties for all patients and a subset of 7 patient who exhibited the largest intrafractional motion. Compared with treatment without any intrafractional intervention, potential reductions in treatment margins were evaluated for treatments with 5-mm and 3-mm threshold-based intervention and four-dimensional (4D) treatments with and without prostate rotation correction. Results: The percentage of time of prostate displacement from the baseline by 3 mm and 5 mm in any direction was 13.4% and 1.8%, respectively, for the general patient population. The ratios were 41% and 15% for the 7 selected patients. Reductions in the posterior margin were 0.2, 0.5, 1.3, and 3.1 mm from the original 7.7 mm, respectively, for 5-mm and 3-mm threshold-based treatments and 4D treatments with and without prostate rotation correction for all patients. They were 1.3, 1.9, 3.1 and 4.9 mm from the original 9.5 mm, corresponding to the 7 selected patients. The treatment margin reductions in other directions were even smaller. Conclusions: Real-time motion tracking and threshold-based intrafractional intervention may play a significant roll in treatment margin reduction for a small fraction of patients but not for the general patient population. Four-dimensional treatments with prostate rotation correction can reduce the treatment margin more significantly.

Li Jinsheng, E-mail: jinsheng.li@fccc.ed [Department of Radiation Oncology, Fox Chase Cancer Center, Philadelphia, Pennsylvania (United States); Jin Lihui; Pollack, Alan; Horwitz, Eric M.; Buyyounouski, Mark K.; Price, Robert A.; Ma Changming [Department of Radiation Oncology, Fox Chase Cancer Center, Philadelphia, Pennsylvania (United States)

2009-12-01T23:59:59.000Z

28

Time efficient fabrication of ultra large scale nano dot arrays using electron beam lithography  

Science Conference Proceedings (OSTI)

An astonishingly simple yet versatile alternative method for the creation of ultra large scale nano dot arrays [1-3] utilising the fact that exposure in electron beam lithography (EBL) is performed by addressing single pixels with defined distances is ... Keywords: Electron beam lithography, Nano dot, Patterning, Photonic crystal, Plasmonics

Jochen Grebing; JüRgen FaíBender; Artur Erbe

2012-09-01T23:59:59.000Z

29

Real-time spatial-phase-locked electron-beam lithography  

E-Print Network (OSTI)

The ability of electron-beam lithography (EBL) to create sub-10-nm features with arbitrary geometry makes it a critical tool in many important applications in nanoscale science and technology. The conventional EBL system ...

Zhang, Feng, 1973-

2005-01-01T23:59:59.000Z

30

Beam loading compensation of traveling wave linacs through the time dependence of the rf drive  

SciTech Connect

Beam loading in traveling-wave linear accelerating structures leads to unacceptable spread of particle energies across an extended train of bunched particles due to beam-induced field and dispersion. Methods for modulating the rf power driving linacs are effective at reducing energy spread, but for general linacs do not have a clear analytic foundation. We report here methods for calculating how to modulate the rf drive in arbitrarily nonuniform traveling-wave linacs within the convective-transport (power-diffusion) model that results in no additional energy spread due to beam loading (but not dispersion). Varying group velocity, loss factor, and cell quality factor within a structure, and nonzero particle velocity, are handled.

Towne N.; Rose J.

2011-09-30T23:59:59.000Z

31

Antenna Beam Steering For Wireless Sensors Using Real Time Phase Shifter  

E-Print Network (OSTI)

As part of the increasing demand for accurate, secure and robust short range wireless sensors for Smart Grid systems, we present the design and the simulation of phased array transmitter with variable delay based phase shifters. Multiple antennas are used to achieve beam steering using active beamforming technique. Our design exploits the multiple signal paths. In addition, the transmitter will provide feasible directional point-to-point communication networks via transmitting the signal to the preferred receiver with the desired coverage. The sensitivity and the accuracy of the system are enhanced in terms of object identification and location, respectively. This wireless sensor appears well suited for use in Smart Grid technologies operating at 2.4GHz ISM band with 250kbps data rate capacity where minimum cost and high integration are valued.

Saha, S.; Unnikrishna, U.; Khanna, P.; Al-Attar, T.

2010-01-01T23:59:59.000Z

32

Real-Time Study of Prostate Intrafraction Motion During External Beam Radiotherapy With Daily Endorectal Balloon  

Science Conference Proceedings (OSTI)

Purpose: To prospectively investigate intrafraction prostate motion during radiofrequency-guided prostate radiotherapy with implanted electromagnetic transponders when daily endorectal balloon (ERB) is used. Methods and Materials: Intrafraction prostate motion from 24 patients in 787 treatment sessions was evaluated based on three-dimensional (3D), lateral, cranial-caudal (CC), and anterior-posterior (AP) displacements. The mean percentage of time with 3D, lateral, CC, and AP prostate displacements >2, 3, 4, 5, 6, 7, 8, 9, and 10 mm in 1 minute intervals was calculated for up to 6 minutes of treatment time. Correlation between the mean percentage time with 3D prostate displacement >3 mm vs. treatment week was investigated. Results: The percentage of time with 3D prostate movement >2, 3, and 4 mm increased with elapsed treatment time (p 5 mm was independent of elapsed treatment time (p = 0.11). The overall mean time with prostate excursions >3 mm was 5%. Directional analysis showed negligible lateral prostate motion; AP and CC motion were comparable. The fraction of time with 3D prostate movement >3 mm did not depend on treatment week of (p > 0.05) over a 4-minute mean treatment time. Conclusions: Daily endorectal balloon consistently stabilizes the prostate, preventing clinically significant displacement (>5 mm). A 3-mm internal margin may sufficiently account for 95% of intrafraction prostate movement for up to 6 minutes of treatment time. Directional analysis suggests that the lateral internal margin could be further reduced to 2 mm.

Both, Stefan, E-mail: Stefan.Both@uphs.upenn.edu [Department of Radiation Oncology, Hospital of University of Pennsylvania, Philadelphia, PA (United States); Wang, Ken Kang-Hsin; Plastaras, John P.; Deville, Curtiland; Bar Ad, Voika; Tochner, Zelig; Vapiwala, Neha [Department of Radiation Oncology, Hospital of University of Pennsylvania, Philadelphia, PA (United States)

2011-12-01T23:59:59.000Z

33

Fast Beam Investigations of Two- and Three-Body Photodissociation by Time- and Position-Coincidence Imaging  

E-Print Network (OSTI)

piezoelectric Figure 1.2 The fast beam photofragment translational spectrometer (FRBM). Figure 1.3 Potential energy

Crider, Paul

2010-01-01T23:59:59.000Z

34

Simple beam profile monitor  

Science Conference Proceedings (OSTI)

An inexpensive beam profile monitor is based on the well proven rotating wire method. The monitor can display beam position and shape in real time for particle beams of most energies and beam currents up to 200{mu}A. Beam shape, position cross-section and other parameters are displayed on a computer screen.

Gelbart, W.; Johnson, R. R.; Abeysekera, B. [ASD Inc. Garden Bay, BC (Canada); Best Theratronics Ltd Ottawa Ontario (Canada); PharmaSpect Ltd., Burnaby BC (Canada)

2012-12-19T23:59:59.000Z

35

All-optical Time-resolved Measurement of Laser Energy Modulation in a Relativistic Electron Beam  

Science Conference Proceedings (OSTI)

Hamiltonian light-front theory has been proposed as a promising method for solving bound states problems in quantum field theory a long time ago, see, e.g., the review article[1] for its various advantages compared to the traditional instant-form theories. Recently the Basis Light-Front Quantization (BLFQ) approach [2, 3] has been developed as a nonperturbative approach to solve Hamiltonian light-front quantum field theory. Numerical efficiency is a key advantage of this approach. The basic idea of BLFQ is to represent the theory in an optimal basis which respects many symmetries of the theory and thus minimizes the dimensionality of the Hamiltonian for a fixed precision. Specifically, the BLFQ approach employs a plane wave basis in the light-front longitudinal direction and a 2D harmonic oscillator basis in the transverse directions. In previous work [3] this approach has been applied to evaluate the anomalous magnetic moment of electrons which are confined in an external trap with an extrapolation to the zero trap limit. In this work we extend and improve this approach in several aspects including the direct evaluation of a free electron system. This article is organized as follows: In Sec. 2 we discuss the key extensions and improvements made in this work over Ref [3]; in Sec. 3 we present the numerical results for the electron anomalous magnetic moment evaluated in different harmonic oscillator bases and compare to the perturbation theory result. Finally we conclude and give an outline for future works in Sec. 4.

Xiang, D.; Colby, E.; Dunning, M.; Gilevich, S.; Hast, C.; Jobe, K.; McCormick, D.; Nelson, J.; Raubenheimer, T.O.; Soong, K.; Stupakov, G.; Szalata, Z.; Walz, D.; Weathersby, S.; Woodley, M.; /SLAC

2012-02-15T23:59:59.000Z

36

Beam History  

NLE Websites -- All DOE Office Websites (Extended Search)

Beam Status Beam History Print Beamline History Request Form To request a beam current histograph from the ALS storage ring beam histograph database, select the year, month, and...

37

Demonstration of a real-time interferometer as a bunch-length monitor in a high-current electron beam accelerator  

SciTech Connect

A real-time interferometer (RTI) has been developed to monitor the bunch length of an electron beam in an accelerator. The RTI employs spatial autocorrelation, reflective optics, and a fast response pyro-detector array to obtain a real-time autocorrelation trace of the coherent radiation from an electron beam thus providing the possibility of online bunch-length diagnostics. A complete RTI system has been commissioned at the A0 photoinjector facility to measure sub-mm bunches at 13 MeV. Bunch length variation (FWHM) between 0.8 ps ({approx}0.24 mm) and 1.5 ps ({approx}0.45 mm) has been measured and compared with a Martin-Puplett interferometer and a streak camera. The comparisons show that RTI is a viable, complementary bunch length diagnostic for sub-mm electron bunches.

Thangaraj, J.; Thurman-Keup, R.; Ruan, J.; Johnson, A. S.; Lumpkin, A.; Santucci, J.; Maxwell, T. [Fermi National Accelerator Laboratory, Batavia, Illinois 60510 (United States); Andonian, G. [Department of Physics and Astronomy, University of California, Los Angeles, California 90095 (United States); RadiaBeam Technologies, Santa Monica, California 90404 (United States); Murokh, A.; Ruelas, M.; Ovodenko, A. [RadiaBeam Technologies, Santa Monica, California 90404 (United States)

2012-04-15T23:59:59.000Z

38

Demonstration of a real-time interferometer as a bunch-lenght monitor in a high-current electron beam accelerator  

Science Conference Proceedings (OSTI)

A real-time interferometer (RTI) has been developed to monitor the bunch length of an electron beam in an accelerator. The RTI employs spatial autocorrelation, reflective optics, and a fast response pyro-detector array to obtain a real-time autocorrelation trace of the coherent radiation from an electron beam thus providing the possibility of online bunch-length diagnostics. A complete RTI system has been commissioned at the A0 photoinjector facility to measure sub-mm bunches at 13 MeV. Bunch length variation (FWHM) between 0.8 ps (-0.24 mm) and 1.5 ps (-0.45 mm) has been measured and compared with a Martin-Puplett interferometer and a streak camera. The comparisons show that RTI is a viable, complementary bunch length diagnostic for sub-mm electron bunches.

Thangaraj, J.; Thurman-Keup, R.; Ruan, J.; Johnson, A.S.; Lumpkin, A; Santucci, J.; Maxwell, T.; /Fermilab; Andonian, G.; /UCLA /RadiaBeam Tech.; Murokh, A.; Ruelas, M.; Ovodenko, A.; /RadiaBeam Tech.

2012-03-01T23:59:59.000Z

39

Magnetically operated beam dump for dumping high power beams in a neutral beamline  

DOE Patents (OSTI)

It is an object of this invention to provide a beam dump system for a neutral beam generator which lowers the time-averaged power density of the beam dump impingement surface. Another object of this invention is to provide a beam dump system for a neutral particle beam based on reionization and subsequent magnetic beam position modulation of the beam onto a beam dump surface to lower the time-averaged power density of the beam dump ion impingement surface.

Dagenhart, W.K.

1984-01-27T23:59:59.000Z

40

Beam History  

NLE Websites -- All DOE Office Websites (Extended Search)

Beam History Print Beamline History Request Form To request a beam current histograph from the ALS storage ring beam histograph database, select the year, month, and day, then...

Note: This page contains sample records for the topic "beam time esaf" 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

Beam injection into RHIC  

SciTech Connect

During the RHIC sextant test in January 1997 beam was injected into a sixth of one of the rings for the first time. The authors describe the injection zone and its bottlenecks. They report on the commissioning of the injection system, on beam based measurements of the kickers and the application program to steer the beam.

Fischer, W.; Hahn, H.; MacKay, W.W.; Satogata, T.; Tsoupas, N.; Zhang, W.

1997-07-01T23:59:59.000Z

42

A coherent acceleration search of the Parkes multi-beam pulsar survey - techniques and the discovery and timing of 16 pulsars  

E-Print Network (OSTI)

A fully coherent acceleration search algorithm has been applied to the Parkes multi- beam pulsar survey of the Galactic plane to search for previously undiscovered relativistic binary pulsars. The search has resulted in the discovery of 16 pulsars including a binary millisecond pulsar and an intermittent pulsar. Despite a number of promising candidates there have been no new discoveries of relativistic binary pulsars. Here we detail the acceleration search performed in our analysis and present coherent timing solutions for each of pulsars discovered. In light of the lack of discoveries of relativistic binary pulsars, we also discuss the technique of acceleration searching and its effectiveness in finding these systems.

Eatough, R P; Lyne, A G; Keith, M J

2013-01-01T23:59:59.000Z

43

Time evolution of the luminosity of colliding heavy-ion beams in BNL Relativistic Heavy Ion Collider and CERN Large Hadron Collider  

E-Print Network (OSTI)

We have studied the time evolution of the heavy ion luminosity and bunch intensities in the Relativistic Heavy Ion Collider (RHIC), at BNL, and in the Large Hadron Collider (LHC), at CERN. First, we present measurements from a large number of RHIC stores (from Run 7), colliding 100 GeV/nucleon Au beams without stochastic cooling. These are compared with two different calculation methods. The first is a simulation based on multi-particle tracking taking into account collisions, intrabeam scattering, radiation damping, and synchrotron and betatron motion. In the second, faster, method, a system of ordinary differential equations with terms describing the corresponding effects on emittances and bunch populations is solved numerically. Results of the tracking method agree very well with the RHIC data. With the faster method, significant discrepancies are found since the losses of particles diffusing out of the RF bucket due to intrabeam scattering are not modeled accurately enough. Finally, we use both methods to make predictions of the time evolution of the future Pb beams in the LHC at injection and collision energy. For this machine, the two methods agree well.

R. Bruce; M. Blaskiewicz; W. Fischer; J. M. Jowett

2010-09-08T23:59:59.000Z

44

Real time x-ray studies during nanostructure formation on silicon via low energy ion beam irradiation using ultrathin iron films  

SciTech Connect

Real time grazing incidence small angle x-ray scattering and x-ray fluorescence (XRF) are used to elucidate nanodot formation on silicon surfaces during low energy ion beam irradiation of ultrathin iron-coated silicon substrates. Four surface modification stages were identified: (1) surface roughening due to film erosion, (2) surface smoothing and silicon-iron mixing, (3) structure formation, and (4) structure smoothing. The results conclude that 2.5 Multiplication-Sign 10{sup 15} iron atoms in a 50 nm depth triggers surface nanopatterning with a correlated nanodots distance of 25 nm. Moreover, there is a wide window in time where the surface can have correlated nanostructures even after the removal of all the iron atoms from the sample as confirmed by XRF and ex-situ x-ray photoelectron spectroscopy (XPS). In addition, in-situ XPS results indicated silicide formation, which plays a role in the structure formation mechanism.

El-Atwani, Osman [School of Materials Engineering, Purdue University, West Lafayette, Indiana 47907 (United States); Birck Nanotechnology Center, Purdue University, West Lafayette, Indiana 47907 (United States); Suslova, Anastassiya; Gonderman, Sean; Fowler, Justin; El-Atwani, Mohamad [School of Nuclear Engineering, Purdue University, West Lafayette, Indiana, 47907 (United States); DeMasi, Alexander; Ludwig, Karl [Physics Department, Boston University, Boston, Massachusetts 02215 (United States); Paul Allain, Jean [School of Materials Engineering, Purdue University, West Lafayette, Indiana 47907 (United States); Birck Nanotechnology Center, Purdue University, West Lafayette, Indiana 47907 (United States); School of Nuclear Engineering, Purdue University, West Lafayette, Indiana, 47907 (United States)

2012-12-24T23:59:59.000Z

45

Operation of beam line facilities for real-time x-ray studies at Sector 7 of the advanced photon source. Final Report  

SciTech Connect

This Final Report documents the research accomplishments achieved in the first phase of operations of a new Advanced Photon Source beam line (7-ID MHATT-CAT) dedicated to real-time x-ray studies. The period covered by this report covers the establishment of a world-class facility for time-dependent x-ray studies of materials. During this period many new and innovative research programs were initiated at Sector 7 with support of this grant, most notably using a combination of ultrafast lasers and pulsed synchrotron radiation. This work initiated a new frontier of materials research: namely, the study of the dynamics of materials under extreme conditions of high intensity impulsive laser irradiation.

Clarke, Roy

2003-09-10T23:59:59.000Z

46

Time-dependent, x-ray spectral unfolds and brightness temperatures for intense Li{sup +} ion beam-driven hohlraums  

SciTech Connect

X-ray-producing hohlraums are being studied as indirect drives for Inertial Confinement Fusion targets. In a 1994 target series on the PBFAII accelerator, cylindrical hohlraum targets were heated by an intense Li{sup +} ion beam and viewed by an array of 13 time-resolved, filtered x-ray detectors (XRDs). The UFO unfold code and its suite of auxiliary functions were used extensively in obtaining time- resolved x-ray spectra and radiation temperatures from this diagnostic. UFO was also used to obtain fitted response functions from calibration data, to simulate data from blackbody x-ray spectra of interest, to determine the suitability of various unfolding parameters (e.g., energy domain, energy partition, smoothing conditions, and basis functions), to interpolate the XRD signal traces, and to unfold experimental data. The simulation capabilities of the code were useful in understanding an anomalous feature in the unfolded spectra at low photon energies ({le} 100 eV). Uncertainties in the differential and energy-integrated unfolded spectra were estimated from uncertainties in the data. The time-history of the radiation temperature agreed well with independent calculations of the wall temperature in the hohlraum.

Fehl, D.L.; Chandler, G.A.; Biggs, F.; Dukart, R.J.; Moats, A.R.; Leeper, R.J.

1996-07-01T23:59:59.000Z

47

Time-dependent, x-ray spectral unfolds and brightness temperatures for intense Li{sup +} ion beam-driven hohlraums  

SciTech Connect

X-ray-producing hohlraums are being studied as indirect drives for inertial confinement fusion targets. In a 1994 target series on the PBFAII accelerator, cylindrical hohlraum targets were heated by an intense Li{sup +} ion beam and viewed by an array of 13 time-resolved, filtered x-ray detectors (XRDs). The unfold operator (UFO) code and its suite of auxiliary functions were used extensively in obtaining time-resolved x-ray spectra and radiation temperatures from this diagnostic. The UFO was also used to obtain fitted response functions from calibration data, to simulate data from blackbody x-ray spectra of interest, to determine the suitability of various unfolding parameters (e.g., energy domain, energy partition, smoothing conditions, and basis functions), to interpolate the XRD signal traces, and to unfold experimental data. The simulation capabilities of the code were useful in understanding an anomalous feature in the unfolded spectra at low photon energies ({le}100 eV). Uncertainties in the differential and energy-integrated unfolded spectra were estimated from uncertainties in the data. The time{endash}history of the radiation temperature agreed well with independent calculations of the wall temperature in the hohlraum. {copyright} {ital 1997 American Institute of Physics.}

Fehl, D.L.; Chandler, G.A.; Biggs, F.; Dukart, R.J.; Moats, A.R.; Leeper, R.J. [Sandia National Laboratories Albuquerque, New Mexico 87185 (United States)] [Sandia National Laboratories Albuquerque, New Mexico 87185 (United States)

1997-01-01T23:59:59.000Z

48

High resolution low dose transmission electron microscopy real-time imaging and manipulation of nano-scale objects in the electron beam  

DOE Patents (OSTI)

The present invention includes a method, apparatus and system for nanofabrication in which one or more target molecules are identified for manipulation with an electron beam and the one or more target molecules are manipulated with the electron beam to produce new useful materials.

Brown, Jr., R. Malcolm (Austin, TX); Barnes, Zack (Austin, TX); Sawatari, Chie (Shizuoka, JP); Kondo, Tetsuo (Kukuoka, JP)

2008-02-26T23:59:59.000Z

49

WE?A?BRA?04: Real?Time Telerobotic 3D Ultrasound for Soft?Tissue Guidance Concurrent with Beam Delivery  

Science Conference Proceedings (OSTI)

Managing internal anatomy motion due to physiological random or quasi? periodical processes is a critical challenge in external beam radiation therapy especially in the context of single? or few?fraction ablative regiments for abdominal targets. Existing and emerging technologies for localizing abdominal targets during beam delivery employ tracking of implanted fiducial markers

D Hristov; J Schlosser; C Kirmizibayrak; V Shamdasani; K Salisbury; D Chang; S Metz

2012-01-01T23:59:59.000Z

50

OBSERVATION OF STRONG - STRONG AND OTHER BEAM - BEAM EFFECTS IN RHIC.  

SciTech Connect

RHIC is currently the only hadron collider in which strong-strong beam-beam effects can be seen. For the first time, coherent beam-beam modes were observed in a bunched beam hadron collider. Other beam-beam effects in RHIC were observed in operation and in dedicated experiments with gold ions, deuterons and protons. Observations include measurements of beam-beam induced tune shifts, lifetime and emittance growth measurements with and without beam-beam interaction, and background rates as a function of tunes. During ramps unequal radio frequencies in the two rings cause the crossing points to move longitudinally. Thus bunches experience beam-beam interactions only in intervals and the tunes are modulated. In this article we summarize the most important beam-beam observations made so far.

Fischer, W; Brennan, J M; Cameron, P; Connolly, R; Montag, C; Peggs, S; Pilat, F; Ptitsyn, V; Tepikian, S; Trbojevic, D

2003-05-12T23:59:59.000Z

51

Booster gold beam injection efficiency and beam loss  

SciTech Connect

The Relativistic Heavy Ion Collider (RHIC) at the BNL requires the AGS to provide gold beam with the intensity of 10{sup 9} ions per bunch. Over the years, the Tandem Van de Graaff has provided steadily increasing intensity of gold ion beams to the AGS Booster. However, the gold ion beam injection efficiency at the Booster has been found to decrease with the rising intensity of injected beams. As the result, for Tandem beams of the highest intensity, the Booster late intensity is lower than with slightly lower intensity Tandem beam. In this article, the authors present two experiments associated with the Booster injection efficiency and beam intensity. One experiment looks at the Booster injection efficiency by adjusting the Tandem beam intensity, and another looks at the beam life time while scraping the beam in the Booster. The studies suggest that the gold beam injection efficiency at the AGS Booster is related to the beam loss in the ring, rather than the intensity of injected beam or circulating beam.

Zhang, S.Y.; Ahrens, L.A.

1998-08-01T23:59:59.000Z

52

BOOSTER GOLD BEAM INJECTION EFFICIENCY AND BEAM LOSS  

SciTech Connect

The Relativistic Heavy Ion Collider (RHIC) at the BNL requires the AGS to provide Gold beam with the intensity of 10{sup 9} ions per bunch. Over the years, the Tandem Van de Graaff has provided steadily increasing intensity of gold ion beams to the AGS Booster. However, the gold beam injection efficiency at the Booster has been found to decrease with the rising intensity of injected beams. As the result, for Tandem beams of the highest intensity, the Booster late intensity is lower than with slightly lower intensity Tandem beam. In this article, the authors present two experiments associated with the Booster injection efficiency and beam intensity. One experiment looks at the Booster injection efficiency by adjusting the Tandem beam intensity, and another looks at the beam life time while scraping the beam in the Booster. The studies suggest that the gold beam injection efficiency at the AGS Booster is related to the beam loss in the ring, rather than the intensity of injected beam or circulating beam. A close look at the effect of the lost gold ion at the Booster injection leads to the prediction that the lost gold ion creates large number of positive ions, and even larger number of electrons. The lost gold beam is also expected to create large numbers of neutral particles. In 1998 heavy ion run, the production of positive ions and electrons due to the lost gold beam has been observed. Also the high vacuum pressure due to the beam loss, presumably because of the neutral particles it created, has been measured. These results will be reported elsewhere.

ZHANG,S.Y.; AHRENS,L.A.

1998-06-22T23:59:59.000Z

53

Beam Purification by Photodetachment  

Science Conference Proceedings (OSTI)

Ion beam purity is of crucial importance to many basic and applied studies. Selective photodetachment has been proposed to suppress unwanted species in negative ion beams while preserving the intensity of the species of interest. A highly efficient technique based on photodetachment in a gas-filled radio frequency quadrupole ion cooler has been demonstrated. In off-line experiments with stable ions, up to 104 times suppression of the isobar contaminants in a number of interesting radioactive negative ion beams has been demonstrated. For selected species, this technique promises experimental possibilities in studies on exotic nuclei, accelerator mass spectrometry, and fundamental properties of negative atomic and molecular ions.

Liu, Yuan [ORNL; Beene, James R [ORNL; Havener, Charles C [ORNL; Galindo-Uribarri, Alfredo {nmn} [ORNL; Andersson, P. [University of Gothenburg, Sweden; Lindahl, A. O. [University of Gothenburg, Sweden; Hanstorp, D. [University of Gothenburg, Sweden; Forstner, Dr. Oliver [University of Vienna, Austria; Gottwald, T. [Johannes Gutenberg-Universitaet Mainz, Mainz, Germany; Wendt, K. [Johannes Gutenberg-Universitaet Mainz, Mainz, Germany

2012-01-01T23:59:59.000Z

54

BEAM SCRUBBING FOR RHIC POLARIZED PROTON RUN.  

SciTech Connect

One of the intensity limiting factor of RHIC polarized proton beam is the electron cloud induced pressure rise. A beam scrubbing study shows that with a reasonable period of time of running high intensity 112-bunch proton beam, the pressure rise can be reduced, allowing higher beam intensity.

ZHANG,S.Y.FISCHER,W.HUANG,H.ROSER,T.

2004-07-05T23:59:59.000Z

55

A large liquid argon time projection chamber for long-baseline, off-axis neutrino oscillation physics with the NuMI beam  

Science Conference Proceedings (OSTI)

Results from neutrino oscillation experiments in the last ten years have revolutionized the field of neutrino physics. While the overall oscillation picture for three neutrinos is now well established and precision measurements of the oscillation parameters are underway, crucial issues remain. In particular, the hierarchy of the neutrino masses, the structure of the neutrino mixing matrix, and, above all, CP violation in the neutrino sector are the primary experimental challenges in upcoming years. A program that utilizes the newly commissioned NuMI neutrino beamline, and its planned upgrades, together with a high-performance, large-mass detector will be in an excellent position to provide decisive answers to these key neutrino physics questions. A Liquid Argon time projection chamber (LArTPC) [2], which combines fine-grained tracking, total absorption calorimetry, and scalability, is well matched for this physics program. The few-millimeter-scale spatial granularity of a LArTPC combined with dE/dx measurements make it a powerful detector for neutrino oscillation physics. Scans of simulated event samples, both directed and blind, have shown that electron identification in {nu}{sub e} charged current interactions can be maintained at an efficiency of 80%. Backgrounds for {nu}{sub e} appearance searches from neutral current events with a {pi}{sup 0} are reduced well below the {approx} 0.5-1.0% {nu}{sub e} contamination of the {nu}{sub {mu}} beam [3]. While the ICARUS collaboration has pioneered this technology and shown its feasibility with successful operation of the T600 (600-ton) LArTPC [4], a detector for off-axis, long-baseline neutrino physics must be many times more massive to compensate for the low event rates. We have a baseline concept [5] based on the ICARUS wire plane structure and commercial methods of argon purification and housed in an industrial liquefied-natural-gas tank. Fifteen to fifty kton liquid argon capacity tanks have been considered. A very preliminary cost estimate for a 50-kton detector is $100M (unloaded) [6]. Continuing R&D will emphasize those issues pertaining to implementation of this very large scale liquid argon detector concept. Key hardware issues are achievement and maintenance of argon purity in the environment of an industrial tank, the assembly of very large electrode planes, and the signal quality obtained from readout electrodes with very long wires. Key data processing issues include an initial focus on rejection of cosmic rays for a surface experiment. Efforts are underway at Fermilab and a small number of universities in the US and Canada to address these issues with the goal of embarking on the construction of industrial-scale prototypes within one year. One such prototype could be deployed in the MiniBooNE beamline or in the NuMI surface building where neutrino interactions could be observed. These efforts are complementary to efforts around the world that include US participation, such as the construction of a LArTPC for the 2-km detector location at T2K [7]. The 2005 APS neutrino study [1] recommendations recognize that ''The development of new technologies will be essential for further advances in neutrino physics''. In a recent talk to EPP2010, Fermilab director P. Oddone, discussing the Fermilab program, states on his slides: ''We want to start a long term R&D program towards massive totally active liquid Argon detectors for extensions of NOvA''. [8]. As such, we are poised to enlarge our R&D efforts to realize the promise of a large liquid argon detector for neutrino physics.

Finley, D.; Jensen, D.; Jostlein, H.; Marchionni, A.; Pordes, S.; Rapidis, P.A.; /Fermilab; Bromberg, C.; /Michigan State U.; Lu, C.; McDonald, T.; /Princeton U.; Gallagher, H.; Mann, A.; Schneps, J.; /Tufts U.; Cline, D.; Sergiampietri, F.; Wang, H.; /UCLA; Curioni, A.; Fleming, B.T.; /Yale U.; Menary, S.; /York U., Canada

2005-09-01T23:59:59.000Z

56

Time growth rate and field profiles of hybrid modes excited by a relativistic elliptical electron beam in an elliptical metallic waveguide with dielectric rod  

Science Conference Proceedings (OSTI)

The dispersion relation of guided electromagnetic waves propagating in an elliptical metallic waveguide with a dielectric rod driven by relativistic elliptical electron beam (REEB) is investigated. The electric field profiles and the growth rates of the waves are numerically calculated by using Mathieu functions. The effects of relative permittivity constant of dielectric rod, accelerating voltage, and current density of REEB on the growth rate are presented.

Jazi, B.; Rahmani, Z.; Abdoli-Arani, A. [Faculty of Physics, Department of Laser and Photonics, University of Kashan, Kashan (Iran, Islamic Republic of); Heidari-Semiromi, E. [Faculty of Physics, Department of Condense Matter, University of Kashan, Kashan (Iran, Islamic Republic of)

2012-10-15T23:59:59.000Z

57

Accelerators, Beams And Physical Review Special Topics - Accelerators And Beams  

SciTech Connect

Accelerator science and technology have evolved as accelerators became larger and important to a broad range of science. Physical Review Special Topics - Accelerators and Beams was established to serve the accelerator community as a timely, widely circulated, international journal covering the full breadth of accelerators and beams. The history of the journal and the innovations associated with it are reviewed.

Siemann, R.H.; /SLAC

2011-10-24T23:59:59.000Z

58

New beam instrumentation in the AGS Booster  

SciTech Connect

The AGS Booster was designed to accelerate beams from 2{times}10{sup 10} polarized protons to 1.5{times}10{sup 13} protons and heavy ions through Au{sup +33}. The range of beam parameters and the high vacuum, and radiation environment presented challenges for the beam instrumentation. Some interesting beam monitors in the Booster and transport lines, will be described. Where available, results will be presented. 21 refs., 7 figs.

Witkover, R.L.

1991-01-01T23:59:59.000Z

59

Autogenerator of beams of charged particles  

DOE Patents (OSTI)

An autogenerating apparatus provides secondary intense relativistic current beam pulses in response to an injected beam pulse. One or more electromagnetic energy storage devices are provided in conjunction with gaps along a beam propagation path for the injected beam pulse. For injected beam pulses which are no longer than double the transit time of electromagnetic waves within the storage devices (which may be resonant cavities), distinct secondary beam pulses are generated by each of the energy storage devices. The beam propagation path, together with the one or more gaps provided therein, operates as a pulse forming transmission line cavity, in which the separate cavities associated with the gaps provide delays for electromagnetic waves generated at the gaps. After doubly traversing the cavity, the electromagnetic waves cause the gap to generate the secondary beam pulses, which are thus delayed by a time interval equal to the double transit time for the induced wave within the cavity.

Adler, R.J.; Mazarakis, M.G.; Miller, R.M.; Shope, S.L.; Smith, D.L.

1983-10-31T23:59:59.000Z

60

Beam-Based Alignment  

NLE Websites -- All DOE Office Websites (Extended Search)

One: One: Single-Bunch Comparative Study of Three Algorithms Peter Tenenbaum LCC-Note-0013 17-February-1999 Abstract We describe the results of a series of simulation studies of beam-based alignment of the NLC main linacs using the program LIAR. Three algorithms for alignment of quadrupoles and girders are consid- ered: the algorithm used in the ZDR, the ZDR algorithm combined with a post-alignment MICADO operation, and an algorithm which requires no steering dipoles but requires twice as many alignment segments per linac as the ZDR algorithm. The third algorithm appears to be the most robust, based on convergence time, required quad mover step sizes, and variation in extracted beam emittance as a function of BNS profile. We also study the effect of structure BPM resolution and ATL misalignments during the alignment process. 1 Introduction Beam-based alignment and steering of the

Note: This page contains sample records for the topic "beam time esaf" 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

BEAM LINE  

NLE Websites -- All DOE Office Websites (Extended Search)

BEAM LINE BEAM LINE 45 W ILHELM ROENTGEN'S INITIAL DISCOVERY of X-radiation in 1895 led immediately to practical applications in medicine. Over the next few decades X rays proved to be an invaluable tool for the investigation of the micro-world of the atom and the development of the quantum theory of matter. Almost a century later, telescopes designed to detect X-radiation are indispensable for understanding the structure and evolution of the macro-world of stars, galaxies, and the Universe as a whole. The X-Ray Universe by WALLACE H. TUCKER X-ray images of the Universe are strikingly different from the usual visible-light images. 46 SUMMER 1995 did not think: I investigated." Undeterred by NASA's rejection of a proposal to search for cosmic X-radiation, Giacconi persuaded the

62

Accelerator beam profile analyzer  

DOE Patents (OSTI)

A beam profile analyzer employing sector or quadrant plates each servo controlled to outline the edge of a beam.

Godel, Julius B. (Bayport, NY); Guillaume, Marcel (Grivegnee, BE); Lambrecht, Richard M. (East Quogue, NY); Withnell, Ronald (East Setauket, NY)

1976-01-01T23:59:59.000Z

63

A pencil beam algorithm for helium ion beam therapy  

Science Conference Proceedings (OSTI)

Purpose: To develop a flexible pencil beam algorithm for helium ion beam therapy. Dose distributions were calculated using the newly developed pencil beam algorithm and validated using Monte Carlo (MC) methods. Methods: The algorithm was based on the established theory of fluence weighted elemental pencil beam (PB) kernels. Using a new real-time splitting approach, a minimization routine selects the optimal shape for each sub-beam. Dose depositions along the beam path were determined using a look-up table (LUT). Data for LUT generation were derived from MC simulations in water using GATE 6.1. For materials other than water, dose depositions were calculated by the algorithm using water-equivalent depth scaling. Lateral beam spreading caused by multiple scattering has been accounted for by implementing a non-local scattering formula developed by Gottschalk. A new nuclear correction was modelled using a Voigt function and implemented by a LUT approach. Validation simulations have been performed using a phantom filled with homogeneous materials or heterogeneous slabs of up to 3 cm. The beams were incident perpendicular to the phantoms surface with initial particle energies ranging from 50 to 250 MeV/A with a total number of 10{sup 7} ions per beam. For comparison a special evaluation software was developed calculating the gamma indices for dose distributions. Results: In homogeneous phantoms, maximum range deviations between PB and MC of less than 1.1% and differences in the width of the distal energy falloff of the Bragg-Peak from 80% to 20% of less than 0.1 mm were found. Heterogeneous phantoms using layered slabs satisfied a {gamma}-index criterion of 2%/2mm of the local value except for some single voxels. For more complex phantoms using laterally arranged bone-air slabs, the {gamma}-index criterion was exceeded in some areas giving a maximum {gamma}-index of 1.75 and 4.9% of the voxels showed {gamma}-index values larger than one. The calculation precision of the presented algorithm was considered to be sufficient for clinical practice. Although only data for helium beams was presented, the performance of the pencil beam algorithm for proton beams was comparable. Conclusions: The pencil beam algorithm developed for helium ions presents a suitable tool for dose calculations. Its calculation speed was evaluated to be similar to other published pencil beam algorithms. The flexible design allows easy customization of measured depth-dose distributions and use of varying beam profiles, thus making it a promising candidate for integration into future treatment planning systems. Current work in progress deals with RBE effects of helium ions to complete the model.

Fuchs, Hermann; Stroebele, Julia; Schreiner, Thomas; Hirtl, Albert; Georg, Dietmar [Christian Doppler Laboratory for Medical Radiation Research for Radiation Oncology, Medical University of Vienna, 1090 Vienna (Austria); Department of Radiation Oncology, Medical University of Vienna/AKH Vienna, 1090 Vienna (Austria) and Comprehensive Cancer Center, Medical University of Vienna/AKH Vienna, 1090 Vienna (Austria); Department of Radiation Oncology, Medical University of Vienna/AKH Vienna (Austria) and Comprehensive Cancer Center, Medical University of Vienna/AKH Vienna, 1090 Vienna (Austria); PEG MedAustron, 2700 Wiener Neustadt (Austria); Department of Nuclear Medicine, Medical University of Vienna, 1090 Vienna (Austria); Christian Doppler Laboratory for Medical Radiation Research for Radiation Oncology, Medical University of Vienna, 1090 Vienna (Austria); Department of Radiation Oncology, Medical University of Vienna/AKH Vienna, 1090 Vienna (Austria) and Comprehensive Cancer Center, Medical University of Vienna/AKH Vienna, 1090 Vienna (Austria)

2012-11-15T23:59:59.000Z

64

New aspects of beam-beam interactions in hadron colliders  

Science Conference Proceedings (OSTI)

Beam-beam phenomena have until now limited the beam currents and luminosity achievable in the Tevatron. injected proton currents are about ten times larger than the anti-proton currents so beam-beam effects have largely acted on the anti-protons and at all stages of the operational cycle. The effects of the anti-protons on the protons have until now been relatively benign but that may change at higher anti-proton currents. After 36 bunches of protons are injected and placed on the proton helix, anti-protons are injected four bunches at a time. After all bunches are injected, acceleration to top energy takes bout 85 seconds. After reaching flat top, the optics around the interaction regions (IRs) is changed to lower {beta}* from 1.6 m to 0.35 m at B0 and D0. The beams are brought into collision by collapsing the separation bumps around the IPs. During a high energy physics store each bunch experiences two head-on collisions with bunches in the opposing beam and seventy long-range interactions. At all other stages of the operational cycle, each bunch experiences only long-range interactions--seventy two in all. Performance limitations from beam-beam effects until now have been primarily due to these long-range interactions. The anti-proton losses at 150 GeV have decreased during the last year mostly due to better control of the orbits, tunes and chromaticities. During this period proton intensities have increased about 50%, thus anti-proton losses at 150 GeV have not been very dependent on proton intensities. Anti-proton and proton losses on the ramp together with proton losses at 150 GeV are the dominant contributors to the Tevatron inefficiency.

Tanaji Sen

2003-06-02T23:59:59.000Z

65

Carbon Fiber Damage in Accelerator Beam  

E-Print Network (OSTI)

Carbon fibers are commonly used as moving targets in Beam Wire Scanners. Because of their thermomechanical properties they are very resistant to particle beams. Their strength deteriorates with time due to radiation damage and low-cycle thermal fatigue. In case of high intensity beams this process can accelerate and in extreme cases the fiber is damaged during a single scan. In this work a model describing the fiber temperature, thermionic emission and sublimation is discussed. Results are compared with fiber damage test performed on SPS beam in November 2008. In conclusions the limits of Wire Scanner operation on high intensity beams are drawn.

Sapinski, M; Guerrero, A; Koopman, J; Métral, E

2009-01-01T23:59:59.000Z

66

Relativistic electron beam generator  

DOE Patents (OSTI)

A relativistic electron beam generator for laser media excitation is described. The device employs a diode type relativistic electron beam source having a cathode shape which provides a rectangular output beam with uniform current density.

Mooney, L.J.; Hyatt, H.M.

1975-11-11T23:59:59.000Z

67

NK Muon Beam  

Science Conference Proceedings (OSTI)

The NK Muon Beam will be a modified version of the existing NT beam line. The decision to employ a modified version of the NT beam line was made based on considerations of cost and availability of the beam line. Preliminary studies considered use of other beam lines, e.g., the NW beam line, and even of moving the bubble chamber with its superconducting coils but were rejected for reasons such as cost, personnel limitations, and potential conflicts with other users.

Koizumi, G.

1988-09-28T23:59:59.000Z

68

NCNR PROPOSAL REVIEW AND BEAM TIME ALLOCATION  

Science Conference Proceedings (OSTI)

... MAGIK reflectometer/diffractometer, 67. 30-m NIST/Exxon/Texaco/U.Minnesota SANS instrument, 43. high-resolution powder diffractometer (BT1), 25 ...

69

Summary of the LARP Mini-Workshop on Beam-Beam Compensation 2007  

SciTech Connect

The LARP Mini-Workshop on Beam-Beam Compensation 2007 was held at SLAC, 2-4 July 2007. It was attended by 33 participants from 10 institutions in Asia, Europe, and America. 26 presentations were given, while more than one third of the time was allocated to discussions. The workshop web site is Ref. [1]. The workshop's main focus was on long-range and head-on beam-beam compensation, with a view towards application in the LHC. Other topics included the beam-beam performance of previous, existing and future circular colliders; beam-beam simulations; new operating modes, theory, and unexplained phenomena. This summary is also published as Ref. [2].

Fischer, Wolfram; /Brookhaven; Bruning, Oliver S.; Koutchouk, J.P.; Zimmermann, F.; /CERN; Sen, T.; Shiltsev, V.; /Fermilab; Ohmi, K.; /KEK, Tsukuba; Furman, M.; /LBL, Berkeley; Cai, Y.; Chao, A.; /SLAC

2011-11-07T23:59:59.000Z

70

Electron Beam Polarization Measurement Using Touschek Lifetime Technique  

SciTech Connect

Electron beam loss due to intra-beam scattering, the Touschek effect, in a storage ring depends on the electron beam polarization. The polarization of an electron beam can be determined from the difference in the Touschek lifetime compared with an unpolarized beam. In this paper, we report on a systematic experimental procedure recently developed at Duke FEL laboratory to study the radiative polarization of a stored electron beam. Using this technique, we have successfully observed the radiative polarization build-up of an electron beam in the Duke storage ring, and determined the equilibrium degree of polarization and the time constant of the polarization build-up process.

Sun, Changchun; /Duke U., DFELL; Li, Jingyi; /Duke U., DFELL; Mikhailov, Stepan; /Duke U., DFELL; Popov, Victor; /Duke U., DFELL; Wu, Wenzhong; /Duke U., DFELL; Wu, Ying; /Duke U., DFELL; Chao, Alex; /SLAC; Xu, Hong-liang; /Hefei, NSRL; Zhang, Jian-feng; /Hefei, NSRL

2012-08-24T23:59:59.000Z

71

Diagnostics for neutral-beam-heated tokamaks  

SciTech Connect

Diagnostic techniques for neutral-beam-heated tokamak plasmas fall into three categories: (1) magnetic diagnostics for measurements of gross stored energy, (2) profile diagnostics for measurements of stored thermal and beam energy, impurity content and plasma rotation, and (3) fast time resolution diagnostics to study MHD fluctuations and micro-turbulence.

Goldston, R.J.

1982-12-01T23:59:59.000Z

72

SUMMARY OF BEAM BEAM OBSERVATIONS DURING STORES IN RHIC.  

Science Conference Proceedings (OSTI)

During stores, the beam-beam interaction has a significant impact on the beam and luminosity lifetimes in RHIC. This was observed in heavy ion, and even more pronounced in proton collisions. Observations include measurements of beam-beam induced tune shifts, lifetime and emittance growth measurements with and without beam-beam interaction, and background rates as a function of tunes. In addition, RHIC is currently the only hadron collider in which strong-strong beam-beam effects can be seen. Coherent beam-beam modes were observed, and suppressed by tune changes. In this article we summarize the most important beam-beam observations made during stores so far.

FISCHER,W.

2003-05-19T23:59:59.000Z

73

The effect of beam intensity on the estimation bias of beam position  

SciTech Connect

For the signals of the beam position monitor (BPM), the signal-to-noise ratio (SNR) is directly related to the beam intensity. Low beam intensity results in poor SNR. The random noise has a modulation effect on both the amplitude and phase of the BPM signals. Therefore, the beam position measurement has a certain random error. In the currently used BPM, time-averaging and waveform clipping are used to improve the measurement. The nonlinear signal processing results in a biased estimate of beam position. A statistical analysis was made to examine the effect of the SNR, which is determined by the beam intensity, on the estimation bias. The results of the analysis suggest that the estimation bias has a dependence not only on the beam position but also on beam intensity. Specifically, the dependence gets strong as the beam intensity decreases. This property has set a lower limit of the beam intensity range which the BPM`s can handle. When the beam intensity is below that limit the estimation bias starts to vary dramatically, resulting in the BPMs failure. According to the analysis, the lowest beam intensity is that at which the SNR of the generated BPM signal is about 15 dB. The limit for NSEP BPM, for instance, is about 6Ell. The analysis may provide the BPM designers with some idea about the potential of the current BPM`S.

Ma, H.

1994-09-01T23:59:59.000Z

74

Tevatron beam-beam compensation project progress  

SciTech Connect

In this paper, we report the progress of the Tevatron Beam-Beam Compensation (BBC) project [1]. Electron beam induced proton and antiproton tuneshifts have been reported in [2], suppression of an antiproton emittance growth has been observed, too [1]. Currently, the first electron lens (TEL1) is in operational use as the Tevatron DC beam cleaner. We have made a lot of the upgrades to improve its stability [3]. The 2nd Tevatron electron lens (TEL2) is under the final phase of development and preparation for installation in the Tevatron.

Shiltsev, V.; Zhang, X.L.; Kuznetsov, G.; Pfeffer, H.; Saewert, G.; /Fermilab; Zimmermann, F.; /CERN; Tiunov, M.; /Novosibirsk, IYF; Bishofberger, K.; /UCLA; Bogdanov, I.; Kashtanov, E.; Kozub, S.; Sytnik, V.; Tkachenko, L.; /Serpukhov, IHEP

2005-05-01T23:59:59.000Z

75

ION BEAM COLLIMATOR  

DOE Patents (OSTI)

A device is described for defining a beam of high energy particles wherein the means for defining the beam in the horizontal and vertical dimension are separately adjustable and the defining members are internally cooled. In general, the device comprises a mounting block having a central opening through which the beam is projected, means for rotatably supporting two pairs of beam- forming members, passages in each member for the flow of coolant; the beam- forming members being insulated from each other and the block, and each having an end projecting into the opening. The beam-forming members are adjustable and may be cooperatively positioned to define the beam passing between the end of the members. To assist in projecting and defining the beam, the member ends have individual means connected thereto for indicating the amount of charge collected thereon due to beam interception.

Langsdorf, A.S. Jr.

1957-11-26T23:59:59.000Z

76

Shimmed electron beam welding process  

DOE Patents (OSTI)

A modified electron beam welding process effects welding of joints between superalloy materials by inserting a weldable shim in the joint and heating the superalloy materials with an electron beam. The process insures a full penetration of joints with a consistent percentage of filler material and thereby improves fatigue life of the joint by three to four times as compared with the prior art. The process also allows variable shim thickness and joint fit-up gaps to provide increased flexibility for manufacturing when joining complex airfoil structures and the like.

Feng, Ganjiang (Clifton Park, NY); Nowak, Daniel Anthony (Alplaus, NY); Murphy, John Thomas (Niskayuna, NY)

2002-01-01T23:59:59.000Z

77

Beam position monitor  

DOE Patents (OSTI)

An apparatus for determining the position of an x-ray beam relative to a desired beam axis where the apparatus is positioned along the beam path so that a thin metal foil target intersects the x-ray beam generating fluorescent radiation. A PIN diode array is positioned so that a portion of the fluorescent radiation is intercepted by the array resulting in a series of electrical signals from the PIN diodes making up the array. The signals are then analyzed and the position of the x-ray beam is determined relative to the desired beam path.

Alkire, Randy W.; Rosenbaum, Gerold; Evans, Gwyndaf

2000-09-21T23:59:59.000Z

78

Beam purification by photodetachment (invited)  

Science Conference Proceedings (OSTI)

Ion beam purity is of crucial importance to many basic and applied studies in nuclear science. Selective photodetachment has been proposed to suppress unwanted species in negative ion beams while preserving the intensity of the species of interest. A highly efficient technique based on photodetachment in a gas-filled radio frequency quadrupole ion cooler has been demonstrated. In off-line experiments with stable ions, up to 10{sup 4} times suppression of the isobar contaminants in a number of interesting radioactive negative ion beams has been demonstrated. For selected species, this technique promises new experimental possibilities in studies on exotic nuclei, accelerator mass spectrometry, and fundamental properties of negative atomic and molecular ions.

Liu, Y.; Beene, J. R.; Galindo-Uribarri, A.; Havener, C. C. [Physics Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831 (United States); Andersson, P.; Forstner, O. [Vera Laboratory, Fakultaet fuer Physik, Universitaet Wien, AT-1090 Wien (Austria); Gottwald, T.; Wendt, K. [Institute of Physics, Johannes Gutenberg-University Mainz, D-55099 Mainz (Germany); Hanstorp, D.; Lindahl, A. O. [Department of Physics, University of Gothenburg, SE-412 96 Gothenburg (Sweden)

2012-02-15T23:59:59.000Z

79

AFRD - Center for Beam Physics  

NLE Websites -- All DOE Office Websites (Extended Search)

Center for Beam Physics Center for Beam Physics Home Organization Outreach and Diversity Highlights Safety Links Intramural Group photo of our staff CBP staff, May 2011 CBP in the News: Read about an innovation in super-precise timing and synchronization; and a look toward the next generation of electron guns with responsiveness and brightness needed by future free-electron lasers such as those in the Next Generation Light Source initiative. Who We Are and What We Do The Center for Beam Physics (CBP) is a resource for meeting the challenges of accelerator science, and a source of many innovative concepts, within the Accelerator and Fusion Research Division. We have core expertise in accelerator physics and theory, accelerator modeling using high performance computing, and instrumentation,

80

Injected Beam Dynamics in SPEAR3  

SciTech Connect

For the top-off operation it is important to understand the time evolution of charge injected into the storage ring. The large-amplitude horizontal oscillation quickly filaments and decoheres, and in some cases exhibits non-linear x-y coupling before damping to the stored orbit. Similarly, in the longitudinal dimension, any mismatch in beam arrival time, beam energy or phase-space results in damped, non-linear synchrotron oscillations. In this paper we report on measurements of injection beam dynamics in the transverse and longitudinal planes using turn-by-turn BPMs, a fast-gated, image-intensified CCD camera and a Hamamatsu C5680 streak camera.

Corbett, Jeff; /SLAC; Fisher, Alan; /SLAC; Huang, Xiaobiao; /SLAC; Safranek, James; /SLAC; Westerman, Stuart; /SLAC; Cheng, Weixing; /Brookhaven; Mok, Walter; /Unlisted

2012-06-21T23:59:59.000Z

Note: This page contains sample records for the topic "beam time esaf" 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

Electron beam device  

DOE Patents (OSTI)

This patent pertains to an electron beam device in which a hollow target is symmetrically irradiated by a high energy, pulsed electron beam about its periphery and wherein the outer portion of the target has a thickness slightly greater than required to absorb the electron beam pulse energy. (auth)

Beckner, E.H.; Clauser, M.J.

1975-08-12T23:59:59.000Z

82

BEAM CONTROL PROBE  

DOE Patents (OSTI)

A probe is described for intercepting a desired portion of a beam of charged particles and for indicating the spatial disposition of the beam. The disclosed probe assembly includes a pair of pivotally mounted vanes moveable into a single plane with adjacent edges joining and a calibrated mechanical arrangement for pivoting the vancs apart. When the probe is disposed in the path of a charged particle beam, the vanes may be adjusted according to the beam current received in each vane to ascertain the dimension of the beam.

Chesterman, A.W.

1959-03-17T23:59:59.000Z

83

EUROv Super Beam Studies  

Science Conference Proceedings (OSTI)

Neutrino Super Beams use conventional techniques to significantly increase the neutrino beam intensity compared to the present neutrino facilities. An essential part of these facilities is an intense proton driver producing a beam power higher than a MW. The protons hit a target able to accept the high proton beam intensity. The produced charged particles are focused by a system of magnetic horns towards the experiment detectors. The main challenge of these projects is to deal with the high beam intensity for many years. New high power neutrino facilities could be build at CERN profiting from an eventual construction of a high power proton driver. The European FP7 Design Study EUROv, among other neutrino beams, studies this Super Beam possibility. This paper will give the latest developments in this direction.

Dracos, Marcos [IPHC, Universite de Strasbourg, CNRS/IN2P3, F-67037 Strasbourg (France)

2011-10-06T23:59:59.000Z

84

Multigigahertz beam-current and position monitor  

SciTech Connect

A self-integrating magnetic-loop device having a risetime of less than 175 ps has been developed to monitor the temporal behavior of the electron beam current and position within each 3.3-ns micropulse generated by the PHERMEX rf linear accelerator. Beam current is measured with a 2-GHz bandwidth by combining these loops in a four-port hybrid summer. Another application of these loops uses two 180/sup 0/ hybrids to give 2-GHz time-resolved beam position to an accuracy of 1 mm. These sensors are nonintrusive to the propagating beam and allow ultrafast beam measurements previously restricted to the technique of recording the Cerenkov-light emission from an intercepting Kapton foil using a streak camera.

Carlson, R.L.; Stout, L.E.

1985-01-01T23:59:59.000Z

85

FEL options for power beaming  

DOE Green Energy (OSTI)

The demand for the output power of communication satellites has been increasing exponentially. The satellite power is generated from solar panels which collect the sunlight and convert it to electrical power. The power per satellite is limited due to the limit in the practical size of the solar panel. One way to meet the power demand is to employ multiple satellites (up to 10) per the internationally agreed-upon ``slot`` in the geosynchronous earth orbit (GEO). However, this approach is very expensive due to the high cost of sending a satellite into a GEO orbit. An alternative approach is power beaming, i.e., to illuminate the solar panels with high power, highly-directed laser beams from earth. The power beaming generates more power per satellite for the same area of the solar panel. The minimum optical beam power, interesting for power beaming application, is P{sub L} = 200kW. The wavelength is chosen to be {lambda} = 0.84 {micro}m, so that it is within one of the transmission windows of the air, and at the same time near the peak of the photo-voltaic conversion efficiency of Si, which is the commonly used material for the solar panels. Free electron lasers (FELs) are well suited for the power beaming application because they can provide high power with coherent wavefront, but without high energy density in media. In this article the authors discuss some principal issues, such as the choice of accelerator and electron gun, the choice of beam parameters, radiation hazards, technological availability, and overall efficiency and reliability of the installation. They also attempt to highlight the compromise between the cost of the primary installation, the operation cost, and the choice of technology, and its maturity. They then present several schemes for the accelerator-FEL systems based on RF accelerators. The initial electron beam accelerator up to the energy of a few MeV is more or less common for all these schemes.

Kim, K.J.; Zholents, A.A.; Zolotorev, M.S. [Lawrence Berkeley National Lab., CA (United States); Vinokurov, N.A. [Budker Inst. of Nuclear Physics, Novosibirsk (Russian Federation)

1997-10-01T23:59:59.000Z

86

Molecular beam kinetics  

SciTech Connect

The design of a crossed molecular beam ''supermachine'' for neutral-- neutral collisions is discussed. The universal electron bombardment ionizer, mass filter, and ion detection system of the detector, the supersonic nozzle sources, the differential pumping arrangement for the sources and detector, the time-of-flight detection of scattered products, and the overall configuration of the apparatus are described. The elastic scattering of two systems, CH$sub 4$ + Ar and NH$sub 3$ + Ar, has been measured using the supermachine with two supersonic nozzle sources. The rainbow structure and the interference oscillations are seen in each system. The best fit to the data was found using a Morse--Spline--Van der Waals (MSV) potential. The three potential parameters epsilon, r/sub m/, and $beta$ were found to be 2.20(+-0.04) x 10$sup -14$ ergs, 3.82(+-0.04)A, and 7.05 +- 0.20 for CH$sub 4$ + Ar, and 2.21(+-0.04) x 10$sup - 14$ ergs 3.93 (+-0.05)A, and 8.45 +- 0.30 for NH$sub 3$ + Ar. A new phenomenon in crossed molecular beams of condensation of a molecule on a cluster to form a complex was observed. A bromine molecule condensed on clusters of chlorine (Cl$sub 2$)/sub chi/ and ammonia (NH$sub 3$)/sub chi/. The value of chi for measurements in these experiments ranges from 7 to 40 for chlorine clusters and from 10 to 70 ammonia clusters. (auth)

Behrens, R. Jr.

1975-11-01T23:59:59.000Z

87

Strong-strong beam-beam simulation on parallel computer  

DOE Green Energy (OSTI)

The beam-beam interaction puts a strong limit on the luminosity of the high energy storage ring colliders. At the interaction points, the electromagnetic fields generated by one beam focus or defocus the opposite beam. This can cause beam blowup and a reduction of luminosity. An accurate simulation of the beam-beam interaction is needed to help optimize the luminosity in high energy colliders.

Qiang, Ji

2004-08-02T23:59:59.000Z

88

Status of RHIC head-on beam-beam compensation project  

Science Conference Proceedings (OSTI)

Two electron lenses are under construction for RHIC to partially compensate the head-on beam-beam effect in order to increase both the peak and average luminosities. The final design of the overall system is reported as well as the status of the component design, acquisition, and manufacturing. An overview of the RHIC head-on beam-beam compensation project is given in [1], and more details in [2]. With 2 head-on beam-beam interactions in IP6 and IP8, a third interaction with a low-energy electron beam is added near IP10 to partially compensate the the head-on beam-beam effect. Two electron lenses are under construction, one for each ring. Both will be located in a region common to both beams, but each lens will act only on one beam. With head-on beam-beam compensation up to a factor of two improvement in luminosity is expected together with a polarized source upgrade. The current RHIC polarized proton performance is documented in Ref. [4]. An electron lens (Fig. 1) consists of an DC electron gun, warm solenoids to focus the electron beam during transport, a superconducting main solenoid in which the interaction with the proton beam occurs, steering magnets, a collector, and instrumentation. The main developments in the last year are given below. The experimental program for polarized program at 100 GeV was expected to be finished by the time the electron lenses are commissioned. However, decadal plans by the RHIC experiments STAR and PHENIX show a continuing interest at both 100 GeV and 250 GeV, and a larger proton beam size has been accommodated in the design (Tab. 1). Over the last year beam and lattice parameters were optimized, and RHIC proton lattices are under development for optimized electron lens performance. The effect of the electron lens magnetic structure on the proton beam was evaluated, and found to be correctable. Experiments were done in RHIC and the Tevatron.

Fischer, W.; Anerella, M.; Beebe, E.; Bruno, D.; Gassner, D.M.; Gu, X.; Gupta, R.C.; Hock, J.; Jain, A.K.; Lambiase, R.; Liu, C.; Luo, Y.; Mapes, M.; Montag, C.; Oerter, B.; Okamura, M.; Pikin, A.I.; Raparia, D.; Tan, Y.; Than, R.; Thieberger, P.; Tuozzolo, J.; Zhang, W.

2011-03-28T23:59:59.000Z

89

Electron beam depolarization in a damping ring  

SciTech Connect

Depolarization of a polarized electron beam injected into a damping ring is analyzed by extending calculations conventionally applied to proton synchrotrons. Synchrotron radiation in an electron ring gives rise to both polarizing and depolarizing effects. In a damping ring, the beam is stored for a time much less than the time for self polarization. Spin flip radiation may therefore be neglected. Synchrotron radiation without spin flips, however, must be considered as the resonance strength depends on the vertical betatron oscillation amplitude which changes as the electron beam is radiation damped. An expression for the beam polarization at extraction is derived which takes into account radiation damping. The results are applied to the electron ring at the Stanford Linear Collider and are compared with numerical matrix formalisms.

Minty, M.

1993-04-01T23:59:59.000Z

90

Optimal Source Tracking and Beaming of LISA  

E-Print Network (OSTI)

We revisit the directionally optimal data streams of LISA first introduced in Nayak etal. It was shown that by using appropriate choice of Time delay interferometric (TDI) combinations, a monochromatic fixed source in the barycentric frame can be optimally tracked in the LISA frame. In this work, we study the beaming properties of these optimal streams. We show that all the three streams V+, Vx and Vo with maximum, minimum and zero directional SNR respectively are highly beamed. We study in detail the frequency dependence of the beaming.

Archana Pai

2006-08-31T23:59:59.000Z

91

SNS BEAM COMMISSIONING TOOLS AND EXPERIENCE  

Science Conference Proceedings (OSTI)

The Spallation Neutron Source (SNS) successfully met the primary construction project completion milestones in April 2006. An important ingredient of this successful commissioning was the development and use of software tools. With the increasing digitalization of beam diagnostics and increasing complexity of Integrated Control Systems of large accelerators, the need for high level software tools is critical for smooth commissioning. At SNS a special Java based infrastructure called XAL was prepared for beam commissioning. XAL provides a hierarchal view of the accelerator, is data base configured, and includes a physics model of the beam. This infrastructure and individual applications development along with a historical time line of the SNS commissioning will be discussed.

Shishlo, Andrei P [ORNL; Galambos, John D [ORNL

2008-01-01T23:59:59.000Z

92

Beam-Gas  

NLE Websites -- All DOE Office Websites (Extended Search)

Gas Gas and Thermal Photon Scattering in the NLC Main Linac as a Source of Beam Halo P. Tenenbaum LCC-Note-0051 12-JAN-2001 Abstract Scattering of primary beam electrons off of residual gas molecules or blackbody radiation photons in the NLC main linac has been identified as a potential source of beam haloes which must be collimated in the beam delivery system. We consider the contributions from four scat- tering mechanisms: inelastic thermal-photon scattering, elastic beam-gas (Coulomb) scattering inelastic beam-gas (Bremsstrahlung) scattering, and atomic-electron scattering. In each case we develop the formalism necessary to estimate the backgrounds generated in the main linac, and determine the expected number of off-energy or large-amplitude particles from each process, assuming a main linac injection energy of 8 GeV and extraction energy of 500 GeV. 1 Introduction The

93

Particle beam injection system  

SciTech Connect

This invention provides a poloidal divertor for stacking counterstreaming ion beams to provide high intensity colliding beams. To this end, method and apparatus are provided that inject high energy, high velocity, ordered, atomic deuterium and tritium beams into a lower energy, toroidal, thermal equilibrium, neutral, target plasma column that is magnetically confined along an endless magnetic axis in a strong restoring force magnetic field having helical field lines to produce counterstreaming deuteron and triton beams that are received bent, stacked and transported along the endless axis, while a poloidal divertor removes thermal ions and electrons all along the axis to increase the density of the counterstreaming ion beams and the reaction products resulting therefrom. By balancing the stacking and removal, colliding, strong focused particle beams, reaction products and reactions are produced that convert one form of energy into another form of energy.

Jassby, Daniel L. (Princeton, NJ); Kulsrud, Russell M. (Princeton, NJ)

1977-01-01T23:59:59.000Z

94

Ion Beam Materials Lab  

NLE Websites -- All DOE Office Websites (Extended Search)

Facilities » Facilities » Ion Beam Materials Lab Ion Beam Materials Lab A new research frontier awaits! Our door is open and we thrive on mutually beneficial partnerships, collaborations that drive innovations and new technologies. April 12, 2012 Ion Beam Danfysik Implanter High Voltage Terminal. Contact Yongqiang Wang (505) 665-1596 Email Devoted to the characterization and modification of surfaces through the use of ion beams The Ion Beam Materials Laboratory (IBML) is a Los Alamos National Laboratory resource devoted to the characterization and modification of surfaces through the use of ion beams. The IBML provides and operates the core facilities, while supporting the design and implementation of specific apparati needed for experiments requested by users of the facility. The result is a facility with

95

Apparatus for laser beam profile measurements  

DOE Patents (OSTI)

Apparatus for measuring the spatial intensity profile of the output beam from a continuous-wave laser oscillator. The rapid and repetitive passing of a small aperture through the otherwise totally blocked output beam of the laser under investigation provides an easily interpretable, real-time measure of the intensity characteristics thereof when detected by a single detector and the signal generated thereby displayed on an oscilloscope synthronized to the motion of the aperture.

Barnes, N.P.; Gettemy, D.J.

1985-01-30T23:59:59.000Z

96

Broad beam ion implanter  

DOE Patents (OSTI)

An ion implantation device for creating a large diameter, homogeneous, ion beam is described, as well as a method for creating same, wherein the device is characterized by extraction of a diverging ion beam and its conversion by ion beam optics to an essentially parallel ion beam. The device comprises a plasma or ion source, an anode and exit aperture, an extraction electrode, a divergence-limiting electrode and an acceleration electrode, as well as the means for connecting a voltage supply to the electrodes.

Leung, Ka-Ngo (Hercules, CA)

1996-01-01T23:59:59.000Z

97

BEAMS Crossword Puzzle  

NLE Websites -- All DOE Office Websites (Extended Search)

puzzle with words from the BEAMS Vocabulary List. Download this Activity Lab Pages Puzzle Puzzle Puzzle (cont) Puzzle (cont) Sample AnswersAnswer Key Ansewr Key Ansewr Key...

98

Electron Beam Melting (EBM)  

Science Conference Proceedings (OSTI)

Oct 18, 2011 ... Additive Manufacturing of Metals: Electron Beam Melting (EBM) I Sponsored by: MS&T Organization Program Organizers: Ian D. Harris, EWI; ...

99

Electron Beam Melting  

Science Conference Proceedings (OSTI)

Oct 9, 2012 ... Additive Manufacturing of Metals: Electron Beam Melting Program Organizers: Ian Harris, EWI; Ola Harrysson, North Carolina State University; ...

100

Laser beam generating apparatus  

DOE Patents (OSTI)

Laser beam generating apparatus including a septum segment disposed longitudinally within the tubular structure of the apparatus. The septum provides for radiatively dissipating heat buildup within the tubular structure and for generating relatively uniform laser beam pulses so as to minimize or eliminate radial pulse delays (the chevron effect). 11 figures.

Warner, B.E.; Duncan, D.B.

1993-12-28T23:59:59.000Z

Note: This page contains sample records for the topic "beam time esaf" 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

Laser beam generating apparatus  

DOE Patents (OSTI)

Laser beam generating apparatus including a septum segment disposed longitudinally within the tubular structure of the apparatus. The septum provides for radiatively dissipating heat buildup within the tubular structure and for generating relatively uniform laser beam pulses so as to minimize or eliminate radial pulse delays (the chevron effect).

Warner, Bruce E. (Livermore, CA); Duncan, David B. (Auburn, CA)

1994-01-01T23:59:59.000Z

102

Laser beam generating apparatus  

DOE Patents (OSTI)

Laser beam generating apparatus including a septum segment disposed longitudinally within the tubular structure of the apparatus is described. The septum provides for radiatively dissipating heat buildup within the tubular structure and for generating relatively uniform laser beam pulses so as to minimize or eliminate radial pulse delays (the chevron effect). 7 figures.

Warner, B.E.; Duncan, D.B.

1994-02-15T23:59:59.000Z

103

Laser beam generating apparatus  

DOE Patents (OSTI)

Laser beam generating apparatus including a septum segment disposed longitudinally within the tubular structure of the apparatus. The septum provides for radiatively dissipating heat buildup within the tubular structure and for generating relatively uniform laser beam pulses so as to minimize or eliminate radial pulse delays (the chevron effect).

Warner, Bruce E. (Livermore, CA); Duncan, David B. (Auburn, CA)

1993-01-01T23:59:59.000Z

104

Beam Diagnostics for FACET  

SciTech Connect

FACET, the Facility for Advanced Accelerator and Experimental Tests, is a new facility being constructed in sector 20 of the SLAC linac primarily to study beam driven plasma wakefield acceleration beginning in summer 2011. The nominal FACET parameters are 23GeV, 3nC electron bunches compressed to about 20 {micro}m long and focussed to about 10 {micro}m wide. Characterization of the beam-plasma interaction requires complete knowledge of the incoming beam parameters on a pulse-to-pulse basis. FACET diagnostics include Beam Position Monitors, Toroidal current monitors, X-ray and Cerenkov based energy spectrometers, optical transition radiation (OTR) profile monitors and coherent transition radiation (CTR) bunch length measurement systems. The compliment of beam diagnostics and their expected performance are reviewed. Beam diagnostic measurements not only provide valuable insights to the running and tuning of the accelerator but also are crucial for the PWFA experiments in particular. Beam diagnostic devices are being set up at FACET and will be ready for beam commissioning in summer 2011.

Li, S.Z.; Hogan, M.J.; /SLAC

2011-08-19T23:59:59.000Z

105

Laser beam alignment system  

DOE Patents (OSTI)

A plurality of pivotal reflectors direct a high-power laser beam onto a workpiece, and a rotatable reflector is movable to a position wherein it intercepts the beam and deflects a major portion thereof away from its normal path, the remainder of the beam passing to the pivotal reflectors through an aperture in the rotating reflector. A plurality of targets are movable to positions intercepting the path of light traveling to the pivotal reflectors, and a preliminary adjustment of the latter is made by use of a low-power laser beam reflected from the rotating reflector, after which the same targets are used to make a final adjustment of the pivotal reflectors with the portion of the high-power laser beam passed through the rotating reflector.

Kasner, William H. (11686 Althea Dr., Pittsburgh, PA 15235); Racki, Daniel J. (712 Union Cemetery Rd., Greensburg, PA 15601); Swenson, Clark E. (228 Scott Dr., Monroeville, PA 15146)

1984-01-01T23:59:59.000Z

106

Beam director design report  

Science Conference Proceedings (OSTI)

A design and fabrication effort for a beam director is documented. The conceptual design provides for the beam to pass first through a bending and focusing system (or ''achromat''), through a second achromat, through an air-to-vacuum interface (the ''beam window''), and finally through the vernier steering system. Following an initial concept study for a beam director, a prototype permanent magnet 30/sup 0/ beam-bending achromat and prototype vernier steering magnet were designed and built. In volume II, copies are included of the funding instruments, requests for quotations, purchase orders, a complete set of as-built drawings, magnetic measurement reports, the concept design report, and the final report on the design and fabrication project. (LEW)

Younger, F.C.

1986-08-01T23:59:59.000Z

107

First Beam to FACET  

Science Conference Proceedings (OSTI)

The SLAC 3km linear electron accelerator has been reconfigured to provide a beam of electrons to the new Facility for Advanced Accelerator Experimental Tests (FACET) while simultaneously providing an electron beam to the Linac Coherent Light Source (LCLS). On June 23, 2011, the first electron beam was transported through this new facility. Commissioning of FACET is in progress. On June 23, 2011, an electron beam was successfully transported through the new FACET system to a dump in Sector 20 in the linac tunnel. This was achieved while the last third of the linac, operating from the same control room, but with a separate injector system, was providing an electron beam to the Linac Coherent Light Source (LCLS), demonstrating that concurrent operation of the two facilities is practical. With the initial checkout of the new transport line essentially complete, attention is now turning toward compressing the electron bunches longitudinally and focusing them transversely to support a variety of accelerator science experiments.

Erickson, R.; Clarke, C.; Colocho, W.; Decker, F.-J.; Hogan, M.; Kalsi, S.; Lipkowitz, N.; Nelson, J.; Phinney, N.; Schuh, P.; Sheppard, J.; Smith, H.; Smith, T.; Stanek, M.; Turner, J.; Warren, J.; Weathersby, S.; Wienands, U.; Wittmer, W.; Woodley, M.; Yocky, G.; /SLAC

2011-12-13T23:59:59.000Z

108

Excitation of Accelerating Plasma Waves by Counter-propagating Laser Beams  

SciTech Connect

Generation of accelerating plasma waves using two counter-propagating laser beams is considered. Colliding-beam accelerator requires two laser pulses: the long pump and the short timing beam. We emphasize the similarities and differences between the conventional laser wakefield accelerator and the colliding-beam accelerator (CBA). The highly nonlinear nature of the wake excitation is explained using both nonlinear optics and plasma physics concepts. Two regimes of CBA are considered: (i) the short-pulse regime, where the timing beam is shorter than the plasma period, and (ii) the parametric excitation regime, where the timing beam is longer than the plasma period. Possible future experiments are also outlined.

Gennady Shvets; Nathaniel J. Fisch; and Alexander Pukhov

2001-08-30T23:59:59.000Z

109

SPEAR3 Beam Line Availability  

NLE Websites -- All DOE Office Websites (Extended Search)

Beam Line Support | Floor Support | Administrative Support SPEAR3 Beam Line Availability Beam Line BL Type Technique(s) Status 1-4 X-ray Small and Wide Angle X-ray Scattering Open...

110

Single-bunch beams for BC-75  

SciTech Connect

On June 8, 1983, a beam consisting of a single S-band bunch was transported through the linac into the beam switchyard (BSY) and analyzed in the C-line (Beamline 27) at 30 GeV. The C-line toroid 2712 measured an intensity of approximately 2 x 10/sup 9/e/sup -//pulse. The exact intensity was uncertain due to the limited response time of the toroid for fast, single-bunch beams. However, the linear Q intensity monitors (Lin Q) showed the transmission of the beam through the linac between Sectors 2 and 30 to be fairly flat with an intensity of 3 x 10/sup 9/e/sup -//pulse in the final 19 sectors. The CID Faraday cup, which is located adjacent to the Gun Lin Q, was used to check the calibration of the Lin Q.

Sodja, J.; Clendenin, J.E.; Erickson, R.A.; Miller, R.H.

1983-06-01T23:59:59.000Z

111

Electron and laser beam welding  

SciTech Connect

This book contains 22 selections. Some of the titles are: Laser welding of chandelles to the plates of the sommier employed in the nuclear power plant core; Electron beam welding of hobbing cutters; Sealing welds in electron beam welding of thick metals; Development and application of high power electron beam welding; Electron beam welding of dissimilar metals (niobium, molybdenum, porous tungsten-molybdenum); Status of electron beam welding in the United States of America; and Electron and laser beam welding in Japan.

1986-01-01T23:59:59.000Z

112

Challenges in Accelerator Beam Instrumentation  

E-Print Network (OSTI)

The challenges in beam instrumentation and diagnostics for present and future particle accelerator projects are presented. A few examples for advanced hadron and lepton beam diagnostics are given.

Wendt, M

2009-01-01T23:59:59.000Z

113

Challenges in Accelerator Beam Instrumentation  

Science Conference Proceedings (OSTI)

The challenges in beam instrumentation and diagnostics for present and future particle accelerator projects are presented. A few examples for advanced hadron and lepton beam diagnostics are given.

Wendt, M.

2009-12-01T23:59:59.000Z

114

Frontiers of Particle Beam Physics  

E-Print Network (OSTI)

Low Emittance e--e+ Beams, Brookhaven National Laboratory,Island, NY, October 1988, Brookhaven National Laboratory,Low Emittance e--e+ Beams, Brookhaven National Laboratory,

Sessler, Andrew M.

2008-01-01T23:59:59.000Z

115

Simulations of beam-beam and beam-wire interactions in RHIC  

SciTech Connect

The beam-beam interaction is one of the dominant sources of emittance growth and luminosity lifetime deterioration. A current carrying wire has been proposed to compensate long-range beam-beam effects in the LHC and strong localized long-range beam-beam effects are experimentally investigated in the RHIC collider. Tune shift, beam transfer function, and beam loss rate are measured in dedicated experiments. In this paper, they report on simulations to study the effect of beam-wire interactions based on diffusive apertures, beam loss rates, and beam transfer function using a parallelized weak-strong beam simulation code (BBSIMC). The simulation results are compared with measurements performed in RHIC during 2007 and 2008.

Kim, Hyung J.; Sen, Tanaji; /Fermilab; Abreu, Natalia P.; Fischer, Wolfram; /Brookhaven

2009-02-01T23:59:59.000Z

116

Electron-beam magnetic switch for a plurality of free-electron lasers  

DOE Patents (OSTI)

Apparatus for forming and utilizing a sequence of electron beam segments, each of the same temporal length (substantially 15 nsec), with consecutive beams being separated by a constant time interval of the order of 3 nsec is described. The beam sequence is used for simultaneous inputs to a plurality of wiggler magnet systems that also accept the laser beams to be amplified by interaction with the co-propagating electron beams. The electron beams are arranged substantially in a circle to allow proper distribution of and simultaneous switching out of the beam segments to their respective wiggler magnets.

Schlitt, L.G.

1982-01-26T23:59:59.000Z

117

Electron beam magnetic switch for a plurality of free electron lasers  

DOE Patents (OSTI)

Apparatus for forming and utilizing a sequence of electron beam segments, each of the same temporal length (substantially 15 nsec), with consecutive beams being separated by a constant time interval of the order of 3 nsec. The beam sequence is used for simultaneous inputs to a plurality of wiggler magnet systems that also accept the laser beams to be amplified by interaction with the co-propagating electron beams. The electron beams are arranged substantially in a circle to allow proper distribution of and simultaneous switching out of the beam segments to their respective wiggler magnets.

Schlitt, Leland G. (Livermore, CA)

1984-01-01T23:59:59.000Z

118

Apparatus and method for increasing the bandwidth of a laser beam  

DOE Patents (OSTI)

A method and apparatus is disclosed that provides a laser output beam having a broad bandwidth and an intensity smooth over time. The bandwidth of the laser output can be varied easily by varying the intensity of a broadband source. The present invention includes an optical modulation apparatus comprising a narrowband laser that outputs a horizontally polarized beam (a signal beam'') and a broadband laser that outputs a vertically polarized beam (a pump beam'') whose intensity varies rapidly. The two beams are coupled into a birefringent laser material so that the respective polarizations coincide with the principal axes of the material. As the two beams travel through the material, the polarization preserving properties of the birefringent material maintain the respective polarizations of the two beams; however there is coupling between the two beams as a result of cross phase modulation, which induces a bandwidth change of the signal beam. The amount of bandwidth change is dependent upon the average intensity of the pump beam. The beams are coupled out from the birefringent material and the modulated signal beam is separated by a polarization selector. The modulated signal beam now has a wider bandwidth, and its shape remains smooth in time. This signal beam can be applied to incoherence inducing systems. The different bandwidths required by these different incoherence inducing systems can be obtained by varying the intensity of the pump beam. 4 figs.

Chaffee, P.H.; Henesian, M.A.; Patterson, F.G.

1990-02-26T23:59:59.000Z

119

Simulation study of beam-beam effects in ion beams with large space charge tuneshift  

Science Conference Proceedings (OSTI)

During low-energy operations with gold-gold collisions at 3.85 GeV beam energy, significant beam lifetime reductions have been observed due to the beam-beam interaction in the presence of large space charge tuneshifts. These beam-beam tuneshift parameters were about an order of magnitude smaller than during regular high energy operations. To get a better understanding of this effect, simulations have been performed. Recent results are presented.

Montag C.

2012-05-20T23:59:59.000Z

120

Neutral particle beam intensity controller  

DOE Patents (OSTI)

The neutral beam intensity controller is based on selected magnetic defocusing of the ion beam prior to neutralization. The defocused portion of the beam is dumped onto a beam dump disposed perpendicular to the beam axis. Selective defocusing is accomplished by means of a magnetic field generator disposed about the neutralizer so that the field is transverse to the beam axis. The magnetic field intensity is varied to provide the selected partial beam defocusing of the ions prior to neutralization. The desired focused neutral beam portion passes along the beam path through a defining aperture in the beam dump, thereby controlling the desired fraction of neutral particles transmitted to a utilization device without altering the kinetic energy level of the desired neutral particle fraction. By proper selection of the magnetic field intensity, virtually zero through 100% intensity control of the neutral beam is achieved.

Dagenhart, W.K.

1984-05-29T23:59:59.000Z

Note: This page contains sample records for the topic "beam time esaf" 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

High intensity electron beam ion trap for charge state boosting of radioactive ion beams  

SciTech Connect

A high intensity electron beam ion trap under development at LLNL could be adapted for charge state boosting of radioactive ion beams, enabling a substantial reduction in the size and cost of a post-accelerator. We report estimates of the acceptance, ionization time, charge state distribution, emittance, and beam intensity for charge state boosting of radioactive ions in this device. The estimates imply that, for tin isotopes, over 10{sup 10} ions/s can be ionized to q = 40+ with an absolute emittance of approximately 1 (pi) mm mrad at an energy of 30 x q.k.

Marrs, R.

1998-09-30T23:59:59.000Z

122

Courses on Beam Physics  

NLE Websites -- All DOE Office Websites (Extended Search)

Beam Physics Beam Physics The following is an incomplete listing of course available for beam physics. United States Particle Accelerator School The US Particle Accelerator School provides educational programs in the field of beams and their associated accelerator technologies not otherwise available to the community of science and technology. Joint Universities Accelerator School Each year JUAS provides a foundation course on accelerator physics and associated technologies. The US-CERN-Japan-Russia Joint Accelerator School The purpose of the US-CERN-Japan-Russia joint school is to better our relations by working together on an advanced topical course every two years, alternating between the U.S., western Europe, Japan and Russia. The last set of courses focused on the frontiers of accelerator technology in

123

1996 Beam Instrumentation Workshop  

NLE Websites -- All DOE Office Websites (Extended Search)

1996 Beam Instrumentation Workshop BIW '96 logo The Advanced Photon Source (APS) Argonne National Laboratory May 6-9, 1996 Dear Colleague: It is my pleasure to invite you to the...

124

BNL | ATF Beam Schedule  

NLE Websites -- All DOE Office Websites (Extended Search)

Beam Schedule (pdf) Beam Schedule (pdf) Sunday Monday Tuesday Wednesday Thursday Friday Saturday 22 1/2 Holiday Holiday 28 January Holiday 4 5 Maintenance 11 12 Maintenance 18 19 Holiday AE52 - DWFA (Euclid), BL2 25 February AE52 - DWFA (Euclid), BL2 1 2 AE50 - PWFA in QNR (UCLA), BL2 8 9 AE50 - PWFA in QNR (UCLA), BL2 15 16 Holiday AE50 - PWFA in QNR (UCLA), BL2 22 March 1 2 AE53 - Nonlinear Compton (UCLA) 8 9 AE53 - Nonlinear Compton (UCLA) 15 16 AE53 - Nonlinear Compton (UCLA) 22 23 29 Sunday Monday Tuesday Wednesday Thursday Friday Saturday User operations (E-beam in use) Ions - Ion generation User operations (laser in use) PWFA - Plasma Wakefield Acceleration User operations (E-beam and laser in use)

125

Intense ion beam generator  

DOE Patents (OSTI)

Methods and apparatus for producing intense megavolt ion beams are disclosed. In one embodiment, a reflex triode-type pulsed ion accelerator is described which produces ion pulses of more than 5 kiloamperes current with a peak energy of 3 MeV. In other embodiments, the device is constructed so as to focus the beam of ions for high concentration and ease of extraction, and magnetic insulation is provided to increase the efficiency of operation.

Humphries, Jr., Stanley (Ithaca, NY); Sudan, Ravindra N. (Ithaca, NY)

1977-08-30T23:59:59.000Z

126

Beam/seam alignment control for electron beam welding  

DOE Patents (OSTI)

This invention relates to a dynamic beam/seam alignment control system for electron beam welds utilizing video apparatus. The system includes automatic control of workpiece illumination, near infrared illumination of the workpiece to limit the range of illumination and camera sensitivity adjustment, curve fitting of seam position data to obtain an accurate measure of beam/seam alignment, and automatic beam detection and calculation of the threshold beam level from the peak beam level of the preceding video line to locate the beam or seam edges.

Burkhardt, Jr., James H. (Knoxville, TN); Henry, J. James (Oak Ridge, TN); Davenport, Clyde M. (Knoxville, TN)

1980-01-01T23:59:59.000Z

127

Small Spot, Brighter Beam  

NLE Websites -- All DOE Office Websites (Extended Search)

Small Spot, Brighter Beam Small Spot, Brighter Beam Small Spot, Brighter Beam Print Do you notice the brighter beam? During the most recent shutdown, all of the corrector magnets were replaced with sextupoles, reducing the horizontal emittance and increasing beam brightness. "This is part of ongoing improvement to keep the ALS on the cutting edge," says Alastair MacDowell, a beamline scientist on Beamline 12.2.2. The brightness has increased by a factor of about three in the storage ring. Beamlines on superbend or center-bend magnets will see the most noticeable increase in brightness, but the horizontal beam size and divergence have been substantially reduced at all beamlines. "We are starting to approach the resolution of many beamlines. Therefore, not every beamline will be able to resolve the full improvement," says Christoph Steier, project leader of the brightness upgrade. Though superbend and center-bend magnet source sizes are reduced by roughly a factor of three, "measured improvements so far range from a factor of 2-2.5," Steier says. He and MacDowell agree that the beamline optics are likely the limiting factor in resolving the full improvement at the beamlines.

128

Wire Scanner Beam Profile Measurements: LANSCE Facility Beam Development  

SciTech Connect

The Los Alamos Neutron Science Center (LANSCE) is replacing Wire Scanner (WS) beam profile measurement systems. Three beam development tests have taken place to test the new wire scanners under beam conditions. These beam development tests have integrated the WS actuator, cable plant, electronics processors and associated software and have used H{sup -} beams of different beam energy and current conditions. In addition, the WS measurement-system beam tests verified actuator control systems for minimum profile bin repeatability and speed, checked for actuator backlash and positional stability, tested the replacement of simple broadband potentiometers with narrow band resolvers, and tested resolver use with National Instruments Compact Reconfigurable Input and Output (cRIO) Virtual Instrumentation. These beam tests also have verified how trans-impedance amplifiers react with various types of beam line background noise and how noise currents were not generated. This paper will describe these beam development tests and show some resulting data.

Gilpatrick, John D. [Los Alamos National Laboratory; Batygin, Yuri K. [Los Alamos National Laboratory; Gonzales, Fermin [Los Alamos National Laboratory; Gruchalla, Michael E. [Los Alamos National Laboratory; Kutac, Vincent G. [Los Alamos National Laboratory; Martinez, Derwin [Los Alamos National Laboratory; Sedillo, James Daniel [Los Alamos National Laboratory; Pillai, Chandra [Los Alamos National Laboratory; Rodriguez Esparza, Sergio [Los Alamos National Laboratory; Smith, Brian G. [Los Alamos National Laboratory

2012-05-15T23:59:59.000Z

129

Apparatus and method for laser beam diagnosis  

DOE Patents (OSTI)

An apparatus and method is disclosed for accurate, real time monitoring of the wavefront curvature of a coherent laser beam. Knowing the curvature, it can be quickly determined whether the laser beam is collimated, or focusing (converging), or de-focusing (diverging). The apparatus includes a lateral interferometer for forming an interference pattern of the laser beam to be diagnosed. The interference pattern is imaged to a spatial light modulator (SLM), whose output is a coherent laser beam having an image of the interference pattern impressed on it. The SLM output is focused to obtain the far-field diffraction pattern. A video camera, such as CCD, monitors the far-field diffraction pattern, and provides an electrical output indicative of the shape of the far-field pattern. Specifically, the far-field pattern comprises a central lobe and side lobes, whose relative positions are indicative of the radius of curvature of the beam. The video camera's electrical output may be provided to a computer which analyzes the data to determine the wavefront curvature of the laser beam.

Salmon, Jr., Joseph T. (Livermore, CA)

1991-01-01T23:59:59.000Z

130

Apparatus and method for laser beam diagnosis  

DOE Patents (OSTI)

An apparatus and method are disclosed for accurate, real time monitoring of the wavefront curvature of a coherent laser beam. Knowing the curvature, it can be quickly determined whether the laser beam is collimated, or focusing (converging), or de-focusing (diverging). The apparatus includes a lateral interferometer for forming an interference pattern of the laser beam to be diagnosed. The interference pattern is imaged to a spatial light modulator (SLM), whose output is a coherent laser beam having an image of the interference pattern impressed on it. The SLM output is focused to obtain the far-field diffraction pattern. A video camera, such as CCD, monitors the far-field diffraction pattern, and provides an electrical output indicative of the shape of the far-field pattern. Specifically, the far-field pattern comprises a central lobe and side lobes, whose relative positions are indicative of the radius of curvature of the beam. The video camera's electrical output may be provided to a computer which analyzes the data to determine the wavefront curvature of the laser beam. 11 figures.

Salmon, J.T. Jr.

1991-08-27T23:59:59.000Z

131

LHC Beam Diffusion Effects: Models and Measurements  

Science Conference Proceedings (OSTI)

Radio Frequency (RF) accelerating system noise and non-idealities can have detrimental impact on the LHC performance through longitudinal motion and longitudinal emittance growth. A theoretical formalism has been developed to relate the beam and RF loop dynamics with the bunch length growth [1]. Measurements were conducted at LHC to validate the formalism, determine the performance limiting RF components, and provide the foundation for beam diffusion estimates for higher energies and intensities. A brief summary of these results is presented in this work. During a long store, the relation between the energy lost to synchrotron radiation and the noise injected to the beam by the RF accelerating voltage determines the growth of the bunch energy spread and longitudinal emittance. Since the proton synchrotron radiation in the LHC is very low, the beam diffusion is extremely sensitive to RF perturbations. The theoretical formalism presented in [1], suggests that the noise experienced by the beam depends on the cavity phase noise power spectrum, filtered by the beam transfer function, and aliased due to the periodic sampling of the accelerating voltage signal V{sub c}. Additionally, the dependence of the RF accelerating cavity noise spectrum on the Low Level RF (LLRF) configurations has been predicted using time-domain simulations and models [2]. In this work, initial measurements at the LHC supporting the above theoretical formalism and simulation predictions are presented.

Mastorides, T.; /SLAC; Rivetta, C.; /SLAC; Fox, J.D.; /SLAC; Van Winkle, D.; /SLAC; Baudrenghien, P.; /CERN; Butterworth, A.; /CERN; Molendijk, J.; /CERN

2010-09-14T23:59:59.000Z

132

Single element laser beam shaper  

DOE Patents (OSTI)

A single lens laser beam shaper for converting laser beams from any spatial profile to a flat-top or uniform spatial profile. The laser beam shaper includes a lens having two aspheric surfaces. The beam shaper significantly simplifies the overall structure in comparison with conventional 2-element systems and therefore provides great ease in alignment and reduction of cost.

Zhang, Shukui (Yorktown, VA); Michelle D. Shinn (Newport News, VA)

2005-09-13T23:59:59.000Z

133

Electron Beam Powder Bed Processes  

Science Conference Proceedings (OSTI)

Advanced Materials, Processes and Applications for Additive Manufacturing : Electron Beam Powder Bed Processes Program Organizers: Andrzej ...

134

Method and apparatus for measuring properties of particle beams using thermo-resistive material properties  

SciTech Connect

A beam position detector for measuring the properties of a charged particle beam, including the beam's position, size, shape, and intensity. One or more absorbers are constructed of thermo-resistive material and positioned to intercept and absorb a portion of the incoming beam power, thereby causing local heating of each absorber. The local temperature increase distribution across the absorber, or the distribution between different absorbers, will depend on the intensity, size, and position of the beam. The absorbers are constructed of a material having a strong dependence of electrical resistivity on temperature. The beam position detector has no moving parts in the vicinity of the beam and is especially suited to beam areas having high ionizing radiation dose rates or poor beam quality, including beams dispersed in the transverse direction and in their time radio frequency structure.

Degtiarenko, Pavel V. (Williamsburg, VA); Dotson, Danny Wayne (Gloucester, VA)

2007-10-09T23:59:59.000Z

135

Beam Characterizations at Femtosecond Electron Beam Facility  

SciTech Connect

The SURIYA project at the Fast Neutron Research Facility (FNRF) has been established and is being commissioning to generate femtosecond (fs) electron bunches. Theses short bunches are produced by a system consisting of an S-band thermionic cathode RF-gun, an alpha magnet (a-magnet) serving as a magnetic bunch compressor, and a SLAC-type linear accelerator (linac). The characteristics of its major components and the beam characterizations as well as the preliminary experimental results will be presented and discussed in this paper.

Rimjaem, S.; Jinamoon, V.; Kangrang, M.; Kusoljariyakul, K.; Saisut, J.; Thongbai, C.; Vilaithong, T.; Rhodes, M.W.; Wichaisirimongkol, P.; /Chiang Mai U.; Wiedemann, H.; /SLAC

2006-03-17T23:59:59.000Z

136

Precision monitoring of relative beam intensity for Mu2e  

SciTech Connect

For future experiments at the intensity frontier, precise and accurate knowledge of beam time structure will be critical to understanding backgrounds. The proposed Mu2e experiment will utilize {approx}200 ns (FW) bunches of 3 x 10{sup 7} protons at 8 GeV with a bunch-to-bunch period of 1695 ns. The out-of-bunch beam must be suppressed by a factor of 10{sup -10} relative to in-bunch beam and continuously monitored. I propose a Cerenkov-based particle telescope to measure secondary production from beam interactions in a several tens of microns thick foil. Correlating timing information with beam passage will allow the determination of relative beam intensity to arbitrary precision given a sufficiently long integration time. The goal is to verify out-of-bunch extinction to the level 10{sup -6} in the span of several seconds. This will allow near real-time monitoring of the initial extinction of the beam resonantly extracted from Fermilabs Debuncher before a system of AC dipoles and collimators, which will provide the final extinction. The effect on beam emittance is minimal, allowing the necessary continuous measurement. I will present the detector design and some concerns about bunch growth during the resonant extraction.

Evans, N.J.; Kopp, S.E.; /Texas U.; Prebys, E.; /Fermilab

2011-04-01T23:59:59.000Z

137

Electron beam accelerator with magnetic pulse compression and accelerator switching  

DOE Patents (OSTI)

An electron beam accelerator comprising an electron beam generator-injector to produce a focused beam of .gtoreq.0.1 MeV energy electrons; a plurality of substantially identical, aligned accelerator modules to sequentially receive and increase the kinetic energies of the beam electrons by about 0.1-1 MeV per module. Each accelerator module includes a pulse-forming network that delivers a voltage pulse to the module of substantially 0.1-1 MeV maximum energy over a time duration of .ltoreq.1 .mu.sec.

Birx, Daniel L. (Brentwood, CA); Reginato, Louis L. (Orinda, CA)

1987-01-01T23:59:59.000Z

138

Electron beam accelerator with magnetic pulse compression and accelerator switching  

DOE Patents (OSTI)

An electron beam accelerator comprising an electron beam generator-injector to produce a focused beam of .gtoreq.0.1 MeV energy electrons; a plurality of substantially identical, aligned accelerator modules to sequentially receive and increase the kinetic energies of the beam electrons by about 0.1-1 MeV per module. Each accelerator module includes a pulse-forming network that delivers a voltage pulse to the module of substantially .gtoreq.0.1-1 MeV maximum energy over a time duration of .ltoreq.1 .mu.sec.

Birx, Daniel L. (Brentwood, CA); Reginato, Louis L. (Orinda, CA)

1988-01-01T23:59:59.000Z

139

Electron beam accelerator with magnetic pulse compression and accelerator switching  

DOE Patents (OSTI)

An electron beam accelerator is described comprising an electron beam generator-injector to produce a focused beam of greater than or equal to .1 MeV energy electrons; a plurality of substantially identical, aligned accelerator modules to sequentially receive and increase the kinetic energies of the beam electron by about .1-1 MeV per module. Each accelerator module includes a pulse-forming network that delivers a voltage pulse to the module of substantially .1-1 MeV maximum energy over a time duration of less than or equal to 1 ..mu..sec.

Birx, D.L.; Reginato, L.L.

1984-03-22T23:59:59.000Z

140

ICFA Beam Dynamics Newsletter  

SciTech Connect

The Collider-Accelerator Department at Brookhaven National Laboratory is building a high-brightness 500 mA capable Energy Recovery Linac (ERL) as one of its main R&D thrusts towards eRHIC, the polarized electron - hadron collider as an upgrade of the operating RHIC facility. The ERL is in final assembly stages, with injection commisioning starting in October 2012. The objective of this ERL is to serve as a platform for R&D into high current ERL, in particular issues of halo generation and control, Higher-Order Mode (HOM) issues, coherent emissions for the beam and high-brightness, high-power beam generation and preservation. The R&D ERL features a superconducting laser-photocathode RF gun with a high quantum efficiency photoccathode served with a load-lock cathode delivery system, a highly damped 5-cell accelerating cavity, a highly flexible single-pass loop and a comprehensive system of beam instrumentation. In this ICFA Beam Dynamics Newsletter article we will describe the ERL in a degree of detail that is not usually found in regular publications. We will discuss the various systems of the ERL, following the electrons from the photocathode to the beam dump, cover the control system, machine protection etc and summarize with the status of the ERL systems.

Ben-Zvi I.; Kuczewski A.; Altinbas, Z.; Beavis, D.; Belomestnykh,; Dai, J. et al

2012-07-01T23:59:59.000Z

Note: This page contains sample records for the topic "beam time esaf" 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

Two-dimensional visualization of cluster beams by microchannel plates  

E-Print Network (OSTI)

An advanced technique for a two-dimensional real time visualization of cluster beams in vacuum as well as of the overlap volume of cluster beams with particle accelerator beams is presented. The detection system consists of an array of microchannel plates (MCP) in combination with a phosphor screen which is read out by a CCD camera. This setup together with the ionization of a cluster beam by an electron or ion beam allows for spatial resolved investigations of the cluster beam position, size, and intensity. Moreover, since electrically uncharged clusters remain undetected, the operation in an internal beam experiment opens the way to monitor the overlap region and thus the position and size of an accelerator beam crossing an originally electrically neutral cluster jet. The observed intensity distribution of the recorded image is directly proportional to the convolution of the spatial ion beam and cluster beam intensities and is by this a direct measure of the two-dimensional luminosity distribution. This information can directly be used for the reconstruction of vertex positions as well as for an input for numerical simulations of the reaction zone. The spatial resolution of the images are dominated by the granularity of the complete MCP device and was found to be in the order of \\sigma~100 \\mu m.

Alfons Khoukaz; Daniel Bonaventura; Silke Grieser; Ann-Katrin Hergemöller; Esperanza Köhler; Alexander Täschner

2013-07-23T23:59:59.000Z

142

Colliding Crystalline Beams  

SciTech Connect

Crystalline Beams* are an ordered state of an ensemble of ions, circulating in a storage ring, with very small velocity fluctuations. They can be obtained from ordinary warm ion beams with the application of powerful cooling techniques (stochastic, electron, laser, ...). Depending on the focussing properties and dimensions of the storage ring, and on the ion beam density, several ground states are possible. All of them can be visualized as a bundle of n{sub s} symmetrically distributed, parallel strings. The longitudinal ion separation {lambda} is the same for all strings. The minimum temperature that can be achieved depends on die background noise of the cooling technique used. It is required for stability that the vibration amplitude of the ions is only a fraction of the separation {lambda}.

Haffmans, A.F.; Maletic, D.; Ruggiero, A.G.

1995-06-01T23:59:59.000Z

143

Method for producing uranium atomic beam source  

DOE Patents (OSTI)

A method for producing a beam of neutral uranium atoms is obtained by vaporizing uranium from a compound UM.sub.x heated to produce U vapor from an M boat or from some other suitable refractory container such as a tungsten boat, where M is a metal whose vapor pressure is negligible compared to that of uranium at the vaporization temperature. The compound, for example, may be the uranium-rhenium compound, URe.sub.2. An evaporation rate in excess of about 10 times that of conventional uranium beam sources is produced.

Krikorian, Oscar H. (Danville, CA)

1976-06-15T23:59:59.000Z

144

Beam specie analyzer for intense neutral beams  

DOE Green Energy (OSTI)

A three-channel neutral particle energy analyzer has been fabricated and calibrated for H/sup 0/ particles. H/sup 0/ with energies 3.5-55 keV was passed through a N/sub 2/ gas cell maintained at charge equilibrium pressures. H/sup +/ ions formed by stripping collisions were energy analyzed by a 45/sup 0/, parabolic, electrostatic analyzer and detected by three Faraday cups spaced to intercept the full-, half-, and third-energy beam components. The conversion efficiency of the analyzer system increased from 0.11 at 3.5 keV to 0.54 at 55 keV with an accuracy of +- 3%.

Barnett, C.F.; Ray, J.A.

1981-03-01T23:59:59.000Z

145

Electron beam dynamics for the ISIS bremsstrahlung beam generation system  

E-Print Network (OSTI)

An electron beam transport system was designed for use in the Bremsstrahlung Beam Generation System of the Integrated Stand-off Inspection System (ISIS). The purpose of this electron transport system was to provide for ...

Block, Robert E. (Robert Edward)

2011-01-01T23:59:59.000Z

146

Beam current sensor  

DOE Patents (OSTI)

A current sensor for measuring the dc component of a beam of charged particles employs a superconducting pick-up loop probe, with twisted superconducting leads in combination with a Superconducting Quantum Interference Device (SQUID) detector. The pick-up probe is in the form of a single-turn loop, or a cylindrical toroid, through which the beam is directed and within which a first magnetic flux is excluded by the Meisner effect. The SQUID detector acts as a flux-to-voltage converter in providing a current to the pick-up loop so as to establish a second magnetic flux within the electrode which nulls out the first magnetic flux. A feedback voltage within the SQUID detector represents the beam current of the particles which transit the pick-up loop. Meisner effect currents prevent changes in the magnetic field within the toroidal pick-up loop and produce a current signal independent of the beam's cross-section and its position within the toroid, while the combination of superconducting elements provides current measurement sensitivities in the nano-ampere range.

Kuchnir, M.; Mills, F.E.

1984-09-28T23:59:59.000Z

147

Beam current sensor  

DOE Patents (OSTI)

A current sensor for measuring the DC component of a beam of charged particles employs a superconducting pick-up loop probe, with twisted superconducting leads in combination with a Superconducting Quantum Interference Device (SQUID) detector. The pick-up probe is in the form of a single-turn loop, or a cylindrical toroid, through which the beam is directed and within which a first magnetic flux is excluded by the Meisner effect. The SQUID detector acts as a flux-to-voltage converter in providing a current to the pick-up loop so as to establish a second magnetic flux within the electrode which nulls out the first magnetic flux. A feedback voltage within the SQUID detector represents the beam current of the particles which transit the pick-up loop. Meisner effect currents prevent changes in the magnetic field within the toroidal pick-up loop and produce a current signal independent of the beam's cross-section and its position within the toroid, while the combination of superconducting elements provides current measurement sensitivites in the nano-ampere range.

Kuchnir, Moyses (Elmhurst, IL); Mills, Frederick E. (Elburn, IL)

1987-01-01T23:59:59.000Z

148

Beam Geometry Calibration of Sodars without Use of a Mast  

Science Conference Proceedings (OSTI)

A new method for calibration of sodar wind speed measurements is described. The method makes no assumptions whatsoever about the sodar operation and its hardware and software, other than the assumption that only one beam is transmitted at a time. ...

Stuart Bradley; Sabine von Hünerbein

2013-09-01T23:59:59.000Z

149

Agile-Beam Phased Array Radar for Weather Observations  

Science Conference Proceedings (OSTI)

Weather radars with conventional antenna cannot provide desired volume scan updates at intervals of one minute or less, which is essential for significant improvement in warning lead time of impending storm hazards. The agile-beam multimission ...

D. S. Zrnic; J. F. Kimpel; D. E. Forsyth; A. Shapiro; G. Crain; R. Ferek; J. Heimmer; W. Benner; T. J. McNellis; R. J. Vogt

2007-11-01T23:59:59.000Z

150

Positive and Negative Ion Beam Merging System for Neutral Beam ...  

APPLICATIONS OF TECHNOLOGY: Semiconductor manufacturing; Low- and medium-energy ion implantation; Fusion plasma systems requiring neutral beam ...

151

Neutral particle beam intensity controller  

DOE Patents (OSTI)

A neutral beam intensity controller is provided for a neutral beam generator in which a neutral beam is established by accelerating ions from an ion source into a gas neutralizer. An amplitude modulated, rotating magnetic field is applied to the accelerated ion beam in the gas neutralizer to defocus the resultant neutral beam in a controlled manner to achieve intensity control of the neutral beam along the beam axis at constant beam energy. The rotating magnetic field alters the orbits of ions in the gas neutralizer before they are neutralized, thereby controlling the fraction of neutral particles transmitted out of the neutralizer along the central beam axis to a fusion device or the like. The altered path or defocused neutral particles are sprayed onto an actively cooled beam dump disposed perpendicular to the neutral beam axis and having a central open for passage of the focused beam at the central axis of the beamline. Virtually zero therough 100% intensity control is achieved by varying the magnetic field strength without altering the ion source beam intensity or its species yield.

Dagenhart, William K. (Oak Ridge, TN)

1986-01-01T23:59:59.000Z

152

A possible method to produce a polarized antiproton beam at intermediate energies  

DOE Green Energy (OSTI)

A feasible and conservative design for a medium energy polarized antiproton beam has been presented. The design requires an intense beam of unpolarized antiprotons ({ge} 10{sup 7}/sec) from a typical secondary beam line in order to achieve reasonable {anti p}p elastic scattering count rates. All three beam spin directions can be achieved. Methods were discussed to reverse the spin directions in modest times, and to change to a polarized proton beam if desired. It is expected that experiments with such a beam would have a profound effect on the understanding of the {anti N}N interaction at intermediate energies.

Spinka, H.; Vaandering, E.W.; Hofmann, J.S. [Argonne National Lab., IL (United States). High Energy Physics Div.

1994-12-31T23:59:59.000Z

153

Beam experiments towards high-intensity beams in RHIC  

SciTech Connect

Proton bunch intensities in RHIC are planned to be increased from 2 {center_dot} 10{sup 11} to 3 {center_dot} 10{sup 11} protons per bunch to increase the luminosity, together with head-on beam-beam compensation using electron lenses. To study the feasibility of the intensity increase, beam experiments are being performed. Recent experimental results are presented.

Montag C.; Ahrens, L.; Brennan, J.M.; Blaskiewicz, M.; Drees, A.; Fischer, W.; Hayes, T.; Huang, H.; Mernick, K.; Robert-Demolaize, G.; Smith, K.; Than, R.; Thieberger, P.; Yip, K.; Zeno, K.; Zhang, S.Y.

2012-05-20T23:59:59.000Z

154

High-Performance Beam Simulator for the LANSCE Linac  

SciTech Connect

A high performance multiparticle tracking simulator is currently under development at Los Alamos. The heart of the simulator is based upon the beam dynamics simulation algorithms of the PARMILA code, but implemented in C++ on Graphics Processing Unit (GPU) hardware using NVIDIA's CUDA platform. Linac operating set points are provided to the simulator via the EPICS control system so that changes of the real time linac parameters are tracked and the simulation results updated automatically. This simulator will provide valuable insight into the beam dynamics along a linac in pseudo real-time, especially where direct measurements of the beam properties do not exist. Details regarding the approach, benefits and performance are presented.

Pang, Xiaoying [Los Alamos National Laboratory; Rybarcyk, Lawrence J. [Los Alamos National Laboratory; Baily, Scott A. [Los Alamos National Laboratory

2012-05-14T23:59:59.000Z

155

Focused ion beam direct fabrication of micro-optical elements: features compared with laser beam and electron beam direct writing  

E-Print Network (OSTI)

Three types of focused ion beam machine: focused ion beam milling (FIB milling), focused ion beam lithography (FIB lithography), and focused ion beam direct deposition (FIB deposition), are described in detail to compare ...

Fu, Yongqi

156

Dependence of the Photon Beam Characteristics on Electron Beam Parameters in Third Generation Synchrotron Light Sources  

E-Print Network (OSTI)

Dependence of the Photon Beam Characteristics on Electron Beam Parameters in Third Generation Synchrotron Light Sources

Ivanyan, M I; Tsakanov, V M

2002-01-01T23:59:59.000Z

157

Chirping the LCLS Electron Beam  

E-Print Network (OSTI)

We explore scenarios for generating a linear time-correlated energy spread in the LCLS electron bunch, prior to the undulator, that is needed for optical (x-ray) pulse compression. The correlated energy spread (`chirp') is formed by generating an energy gradient along the length of the electron bunch using RF phasing and/or longitudinal wakefields of the accelerating structures. The sign of the correlation is an important limitation. Excluding a complete re-design of the compression systems, the best possibility is to use `over-compression' to effect the required energy chirp. This is easily done with only a slight strength increase (~10 %) in the chicane bends of the second compressor. In this case, the bend-plane emittance dilution associated with the increased coherent synchrotron radiation (CSR) in the bunch compressor may, however, significantly compromise the electron beam density. The CSR calculations for the momentary extremely short (~1 m) electron bunch during over-compressio...

P. Emma

2000-01-01T23:59:59.000Z

158

Beam-stack search: Integrating backtracking with beam search  

E-Print Network (OSTI)

We describe a method for transforming beam search into a complete search algorithm that is guaranteed to find an optimal solution. Called beam-stack search, the algorithm uses a new data structure, called a beam stack, that makes it possible to integrate systematic backtracking with beam search. The resulting search algorithm is an anytime algorithm that finds a good, sub-optimal solution quickly, like beam search, and then backtracks and continues to find improved solutions until convergence to an optimal solution. We describe a memory-efficient implementation of beam-stack search, called divide-and-conquer beam-stack search, as well as an iterative-deepening version of the algorithm. The approach is applied to domain-independent STRIPS planning, and computational results show its advantages.

Rong Zhou; Eric A. Hansen

2005-01-01T23:59:59.000Z

159

Laser beam guard clamps  

DOE Patents (OSTI)

A quick insert and release laser beam guard panel clamping apparatus having a base plate mountable on an optical table, a first jaw affixed to the base plate, and a spring-loaded second jaw slidably carried by the base plate to exert a clamping force. The first and second jaws each having a face acutely angled relative to the other face to form a V-shaped, open channel mouth, which enables wedge-action jaw separation by and subsequent clamping of a laser beam guard panel inserted through the open channel mouth. Preferably, the clamping apparatus also includes a support structure having an open slot aperture which is positioned over and parallel with the open channel mouth.

Dickson, Richard K. (Stockton, CA)

2010-09-07T23:59:59.000Z

160

SSRL BEAM PORT SCHEDULE  

NLE Websites -- All DOE Office Websites (Extended Search)

1-5 1-5 Nov. 10, 2008 Nov. 11, 2008 Nov. 12, 2008 Nov. 13, 2008 Nov. 14, 2008 Nov. 15, 2008 Nov. 16, 2008 DOWN FACI FACI FACI FACI FACI FACI FACI FACI FACI FACI FACI FACI FACI FACI FACI FACI FACI FACI FACI FACI BEAM LINE 7-1 Nov. 10, 2008 Nov. 11, 2008 Nov. 12, 2008 Nov. 13, 2008 Nov. 14, 2008 Nov. 15, 2008 Nov. 16, 2008 DOWN FACI FACI FACI FACI FACI FACI

Note: This page contains sample records for the topic "beam time esaf" 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

SSRL BEAM PORT SCHEDULE  

NLE Websites -- All DOE Office Websites (Extended Search)

1-5 1-5 Nov. 05, 2007 Nov. 06, 2007 Nov. 07, 2007 Nov. 08, 2007 Nov. 09, 2007 Nov. 10, 2007 Nov. 11, 2007 Unscheduled FACI FACI FACI FACI FACI FACI FACI FACI FACI FACI FACI FACI FACI FACI FACI FACI FACI FACI FACI FACI BEAM LINE 7-1 Nov. 05, 2007 Nov. 06, 2007 Nov. 07, 2007 Nov. 08, 2007 Nov. 09, 2007 Nov. 10, 2007 Nov. 11, 2007 Unscheduled FACI FACI FACI FACI FACI FACI

162

SSRL BEAM PORT SCHEDULE  

NLE Websites -- All DOE Office Websites (Extended Search)

4 4 Mar. 15, 2004 Mar. 16, 2004 Mar. 17, 2004 Mar. 18, 2004 Mar. 19, 2004 Mar. 20, 2004 Mar. 21, 2004 DOWN DOWN DOWN DOWN DOWN DOWN DOWN DOWN DOWN DOWN DOWN DOWN DOWN DOWN DOWN DOWN DOWN DOWN DOWN DOWN DOWN BEAM LINE 1-5 Mar. 15, 2004 Mar. 16, 2004 Mar. 17, 2004 Mar. 18, 2004 Mar. 19, 2004 Mar. 20, 2004 Mar. 21, 2004 DOWN DOWN DOWN DOWN DOWN DOWN DOWN

163

SSRL BEAM PORT SCHEDULE  

NLE Websites -- All DOE Office Websites (Extended Search)

5-1 5-1 Nov. 28, 2005 Nov. 29, 2005 Nov. 30, 2005 Dec. 01, 2005 Dec. 02, 2005 Dec. 03, 2005 Dec. 04, 2005 MA FACI FACI FACI FACI FACI FACI FACI FACI FACI FACI FACI FACI FACI FACI FACI FACI FACI FACI FACI FACI BEAM LINE 5-2 Nov. 28, 2005 Nov. 29, 2005 Nov. 30, 2005 Dec. 01, 2005 Dec. 02, 2005 Dec. 03, 2005 Dec. 04, 2005 MA FACI FACI FACI FACI FACI FACI

164

Ion beam generating apparatus  

DOE Patents (OSTI)

An ion generating apparatus utilizing a vacuum chamber, a cathode and an anode in the chamber. A source of electrical power produces an arc or discharge between the cathode and anode. The arc is sufficient to vaporize a portion of the cathode to form a plasma. The plasma is directed to an extractor which separates the electrons from the plasma, and accelerates the ions to produce an ion beam.

Brown, Ian G. (1088 Woodside Rd., Berkeley, CA 94708); Galvin, James (2 Commodore #276, Emeryville, CA 94608)

1987-01-01T23:59:59.000Z

165

Ion beam generating apparatus  

DOE Patents (OSTI)

An ion generating apparatus utilizing a vacuum chamber, a cathode and an anode in the chamber. A source of electrical power produces an arc or discharge between the cathode and anode. The arc is sufficient to vaporize a portion of the cathode to form a plasma. The plasma is directed to an extractor which separates the electrons from the plasma, and accelerates the ions to produce an ion beam. 10 figs.

Brown, I.G.; Galvin, J.

1987-12-22T23:59:59.000Z

166

Relativistic electron beam device  

DOE Patents (OSTI)

A design is given for an electron beam device for irradiating spherical hydrogen isotope bearing targets. The accelerator, which includes hollow cathodes facing each other, injects an anode plasma between the cathodes and produces an approximately 10 nanosecond, megajoule pulse between the anode plasma and the cathodes. Targets may be repetitively positioned within the plasma between the cathodes, and accelerator diode arrangement permits materials to survive operation in a fusion power source. (auth)

Freeman, J.R.; Poukey, J.W.; Shope, S.L.; Yonas, G.

1975-07-01T23:59:59.000Z

167

Stationary nonlinear Airy beams  

Science Conference Proceedings (OSTI)

We demonstrate the existence of an additional class of stationary accelerating Airy wave forms that exist in the presence of third-order (Kerr) nonlinearity and nonlinear losses. Numerical simulations and experiments, in agreement with the analytical model, highlight how these stationary solutions sustain the nonlinear evolution of Airy beams. The generic nature of the Airy solution allows extension of these results to other settings, and a variety of applications are suggested.

Lotti, A. [Dipartimento di Fisica e Matematica, Universita del'Insubria, Via Valleggio 11, I-22100 Como (Italy); Centre de Physique Theorique, CNRS, Ecole Polytechnique, F-91128 Palaiseau (France); Faccio, D. [Dipartimento di Fisica e Matematica, Universita del'Insubria, Via Valleggio 11, I-22100 Como (Italy); School of Engineering and Physical Sciences, SUPA, Heriot-Watt University, Edinburgh EH14 4AS (United Kingdom); Couairon, A. [Centre de Physique Theorique, CNRS, Ecole Polytechnique, F-91128 Palaiseau (France); Papazoglou, D. G. [Institute of Electronic Structure and Laser (IESL), Foundation for Research and Technology, Hellas (FORTH), P.O. Box 1527, GR-71110 Heraklion (Greece); Materials Science and Technology Department, University of Crete, GR-71003 Heraklion (Greece); Panagiotopoulos, P.; Tzortzakis, S. [Institute of Electronic Structure and Laser (IESL), Foundation for Research and Technology, Hellas (FORTH), P.O. Box 1527, GR-71110 Heraklion (Greece); Abdollahpour, D. [Institute of Electronic Structure and Laser (IESL), Foundation for Research and Technology, Hellas (FORTH), P.O. Box 1527, GR-71110 Heraklion (Greece); Physics Department, University of Crete, GR-71003 Heraklion (Greece)

2011-08-15T23:59:59.000Z

168

Towards demonstration of electron cooling with bunched electron beam  

SciTech Connect

All electron cooling systems which were in operation so far employed electron beam generated with an electrostatic electron gun in DC operating mode, immersed in a longitudinal magnetic field. At low energies magnetic field is also being used to transport electron beam through the cooling section from the gun to the collector. At higher energies (few MeV), it was shown that one can have simpler electron beam transport without continuous magnetic field. Because of a rather weak magnetic field on the cathode and in the cooling section the latter approach was referred to as 'non-magnetized cooling', since there was no suppression of the transverse angular spread of the electron beam with the magnetic field in the cooling section. Such a cooler successfully operated at FNAL (2005-11) at electron beam energy of 4.3 MeV. Providing cooling at even higher energies would be easier with RF acceleration of electron beam, and thus using bunched electron beam for cooling. Significant efforts were devoted to explore various aspects of such bunched electron beam cooling as part of R and D of high-energy electron cooling for RHIC. However, experimental studies of such cooling are still lacking. Establishing this technique experimentally would be extremely useful for future high-energy applications. Presently there is an ongoing effort to build Proof-of-Principle (PoP) experiment of Coherent Electron Cooling (CEC) at RHIC, which promises to be superior to conventional electron cooling for high energies. Since the CEC experiment is based on bunched electron beam and it has sections where electron beam co-propagates with the ion beam at the same velocity, it also provides a unique opportunity to explore experimentally conventional electron cooling but for the first time with a bunched electron beam. As a result, it allows us to explore techniques needed for the high-energy electron cooling such as 'painting' with a short electron beam and control of ion beam distribution under cooling which is essential if cooling is provided in a collider. The software needed for comparison with the experiments is already developed as part of the previous high-energy electron cooling studies for RHIC. Since electron beam will be non-magnetized and there will be no magnetic field in the cooling section it will be also a first demonstration of fully non-magnetized cooling. The purpose of these studies was to explore whether we would be able to observe conventional electron cooling with parameters expected in the CEC PoP experiment. Below we summarize requirements on electron beam and cooling section needed for such demonstration.

Fedotov, A.

2012-01-11T23:59:59.000Z

169

Observation of Beam ION Instability in Spear3  

SciTech Connect

Weak vertical coupled bunch instability with oscillation amplitude at {mu}m level has been observed in SPEAR3. The instability becomes stronger when there is a vacuum pressure rise by partially turning off vacuum pumps and it becomes weaker when the vertical beam emittance is increased by turning off the skew quadrupole magnets. These confirmed that the instability was driven by ions in the vacuum. The threshold of the beam ion instability when running with a single bunch train is just under 200 mA. This paper presents the comprehensive observations of the beam ion instability in SPEAR3. The effects of vacuum pressure, beam current, beam filling pattern, chromaticity, beam emittance and bunch-by-bunch feedback are investigated in great detail. In an electron accelerator, ions generated from the residual gas molecules can be trapped by the beam. Then these trapped ions interact resonantly with the beam and cause beam instability and emittance blow-up. Most existing light sources use a long single bunch train filling pattern, followed by a long gap to avoid multi-turn ion trapping. However, such a gap does not preclude ions from accumulating during one passage of the single bunch train beam, and those ions can still cause a Fast Ion Instability (FII) as predicted by Raubenheimer and Zimmermann. FII has been observed in ALS, and PLS by artificially increasing the vacuum pressure by injecting helium gas into the vacuum chamber or by turning off the ion pumps in order to observe the beam ion instability. In some existing rings, for instance B factory, the beam ion instability was observed at the beginning of the machine operation after a long period of shutdown and then it automatically disappeared when the vacuum was better. However, when the beam emittance becomes smaller, the FII can occur at nominal conditions as observed in PLS, SOLEIL and SSRF. This paper reports the observations of beam ion instabilities in SPEAR3 under different condition during a period of one year, which includes single bunch train instability (FII) and multi-bunch train instability. Note that the instability may be not the same even with the same beam due to the change of the vacuum with time. SPEAR3 has a circumference of 234 m with a harmonic number of 372. SPEAR3 runs with six bunch train filling pattern in order to suppress the possible beam ion instability. Table 1 lists the main parameters of SPEAR3. The vacuum of SPEAR3 ranges from 0.1 to 0.5 nTorr, which varies from section to section.

Teytelman, D.; /Dimtel, Redwood City; Cai, Y.; Corbett, W.J.; Raubenheimer, T.O.; Safranek, J.A.; Schmerge, J.F.; Sebek, J.J.; Wang, L.; /SLAC

2011-12-14T23:59:59.000Z

170

Integrals for IBS and beam cooling  

SciTech Connect

Simulation of beam cooling usually requires performing certain integral transformations every time step or so, which is a significant burden on the CPU. Examples are the dispersion integrals (Hilbert transforms) in the stochastic cooling, wake fields and IBS integrals. An original method is suggested for fast and sufficiently accurate computation of the integrals. This method is applied for the dispersion integral. Some methodical aspects of the IBS analysis are discussed.

Burov, A.; /Fermilab

2005-01-01T23:59:59.000Z

171

Beam-Beam Interaction Simulations with Guinea Pig  

NLE Websites -- All DOE Office Websites (Extended Search)

5 5 SLAC-TN-03-070 September 2003 Beam-Beam Interaction Simulations with Guinea Pig C. Sramek, T. O. Raubenheimer, A. Seryi, M. Woods, J. Yu Stanford Linear Accelerator Center Stanford University Stanford, CA Abstract: At the interaction point of a particle accelerator, various phenomena occur that are known as beam-beam effects. Incident bunches of electrons (or positrons) experience strong electromagnetic fields from the opposing bunches, which leads to electron deflection, beamstrahlung and the creation of electron/positron pairs and hadrons due to two-photon exchange. In addition, the beams experience a "pinch effect" which focuses each beam and results in either a reduction or expansion of their vertical size. Finally, if a

172

BEAM HALO FORMATION IN HIGH-INTENSITY BEAMS.  

SciTech Connect

Studies of beam halo became unavoidable feature of high-intensity machines where uncontrolled beam loss should be kept to extremely small level. For a well controlled stable beam such a loss is typically associated with the low density halo surrounding beam core. In order to minimize uncontrolled beam loss or improve performance of an accelerator, it is very important to understand what are the sources of halo formation in a specific machine of interest. The dominant mechanisms are, in fact, different in linear accelerators, circular machines or Energy Recovering Linacs (ERL). In this paper, we summarize basic mechanisms of halo formation in high-intensity beams and discuss their application to various types of accelerators of interest, such as linacs, rings and ERL.

FEDOTOV, A.V.

2005-03-18T23:59:59.000Z

173

A low energy beam transport system for proton beam  

SciTech Connect

A low energy beam transport (LEBT) system has been built for a compact pulsed hadron source (CPHS) at Tsinghua University in China. The LEBT, consisting of two solenoids and three short-drift sections, transports a pulsed proton beam of 60 mA of energy of 50 keV to the entrance of a radio frequency quadrupole (RFQ). Measurement has shown a normalized RMS beam emittance less than 0.2 {pi} mm mrad at the end of the LEBT. Beam simulations were carried out to compare with the measurement and are in good agreement. Based on the successful CPHS LEBT development, a new LEBT for a China ADS projector has been designed. The features of the new design, including a beam chopper and beam simulations of the LEBT are presented and discussed along with CPHS LEBT development in this article.

Yang, Y. [Institute of Modern Physics, CAS, Lanzhou 730000 (China); University of Chinese Academy of Sciences, Beijing 100039 (China); Zhang, Z. M.; Wu, Q.; Zhang, W. H.; Ma, H. Y.; Sun, L. T.; Zhang, X. Z.; Liu, Z. W.; He, Y.; Zhao, H. W.; Xie, D. Z. [Institute of Modern Physics, CAS, Lanzhou 730000 (China)

2013-03-15T23:59:59.000Z

174

Beam Loss Monitors for NSLS-II Storage Ring  

SciTech Connect

The shielding for the NSLS-II storage ring will provide adequate protection for the full injected beam losses in two cells of the ring around the injection point, but the remainder of the ring is shielded for lower losses of <10% top-off injection beam current. This will require a system to insure that beam losses do not exceed levels for a period of time that could cause excessive radiation exposure outside the shield walls. This beam Loss Control and Monitoring system will have beam loss monitors that will measure where the beam charge is lost around the ring, to warn operators if losses approach the design limits. To measure the charge loss quantitatively, we propose measuring the electron component of the shower as beam electrons hit the vacuum chamber (VC) wall. This will be done using the Cerenkov light as electrons transit ultra-pure fused silica rods placed close to the inner edge of the VC. The entire length of the rod will collect light from the electrons of the spread out shower resulting from the small glancing angle of the lost beam particles to the VC wall. The design and measurements results of the prototype Cerenkov BLM will be presented.

Kramer, S.L.; Cameron, P.

2011-03-28T23:59:59.000Z

175

SSRL BEAM PORT SCHEDULE  

NLE Websites -- All DOE Office Websites (Extended Search)

5 5 Mar. 15, 2004 Mar. 16, 2004 Mar. 17, 2004 Mar. 18, 2004 Mar. 19, 2004 Mar. 20, 2004 Mar. 21, 2004 DOWN DOWN DOWN DOWN DOWN DOWN DOWN DOWN DOWN DOWN DOWN DOWN DOWN DOWN DOWN DOWN DOWN DOWN DOWN DOWN DOWN BEAM LINE 9-1 Mar. 15, 2004 Mar. 16, 2004 Mar. 17, 2004 Mar. 18, 2004 Mar. 19, 2004 Mar. 20, 2004 Mar. 21, 2004 Unscheduled CHANGE/8837 A.COHE 8837 A.COHEN 8837 A.COHEN 8837 A.COHEN 8837 A.COHEN 8837 A.COHEN

176

SSRL BEAM PORT SCHEDULE  

NLE Websites -- All DOE Office Websites (Extended Search)

1-4 1-4 Oct. 30, 2006 Oct. 31, 2006 Nov. 01, 2006 Nov. 02, 2006 Nov. 03, 2006 Nov. 04, 2006 Nov. 05, 2006 DOWN Unscheduled Unscheduled Unscheduled Unscheduled Unscheduled Unscheduled Unscheduled Unscheduled Unscheduled Unscheduled Unscheduled Unscheduled Unscheduled Unscheduled Unscheduled Unscheduled Unscheduled Unscheduled Unscheduled Unscheduled BEAM LINE 2-1 Oct. 30, 2006 Oct. 31, 2006 Nov. 01, 2006 Nov. 02, 2006 Nov. 03, 2006 Nov. 04, 2006 Nov. 05, 2006 DOWN 8859 B.JOHNSON 8859 B.JOHNSON 8859 B.JOHNSON 8859 B.JOHNSON 8859 B.JOHNSON 8859 B.JOHNSON

177

Precision Absolute Beam Current Measurement of Low Power Electron Beam  

SciTech Connect

Precise measurements of low power CW electron beam current for the Jefferson Lab Nuclear Physics program have been performed using a Tungsten calorimeter. This paper describes the rationale for the choice of the calorimeter technique, as well as the design and calibration of the device. The calorimeter is in use presently to provide a 1% absolute current measurement of CW electron beam with 50 to 500 nA of average beam current and 1-3 GeV beam energy. Results from these recent measurements will also be presented.

Ali, M. M.; Bevins, M. E.; Degtiarenko, P.; Freyberger, A.; Krafft, G. A.

2012-11-01T23:59:59.000Z

178

Implications of beam phase and RFSUM measured near transition  

SciTech Connect

Understanding the transition-crossing process is crucial for improving Booster performance at high intensity. The synchronous phase appears to drop toward 90{sup o} right after transition regardless of beam intensity, more so at higher beam intensity. The implication is that the effective rf voltage (RFSUM) will run into a limit right after transition when the synchronous phase reaches 90{sup o} for high intensity beam. A reduction in RFSUM is also observed at the same time. Solutions, such as raising the rf voltage during the transition period or controlling the RFSUM reduction by increasing longitudinal emittance before transition, are potentially important for high intensity operation.

Xi Yang; James MacLachlan

2004-04-09T23:59:59.000Z

179

LANL: Ion Beam Materials Laboratory  

NLE Websites -- All DOE Office Websites (Extended Search)

Ion Beam Materials Laboratory (IBML) is a Los Ion Beam Materials Laboratory (IBML) is a Los Alamos National Laboratory resource devoted to materi- als research through the use of ion beams. Current major research areas include surface characterization through ion beam analysis techniques, surface modification and materials synthesis through ion implantation technology, and radiation damage stud- ies in gases, liquids, and solids. The laboratory's core is a 3.2 MV tandem ion accelerator and a 200 kV ion implanter together with several beam lines. Attached to each beam line is a series of experimental stations that support various research programs. The operation of IBML and its interactions with users are organized around core facilities and experimental stations. The IBML provides and operates the core facilities as well as supports

180

Fast Beam Conditions Monitor BCM1F for the CMS Experiment  

E-Print Network (OSTI)

The CMS Beam Conditions and Radiation Monitoring System, BRM, will support beam tuning, protect the CMS detector from adverse beam conditions, and measure the accumulated dose close to or inside all sub-detectors. It is composed of different sub-systems measuring either the particle flux near the beam pipe with time resolution between nano- and microseconds or the integrated dose over longer time intervals. This paper presents the Fast Beam Conditions Monitor, BCM1F, which is designed for fast flux monitoring measuring both beam halo and collision products. BCM1F is located inside the CMS pixel detector volume close to the beam-pipe. It uses sCVD diamond sensors and radiation hard front-end electronics, along with an analog optical readout of the signals. The commissioning of the system and its successful operation during the first be ams of the LHC are described.

Bell, A; Hall-Wilton, R; Lange, W; Lohmann, W; Macpherson, A; Ohlerich, M; Rodriguez, N; Ryjov, V; Schmidt, R S; Stone, R L

2010-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "beam time esaf" from the National Library of EnergyBeta (NLEBeta).
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181

Apparatus and method for increasing the bandwidth of a laser beam  

SciTech Connect

A method and apparatus is disclosed that provides a laser output beam having a broad bandwidth and an intensity smooth over time. The bandwidth of the laser output can be varied easily by varying the intensity of a broadband source. The present invention includes an optical modulation apparatus comprising a narrowband laser that outputs a horizontally polarized beam (a "signal beam") and a broadband laser that outputs a vertically polarized beam (a "pump beam") whose intensity varies rapidly. The two beam are coupled into a birefringent laser material so that the respective polarizations coincide with the principal axes of the material. As the two beams travel through the material, the polarization preserving properties of the birefringent material maintain the respective polarizations of the two beam; however there is coupling between the two beams as a result of cross phase modulations, which induces a bandwidth change of the signal beam. The amount of bandwidth change is dependent upon the average intensity of the pump beam. The beams are coupled out from the birefringent material and the modulated signal beam is separated by a polarization selector. The modulated signal beam now has a wider bandwidth, and its shape remains smooth in time. This signal beam can be applied to incoherence inducing systems. The different bandwidths required by these different incoherence inducing systems can be obtained by varying the intensity of the pump beam. The United States Government has rights in this invention pursuant to Contract No. W7405-ENG-48 between the United States Department of Energy and the University of California for the operation of Lawrence Livermore National Laboratory.

Chaffee, Paul H. (Bolina, CA)

1991-01-01T23:59:59.000Z

182

Beam-line cryopump  

DOE Green Energy (OSTI)

A cryopumping module using metallic surfaces at liquid helium temperature for condensation of hydrogen and deuterium gas has been constructed. This pump, a prototype of four units which will provide pumping for the Livermore 200 kV test stand, will be used to verify the concept and establish engineering parameters. Upon completion of engineering tests and evaluation the pump will be installed in an operating beam line. The design point pumping capacity is 80,000 liters per second for hydrogen and deuterium at 10$sup -4$ torr based on sticking coefficients of 0.15 and 0.25, respectively. Both the liquid helium temperature pumping surface and the liquid nitrogen temperature radiation shields are constructed of quilted double wall cylindrical shells. The pumping shell dimensions are 1.5 meters dia. x 0.6 meters long. Cryogen circulation is convection current driven in both cases. Liquid helium is supplied from an overhead Dewar through bayonet coupling. In the 200 kV beam line, pumping modules will be supplied via transfer lines from a central Dewar. Voltage standoff will be accomplished in the transfer lines. (auth)

Duffy, T.J.; Oddon, L.D.

1975-11-12T23:59:59.000Z

183

Compact time-of-flight mass spectrometer  

SciTech Connect

This paper describes a time-of-flight mass spectrometer developed for measuring the parameters of a pulsed hydrogen beam. The duration of an electron-beam current pulse in the ionizer of the mass spectrometer can be varied within 2-20 usec, the pulse electron current is 0.6 mA, and the electron energy is 250 eV. The time resolution of the mass spectrometer is determined by the repetition period of the electron-beam current pulses and is 40 usec. The mass spectrometer has 100% transmission in the direction of motion of molecular-beam particles. The dimension of the mass spectrometer is 7 cm in this direction. The mass resolution is sufficient for determination of the composition of the hydrogen beam.

Belov, A.S.; Kubalov, S.A.; Kuzik, V.F.; Yakushev, V.P.

1986-02-01T23:59:59.000Z

184

Beam emittance measurements at Fermilab  

Science Conference Proceedings (OSTI)

We give short overview of various beam emittance measurement methods, currently applied at different machine locations for the Run II collider physics program at Fermilab. All these methods are based on beam profile measurements, and we give some examples of the related instrumentation techniques. At the end we introduce a multi-megawatt proton source project, currently under investigation at Fermilab, with respect to the beam instrumentation challenges.

Wendt, Manfred; Eddy, Nathan; Hu, Martin; Scarpine, Victor; Syphers, Mike; Tassotto, Gianni; Thurman-Keup, Randy; Yang, Ming-Jen; Zagel, James; /Fermilab

2008-01-01T23:59:59.000Z

185

Flattening Filter Free vs Flattened Beams for Breast Irradiation  

SciTech Connect

Purpose: Flattening filter free (FFF) beams offer the potential for a higher dose rate, shorter treatment time, and lower peripheral dose. To investigate their role in large-field treatments, this study compared flattened and FFF beams for breast irradiation. Methods and Materials: Ten left breast clinical plans comprising 2 tangential beams and a medially located 3-field simultaneous integrated boost (SIB) were replanned. Full intensity modulated radiotherapy (IMRT), hybrid IMRT, electronic tissue compensator (ETC), and multiple static field treatment plans were created for the elective breast volume using flattened and FFF beams, in combination with a 3-field IMRT SIB. Plan quality was assessed and delivery times were measured for all plans for 1 patient. Out-of-field doses were measured using an ionization chamber for an IMRT plan optimized on a corner of simple cubic phantom for both flattened and FFF beams. Results: For each technique, mean target volume metrics (planning target volume coverage, homogeneity, conformity) were typically within 3% for flattened and FFF beams. Larger mean differences in boost conformity favoring flattened hybrid (7.2%) and full IMRT (5.5%) plans may have reflected limitations in plan normalization. Calculated heart and ipsilateral lung doses were comparable; however, both flattened and FFF low-dose phantom measurements were substantially higher than calculated values, rendering the comparison of low dose in the contralateral breast uncertain. Beam delivery times were on average 31% less for FFF. Conclusions: In general, target volume metrics for flattened and FFF plans were comparable. The planning system did not seem to allow for accurate peripheral dose evaluation. FFF was associated with a potentially shorter treatment time. All 4 IMRT techniques allowed FFF beams to generate acceptable plans for breast IMRT.

Spruijt, Kees H., E-mail: k.spruijt@vumc.nl [Department of Radiation Oncology, VU University Medical Center, De Boelelaan 1117, 1081HV Amsterdam (Netherlands); Dahele, Max; Cuijpers, Johan P.; Jeulink, Marloes; Rietveld, Derek; Slotman, Ben J.; Verbakel, Wilko F.A.R. [Department of Radiation Oncology, VU University Medical Center, De Boelelaan 1117, 1081HV Amsterdam (Netherlands)

2013-02-01T23:59:59.000Z

186

Broad-band beam buncher  

DOE Patents (OSTI)

A broad-band beam buncher is disclosed, comprising an evacuated housing, an electron gun therein for producing an electron beam, a buncher cavity having entrance and exit openings through which the beam is directed, grids across such openings, a source providing a positive DC voltage between the cavity and the electron gun, a drift tube through which the electron beam travels in passing through such cavity, grids across the ends of such drift tube, gaps being provided between the drift tube grids and the entrance and exit grids, a modulator for supplying an ultrahigh frequency modulating signal to the drift tube for producing velocity modulation of the electrons in the beam, a drift space in the housing through which the velocity modulated electron beam travels and in which the beam is bunched, and a discharge opening from such drift tube and having a grid across such opening through which the bunched electron beam is discharged into an accelerator or the like. The buncher cavity and the drift tube may be arranged to constitute an extension of a coaxial transmission line which is employed to deliver the modulating signal from a signal source. The extended transmission line may be terminated in its characteristic impedance to afford a broad-band response and the device as a whole designed to effect broad-band beam coupling, so as to minimize variations of the output across the response band.

Goldberg, David A. (Walnut Creek, CA); Flood, William S. (Berkeley, CA); Arthur, Allan A. (Martinez, CA); Voelker, Ferdinand (Orinda, CA)

1986-01-01T23:59:59.000Z

187

Electron Beam Melting (EBM) II  

Science Conference Proceedings (OSTI)

Oct 19, 2011 ... Additive Manufacturing of Metals: Electron Beam Melting (EBM) II Sponsored by: MS&T Organization Program Organizers: Ian D. Harris, EWI; ...

188

NEUTRAL-BEAM INJECTION  

SciTech Connect

The emphasis in the preceding chapters has been on magnetic confinement of high temperature plasmas. The question of production and heating of such plasmas has been dealt with relatively more briefly. It should not be inferred, however, that these matters must therefore be either trivial or unimportant. A review of the history reveals that in the early days all these aspects of the controlled fusion problem were considered to be on a par, and were tackled simultaneously and with equal vigor. Only the confinement problem turned out to be much more complex than initially anticipated, and richer in challenge to the plasma physicist than the questions of plasma production and heating. On the other hand, the properties of high-temperature plasmas and plasma confinement can only be studied experimentally after the problems of production and of heating to adequate temperatures are solved. It is the purpose of this and the next chapter to supplement the preceding discussions with more detail on two important subjects: neutral-beam injection and radio-frequency heating. These are the major contenders for heating in present and future tokamak and mirror fusion experiments, and even in several proposed reactors. For neutral beams we emphasize here the technology involved, which has undergone a rather remarkable development. The physics of particle and energy deposition in the plasma, and the discussion of the resulting effects on the confined plasma, have been included in previous chapters, and some experimental results are quoted there. Other heating processes of relevance to fusion are mentioned elsewhere in this book, in connection with the experiments where they are used: i.e. ohmic heating, adiabatic compression heating, and alpha-particle heating in Chapter 3 by H.P. Furth; more ohmic heating in Chapter 7, and shock-implosion heating, laser heating, and relativistic-electron beam heating in Chapter 8, both by W. E. Quinn. These methods are relatively straightforward in their physics and their technology, or in any case they are considered to be adequately covered by these other authors.

Kunkel, W.B.

1980-06-01T23:59:59.000Z

189

Heavy Oil Upgrading from Electron Beam (E-Beam) Irradiation  

E-Print Network (OSTI)

Society's growing demands for energy results in rapid increase in oil consumption and motivates us to make unconventional resources conventional resources. There are enormous amounts of heavy oil reserves in the world but the lack of cost effective technologies either for extraction, transportation, or refinery upgrading hinders the development of heavy oil reserves. One of the critical problems with heavy oil and bitumen is that they require large amounts of thermal energy and expensive catalysts to upgrade. This thesis demonstrates that electron beam (E-Beam) heavy oil upgrading, which uses unique features of E-Beam irradiation, may be used to improve conventional heavy oil upgrading. E-Beam processing lowers the thermal energy requirements and could sharply reduce the investment in catalysts. The design of the facilities can be simpler and will contribute to lowering the costs of transporting and processing heavy oil and bitumen. E-Beam technology uses the high kinetic energy of fast electrons, which not only transfer their energy but also interact with hydrocarbons to break the heavy molecules with lower thermal energy. In this work, we conducted three major stages to evaluate the applicability of E-Beam for heavy oil upgrading. First, we conducted laboratory experiments to investigate the effects of E-Beam on hydrocarbons. To do so, we used a Van de Graff accelerator, which generates the high kinetic energy of electrons, and a laboratory scale apparatus to investigate extensively how radiation effects hydrocarbons. Second, we studied the energy transfer mechanism of E-Beam upgrading to optimize the process. Third, we conducted a preliminary economic analysis based on energy consumption and compared the economics of E-Beam upgrading with conventional upgrading. The results of our study are very encouraging. From the experiments we found that E-Beam effect on hydrocarbon is significant. We used less thermal energy for distillation of n-hexadecane (n-C16) and naphtha with E-Beam. The results of experiments with asphaltene indicate that E-Beam enhances the decomposition of heavy hydrocarbon molecules and improves the quality of upgraded hydrocarbon. From the study of energy transfer mechanism, we estimated heat loss, fluid movement, and radiation energy distribution during the reaction. The results of our economic evaluation show that E-Beam upgrading appears to be economically feasible in petroleum industry applications. These results indicate significant potential for the application of E-Beam technology throughout the petroleum industry, particularly near production facilities, transportation pipelines, and refining industry.

Yang, Daegil

2009-12-01T23:59:59.000Z

190

Tuning the beam: a physics perspective on beam diagnostic instrumentation  

SciTech Connect

In a nutshell, the role of a beam diagnostic measurement is to provide information needed to get a particle beam from Point A (injection point) to Point B (a target) in a useable condition, with 'useable' meaning the right energy and size and with acceptable losses. Specifications and performance requirements of diagnostics are based on the physics of the particle beam to be measured, with typical customers of beam parameter measurements being the accelerator operators and accelerator physicists. This tutorial will be a physics-oriented discussion of the interplay between tuning evolutions and the beam diagnostics systems that support the machine tune. This will include the differences between developing a tune and maintaining a tune, among other things. Practical longitudinal and transverse tuning issues and techniques from a variety of proton and electron machines will also be discussed.

Gulley, Mark S [Los Alamos National Laboratory

2010-01-01T23:59:59.000Z

191

SSRL BEAM PORT SCHEDULE  

NLE Websites -- All DOE Office Websites (Extended Search)

5-4 5-4 Nov. 05, 2007 Nov. 06, 2007 Nov. 07, 2007 Nov. 08, 2007 Nov. 09, 2007 Nov. 10, 2007 Nov. 11, 2007 Unscheduled 8820 D.LU 8820 D.LU 8820 D.LU 8820 D.LU 8820 D.LU 8820 D.LU CHANGE/8820 D.LU 8820 D.LU 8820 D.LU 8820 D.LU 8820 D.LU 8820 D.LU 8820 D.LU 8820 D.LU 8820 D.LU 8820 D.LU 8820 D.LU 8820 D.LU 8820 D.LU 8820 D.LU BEAM LINE 8-1 Nov. 05, 2007 Nov. 06, 2007 Nov. 07, 2007 Nov. 08, 2007 Nov. 09, 2007 Nov. 10, 2007 Nov. 11, 2007 8821 D.Brehmer 8821 D.Brehmer 8821 D.Brehmer 3064* S.SUN 3075 M.GARNER 3075 M.GARNER 3075 M.GARNER

192

SSRL BEAM PORT SCHEDULE  

NLE Websites -- All DOE Office Websites (Extended Search)

4, 2013 Nov. 11, 2013 Nov. 18, 2013 Nov. 25, 2013 4, 2013 Nov. 11, 2013 Nov. 18, 2013 Nov. 25, 2013 Dec. 02, 2013 Dec. 09, 2013 Dec. 16, 2013 Dec. 23, 2013 Dec. 30, 2013 Jan. 06, 2014 Jan. 13, 2014 Jan. 20, 2014 Jan. 27, 2014 Feb. 03, 2014 Back to Table of Contents WEEK OF Nov. 04, 2013 Ops Re-start Nov. 04, 2013 Nov. 05, 2013 Nov. 06, 2013 Nov. 07, 2013 Nov. 08, 2013 Nov. 09, 2013 Nov. 10, 2013 BEAM LINE 5-4 Nov. 04, 2013 Nov. 05, 2013 Nov. 06, 2013 Nov. 07, 2013 Nov. 08, 2013 Nov. 09, 2013 Nov. 10, 2013 DOWN DOWN DOWN DOWN DOWN DOWN DOWN

193

SSRL BEAM PORT SCHEDULE  

NLE Websites -- All DOE Office Websites (Extended Search)

1-4 1-4 Nov. 28, 2005 Nov. 29, 2005 Nov. 30, 2005 Dec. 01, 2005 Dec. 02, 2005 Dec. 03, 2005 Dec. 04, 2005 MA 8840 J.POPLE 8840 J.POPLE 8840 J.POPLE 8840 J.POPLE 8840 J.POPLE 8840 J.POPLE CHANGE/8840 J.POPL 8840 J.POPLE 8840 J.POPLE 8840 J.POPLE 8840 J.POPLE 8840 J.POPLE 8840 J.POPLE 8840 J.POPLE 8840 J.POPLE 8840 J.POPLE 8840 J.POPLE 8840 J.POPLE 8840 J.POPLE 8840 J.POPLE BEAM LINE 2-1 Nov. 28, 2005 Nov. 29, 2005 Nov. 30, 2005 Dec. 01, 2005 Dec. 02, 2005 Dec. 03, 2005 Dec. 04, 2005 MA 8859 B.JOHNSON 8859 B.JOHNSON 8859 B.JOHNSON 8859 B.JOHNSON 8859 B.JOHNSON 8859 B.JOHNSON

194

SSRL BEAM PORT SCHEDULE  

NLE Websites -- All DOE Office Websites (Extended Search)

5-4 5-4 Nov. 15, 2010 Nov. 16, 2010 Nov. 17, 2010 Nov. 18, 2010 Nov. 19, 2010 Nov. 20, 2010 Nov. 21, 2010 8820 D.LU 8820 D.LU 8820 D.LU 8820 D.LU 8820 D.LU 8820 D.LU 8820 D.LU 8820 D.LU 8820 D.LU 8820 D.LU 8820 D.LU 8820 D.LU 8820 D.LU 8820 D.LU 8820 D.LU 8820 D.LU 8820 D.LU 8820 D.LU 8820 D.LU 8820 D.LU 8820 D.LU BEAM LINE 8-1 Nov. 15, 2010 Nov. 16, 2010 Nov. 17, 2010 Nov. 18, 2010 Nov. 19, 2010 Nov. 20, 2010 Nov. 21, 2010 Unscheduled Unscheduled Unscheduled 3269 S.SUN 3269 S.SUN 3269 S.SUN 3269 S.SUN

195

SSRL BEAM PORT SCHEDULE  

NLE Websites -- All DOE Office Websites (Extended Search)

1, 2002 Nov. 18, 2002 Nov. 25, 2002 Dec. 02, 2002 1, 2002 Nov. 18, 2002 Nov. 25, 2002 Dec. 02, 2002 Dec. 09, 2002 Dec. 16, 2002 Dec. 23, 2002 Dec. 30, 2002 Jan. 06, 2003 Jan. 13, 2003 Jan. 20, 2003 Jan. 27, 2003 Feb. 03, 2003 Feb. 10, 2003 Feb. 17, 2003 Feb. 24, 2003 Mar. 03, 2003 Mar. 10, 2003 Mar. 17, 2003 Mar. 24, 2003 Mar. 31, 2003 Back to Table of Contents WEEK OF Nov. 11, 2002 Nov. 11, 2002 Nov. 12, 2002 Nov. 13, 2002 Nov. 14, 2002 Nov. 15, 2002 Nov. 16, 2002 Nov. 17, 2002 BEAM LINE 1-4 Nov. 11, 2002 Nov. 12, 2002 Nov. 13, 2002 Nov. 14, 2002 Nov. 15, 2002 Nov. 16, 2002 Nov. 17, 2002 Unscheduled Unscheduled Unscheduled Unscheduled Unscheduled Unscheduled Unscheduled

196

SSRL BEAM PORT SCHEDULE  

NLE Websites -- All DOE Office Websites (Extended Search)

Nov. 04, 2013 Nov. 11, 2013 Nov. 18, 2013 Nov. 25, 2013 Nov. 04, 2013 Nov. 11, 2013 Nov. 18, 2013 Nov. 25, 2013 Dec. 02, 2013 Dec. 09, 2013 Dec. 16, 2013 Dec. 23, 2013 Dec. 30, 2013 Jan. 06, 2014 Jan. 13, 2014 Jan. 20, 2014 Jan. 27, 2014 Feb. 03, 2014 Back to Table of Contents WEEK OF Nov. 04, 2013 Ops Re-start Nov. 04, 2013 Nov. 05, 2013 Nov. 06, 2013 Nov. 07, 2013 Nov. 08, 2013 Nov. 09, 2013 Nov. 10, 2013 BEAM LINE 1-4 Nov. 04, 2013 Nov. 05, 2013 Nov. 06, 2013 Nov. 07, 2013 Nov. 08, 2013 Nov. 09, 2013 Nov. 10, 2013 DOWN DOWN DOWN 8891 C.TASSONE 8891 C.TASSONE 8891 C.TASSONE 8891 C.TASSONE

197

SSRL BEAM PORT SCHEDULE  

NLE Websites -- All DOE Office Websites (Extended Search)

1-4 1-4 Nov. 05, 2007 Nov. 06, 2007 Nov. 07, 2007 Nov. 08, 2007 Nov. 09, 2007 Nov. 10, 2007 Nov. 11, 2007 Unscheduled Unscheduled 8051 M.TONEY 8051 M.TONEY 8051 M.TONEY 8051 M.TONEY 8051 M.TONEY Unscheduled CHANGE/8051 M.TONE 8051 M.TONEY 8051 M.TONEY 8051 M.TONEY 8051 M.TONEY 8051 M.TONEY Unscheduled 8051 M.TONEY 8051 M.TONEY 8051 M.TONEY 8051 M.TONEY 8051 M.TONEY 8051 M.TONEY BEAM LINE 2-1 Nov. 05, 2007 Nov. 06, 2007 Nov. 07, 2007 Nov. 08, 2007 Nov. 09, 2007 Nov. 10, 2007 Nov. 11, 2007 8859 B.JOHNSON 8859 B.JOHNSON 8859 B.JOHNSON 8859 B.JOHNSON 3157* M.MONTERO-CA 3087 L.FUENTES-COB 3087 L.FUENTES-COB

198

SSRL BEAM PORT SCHEDULE  

NLE Websites -- All DOE Office Websites (Extended Search)

1-5 1-5 Nov. 28, 2005 Nov. 29, 2005 Nov. 30, 2005 Dec. 01, 2005 Dec. 02, 2005 Dec. 03, 2005 Dec. 04, 2005 MA 8845 A.GONZALEZ 8845 A.GONZALEZ 8845 A.GONZALEZ 8845 A.GONZALEZ 8845 A.GONZALEZ 8845 A.GONZALEZ 8845 A.GONZALEZ 8845 A.GONZALEZ 8845 A.GONZALEZ 8845 A.GONZALEZ 8845 A.GONZALEZ 8845 A.GONZALEZ 8845 A.GONZALEZ 8845 A.GONZALEZ 8845 A.GONZALEZ 8845 A.GONZALEZ 8845 A.GONZALEZ 8845 A.GONZALEZ 8845 A.GONZALEZ 8845 A.GONZALEZ BEAM LINE 7-1 Nov. 28, 2005 Nov. 29, 2005 Nov. 30, 2005 Dec. 01, 2005 Dec. 02, 2005 Dec. 03, 2005 Dec. 04, 2005 MA DOWN DOWN DOWN DOWN DOWN DOWN

199

Pulsed electron beam precharger  

Science Conference Proceedings (OSTI)

Florida State University is investigating the concept of pulsed electron beams for fly ash precipitation. This report describes the results and data on three of the subtasks of this project and preliminary work only on the remaining five subtasks. Described are the modification of precharger for pulsed and DC energization of anode; installation of the Q/A measurement system; and modification and installation of pulsed power supply to provide both pulsed and DC energization of the anode. The other tasks include: measurement of the removal efficiency for monodisperse simulated fly ash particles; measurement of particle charge; optimization of pulse energization schedule for maximum removal efficiency; practical assessment of results; and measurement of the removal efficiency for polydisperse test particles. 15 figs., 1 tab. (CK)

Finney, W.C. (ed.); Shelton, W.N.

1990-01-01T23:59:59.000Z

200

The Scheme of Beam Synchronization in MEIC  

Science Conference Proceedings (OSTI)

Synchronizing colliding beams at single or multiple collision points is a critical R&D issue in the design of a medium energy electron-ion collider (MEIC) at Jefferson Lab. The path-length variation due to changes in the ion energy, which varies over 20 to 100 GeV, could be more than several times the bunch spacing. The scheme adopted in the present MEIC baseline is centered on varying the number of bunches (i.e., harmonic number) stored in the collider ring. This could provide a set of discrete energies for proton or ions such that the beam synchronization condition is satisfied. To cover the ion energy between these synchronized values, we further propose to vary simultaneously the electron ring circumference and the frequency of the RF systems in both collider rings. We also present in this paper the requirement of frequency tunability of SRF cavities to support the scheme.

Zhang, Yuhong; Derbenev, Yaroslav S.; Hutton, Andrew M.

2013-06-01T23:59:59.000Z

Note: This page contains sample records for the topic "beam time esaf" 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

Beam line windows at LAMPF  

Science Conference Proceedings (OSTI)

The A-6 main beam-line window at LAMPF separates the vacuum of the main beam line from the isotope production station, proton irradiation ports, and the beam stop, which operate in air. This window must withstand the design beam current of 1 mA at 800 MeV for periods of at least 3000 hours without failure. The window is water cooled and must be strong enough to withstand the 2.1 MPa (300 psig) cooling water pressure, as well as beam-induced thermal stresses. Two designs have been used to meet these goals, a stepped-plate window and a hemispherical window, both made from a precipitation-hardened nickel base alloy, Alloy 718. Calculations of the temperatures and stresses in each of these windows are presented.

Brown, R.D.; Grisham, D.L.; Lambert, J.E.

1985-01-01T23:59:59.000Z

202

IonBeamMicroFab  

NLE Websites -- All DOE Office Websites (Extended Search)

Ion Beam Manufacture of Microscale Ion Beam Manufacture of Microscale Tools and Components Manufacturing Technologies Sandia Manufacturing Science &Technology's Focused Ion Beam (FIB) laboratory provides an opportunity for research, development and prototyping. Currently, our scientists are devel- oping methods for ion beam sculpting microscale tools, components and devices. This includes shaping of specialty tools such as end-mills, turning tools and indenters. Many of these have been used in ultra-precision machining DOE applications. Additionally, staff are developing the capability to ion mill geo- metrically-complex features and substrates. This includes the ability to sputter predeter- mined curved shapes of various symmetries and periodicities. Capabilities and Expertise * Two custom-built focused ion beam sys-

203

Laser-beam-alignment system  

DOE Patents (OSTI)

A plurality of pivotal reflectors direct a high-power laser beam onto a workpiece, and a rotatable reflector is movable to a position wherein it intercepts the beam and deflects a major portion thereof away from its normal path, the remainder of the beam passing to the pivotal reflectors through an aperture in the rotating reflector. A plurality of targets are movable to positions intercepting the path of light traveling to the pivotal reflectors, and a preliminary adjustment of the latter is made by use of a low-power laser beam reflected from the rotating reflector, after which the same targets are used to make a final adjustment of the pivotal reflectors with the portion of the high-power laser beam passed through the rotating reflector. The system was developed to cut the casings of spent nuclear fuel elements into segments as the initial step in recovering usable fuel. (WHK)

Kasner, W.H.; Racki, D.J.; Swenson, C.E.

1982-02-26T23:59:59.000Z

204

System for obtaining smooth laser beams where intensity variations are reduced by spectral dispersion of the laser light (SSD)  

DOE Patents (OSTI)

In an SSD (smoothing by spectral dispersion) system which reduces the time-averaged spatial variations in intensity of the laser light to provide uniform illumination of a laser fusion target, an electro-optic phase modulator through which a laser beam passes produces a broadband output beam by imposing a frequency modulated bandwidth on the laser beam. A grating provides spatial and angular spectral dispersion of the beam. Due to the phase modulation, the frequencies ("colors") cycle across the beam. The dispersed beam may be amplified and frequency converted (e.g., tripled) in a plurality of beam lines. A distributed phase plate (DPP) in each line is irradiated by the spectrally dispersed beam and the beam is focused on the target where a smooth (uniform intensity) pattern is produced. The color cycling enhances smoothing and the use of a frequency modulated laser pulse prevents the formation of high intensity spikes which could damage the laser medium in the power amplifiers.

Skupsky, Stanley (Rochester, NY); Kessler, Terrance J. (Rochester, NY); Short, Robert W. (Rochester, NY); Craxton, Stephen (Rochester, NY); Letzring, Samuel A. (Honeoye Falls, NY); Soures, John (Pittsford, NY)

1991-01-01T23:59:59.000Z

205

Laser beam alignment apparatus and method  

DOE Patents (OSTI)

The disclosure relates to an apparatus and method for laser beam alignment. Thermoelectric properties of a disc in a laser beam path are used to provide an indication of beam alignment and/or automatic laser alignment.

Gruhn, Charles R. (Martinez, CA); Hammond, Robert B. (Los Alamos, NM)

1981-01-01T23:59:59.000Z

206

Transformer ratio improvement for beam based plasma accelerators  

SciTech Connect

Increasing the transformer ratio of wakefield accelerating systems improves the viability of present novel accelerating schemes. The use of asymmetric bunches to improve the transformer ratio of beam based plasma systems has been proposed for some time[1, 2] but suffered from lack appropriate beam creation systems. Recently these impediments have been overcome [3, 4] and the ability now exists to create bunches with current profiles shaped to overcome the symmetric beam limit of R {<=} 2. We present here work towards experiments designed to measure the transformer ratio of such beams, including theoretical models and simulations using VORPAL (a 3D capable PIC code) [5]. Specifically we discuss projects to be carried out in the quasi-nonlinear regime [6] at the UCLA Neptune Laboratory and the Accelerator Test Facility at Brookhaven National Lab.

O'Shea, Brendan; Rosenzweig, James; Barber, Samuel; Fukasawa, Atsushi; Williams, Oliver; Muggli, Patric; Yakimenko, Vitaly; Kusche, Karl [University of California, Los Angeles, Department of Physics and Astronomy, Los Angeles, CA 90095 (United States); University of Southern California, Department of Electrical Engineering, Los Angeles, CA 90089 U.S.A. and Max-Planck-Institut fuer Physik, Foehringer Ring 6, 80805 Muenchen (Germany); Accelerator Test Facility, Brookhaven National Lab, Upton, NY, 11973 (United States)

2012-12-21T23:59:59.000Z

207

Conventional Positron Target for a Tesla Formatted Beam  

NLE Websites -- All DOE Office Websites (Extended Search)

3 3 SLAC-TN-03-072 November 2003 Abstract This note documents a set of expressions used to explore the issue of whether or not it is reasonable to consider a conventional positron source for a Tesla formatted beam. The critical issue is that of energy deposition in the conversion target and the comparison of the induced stress with the ultimate tensile strength of the target material. Since the length of the incident beam pulse is large in comparison to the ratio of beam size to the speed of sound, the concurrent pressure pulse dissipates in a time short compared to the overall pulse duration and one is left with only the Conventional Positron Target for a Tesla Formatted Beam John C. Sheppard Stanford Linear Accelerator Center

208

Summary of working group g: beam material interaction  

E-Print Network (OSTI)

For the first time, the workshop on High-Intensity and High-Brightness Hadron Beams (HB2010), held at Morschach, Switzerland and organized by the Paul Scherrer Institute, included a Working group dealing with the interaction between beam and material. Due to the high power beams of existing and future facilities, this topic is already of great relevance for such machines and is expected to become even more important in the future. While more specialized workshops related to topics of radiation damage, activation or thermo - mechanical calculations, already exist, HB2010 provided the occasion to discuss the interplay of these topics, focusing on components like targets, beam dumps and collimators, whose reliability are crucial for a user facility. In addition, a broader community of people working on a variety of issues related to the operation of accelerators could be informed and their interest sparked.

Kiselev, D; Schmidt, R

2011-01-01T23:59:59.000Z

209

Beam emission imaging system for 2D plasma turbulence measurements  

SciTech Connect

A two-dimensional analog to the beam emission spectroscopy (BES) diagnostic has been designed to acquire vorticity and plasma flow-field information by resolving the spatial and temporal intermittency of plasma turbulent structures. The beam emission imaging diagnostic measures collisionally induced neutral beam fluorescence to infer local plasma density variations. It consists of a high-throughput, interline-transfer CCD camera viewing, with narrow spectral bandwidth, a 10 cm high diagnostic neutral beam as it traverses the plasma. The camera is coupled to a gated image intensifier that provides for two images with exposure times up to a few ms to be separated by as little as 10 [mu]s. Sensitivity to density fluctuations of [ital [tilde n

Thorson, T.A.; Durst, R.D.; Fonck, R.J. (Department of Nuclear Engineering and Engineering Physics, University of Wisconsin, Madison, Wisconsin 53706 (United States))

1995-01-01T23:59:59.000Z

210

Beam Fields in an Integrated Cavity, Coupler and Window Configuration  

SciTech Connect

In a multi-bunch high current storage ring, beam generated fields couple strongly into the RF cavity coupler structure when beam arrival times are in resonance with cavity fields. In this study the integrated effect of beam fields over several thousand RF periods is simulated for the complete cavity, coupler, window and waveguide system of the PEP-II B-factory storage ring collider. We show that the beam generated fields at frequencies corresponding to several bunch spacings for this case gives rise to high field strength near the ceramic window which could limit the performance of future high current storage rings such as PEP-X or Super B-factories.

Weathersby, Stephen; Novokhatski, Alexander; /SLAC

2010-02-10T23:59:59.000Z

211

Tomographic determination of the power distribution in electron beams  

DOE Patents (OSTI)

A tomographic technique for determining the power distribution of an electron beam using electron beam profile data acquired from a modified Faraday cup to create an image of the current density in high and low power beams. A refractory metal disk with a number of radially extending slits is placed above a Faraday cup. The beam is swept in a circular pattern so that its path crosses each slit in a perpendicular manner, thus acquiring all the data needed for a reconstruction in one circular sweep. Also, a single computer is used to generate the signals actuating the sweep, to acquire that data, and to do the reconstruction, thus reducing the time and equipment necessary to complete the process.

Teruya, Alan T. (Livermore, CA); Elmer, John W. (Pleasanton, CA)

1996-01-01T23:59:59.000Z

212

Neutrino Beams for Scattering Experiment  

NLE Websites -- All DOE Office Websites (Extended Search)

Options for Neutrino Scattering Measurements Options for Neutrino Scattering Measurements Draft Skeleton Table Beam Characteristics K2K CERN AD FNAL Debuncher FNAL Booster NuMI LE NuMI ME NuMI HE Peak E(nu) (GeV) X X ~2.5 1 3.5 7.5 13 Maximum E(nu) (GeV) (->1% peak rate) X X 8.9 3 50 50+ 50+ Nu(mu) CC Rate (per ton-year) X 1.4 0 5,000 210,000 1,100,000 2,000,000 Nubar(mu) CC Rate (per ton-year) X 3.4 ~18 (Time Separated) ~360 (Prompt) 1,000 21,000 32,000 20,000 Nu(e) CC Rate (per ton-year) X 0 0 1 2,300 9,500 12,000 Nubar(e) CC Rate (per ton-year) X 0.4 ~18 (Time Separated) 0.5 630 660 600 Flux uncertainty X X 10% 10% 20% 20% 20% QE events / 100 ton-years X 169 nubar(mu) 47 nu(mu) 17 nubar(e) 525 nubar(e) 500,000 nu(mu) 100,000 nu(mu) X X X Floor space (m**2) X X New Hall New Hall 20 x 2.5 20 x 2.5 20 x 2.5 Run Type X X Parasitic Parasitic Parasitic Parasitic Parasitic

213

LHCb Beam-Gas Imaging Results  

E-Print Network (OSTI)

The high resolution of the LHCb vertex detector makes it possible to perform precise measurements of vertices of beam-gas and beam-beam interactions and allows beam parameters such as positions, angles and widths to be determined. Using the directly measured beam properties the novel beam-gas imaging method is applied in LHCb for absolute luminosity determination. In this contribution we briefly describe the method and the preliminary results obtained with May 2010 data.

P. Hopchev

2011-07-07T23:59:59.000Z

214

Ion Beam Modification of Materials  

SciTech Connect

This volume contains the proceedings of the 14th International Conference on Ion Beam Modification of Materials, IBMM 2004, and is published by Elsevier-Science Publishers as a special issue of Nuclear Instruments and Methods B. The conference series is the major international forum to present and discuss recent research results and future directions in the field of ion beam modification, synthesis and characterization of materials. The first conference in the series was held in Budapest, Hungary, 1978, and subsequent conferences were held every two years at locations around the Globe, most recently in Japan, Brazil, and the Netherlands. The series brings together physicists, materials scientists, and ion beam specialists from all over the world. The official conference language is English. IBMM 2004 was held on September 5-10, 2004. The focus was on materials science involving both basic ion-solid interaction processes and property changes occurring either during or subsequent to ion bombardment and ion beam processing in relation to materials and device applications. Areas of research included Nanostructures, Multiscale Modeling, Patterning of Surfaces, Focused Ion Beams, Defects in Semiconductors, Insulators and Metals, Cluster Beams, Radiation Effects in Materials, Photonic Devices, Ion Implantation, Ion Beams in Biology and Medicine including New Materials, Imaging, and Treatment.

Averback, B; de la Rubia, T D; Felter, T E; Hamza, A V; Rehn, L E

2005-10-10T23:59:59.000Z

215

Intense low energy positron beams  

Science Conference Proceedings (OSTI)

Intense positron beams are under development or being considered at several laboratories. Already today a few accelerator based high intensity, low brightness e{sup +} beams exist producing of the order of 10{sup 8} {minus} 10{sup 9} e{sup +}/sec. Several laboratories are aiming at high intensity, high brightness e{sup +} beams with intensities greater than 10{sup 9} e{sup +}/sec and current densities of the order of 10{sup 13} {minus} 10{sup 14} e{sup +} sec{sup {minus}} {sup 1}cm{sup {minus}2}. Intense e{sup +} beams can be realized in two ways (or in a combination thereof) either through a development of more efficient B{sup +} moderators or by increasing the available activity of B{sup +} particles. In this review we shall mainly concentrate on the latter approach. In atomic physics the main trust for these developments is to be able to measure differential and high energy cross-sections in e{sup +} collisions with atoms and molecules. Within solid state physics high intensity, high brightness e{sup +} beams are in demand in areas such as the re-emission e{sup +} microscope, two dimensional angular correlation of annihilation radiation, low energy e{sup +} diffraction and other fields. Intense e{sup +} beams are also important for the development of positronium beams, as well as exotic experiments such as Bose condensation and Ps liquid studies.

Lynn, K.G.; Jacobsen, F.M.

1993-12-31T23:59:59.000Z

216

Managing time  

Science Conference Proceedings (OSTI)

Professionals overwhelmed with information glut can find hope from new insights about time management.

Peter J. Denning

2011-03-01T23:59:59.000Z

217

SSRL BEAM PORT SCHEDULE  

NLE Websites -- All DOE Office Websites (Extended Search)

7-1 7-1 Oct. 26, 2009 Oct. 27, 2009 Oct. 28, 2009 Oct. 29, 2009 Oct. 30, 2009 Oct. 31, 2009 Nov. 01, 2009 CHANGE/8803* C.SMI 8803* C.SMITH 8803* C.SMITH 8803* C.SMITH 8803* C.SMITH 8803* C.SMITH 8803* C.SMITH 8803* C.SMITH 8803* C.SMITH 8803* C.SMITH 8803* C.SMITH 8803* C.SMITH 8803* C.SMITH 8803* C.SMITH 8803* C.SMITH 8803* C.SMITH 8803* C.SMITH 8803* C.SMITH 8803* C.SMITH 8803* C.SMITH 8803* C.SMITH BEAM LINE 9-1 Oct. 26, 2009 Oct. 27, 2009 Oct. 28, 2009 Oct. 29, 2009 Oct. 30, 2009 Oct. 31, 2009 Nov. 01, 2009 CHANGE/8861* I.MAT 8861* I.MATHEWS 8861* I.MATHEWS 8861* I.MATHEWS 8861* I.MATHEWS 8861* I.MATHEWS 8861* I.MATHEWS

218

SSRL BEAM PORT SCHEDULE  

NLE Websites -- All DOE Office Websites (Extended Search)

7-1 7-1 Nov. 15, 2010 Nov. 16, 2010 Nov. 17, 2010 Nov. 18, 2010 Nov. 19, 2010 Nov. 20, 2010 Nov. 21, 2010 8845 A.GONZALEZ 8845 A.GONZALEZ 8845 A.GONZALEZ 8845 A.GONZALEZ 8845 A.GONZALEZ 2B87 I.SEVRIOUKOVA 2B87 I.SEVRIOUKOVA 8845 A.GONZALEZ 8845 A.GONZALEZ 8845 A.GONZALEZ 8845 A.GONZALEZ MC CHECKOUT/2B87 2B87 I.SEVRIOUKOVA 2B87 I.SEVRIOUKOVA 8845 A.GONZALEZ 8845 A.GONZALEZ 8845 A.GONZALEZ 8845 A.GONZALEZ 2B87 I.SEVRIOUKOVA 2B87 I.SEVRIOUKOVA 2B87 I.SEVRIOUKOVA BEAM LINE 9-1 Nov. 15, 2010 Nov. 16, 2010 Nov. 17, 2010 Nov. 18, 2010 Nov. 19, 2010 Nov. 20, 2010 Nov. 21, 2010 8866 T.DOUKOV 8866 T.DOUKOV 8866 T.DOUKOV 8866 T.DOUKOV 8866 T.DOUKOV FACI FACI

219

SSRL BEAM PORT SCHEDULE  

NLE Websites -- All DOE Office Websites (Extended Search)

Feb. 14, 2005 Feb. 21, 2005 Feb. 28, 2005 Mar. 07, 2005 Feb. 14, 2005 Feb. 21, 2005 Feb. 28, 2005 Mar. 07, 2005 Mar. 14, 2005 Mar. 21, 2005 Mar. 28, 2005 Apr. 04, 2005 Apr. 11, 2005 Apr. 18, 2005 Apr. 25, 2005 May 02, 2005 May 09, 2005 May 16, 2005 May 23, 2005 May 30, 2005 Jun. 06, 2005 Jun. 13, 2005 Jun. 20, 2005 Jun. 27, 2005 Jul. 04, 2005 Jul. 11, 2005 Jul. 18, 2005 Jul. 25, 2005 Aug. 01, 2005 Back to Table of Contents WEEK OF Feb. 14, 2005 Feb. 14, 2005 Feb. 15, 2005 Feb. 16, 2005 Feb. 17, 2005 Feb. 18, 2005 Feb. 19, 2005 Feb. 20, 2005 BEAM LINE 1-5 Feb. 14, 2005 Feb. 15, 2005 Feb. 16, 2005 Feb. 17, 2005 Feb. 18, 2005 Feb. 19, 2005 Feb. 20, 2005 8858 D.HARRINGTON 8858 D.HARRIN/DOWN 8858 D.HARRINGTON 8858 D.HARRINGTON 8858 D.HARRINGTON 8858 D.HARRINGTON 8858 D.HARRINGTON

220

SSRL BEAM PORT SCHEDULE  

NLE Websites -- All DOE Office Websites (Extended Search)

1, 2013 Nov. 18, 2013 Nov. 25, 2013 Dec. 02, 2013 1, 2013 Nov. 18, 2013 Nov. 25, 2013 Dec. 02, 2013 Dec. 09, 2013 Dec. 16, 2013 Dec. 23, 2013 Dec. 30, 2013 Jan. 06, 2014 Jan. 13, 2014 Jan. 20, 2014 Jan. 27, 2014 Feb. 03, 2014 Feb. 10, 2014 Feb. 17, 2014 Feb. 24, 2014 Back to Table of Contents WEEK OF Nov. 11, 2013 Nov. 11, 2013 Nov. 12, 2013 Nov. 13, 2013 Nov. 14, 2013 Nov. 15, 2013 Nov. 16, 2013 Nov. 17, 2013 BEAM LINE 7-1 Nov. 11, 2013 Nov. 12, 2013 Nov. 13, 2013 Nov. 14, 2013 Nov. 15, 2013 Nov. 16, 2013 Nov. 17, 2013 8803 C.Smith 8803 C.Smith 8803 C.Smith 8803 C.Smith 8803 C.Smith 4B02 A.Yeh 8050 C.Smith 8803 C.Smith 8803 C.Smith 8803 C.Smith 8803 C.Smith Unscheduled MC CHECKOUT/8050 8050 C.Smith

Note: This page contains sample records for the topic "beam time esaf" 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

Electron beam machining using rotating and shaped beam power distribution  

DOE Patents (OSTI)

An apparatus and method for electron beam (EB) machining (drilling, cutting and welding) that uses conventional EB guns, power supplies, and welding machine technology without the need for fast bias pulsing technology. The invention involves a magnetic lensing (EB optics) system and electronic controls to: 1) concurrently bend, focus, shape, scan, and rotate the beam to protect the EB gun and to create a desired effective power-density distribution, and 2) rotate or scan this shaped beam in a controlled way. The shaped beam power-density distribution can be measured using a tomographic imaging system. For example, the EB apparatus of this invention has the ability to drill holes in metal having a diameter up to 1000 .mu.m (1 mm or larger), compared to the 250 .mu.m diameter of laser drilling.

Elmer, John W. (Pleasanton, CA); O' Brien, Dennis W. (Livermore, CA)

1996-01-01T23:59:59.000Z

222

Compact Alignment for Diagnostic Laser Beams  

Physicist and optical engineer Mike Rushford developed the laser beam . centering and pointing system. The laser beam . centering and pointing system

223

NIST SURF: Beamline 10: Electron beam imaging  

Science Conference Proceedings (OSTI)

Beamline 10: Electron beam imaging. Description: ... In its unperturbed state, the vertical electron beam size is quite small, in the order of a few 10 µm. ...

2012-11-19T23:59:59.000Z

224

PowerBeam Inc | Open Energy Information  

Open Energy Info (EERE)

PowerBeam, Inc. Place Sunnyvale, California Zip CA 94085 Product PowerBeam holds the patent to a power transmission technology that produces wireless electricity. Coordinates...

225

Design of the AGS Booster Beam Position Monitor electronics  

SciTech Connect

The operational requirements of the AGS Booster Beam Position Monitor system necessitate the use of electronics with wide dynamic range and broad instantaneous bandwidth. Bunch synchronization is provided by a remote timing sequencer coupled to the local ring electronics via digital fiber-optic links. The Sequencer and local ring circuitry work together to provide single turn trajectory or average orbit and intensity information, integrated over 1 to 225 bunches. Test capabilities are built in for the purpose of enhancing BPM system accuracy. This paper describes the design of the Booster Beam Position Monitor electronics, and presents performance details of the front end processing, acquisition and timing circuitry.

Ciardullo, D.J.; Smith, G.A.; Beadle, E.R.

1991-01-01T23:59:59.000Z

226

Design of the AGS Booster Beam Position Monitor electronics  

SciTech Connect

The operational requirements of the AGS Booster Beam Position Monitor system necessitate the use of electronics with wide dynamic range and broad instantaneous bandwidth. Bunch synchronization is provided by a remote timing sequencer coupled to the local ring electronics via digital fiber-optic links. The Sequencer and local ring circuitry work together to provide single turn trajectory or average orbit and intensity information, integrated over 1 to 225 bunches. Test capabilities are built in for the purpose of enhancing BPM system accuracy. This paper describes the design of the Booster Beam Position Monitor electronics, and presents performance details of the front end processing, acquisition and timing circuitry.

Ciardullo, D.J.; Smith, G.A.; Beadle, E.R.

1991-12-31T23:59:59.000Z

227

Circular, confined distribution for charged particle beams  

DOE Patents (OSTI)

A charged particle beam line is formed with magnetic optics that manipulate the charged particle beam to form the beam having a generally rectangular configuration to a circular beam cross-section having a uniform particle distribution at a predetermined location. First magnetic optics form a charged particle beam to a generally uniform particle distribution over a square planar area at a known first location. Second magnetic optics receive the charged particle beam with the generally square configuration and affect the charged particle beam to output the charged particle beam with a phase-space distribution effective to fold corner portions of the beam toward the core region of the beam. The beam forms a circular configuration having a generally uniform spatial particle distribution over a target area at a predetermined second location. 26 figs.

Garnett, R.W.; Dobelbower, M.C.

1995-11-21T23:59:59.000Z

228

Circular, confined distribution for charged particle beams  

DOE Patents (OSTI)

A charged particle beam line is formed with magnetic optics that manipulate the charged particle beam to form the beam having a generally rectangular configuration to a circular beam cross-section having a uniform particle distribution at a predetermined location. First magnetic optics form a charged particle beam to a generally uniform particle distribution over a square planar area at a known first location. Second magnetic optics receive the charged particle beam with the generally square configuration and affect the charged particle beam to output the charged particle beam with a phase-space distribution effective to fold corner portions of the beam toward the core region of the beam. The beam forms a circular configuration having a generally uniform spatial particle distribution over a target area at a predetermined second location.

Garnett, Robert W. (Los Alamos, NM); Dobelbower, M. Christian (Toledo, OH)

1995-01-01T23:59:59.000Z

229

Thermal response of ceramic components during electron beam brazing  

DOE Green Energy (OSTI)

Ceramics are being used increasingly in applications where high temperatures are encountered such as automobile and gas turbine engines. However, the use of ceramics is limited by a lack of methods capable of producing strong, high temperature joints. This is because most ceramic-ceramic joining techniques, such as brazing, require that the entire assembly be exposed to high temperatures in order to assure that the braze material melts. Alternatively, localized heating using high energy electron beams may be used to selectively heat the braze material. In this work, high energy electron beam brazing of a ceramic part is modeled numerically. The part considered consists of a ceramic cylinder and disk between which is sandwiched an annular washer of braze material. An electron beam impinges on the disk, melting the braze metal. The resulting coupled electron and thermal transport equations are solved using Monte Carlo and finite element techniques. Results indicate that increased electron beam current decreases time to melt as well as required cooling time. Vacuum furnace brazing was also simulated and predicted results indicate increased processing times relative to electron beam brazing.

Voth, T.E.; Gianoulakis, S.E.; Halbleib, J.A.

1996-03-01T23:59:59.000Z

230

Particle beam fusion  

SciTech Connect

Today, in keeping with Sandia Laboratories` designation by the Department of Energy as the lead laboratory for the pulsed power approach to fusion, its efforts include major research activities and the construction of new facilities at its Albuquerque site. Additionally, in its capacity as lead laboratory, Sandia coordinates DOE-supported pulsed power fusion work at other government operated laboratories, with industrial contractors, and universities. The beginning of Sandia`s involvement in developing fusion power was an outgrowth of its contributions to the nation`s nuclear weapon program. The Laboratories` work in the early 1960`s emphasized the use of pulsed radiation environments to test the resistance of US nuclear weapons to enemy nuclear bursts. A careful study of options for fusion power indicated that Sandia`s expertise in the pulsed power field could provide a powerful match to ignite fusion fuel. Although creating test environments is an achieved goal of Sandia`s overall program, this work and other military tasks protected by appropriate security regulations will continue, making full use of the same pulsed power technology and accelerators as the fusion-for-energy program. Major goals of Sandia`s fusion program including the following: (1) complete a particle accelerator to deliver sufficient beam energy for igniting fusion targets; (2) obtain net energy gain, this goal would provide fusion energy output in excess of energy stored in the accelerator; (3) develop a technology base for the repetitive ignition of pellets in a power reactor. After accomplishing these goals, the technology will be introduced to the nation`s commercial sector.

1980-12-31T23:59:59.000Z

231

Repetitively pumped electron beam device  

DOE Patents (OSTI)

Disclosed is an apparatus for producing fast, repetitive pulses of controllable length of an electron beam by phased energy storage in a transmission line of length matched to the number of pulses and specific pulse lengths desired. 12 figs.

Schlitt, L.G.

1979-07-24T23:59:59.000Z

232

INSTABILITIES OF RELATIVISTIC PARTICLE BEAMS  

E-Print Network (OSTI)

1965). K. W. Robinson, in SLAC Storage Ring Stumner Study,Beams, a Summary. Report, SLAC-49, L. J. Laslett, V. K.La.slett and A. M. Sessler, in SLAC-49, Sept. 1965 (see Ref.

Sessler, Andrew M.

2008-01-01T23:59:59.000Z

233

Center for Beam Physics, 1992  

Science Conference Proceedings (OSTI)

This report contains the following information on the center for beam physics: Facilities; Organizational Chart; Roster; Profiles of Staff; Affiliates; Center Publications (1991--1993); and 1992 Summary of Activities.

Not Available

1993-06-01T23:59:59.000Z

234

Repetitively pumped electron beam device  

DOE Patents (OSTI)

Apparatus for producing fast, repetitive pulses of controllable length of an electron beam by phased energy storage in a transmission line of length matched to the number of pulses and specific pulse lengths desired.

Schlitt, Leland G. (Livermore, CA)

1979-01-01T23:59:59.000Z

235

The Fermilab neutrino beam program  

Science Conference Proceedings (OSTI)

This talk presents an overview of the Fermilab Neutrino Beam Program. Results from completed experiments as well as the status and outlook for current experiments is given. Emphasis is given to current activities towards planning for a future program.

Rameika, Regina A.; /Fermilab

2007-01-01T23:59:59.000Z

236

Particle beam generator using a radioactive source  

DOE Patents (OSTI)

The apparatus of the present invention selects from particles emitted by a radioactive source those particles having momentum within a desired range and focuses the selected particles in a beam having at least one narrow cross-dimension, and at the same time attenuates potentially disruptive gamma rays and low energy particles. Two major components of the present invention are an achromatic bending and focusing system, which includes sector magnets and quadrupole, and a quadrupole doublet final focus system. Permanent magnets utilized in the apparatus are constructed of a ceramic (ferrite) material which is inexpensive and easily machined.

Underwood, D.G.

1991-12-31T23:59:59.000Z

237

Particle beam generator using a radioactive source  

DOE Patents (OSTI)

The apparatus of the present invention selects from particles emitted by a radioactive source those particles having momentum within a desired range and focuses the selected particles in a beam having at least one narrow cross-dimension, and at the same time attenuates potentially disruptive gamma rays and low energy particles. Two major components of the present invention are an achromatic bending and focusing system, which includes sector magnets and quadrupole, and a quadrupole doublet final focus system. Permanent magnets utilized in the apparatus are constructed of a ceramic (ferrite) material which is inexpensive and easily machined.

Underwood, D.G.

1993-03-30T23:59:59.000Z

238

Confined energy distribution for charged particle beams  

SciTech Connect

A charged particle beam is formed to a relatively larger area beam which is well-contained and has a beam area which relatively uniformly deposits energy over a beam target. Linear optics receive an accelerator beam and output a first beam with a first waist defined by a relatively small size in a first dimension normal to a second dimension. Nonlinear optics, such as an octupole magnet, are located about the first waist and output a second beam having a phase-space distribution which folds the beam edges along the second dimension toward the beam core to develop a well-contained beam and a relatively uniform particle intensity across the beam core. The beam may then be expanded along the second dimension to form the uniform ribbon beam at a selected distance from the nonlinear optics. Alternately, the beam may be passed through a second set of nonlinear optics to fold the beam edges in the first dimension. The beam may then be uniformly expanded along the first and second dimensions to form a well-contained, two-dimensional beam for illuminating a two-dimensional target with a relatively uniform energy deposition.

Jason, Andrew J. (Los Alamos, NM); Blind, Barbara (Los Alamos, NM)

1990-01-01T23:59:59.000Z

239

Beam cooling: Principles and achievements  

SciTech Connect

After a discussion of Liouville's theorem, and its implications for beam cooling, a brief description is given of each of the various methods of beam cooling: stochastic, electron, radiation, laser, ionization, etc. For each, we present the type of particle for which it is appropriate, its range of applicability, and the currently achieved degree of cooling. For each method we also discuss the present applications and, also, possible future developments and further applications.

Mohl, Dieter; Sessler, Andrew M.

2003-05-18T23:59:59.000Z

240

Entropic Time  

Science Conference Proceedings (OSTI)

The formulation of quantum mechanics within the framework of entropic dynamics includes several new elements. In this paper we concentrate on one of them: the implications for the theory of time. Entropic time is introduced as a book-keeping device to keep track of the accumulation of changes. One new feature is that, unlike other concepts of time appearing in the so-called fundamental laws of physics, entropic time incorporates a natural distinction between past and future.

Caticha, Ariel [Department of Physics, University at Albany-SUNY, Albany, NY 12222 (United States)

2011-03-14T23:59:59.000Z

Note: This page contains sample records for the topic "beam time esaf" 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

Instrumentation system for long-pulse MFTF neutral beams  

SciTech Connect

The instrumentation system for long pulse neutral beams for MFTFS consists of monitoring and protective circuitry. Global synchronization of high speed monitoring data across twenty-four neutral beams is achieved via an experiment wide fiber optic timing system. Fiber optics are also used as a means of isolating signals at elevated voltages. An excess current monitor, interrupt monitor, sparkdown detector, spot detector and gradient grid ratio detector form the primary protection for the neutral beam source. A unique hierarchical interlocking scheme allows other protective devices to be factored into the shutdown circuitry of the power supply so that the initiating cause of a shutdown can be isolated and even allows some non-critical devices to be safely ignored for a period of time.

Risch, D.M.

1981-09-30T23:59:59.000Z

242

Electron Beam Alignment Strategy in the LCLS Undulators  

SciTech Connect

The x-ray FEL process puts very tight tolerances on the straightness of the electron beam trajectory (2 {micro}m rms) through the LCLS undulator system. Tight but less stringent tolerances of 80 {micro}m rms vertical and 140 {micro}m rms horizontally are to be met for the placement of the individual undulator segments with respect to the beam axis. The tolerances for electron beam straightness can only be met through beam-based alignment (BBA) based on electron energy variations. Conventional alignment will set the start conditions for BBA. Precision-fiducialization of components mounted on remotely adjustable girders and the use of beam-finder wires (BFW) will satisfy placement tolerances. Girder movement due to ground motion and temperature changes will be monitored continuously by an alignment monitoring system (ADS) and remotely corrected. This stabilization of components as well as the monitoring and correction of the electron beam trajectory based on BPMs and correctors will increase the time between BBA applications. Undulator segments will be periodically removed from the undulator Hall and measured to monitor radiation damage and other effects that might degrade undulator tuning.

Nuhn, H.-D.; Emma, P.J.; Gassner, G.L.; LeCocq, C.M.; Peters, E.; Ruland, R.E.; /SLAC

2007-01-03T23:59:59.000Z

243

EXPERIMENTAL RESULTS FROM A MICROWAVE CAVITY BEAM POSITION MONITOR.  

Science Conference Proceedings (OSTI)

Future Linear Colliders have hard requirements for the beam transverse position stability in the accelerator. A beam Position Monitor (BPM) with the resolution better than 0.1 micron in the single bunch regime is needed to control the stability of the beam position along the linac. Proposed BPM is based on the measurement of the asymmetrical mode excited by single bunch in the cavity. Four stages of signal processing (space-, time-, frequency- and phase-filtering providing the required signal-to-noise ratio) are used to obtain extremely high resolution. The measurement set-up was designed by BINP and installed at ATF/BNL to test experimentally this concept. The set-up includes three two-coordinates BPM's at the frequency of 13.566 GHz, and reference intensity/phase cavity. BPM's were mounted on support table. The two-coordinates movers allow to move and align BPM's along the straight line, using the signals from the beam. The position of each monitor is controlled by the sensors with the accuracy 0.03 micron. The information from three monitors allows to exclude angle and position jitter of the beam and measure BPM resolution. In the experiments the resolution of about 0.15 micron for 0.25 nC beam intensity was obtained, that is close to the value required.

BALAKIN,V.; BAZHAN,A.; LUNEV,P.; SOLYAK,N.; VOGEL,V.; ZHOGOLEV,P.; LISITSYN,A.; YAKIMENKO,V.

1999-03-29T23:59:59.000Z

244

Direct e-beam lithography of PDMS  

Science Conference Proceedings (OSTI)

In this paper, the viability of directly exposing thin films of liquid poly(dimethylsiloxane) (PDMS) to electron beam (e-beam) irradiation using e-beam lithographic methods for the purpose of creating permanent micro-scale components has been investigated. ... Keywords: Lithography, PDMS, Poly(dimethylsiloxane), e-Beam

J. Bowen; D. Cheneler; A. P. G. Robinson

2012-09-01T23:59:59.000Z

245

Resistive wall heating due to image current on the beam chamber for a superconducting undulator.  

SciTech Connect

The image-current heating on the resistive beam chamber of a superconducting undulator (SCU) was calculated based on the normal and anomalous skin effects. Using the bulk resistivity of copper for the beam chamber, the heat loads were calculated for the residual resistivity ratios (RRRs) of unity at room temperature to 100 K at a cryogenic temperature as the reference. Then, using the resistivity of the specific aluminum alloy 6053-T5, which will be used for the SCU beam chamber, the heat loads were calculated. An electron beam stored in a storage ring induces an image current on the inner conducting wall, mainly within a skin depth, of the beam chamber. The image current, with opposite charge to the electron beam, travels along the chamber wall in the same direction as the electron beam. The average current in the storage ring consists of a number of bunches. When the pattern of the bunched beam is repeated according to the rf frequency, the beam current may be expressed in terms of a Fourier series. The time structure of the image current is assumed to be the same as that of the beam current. For a given resistivity of the chamber inner wall, the application ofthe normal or anomalous skin effect will depend on the harmonic numbers of the Fourier series of the beam current and the temperature of the chamber. For a round beam chamber with a ratius r, much larger than the beam size, one can assume that the image current density as well as the density square, may be uniform around the perimeter 2{pi}r. For the SCU beam chamber, which has a relatively narrow vertical gap compared to the width, the effective perimeter was estimated since the heat load should be proportional to the inverse of the perimeter.

Kim, S. H. (Accelerator Systems Division (APS))

2012-03-27T23:59:59.000Z

246

INTRA - BEAM SCATTERING MEASUREMENTS IN RHIC.  

DOE Green Energy (OSTI)

RHIC in gold operation shows significant intra-beam scattering due to the high charge state of the stored ions. Intra-beam scattering leads to longitudinal and transverse emittance growth. The longitudinal emittance growth causes debunching in operation; the transverse emittance growth contributes to the reduction of the beam and luminosity lifetimes. The longitudinal and transverse beam growth was measured. Beam growth measurement are compared with computations.

FISCHER,W.; CONNOLLY,R.; TEPIKIAN,S.; VAN ZEIJTS,J.; ZENO,K.

2002-06-02T23:59:59.000Z

247

TIMING APPARATUS  

DOE Patents (OSTI)

The timing device comprises an escapement wheel and pallet, a spring drive to rotate the escapement wheel to a zero position, means to wind the pretensioned spring proportional to the desired signal time, and a cam mechanism to control an electrical signal switch by energizing the switch when the spring has been wound to the desired position, and deenergizing it when it reaches the zero position. This device produces an accurately timed signal variably witain the control of the operator.

Bennett, A.E.; Geisow, J.C.H.

1956-04-17T23:59:59.000Z

248

Commissioning of the CMS zero degree calorimeter using LHC beam  

E-Print Network (OSTI)

This paper reports on the commissioning and first running experience of the CMS Zero Degree Calorimeters during December 2009. All channels worked correctly. The ZDCs were timed into the data acquisition system using beam splash events. These data also allowed us to make a first estimate of channel-by-channel variations in gain.

O. Grachov; M. Murray; J. Wood; Y. Onel; S. Sen; T. Yetkin

2010-08-06T23:59:59.000Z

249

Machine and Beam Delivery Updates  

NLE Websites -- All DOE Office Websites (Extended Search)

MAchine and Beam delivery Updates FY13 MAchine and Beam delivery Updates FY13 Summary of Beam Delivery: FACET Summary Feb_15_22.pdf FACET Summary Feb_15_22.pdf FACET Summary Feb_23_Mar_1.pdf FACET Summary Feb_23_Mar_1.pdf FACET Summary Mar_2_8.pdf FACET Summary Mar_2_8.pdf FACET Summary Mar_9_15.pdf FACET Summary Mar_9_15.pdf FACET Summary Mar_16_22.pdf FACET Summary Mar_16_22.pdf FACET Summary Mar_23_29.pdf FACET Summary Mar_23_29.pdf FACET Summary Mar_30_Apr_5.pdf FACET Summary Mar_30_Apr_5.pdf FACET Summary Apr_6_12.pdf FACET Summary Apr_6_12.pdf FACET Summary Apr_27_May_3.pdf FACET Summary Apr_27_May_3.pdf FACET Summary May_4_10.pdf FACET Summary May_4_10.pdf Emittance Stability in Sector 2_31513.pdf Emittance Stability in Sector 2_31513.pdf FACET beam operations readiness with R56.pdf FACET beam operations readiness with R56.pdf (6/19/2013)

250

PBFA II lithium beam characterization from inner-shell x-ray images  

SciTech Connect

The Particle Beam Fusion Accelerator (PBFA II) is not driving targets with ICF-relevant lithium ion beams. During the most recent lithium beam target series, time-integrated x-ray pinhole cameras viewed the ion-induced inner-shell x-ray fluorescence from the central gold cone target and a titanium-coated strip. Ion beam profiles at a nominal 10 mm radius and fixed azimuthal direction were obtained from images of the Ti K{sub {alpha}}, fluorescence of a Ti-coated Al diagnostic wire. The gold cone gave us beam profiles at a nominal 3 mm radius and at all azimuthal angles from the Au L{sub {alpha}} fluorescence. From these profiles, we obtained the ion beam vertical focus position, full-width-at-half-maximum, and the degree of azimuthal uniformity for the lithium target shots. For these initial results, beam steering problems were evident. Azimuthal uniformity was measured from the ion beam footprint on the outer Au case (predominantly Au L{sub {alpha}}) of the hohlraum target and were found to be in the same range (up to 30%) as for previous proton beam target series. We then present plans for Li beam diagnostics for an upcoming target experimental series.

Moats, A.R.; Derzon, M.S.; Chandler, G.A.; Dukart, R.J.; Haill, T.A.

1994-05-01T23:59:59.000Z

251

Dye laser amplifier including an improved window configuration for its dye beam  

DOE Patents (OSTI)

A dye laser amplifier in which a continuously replenished supply of dye is excited with a first light beam in order to amplify the intensity of a second different light beam passing therethrough is disclosed herein. This amplifier includes a cell though which a continuous stream of the dye is caused to pass, and means for directing the first beam into the cell while the second beam is directed into and through the same cell. There is also disclosed herein a specific improvement to this amplifier which resides in the use of a pair of particularly configured windows through which the second beam passes along fixed paths as the second beam enters and exits the dye cell. Each of these windows has a relatively thick main section which is substantially larger in dimensions transverse to its beam path than the cross section of the second beam itself, whereby to add structural integrity to the overall window. At the same time, the latter includes a second section which is disposed entirely within the confines of the main section and through which the second beam is intended to pass in its entirety. This second section is made substantially thinner than the main section in order to reduce optical distortion as the second beam passes therethrough.

O' Neil, Richard W. (Pleasanton, CA); Davin, James M. (Livermore, CA)

1992-01-01T23:59:59.000Z

252

Dye laser amplifier including an improved window configuration for its dye beam  

DOE Patents (OSTI)

A dye laser amplifier in which a continuously replenished supply of dye is excited with a first light beam in order to amplify the intensity of a second different light beam passing therethrough is disclosed herein. This amplifier includes a cell though which a continuous stream of the dye is caused to pass, and means for directing the first beam into the cell while the second beam is directed into and through the same cell. There is also disclosed herein a specific improvement to this amplifier which resides in the use of a pair of particularly configured windows through which the second beam passes along fixed paths as the second beam enters and exits the dye cell. Each of these windows has a relatively thick main section which is substantially larger in dimensions transverse to its beam path than the cross section of the second beam itself, whereby to add structural integrity to the overall window. At the same time, the latter includes a second section which is disposed entirely within the confines of the main section and through which the second beam is intended to pass in its entirety. This second section is made substantially thinner than the main section in order to reduce optical distortion as the second beam passes therethrough. 4 figs.

O' Neil, R.W.; Davin, J.M.

1992-12-01T23:59:59.000Z

253

Spherical shock-ignition experiments with the 40 + 20-beam configuration on OMEGA  

Science Conference Proceedings (OSTI)

Spherical shock-ignition experiments on OMEGA used a novel beam configuration that separates low-intensity compression beams and high-intensity spike beams. Significant improvements in the performance of plastic-shell, D{sub 2} implosions were observed with repointed beams. The analysis of the coupling of the high-intensity spike beam energy into the imploding capsule indicates that absorbed hot-electron energy contributes to the coupling. The backscattering of laser energy was measured to reach up to 36% at single-beam intensities of {approx}8 Multiplication-Sign 10{sup 15} W/cm{sup 2}. Hard x-ray measurements revealed a relatively low hot-electron temperature of {approx}30 keV independent of intensity and timing. At the highest intensity, stimulated Brillouin scattering occurs near and above the quarter-critical density and the two-plasmon-decay instability is suppressed.

Theobald, W.; Anderson, K. S.; Delettrez, J. A.; Glebov, V. Yu.; Gotchev, O. V.; Hohenberger, M.; Hu, S. X.; Marshall, F. J.; Sangster, T. C.; Seka, W.; Stoeckl, C.; Yaakobi, B. [Laboratory for Laser Energetics and Fusion Science Center, University of Rochester, Rochester, New York 14623 (United States); Nora, R.; Betti, R.; Meyerhofer, D. D. [Laboratory for Laser Energetics and Fusion Science Center, University of Rochester, Rochester, New York 14623 (United States); Department of Mechanical Engineering and Physics at the University of Rochester, Rochester, New York 14623 (United States); Lafon, M. [Laboratory for Laser Energetics and Fusion Science Center, University of Rochester, Rochester, New York 14623 (United States); University of Bordeaux, CEA, CNRS, CELIA (Centre Lasers Intenses et Applications), F-33400 Talence (France); Casner, A. [CEA, DAM, DIF, F-91297 Arpajon (France); Ribeyre, X.; Schurtz, G. [University of Bordeaux, CEA, CNRS, CELIA (Centre Lasers Intenses et Applications), F-33400 Talence (France); Frenje, J. A. [Massachusetts Institute of Technology, Cambridge, Massachusetts 02139 (United States); and others

2012-10-15T23:59:59.000Z

254

ATOMIC BEAM POLARIZATION MEASUREMENT OF THE RHIC POLARIZED H-JET TARGET.  

DOE Green Energy (OSTI)

The RHIC polarized H-Jet measures the polarization of the RHIC proton beam via elastic scattering off a nuclear polarized atomic hydrogen beam. The atomic beam is produced by a dissociator, a beam forming system and sextupole magnets. Nuclear polarization is achieved by exchanging occupation numbers of hyperfine states using high frequency transitions. The polarization was measured using a modified form of a Breit-Rabi polarimeter including focusing magnets and another set of high frequency transitions. The sampling of a large part of the beam and low noise electronics made it possible to measure the polarization to a high degree of accuracy in a very short time period (1 min). Using this system, we measured no depolarization of the atomic beam due to the RF fields of the bunched proton beam. Time-of-Flight measurements were done using a fast chopper and a QMA at the position of the RHIC interaction point to determine the areal density of the atomic beam seen by the RHIC beam.

MAKDISI,Y.; NASS,A.; GRAHAM,D.; KPONOU,A.; MAHLER,G.; MENG,W.; RITTER,J.; ET AL.

2005-01-28T23:59:59.000Z

255

BEAM DIFFUSION MEASUREMENTS AT RHIC.  

Science Conference Proceedings (OSTI)

During a store, particles from the beam core continually diffuse outwards into the halo through a variety of mechanisms. Understanding the diffusion rate as a function of particle amplitude can help discover which processes are important to halo growth. A collimator can be used to measure the amplitude growth rate as a function of the particle amplitude. In this paper we present results of diffusion measurements performed at the Relativistic Heavy Ion Collider (RHIC) with fully stripped gold ions, deuterons, and protons. We compare these results with measurements from previous years, and simulations, and discuss any factors that relate to beam growth in RHIC.

FLILLER,R.P.,IIIDREES,A.GASSNER,D.MCINTYRE,G.PEGGS,S.TRBOJEVIC,D.

2003-05-12T23:59:59.000Z

256

Mechanical beam isolator for high-power laser systems  

DOE Patents (OSTI)

A mechanical beam isolator uses rod-shaped elements having a Gaussian configuration to interrupt the path of a beam of photons or particles when the time-scale of the needed interruption is of the order of a microsecond or less. One or more of these rods is mounted transversely to, and penetrates through, a rotating shaft supported by bearings. Owing to the Gaussian geometry of the rods, they are able to withstand much higher rotation speeds, without tensile failure, than rods having any other geometrical shape.

Post, Richard F. (Walnut Creek, CA); Vann, Charles S. (Fremont, CA)

1998-01-01T23:59:59.000Z

257

Beam Breakup Studies for New Cryo-Unit  

SciTech Connect

In this paper, we report the numerical simulations of cumulative beam breakup studies for a new cryo-unit for booster design at Jefferson lab. The system consists of two 1-cell and one 7-cell superconducting RF cavities. Combining two 1-cell into a 2-cell together with a 7-cell is also an option. Simulations have been performed using the 2-dimensional time-domain code. The 1-cell+1-cell+7-cell combination confirms beam stability, however, the arrangement 2-cell+7-cell shows instability.

S. Ahmed, I. Shin, R. Kazimi, F. Marhauser ,F. Hannon ,G. Krafft ,B. Yunn ,A. Hofler

2011-03-01T23:59:59.000Z

258

A Two Bunch Beam Position Monitor  

SciTech Connect

A new beam position monitor digitizer module has been designed, tested and tuned at SLAC. This module, the electron-positron beam position monitor (epBPM), measures position of single electron and positron bunches for the SLC, LINAC, PEPII injections lines and final focus. The epBPM has been designed to improve resolution of beam position measurements with respect to existing module and to speed feedback correction. The required dynamic range is from 5 x 10{sup 8} to 10{sup 11} particles per bunch (46dB). The epBPM input signal range is from {+-}2.5 mV to {+-}500 mV. The pulse-to-pulse resolution is less than 2 {mu}m for 5 x 10{sup 10} particles per bunch for the 12 cm long striplines, covering 30{sup o} at 9 mm radius. The epBPM module has been made in CAMAC standard, single width slot, with SLAC type timing connector. 45 modules have been fabricated. The epBPM module has four input channels X{sup +}, X{sup -}, Y{sup +}, Y{sup -} (Fig. 1), named to correspond with coordinates of four striplines - two in horizontal and two in vertical planes, processing signals to the epBPM inputs. The epBPM inputs are split for eight signal processing channels to catch two bunches, first - the positron, then the electron bunch in one cycle of measurements. The epBPM has internal and external trigger modes of operations. The internal mode has two options - with or without external timing, catching only first bunch in the untimed mode. The epBPM has an on board calibration circuit for measuring gain of the signal processing channels and for timing scan of programmable digital delays to synchronize the trigger and the epBPM input signal's peak. There is a mode for pedestal measurements. The epBPM has 3.6 {mu}s conversion time.

Medvedko, E.; Aiello, R.; Smith, S.; /SLAC

2011-09-12T23:59:59.000Z

259

Transverse beam shape measurements of intense proton beams using optical transition radiation  

SciTech Connect

A number of particle physics experiments are being proposed as part of the Department of Energy HEP Intensity Frontier. Many of these experiments will utilize megawatt level proton beams onto targets to form secondary beams of muons, kaons and neutrinos. These experiments require transverse size measurements of the incident proton beam onto target for each beam spill. Because of the high power levels, most beam intercepting profiling techniques will not work at full beam intensity. The possibility of utilizing optical transition radiation (OTR) for high intensity proton beam profiling is discussed. In addition, previous measurements of OTR beam profiles from the NuMI beamline are presented.

Scarpine, Victor E.; /Fermilab

2012-03-01T23:59:59.000Z

260

Experience at the Los Alamos Meson Physics Facility with the use of alloy Inconel 718 as an enclosure for a beam degrader and as a proton beam entry window  

Science Conference Proceedings (OSTI)

Operation of the Los Alamos Meson Physics Facility (LAMPF) began in 1972 and continues at present. An injector delivers protons to a 0.8 kin long linear accelerator which produces a particle energy of 800 MeV; the protons are then transported to a variety of experimental areas. The proton beam is transported in a vacuum tube, controlled and bent by electromagnets. The highest intensity beam, at a maximum level of 1 mA, is delivered to the experimental area designated as Area A. At the end of the experimental area, the beam is transported through an interface between beamline vacuum and one atmosphere air pressure. This interface is made of metal and is generally referred to as a beam entry window. At LAMPF, after the beam has exited the vacuum tube, it becomes incident on a number of experiments or ``targets.`` These include capsules for radiation damage studies, a beam ``degrader`` for the long-term neutrino experiment, and as many nine targets in the Isotope Production (IP) stringer system used to produce medically significant isotopes. Following the IP system is a beam stop used for the purpose its name implies. The beam stop also contains a beam entry window, whose purpose is to separate the 250 psig water cooling environment from I atmosphere of air. The beam entry window, the beam degrader, and the beam stop window are made of alloy Inconel 718, have endured a lengthy irradiation service time at LAMPF, and are the subject of this report.

Sommer, W.F.; Ferguson, P.D.; Brown, R.D.; Cedillo, C.M.; Zimmerman, E.

1994-09-01T23:59:59.000Z

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261

Comparison between the radial density buildup in the TARA plugs using hydrogen versus deuterium neutral beams  

DOE Green Energy (OSTI)

The WOLF code is used to compare the beam divergences from a TARA source using hydrogen and deuterium. Factors which influence the divergence which are investigated are the electron temperature, initial ion energy, electrode positions and ion beam current density. The beam divergence for 20 keV hydrogen is found to be only 20% smaller than for 25 keV deuterium for the same electrode positions. Since the optimal positioning of the electrodes is found to be independent of mesh spacing, a large parameter study is undertaken using little computer time. A time-dependent radial Fokker-Planck code is next used to examine the radial density buildup in a plug of the TARA tandem mirror. For both hydrogen and deuterium neutral beams, the influences of beam positioning, current and energy, edge neutral pressure and assumed electron temperature are studied.

Blackfield, D.T.

1983-11-01T23:59:59.000Z

262

Particle beam fusion research at Sandia National Laboratories  

SciTech Connect

Sandia`s Particle Beam Fusion Program is investigating several driver options, based on pulsed power technology, with the goal of demonstrating a practical ignitor for Inertial Confinement Fusion (ICF) Reactors. The interrelated aspects of power conditioning and compression, beam-target interaction, and target ignition are being studied. The issues of efficiency, reliability and multiple pulse capability are being integrated into the program to provide a viable approach to an experimental power reactor. On a shorter time scale the authors expect to derive important military-related benefits from attendant research and facility development. The two most important advantages of pulsed power driven fusion are the inherent low cost and high efficiency of high current particle accelerators. However, comparison of the relative merits of particle beams and focused laser beams must include many other factors such as beam transport, and target coupling, as well as target design and fabrication. These issues are being investigated to determine if the perceived practical benefits of particle beam fusion can indeed be realized. The practical considerations are exemplified in a comparison of the leading ICF drivers. The plan being followed by Sandia involves using the Electron Beam Fusion Accelerator (EBFA) to meet three objectives by 1985: significant burn using EBFA 1, net energy gain based on an upgrade of EBFA to the 2 megajoule (MJ) level (EBFA 2), and demonstration of a single module of EBFA 2 operated in the repetitive pulse mode. These goals are dependent, of course, on success in solving several key technical problems under investigation. If these technical problems can be solved, then practical applications to fusion power could be considered. The potential for these applications has been studied using economic models that allow one to derive the cost of power based on various assumptions.

1978-12-31T23:59:59.000Z

263

Neutron beam imaging at neutron spectrometers at Dhruva  

SciTech Connect

A low efficiency, 2-Dimensional Position Sensitive Neutron Detector based on delay line position encoding is developed. It is designed to handle beam flux of 10{sup 6}-10{sup 7} n/cm{sup 2}/s and for monitoring intensity profiles of neutron beams. The present detector can be mounted in transmission mode, as the hardware allows maximum neutron transmission in sensitive region. Position resolution of 1.2 mm in X and Y directions, is obtained. Online monitoring of beam images and intensity profile of various neutron scattering spectrometers at Dhruva are presented. It shows better dynamic range of intensity over commercial neutron camera and is also time effective over the traditionally used photographic method.

Desai, Shraddha S.; Rao, Mala N. [Solid State Physics Division, Bhabha Atomic Research Centre, Trombay, Mumbai 400 085 (India)

2012-06-05T23:59:59.000Z

264

BNL | ATF Beam Diagnostics  

NLE Websites -- All DOE Office Websites (Extended Search)

Detectors Detectors Detector Response (V/W=V*ps/pJ) Noise Eq. Power (NEP, W/Hz1/2) Wavelength Liquid He Bolometer 2.73E+5 1.87E-13 > 15 um Golay Cell ~1500 @ 10 THz w/15 Hz modulation ~1E-10 0.2 THz to 20 THz (1.5 mm to 15 um) LN2 (blue) cooled HgCdTe >10,000 ~4E-30 2 um to 24 um Te (red) cooled HgCdTe N/A ~2.5E-10 2 um to 9 um Silicon detector for X-ray (PDF) Liquid He Bolometer Manual (PDF) Rapid Scanning Imaging Spectrograph/Monochromator Manual (PDF) Shad-o-snap 1024 X-ray Camera The Shad-o-Snap 1024 x-ray camera is part of the new product line of easy-to-use, "smart" USB cameras developed by Rad-icon Imaging Corp. This microprocessor based camera offers simple timing control combined with new readout modes and easy image transfers as TIFF or raw integer image files.

265

Beam heating of target foils  

SciTech Connect

A target rotator, built to reduce the effects of beam spot heating, is fully adjustable, holds three targets, is chamber independent, and takes up limited space. The expected temperature rise in the target is calculated from the Stefan--Boltzmann law. (PMA)

Corwin, W.C.

1975-01-01T23:59:59.000Z

266

Analytic fluid theory of beam spiraling in high-intensity cyclotrons  

E-Print Network (OSTI)

Using a two-dimensional fluid description, we investigate the nonlinear radial-longitudinal dynamics of intense beams in isochronous cyclotrons in the nonrelativistic limit. With a multiscale analysis separating the time ...

Cerfon, A. J.

267

Vlasov simulations of beams with a moving grid  

SciTech Connect

Thanks to the rapid increase of computing power in recent years, simulations of plasmas and particle beams based on direct solution of the Vlasov equation on a multi-dimensional phase-space grid are becoming attractive as an alternative to Particle-In-Cell (PIC) simulations. Their strength lies essentially in the fact that they are noiseless and that all parts of phase space, including the tail of the distribution, are equally well resolved. Their major drawback is that, for inhomogeneous systems, many of the grid points (where no particles are present) are wasted. This is especially the case for beam simulations where the beam moves rapidly through the phase space (due to varying alternating-gradient focusing forces, for example). This inefficiency has made such Vlasov simulations unsuitable for those cases. One of the methods which has proven very efficient for the direct resolution of the Vlasov equation is the semi-Lagrangian method [1, 3]. It consists in updating the values of the distribution function at the grid nodes by following the characteristics ending at these nodes backwards and interpolating the value at the bottom of the characteristics from the known values at the previous time step. In general the interpolation grid is fixed, but this is not mandatory. This paper introduces the concept of a moving grid which is mapped at each time step from a logical uniform grid to the beam, so that it contains the whole beam without needing too many points with vanishing values of the distribution function. In order to implement this new method, we introduce a new time stepping algorithm which does not rely on the time splitting procedure traditionally used in Vlasov solvers.

Sonnendrucker, E.; Filbet, F.; Friedman, A.; Oudet, E.; Vay, J-L.

2003-10-03T23:59:59.000Z

268

Theory of microdroplet and microbubble deformation by Gaussian laser beam  

E-Print Network (OSTI)

The theory for linear deformations of fluid microparticles in a laser beam of Gaussian profile is presented, when the beam focus is at the particle center as in optical trapping. Three different fluid systems are considered: water microdroplet in air, air microbubble in water, and a special oil-emulsion in water system used in experiments with optical deformation of fluid interfaces. We compare interface deformations of the three systems when illuminated by a wide (compared to particle radius) and narrow laser beams and analyse differences. Deformations of droplets are radically different from bubbles under otherwise identical conditions, due to the opposite lensing effect (converging and diverging, respectively) of the two; a droplet is deformed far more than a bubble, cetera paribus. Optical contrast is found to be of great importance to the shape obtained when comparing the relatively low-contrast oil-emulsion system to that of water droplets. We finally analyse the dynamics of particle motion when the laser beam is turned on, and compare a static beam to the case of a short pulse. The very different surface tension coefficient implies a very different time scale for dynamics: microseconds for the water-air interface and tens of milliseconds for the oil-emulsion. Surface oscillations of a water microdroplet are found always to be underdamped, while those of the oil-emulsion are overdamped; deformations of a microbubble can be either, depending on physical parameters.

Simen Å Ellingsen

2012-12-12T23:59:59.000Z

269

Novel materials synthesis using an intense pulsed ion beam  

Science Conference Proceedings (OSTI)

Initial experiments on evaporation from metallic and ceramic targets using a pulsed light ion beam source is reported. The source is an intense ion beam produced by a 1.2 MV, 300 kJ Anaconda generator fitted with an extraction diode. Beam fluences of 10--20 J/cm{sup 2} gives a deposition rate of about 30--50 nm per shot, for both brass and YBa{sub 2}Cu{sub 3}O{sub 7-x} (1-2-3) targets. This is about 1000 times greater than comparable rates from pulsed laser deposition (PLD). Single-shot ablated 1-2-3 films, deposited on Si, were analyzed using RBS; the measured stoichiometry was close to 1-2-3 in favorable cases, but shot-to-shot reproducibility was poor. Approximately 1% of the available ion beam energy was utilized for these initial experiments. The potential for producing large area coatings from multi-cation targets and nanophase powders using pulsed ion beam deposition will be discussed.

Gautier, D.C.; Muenchausen, R.E.; Rej, D.J.; Roberts, B.F.; Waganarr, W.J. [Los Alamos National Lab., NM (United States); Johnston, G. [New Mexico Univ., Albuquerque, NM (United States)

1992-12-31T23:59:59.000Z

270

Novel materials synthesis using an intense pulsed ion beam  

Science Conference Proceedings (OSTI)

Initial experiments on evaporation from metallic and ceramic targets using a pulsed light ion beam source is reported. The source is an intense ion beam produced by a 1.2 MV, 300 kJ Anaconda generator fitted with an extraction diode. Beam fluences of 10--20 J/cm[sup 2] gives a deposition rate of about 30--50 nm per shot, for both brass and YBa[sub 2]Cu[sub 3]O[sub 7-x] (1-2-3) targets. This is about 1000 times greater than comparable rates from pulsed laser deposition (PLD). Single-shot ablated 1-2-3 films, deposited on Si, were analyzed using RBS; the measured stoichiometry was close to 1-2-3 in favorable cases, but shot-to-shot reproducibility was poor. Approximately 1% of the available ion beam energy was utilized for these initial experiments. The potential for producing large area coatings from multi-cation targets and nanophase powders using pulsed ion beam deposition will be discussed.

Gautier, D.C.; Muenchausen, R.E.; Rej, D.J.; Roberts, B.F.; Waganarr, W.J. (Los Alamos National Lab., NM (United States)); Johnston, G. (New Mexico Univ., Albuquerque, NM (United States))

1992-01-01T23:59:59.000Z

271

Thermal imaging diagnostics of high-current electron beams  

SciTech Connect

The thermal imaging diagnostics of measuring pulsed electron beam energy density is presented. It provides control of the electron energy spectrum and a measure of the density distribution of the electron beam cross section, the spatial distribution of electrons with energies in the selected range, and the total energy of the electron beam. The diagnostics is based on the thermal imager registration of the imaging electron beam thermal print in a material with low bulk density and low thermal conductivity. Testing of the thermal imaging diagnostics has been conducted on a pulsed electron accelerator TEU-500. The energy of the electrons was 300-500 keV, the density of the electron current was 0.1-0.4 kA/cm{sup 2}, the duration of the pulse (at half-height) was 60 ns, and the energy in the pulse was up to 100 J. To register the thermal print, a thermal imager Fluke-Ti10 was used. Testing showed that the sensitivity of a typical thermal imager provides the registration of a pulsed electron beam heat pattern within one pulse with energy density over 0.1 J/cm{sup 2} (or with current density over 10 A/cm{sup 2}, pulse duration of 60 ns and electron energy of 400 keV) with the spatial resolution of 0.9-1 mm. In contrast to the method of using radiosensitive (dosimetric) materials, thermal imaging diagnostics does not require either expensive consumables, or plenty of processing time.

Pushkarev, A.; Kholodnaya, G.; Sazonov, R.; Ponomarev, D. [Tomsk Polytechnic University, 30 Lenin Ave., Tomsk, 634050 (Russian Federation)

2012-10-15T23:59:59.000Z

272

The [delta]f algorithm for beam dynamics  

Science Conference Proceedings (OSTI)

An algorithm is developed to study particle dynamics of beams including collective interaction with high accuracy and low noise. Particle dynamics with collective interactions is treated through particle simulation, where the main or average distribution f[sub 0] and the deviation away from it [delta]f are separately followed. The main distribution f[sub 0] is handled by an analytic equilibrium solution and the perturbation away from it [delta]f is followed by the method of characteristics. We call this the [delta]f algorithm. We specifically model a synchrotron collider which includes the collision section where collective effects of collisions are simulated by this [delta]f algorithm and the rest of the collider where single particle dynamics are treated by simple harmonic transport. The most important target of this simulation is to understand and predict the long-time behavior of the beam luminosity and lifetime. The [delta]f method allows the study the effect of small perturbations over long timescales on beam lifetime by eliminating the numerical noise problem inherent in Particle-in-Cell techniques. In the [delta]f code using the reference parameters of the SSC (Superconducting Super Collider), beam blow-up near resonances and oscillations in the tune shift, [Delta][nu], far from resonances are observed. In studying long timescale particle diffusion in the phase space of the beams away from resonances, the [delta]f code performance is compared with a tracking code which does not incorporate collective interaction.

Koga, J.; Tajima, T.

1993-05-01T23:59:59.000Z

273

The {delta}f algorithm for beam dynamics  

Science Conference Proceedings (OSTI)

An algorithm is developed to study particle dynamics of beams including collective interaction with high accuracy and low noise. Particle dynamics with collective interactions is treated through particle simulation, where the main or average distribution f{sub 0} and the deviation away from it {delta}f are separately followed. The main distribution f{sub 0} is handled by an analytic equilibrium solution and the perturbation away from it {delta}f is followed by the method of characteristics. We call this the {delta}f algorithm. We specifically model a synchrotron collider which includes the collision section where collective effects of collisions are simulated by this {delta}f algorithm and the rest of the collider where single particle dynamics are treated by simple harmonic transport. The most important target of this simulation is to understand and predict the long-time behavior of the beam luminosity and lifetime. The {delta}f method allows the study the effect of small perturbations over long timescales on beam lifetime by eliminating the numerical noise problem inherent in Particle-in-Cell techniques. In the {delta}f code using the reference parameters of the SSC (Superconducting Super Collider), beam blow-up near resonances and oscillations in the tune shift, {Delta}{nu}, far from resonances are observed. In studying long timescale particle diffusion in the phase space of the beams away from resonances, the {delta}f code performance is compared with a tracking code which does not incorporate collective interaction.

Koga, J.; Tajima, T.

1993-05-01T23:59:59.000Z

274

Subtropical Climatology of Direct Beam Solar Radiation  

Science Conference Proceedings (OSTI)

A climatology of direct beam irradiance has been compiled for Mauna Loa Observatory. A broadband transmittance, calculated from the direct-beam data, has been stratified into clear sky and optically thin and thick cloud regimes; statistics of ...

T. M. Thompson; S. K. Cox

1982-03-01T23:59:59.000Z

275

APPARATUS FOR ELECTRON BEAM HEATING CONTROL  

DOE Patents (OSTI)

An improved electron beam welding or melting apparatus is designed which utilizes a high voltage rectifier operating below its temperature saturation region to decrease variations in electron beam current which normally result from the gas generated in such apparatus. (AEC)

Jones, W.H.; Reece, J.B.

1962-09-18T23:59:59.000Z

276

Enhanced laser beam coupling to a plasma  

DOE Patents (OSTI)

Density perturbations are induced in a heated plasma by means of a pair of oppositely directed, polarized laser beams of the same frequency. The wavelength of the density perturbations is equal to one half the wavelength of the laser beams. A third laser beam is linearly polarized and directed at the perturbed plasma along a line that is perpendicular to the direction of the two opposed beams. The electric field of the third beam is oriented to lie in the plane containing the three beams. The frequency of the third beam is chosen to cause it to interact resonantly with the plasma density perturbations, thereby efficiently coupling the energy of the third beam to the plasma.

Steiger, Arno D. (Pleasanton, CA); Woods, Cornelius H. (Livermore, CA)

1976-01-01T23:59:59.000Z

277

IMPACT simulation and the SNS linac beam  

E-Print Network (OSTI)

dynamics studies of the SNS linac systems were performedIMPACT SIMULATION AND THE SNS LINAC BEAM * Y. Zhang 1 , J.tracking simulations for the SNS linac beam dynamics studies

Zhang, Y.

2009-01-01T23:59:59.000Z

278

Digestion time  

NLE Websites -- All DOE Office Websites (Extended Search)

Digestion time Digestion time Name: Don Mancosh Location: N/A Country: N/A Date: N/A Question: I have always given the rule of thumb in class that material we eat is with us for about 24 hours before exiting the body. The question arises about the time value of liquids. Getting a big coke prior to a 3 hour drive generally means that there will be a stop along the way. Is there a generalization made about liquids in the body similar to the one for solid food? Replies: A physician would give a better answer, but I hazard this: the only liquids which people consume (deliberately) in significant quantities are water, ethyl alcohol and various oils. Water and alcohol are absorbed on a time scale of seconds to minutes through the mouth, stomach and digestive tract. The oils are huge molecules, so I'd guess like any other greasy food they get absorbed in the upper digestive tract. Some of them, perhaps the longest and most nonpolar, are not absorbed at all --- cf. the old-time remedy of mineral oil for constipation --- so there should be some average time-before-what's-left-is-excreted such as you're looking for, and my (wild) guess is that it would not differ substantially from that for food. You can define an average lifetime in the body for alcohol, since the natural level is zero. Rough guidelines are widespread in the context of drunk driving laws. But this is not really possible for water. One's body is normally full up to the brim with water, and there's no way for the body to distinguish between water molecules recently absorbed and molecules that've been moping around since the Beatles split up. Thus the water entering the toilet bowl after the pit stop is not in general the same water as was in the big coke. If you were to consider for water just the average time between drinking and peeing, it would seem to depend strongly on how well hydrated the body was before the drink, and how much was drunk. During sustained heavy exertion in the sun and dry air one can easily drink a pint of water an hour without peeing at all. On the other hand, if one is willing to drink enough water fast enough, so as to establish a high excess of body water one can pee 8 ounces 15 minutes or less after drinking 8 ounces.

279

LOW ENERGY BEAM PROCESSES IN ELECTRONIC MATERIALS ...  

Science Conference Proceedings (OSTI)

LOW ENERGY BEAM PROCESSES IN ELECTRONIC MATERIALS: Session II: Shallow Junction and Low Energy Implantation. Sponsored by: EMPMD Thin ...

280

Electron Beam Melting: The New Directional Solidification  

Science Conference Proceedings (OSTI)

About this Abstract. Meeting, Materials Science & Technology 2011. Symposium, Additive Manufacturing of Metals. Presentation Title, Electron Beam Melting: ...

Note: This page contains sample records for the topic "beam time esaf" 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.


281

Electron-Beam Irradiation of Solar Cells  

Science Conference Proceedings (OSTI)

Electron-Beam Irradiation of Solar Cells. Summary: The Dosimetry Group operates a system capable of performing electron ...

2013-02-27T23:59:59.000Z

282

The upgraded rf system for the AGS and high intensity proton beams  

SciTech Connect

The AGS has been upgraded over the past three years to produce a record beam intensity of 6 {times} 10{sup 13} protons per pulse for the fixed-target physics program. The major elements of the upgrade are: the new 1.5 GeV Booster synchrotron, the main magnet power supply, a high frequency longitudinal dilution cavity, a feedback damper for transverse instabilities, a fast gamma transition jump system, and a new high-power rf system. The new rf system and its role in achieving the high intensity goal are the subjects of this report. The rf system is heavily beam loaded, with 7 Amps of rf current in the beam and a peak power of 0.75 MW delivered to the beam by ten cavities. As an example of the scale of beam loading, at one point in the acceleration cycle the cavities are operated at 1.5 kV/gap; whereas, were it not for the new power amplifiers, the beam-induced voltage on the cavities would be over 25 kV/gap. The upgraded rf system, comprising: new power amplifiers, wide band rf feedback, improved cavities, and new low-level beam control electronics, is described. Results of measurements with beam, which characterize the system`s performance, are presented. A typical high intensity acceleration cycle is described with emphasis on the key challenges of beam loading.

Brennan, J.M. [Brookhaven National Lab., Upton, NY (United States). AGS Dept.

1995-05-01T23:59:59.000Z

283

ION BEAM FOCUSING MEANS FOR CALUTRON  

DOE Patents (OSTI)

An ion beam focusing arrangement for calutrons is described. It provides a virtual focus of origin for the ion beam so that the ions may be withdrawn from an arc plasma of considerable width providing greater beam current and accuracy. (T.R.H.)

Backus, J.G.

1959-06-01T23:59:59.000Z

284

Ion-beam Plasma Neutralization Interaction Images  

SciTech Connect

Neutralization of the ion beam charge and current is an important scientific issue for many practical applications. The process of ion beam charge and current neutralization is complex because the excitation of nonlinear plasma waves may occur. Computer simulation images of plasma neutralization of the ion beam pulse are presented.

Igor D. Kaganovich; Edward Startsev; S. Klasky; Ronald C. Davidson

2002-04-09T23:59:59.000Z

285

Light modulated electron beam driven radiofrequency emitter  

DOE Patents (OSTI)

The disclosure relates to a light modulated electron beam-driven radiofrequency emitter. Pulses of light impinge on a photoemissive device which generates an electron beam having the pulse characteristics of the light. The electron beam is accelerated through a radiofrequency resonator which produces radiofrequency emission in accordance with the electron, hence, the light pulses.

Wilson, M.T.; Tallerico, P.J.

1979-10-10T23:59:59.000Z

286

A new luminescence beam profile monitor for intense proton and heavy ion beams  

DOE Green Energy (OSTI)

A new luminescence beam profile monitor is realized in the polarized hydrogen gas jet target at the Relativistic Heavy Ion Collider (RHIC) facility. In addition to the spin polarization of the proton beam being routinely measured by the hydrogen gas jet, the luminescence produced by beam-hydrogen excitation leads to a strong Balmer series lines emission. A selected hydrogen Balmer line is spectrally filtered and imaged to produce the transverse RHIC proton beam shape with unprecedented details on the RHIC beam profile. Alternatively, when the passage of the high energy RHIC gold ion beam excited only the residual gas molecules in the beam path, sufficient ion beam induced luminescence is produced and the transverse gold ion beam profile is obtained. The measured transverse beam sizes and the calculated emittances provide an independent confirmation of the RHIC beam characteristics and to verify the emittance conservation along the RHIC accelerator. This optical beam diagnostic technique by making use of the beam induced fluorescence from injected or residual gas offers a truly noninvasive particle beam characterization, and provides a visual observation of proton and heavy ion beams. Combined with a longitudinal bunch measurement system, a 3-dimensional spatial particle beam profile can be reconstructed tomographically.

Tsang,T.; Bellavia, S.; Connolly, R.; Gassner, D.; Makdisi, Y.; Russo, T.; Thieberger, P.; Trbojevic, D.; Zelenski, A.

2008-10-01T23:59:59.000Z

287

Corrugated Pipe as a Beam Dechirper  

SciTech Connect

We have studied the use of a metallic pipe with small corrugations for the purpose of passively dechirping, through its wakefield, a short, intense electron bunch. The corrugated pipe is attractive for this purpose because its wake: (i) has near maximal possible amplitude for a given aperture and (ii) has a relatively large oscillation wave length, even when the aperture is small. We showed how the corrugated structure can satisfy dechirping requirements encountered in the NGLS project at LBNL. We found that a linear chirp of -40 MeV/mm can be induced by an NGLS-like beam, by having it pass through a corrugated, metallic pipe of radius 3 mm, length 8.2 m, and corrugation parameters full depth 450 {mu}m and period 1000 {mu}m. This structure is about 15 times as effective in the role of dechirper as an S-band accelerator structure used passively.

Bane, K.L.F.; Stupakov, G.; /SLAC

2012-04-20T23:59:59.000Z

288

Radio Frequency Station - Beam Dynamics Interaction in Circular Accelerators  

Science Conference Proceedings (OSTI)

The longitudinal beam dynamics in circular accelerators is mainly defined by the interaction of the beam current with the accelerating Radio Frequency (RF) stations. For stable operation, Low Level RF (LLRF) feedback systems are employed to reduce coherent instabilities and regulate the accelerating voltage. The LLRF system design has implications for the dynamics and stability of the closed-loop RF systems as well as for the particle beam, and is very sensitive to the operating range of accelerator currents and energies. Stability of the RF loop and the beam are necessary conditions for reliable machine operation. This dissertation describes theoretical formalisms and models that determine the longitudinal beam dynamics based on the LLRF implementation, time domain simulations that capture the dynamic behavior of the RF station-beam interaction, and measurements from the Positron-Electron Project (PEP-II) and the Large Hadron Collider (LHC) that validate the models and simulations. These models and simulations are structured to capture the technical characteristics of the system (noise contributions, non-linear elements, and more). As such, they provide useful results and insight for the development and design of future LLRF feedback systems. They also provide the opportunity to study diverse longitudinal beam dynamics effects such as coupled-bunch impedance driven instabilities and single bunch longitudinal emittance growth. Coupled-bunch instabilities and RF station power were the performance limiting effects for PEP-II. The sensitivity of the instabilities to individual LLRF parameters, the effectiveness of alternative operational algorithms, and the possible tradeoffs between RF loop and beam stability were studied. New algorithms were implemented, with significant performance improvement leading to a world record current during the last PEP-II run of 3212 mA for the Low Energy Ring. Longitudinal beam emittance growth due to RF noise is a major concern for LHC. Simulations studies and measurements were conducted that clearly show the correlation between RF noise and longitudinal bunch emittance, identify the major LLRF noise contributions, and determine the RF component dominating this effect. With these results, LHC upgrades and alternative algorithms are evaluated to reduce longitudinal emittance growth during operations. The applications of this work are described with regard to future machines and analysis of new technical implementations, as well as to possible future work which would continue the directions of this dissertation.

Mastoridis, Themistoklis; /Stanford U., Elect. Eng. Dept. /SLAC

2011-03-01T23:59:59.000Z

289

Accelerating polarized beams in Tevatron  

SciTech Connect

In this paper, we will examine the totality of equipment, manpower and cost necessary to obtain a polarized proton beam in the Tevatron. We will not, however, be concerned with the acquisition and acceleration of polarized /bar p/ beams. Furthermore we will consider only a planar main ring without overpass, although it is expected that Siberian snake schemes could be made to apply equally well to non-planar machines. In addition to not wanting to tackle here the task of reformulating the theory for a non-planar closed orbit, we also anticipate that as part of the Tevatron upgrade the main ring will in the not too distant future, be replaced by a planar main injector situated in a separate tunnel. 4 refs., 11 figs., 1 tab.

Teng, L.C.

1989-02-01T23:59:59.000Z

290

Center for Beam Physics, 1993  

Science Conference Proceedings (OSTI)

The Center for Beam Physics is a multi-disciplinary research and development unit in the Accelerator and Fusion Research Division at Lawrence Berkeley Laboratory. At the heart of the Center`s mission is the fundamental quest for mechanisms of acceleration, radiation and focusing of energy. Dedicated to exploring the frontiers of the physics of (and with) particle and photon beams, its primary mission is to promote the science and technology of the production, manipulation, storage and control systems of charged particles and photons. The Center serves this mission via conceptual studies, theoretical and experimental research, design and development, institutional project involvement, external collaborations, association with industry and technology transfer. This roster provides a glimpse at the scientists, engineers, technical support, students, and administrative staff that make up this team and a flavor of their multifaceted activities during 1993.

Not Available

1994-05-01T23:59:59.000Z

291

Scattering apodizer for laser beams  

SciTech Connect

A method is disclosed for apodizing a laser beam to smooth out the production of diffraction peaks due to optical discontinuities in the path of the laser beam, such method comprising introduction of a pattern of scattering elements for reducing the peak intensity in the region of such optical discontinuities, such pattern having smoothly tapering boundaries in which the distribution density of the scattering elements is tapered gradually to produce small gradients in the distribution density, such pattern of scattering elements being effective to reduce and smooth out the diffraction effects which would otherwise be produced. The apodizer pattern may be produced by selectively blasting a surface of a transparent member with fine abrasive particles to produce a multitude of minute pits. In one embodiment, a scattering apodizer pattern is employed to overcome diffraction patterns in a multiple element crystal array for harmonic conversion of a laser beam. The interstices and the supporting grid between the crystal elements are obscured by the gradually tapered apodizer pattern of scattering elements.

Summers, Mark A. (Livermore, CA); Hagen, Wilhelm F. (Livermore, CA); Boyd, Robert D. (Livermore, CA)

1985-01-01T23:59:59.000Z

292

Scattering apodizer for laser beams  

DOE Patents (OSTI)

A method is disclosed for apodizing a laser beam to smooth out the production of diffraction peaks due to optical discontinuities in the path of the laser beam, such method comprising introduction of a pattern of scattering elements for reducing the peak intensity in the region of such optical discontinuities, such pattern having smoothly tapering boundaries in which the distribution density of the scattering elements is tapered gradually to produce small gradients in the distribution density, such pattern of scattering elements being effective to reduce and smooth out the diffraction effects which would otherwise be produced. The apodizer pattern may be produced by selectively blasting a surface of a transparent member with fine abrasive particles to produce a multitude of minute pits. In one embodiment, a scattering apodizer pattern is employed to overcome diffraction patterns in a multiple element crystal array for harmonic conversion of a laser beam. The interstices and the supporting grid between the crystal elements are obscured by the gradually tapered apodizer pattern of scattering elements.

Summers, M.A.; Hagen, W.F.; Boyd, R.D.

1984-01-01T23:59:59.000Z

293

BEAM STUDIES AT THE SNS LINAC  

Science Conference Proceedings (OSTI)

The most recent beam dynamics studies at the Spallation Neutron Source (SNS) linac, including major beam loss reduction efforts in the normal conducting linac and in the superconducting linac (SCL), and the simulation and measurement of longitudinal beam halo and longitudinal acceptance at the entrance of the SCL are discussed. Oscillation of the beam centroid around the linac synchronous phase and the phase adiabatic damping curves in the SNS linac are investigated with linac longitudinal models and measured with all the linac beam phase monitors.

Zhang, Yan [ORNL

2009-01-01T23:59:59.000Z

294

An Alternative Form of Laser Beam Characterization  

SciTech Connect

Careful characterization of laser beams used in materials processing such as welding and drilling is necessary to obtain robust, reproducible processes and products. Recently, equipment and techniques have become available which make it possible to rapidly and conveniently characterize the size, shape, mode structure, beam quality (Mz), and intensity of a laser beam (incident power/unit area) as a function of distance along the beam path. This facilitates obtaining a desired focused spot size and also locating its position. However, for a given position along the beam axis, these devices typically measure where the beam intensity level has been reduced to I/ez of maximum intensity at that position to determine the beam size. While giving an intuitive indication of the beam shape since the maximum intensity of the beam varies greatly, the contour so determined is not an iso-contour of any parameter related to the beam intensity or power. In this work we shall discuss an alternative beam shape formulation where the same measured information is plotted as contour intervals of intensity.

KNOROVSKY,GERALD A.; MACCALLUM,DANNY O.

2000-06-30T23:59:59.000Z

295

Generation of low-divergence laser beams  

DOE Patents (OSTI)

Apparatus for transforming a conventional beam of coherent light, having a Gaussian energy distribution and relatively high divergence, into a beam in which the energy distribution approximates a single, non-zero-order Bessel function and which therefore has much lower divergence. The apparatus comprises a zone plate having transmitting and reflecting zones defined by the pattern of light interference produced by the combination of a beam of coherent light with a Gaussian energy distribution and one having such a Bessel distribution. The interference pattern between the two beams is a concentric array of multiple annuli, and is preferably recorded as a hologram. The hologram is then used to form the transmitting and reflecting zones by photo-etching portions of a reflecting layer deposited on a plate made of a transmitting material. A Bessel beam, containing approximately 50% of the energy of the incident beam, is produced by passing a Gaussian beam through such a Bessel zone plate. The reflected beam, also containing approximately 50% of the incident beam energy and having a Bessel energy distribution, can be redirected in the same direction and parallel to the transmitted beam. Alternatively, a filter similar to the Bessel zone plate can be placed within the resonator cavity of a conventional laser system having a front mirror and a rear mirror, preferably axially aligned with the mirrors and just inside the front mirror to generate Bessel energy distribution light beams at the laser source. 11 figures.

Kronberg, J.W.

1993-09-14T23:59:59.000Z

296

Generation of low-divergence laser beams  

DOE Patents (OSTI)

This invention is comprised of an apparatus for transforming a conventional beam of coherent light, having a Gaussian energy distribution and relatively high divergence, into a beam in which the energy distribution approximates a single, non-zero-order Bessel function and which therefore has much lower divergence. The apparatus comprises a zone plate having transmitting and reflecting zones defined by the pattern of light interference produced by the combination of a beam of coherent light with a Gaussian energy distribution and one having such a Bessel distribution. The interference pattern between the two beams is a concentric array of multiple annuli, and is preferably recorded as a hologram. The hologram is then used to form the transmitting, and reflecting zones by photo-etching portions of a reflecting layer deposited on a plate made of a transmitting material. A Bessel beam, containing approximately 50% of the energy of the incident beam, is produced by passing a Gaussian beam through such a Bessel zone plate. The reflected beam, also containing approximately 50% of the incident beam energy and having a Bessel energy distribution, can be redirected in the same direction and parallel to the transmitted beam. Alternatively, a filter similar to the Bessel zone plate can be placed within the resonator cavity of a conventional laser system having a front mirror and a rear mirror, preferably axially aligned with the mirrors and just inside the front mirror to generate Bessel energy distribution light beams at the laser source.

Kronberg, J.W.

1992-12-31T23:59:59.000Z

297

Generation of low-divergence laser beams  

DOE Patents (OSTI)

Apparatus for transforming a conventional beam of coherent light, having a Gaussian energy distribution and relatively high divergence, into a beam in which the energy distribution approximates a single, non-zero-order Bessel function and which therefore has much lower divergence. The apparatus comprises a zone plate having transmitting and reflecting zones defined by the pattern of light interference produced by the combination of a beam of coherent light with a Gaussian energy distribution and one having such a Bessel distribution. The interference pattern between the two beams is a concentric array of multiple annuli, and is preferably recorded as a hologram. The hologram is then used to form the transmitting and reflecting zones by photo-etching portions of a reflecting layer deposited on a plate made of a transmitting material. A Bessel beam, containing approximately 50% of the energy of the incident beam, is produced by passing a Gaussian beam through such a Bessel zone plate. The reflected beam, also containing approximately 50% of the incident beam energy and having a Bessel energy distribution, can be redirected in the same direction and parallel to the transmitted beam. Alternatively, a filter similar to the Bessel zone plate can be placed within the resonator cavity of a conventional laser system having a front mirror and a rear mirror, preferably axially aligned with the mirrors and just inside the front mirror to generate Bessel energy distribution light beams at the laser source.

Kronberg, James W. (108 Independent Blvd., Aiken, SC 29801)

1993-01-01T23:59:59.000Z

298

Time-of-flight direct recoil ion scattering spectrometer  

DOE Patents (OSTI)

A time of flight direct recoil and ion scattering spectrometer beam line (10). The beam line (10) includes an ion source (12) which injects ions into pulse deflection regions (14) and (16) separated by a drift space (18). A final optics stage includes an ion lens and deflection plate assembly (22). The ion pulse length and pulse interval are determined by computerized adjustment of the timing between the voltage pulses applied to the pulsed deflection regions (14) and (16).

Krauss, Alan R. (Naperville, IL); Gruen, Dieter M. (Downers Grove, IL); Lamich, George J. (Orland Park, IL)

1994-01-01T23:59:59.000Z

299

H/sup -/ beam emittance measurements for the Penning and the asymmetric, grooved magnetron surface-plasma sources  

DOE Green Energy (OSTI)

Beam intensity and emittance measurements show that the H/sup -/ beam from our Penning surface-plasma source (SPS) has twice the intensity and ten times the brightness of the H/sup -/ beam from an asymmetric, grooved magnetron SPS. H/sup -/ ion temperatures of 5 eV for the Penning SPS and 22 eV for the asymmetric, grooved magnetron are deduced by using a simple emittance theory and the present emittance measurements.

Smith, H.V. Jr.; Allison, P.

1982-04-01T23:59:59.000Z

300

S&TR | March/April 2008: Standardizing the Art of Electron-Beam Welding  

NLE Websites -- All DOE Office Websites (Extended Search)

Standardizing the Art of Electron-Beam Welding. Standardizing the Art of Electron-Beam Welding. WELDED materials are an integral part of everyday life. Appliances, cars, and bridges are all made by welding materials together. But not all welds are created equal. Welding methods vary in complexity, time, and cost, depending on a product's requirements and purpose. In electron-beam (EBeam) welding, an electron beam generated in a vacuum creates a fusing heat source that can unite almost any metals. This method produces deep welds without adding excessive heat that can adversely affect the properties of the surrounding metal. In the nuclear energy and aerospace industries, electron-beam welding is preferred for manufacturing high-value welds-those in which defects cannot be tolerated. The Department of Energy's (DOE's) nuclear weapons

Note: This page contains sample records for the topic "beam time esaf" 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

Integral window/photon beam position monitor and beam flux detectors for x-ray beams  

DOE Patents (OSTI)

A monitor/detector assembly in a synchrotron for either monitoring the position of a photon beam or detecting beam flux may additionally function as a vacuum barrier between the front end and downstream segment of the beamline in the synchrotron. A base flange of the monitor/detector assembly is formed of oxygen free copper with a central opening covered by a window foil that is fused thereon. The window foil is made of man-made materials, such as chemical vapor deposition diamond or cubic boron nitrate and in certain configurations includes a central opening through which the beams are transmitted. Sensors of low atomic number materials, such as aluminum or beryllium, are laid on the window foil. The configuration of the sensors on the window foil may be varied depending on the function to be performed. A contact plate of insulating material, such as aluminum oxide, is secured to the base flange and is thereby clamped against the sensor on the window foil. The sensor is coupled to external electronic signal processing devices via a gold or silver lead printed onto the contact plate and a copper post screw or alternatively via a copper screw and a copper spring that can be inserted through the contact plate and coupled to the sensors. In an alternate embodiment of the monitor/detector assembly, the sensors are sandwiched between the window foil of chemical vapor deposition diamond or cubic boron nitrate and a front foil made of similar material.

Shu, Deming (Darien, IL); Kuzay, Tuncer M. (Naperville, IL)

1995-01-01T23:59:59.000Z

302

Time Brightness  

NLE Websites -- All DOE Office Websites (Extended Search)

Perlmutter, et al., in Thermonuclear Supernovae, NATO ASI, v. 486 (1997) Perlmutter, et al., in Thermonuclear Supernovae, NATO ASI, v. 486 (1997) Cosmology from . . . Time Brightness ... . . . 50-100 Fields Lunar Calendar Scheduled Follow-Up Imaging at Hubble, Cerro Tololo, WIYN, Isaac Newton Scheduled Follow-Up Spectroscopy at Keck Almost 1000 Galaxies per Field RESULT: ~24 Type Ia supernovae discovered while still brightening, at new moon Berkeley Lab Keck WIYN Cerro Tololo Isaac Newton Hubble Strategy We developed a strategy to guarantee a group of supernova discoveries on a certain date. Just after a new moon, we observe some 50 to 100 high-galactic lattitute fields-each containing almost a thousand high-redshift galaxies-in two nights on the Cerro Tololo 4-meter telescope with Tyson & Bernstein's wide-field camera. We return three weeks later to observe the same

303

Projection imaging of photon beams by the Cerenkov effect  

SciTech Connect

Purpose: A novel technique for beam profiling of megavoltage photon beams was investigated for the first time by capturing images of the induced Cerenkov emission in water, as a potential surrogate for the imparted dose in irradiated media. Methods: A high-sensitivity, intensified CCD camera (ICCD) was configured to acquire 2D projection images of Cerenkov emission from a 4 Multiplication-Sign 4 cm{sup 2} 6 MV linear accelerator (LINAC) x-ray photon beam operating at a dose rate of 400 MU/min incident on a water tank with transparent walls. The ICCD acquisition was gated to the LINAC sync pulse to reduce background light artifacts, and the measurement quality was investigated by evaluating the signal to noise ratio and measurement repeatability as a function of delivered dose. Monte Carlo simulations were used to derive a calibration factor for differences between the optical images and deposited dose arising from the anisotropic angular dependence of Cerenkov emission. Finally, Cerenkov-based beam profiles were compared to a percent depth dose (PDD) and lateral dose profile at a depth of d{sub max} from a reference dose distribution generated from the clinical Varian ECLIPSE treatment planning system (TPS). Results: The signal to noise ratio was found to be 20 at a delivered dose of 66.6 cGy, and proportional to the square root of the delivered dose as expected from Poisson photon counting statistics. A 2.1% mean standard deviation and 5.6% maximum variation in successive measurements were observed, and the Monte Carlo derived calibration factor resulted in Cerenkov emission images which were directly correlated to deposited dose, with some spatial issues. The dose difference between the TPS and PDD predicted by Cerenkov measurements was within 20% in the buildup region with a distance to agreement (DTA) of 1.5-2 mm and {+-}3% at depths beyond d{sub max}. In the lateral profile, the dose difference at the beam penumbra was within {+-}13% with a DTA of 0-2 mm, {+-}5% in the central beam region, and 2%-3% in the beam umbra. Conclusions: The results from this initial study demonstrate the first documented use of Cerenkov emission imaging to profile x-ray photon LINAC beams in water. The proposed modality has several potential advantages over alternative methods, and upon future refinement may prove to be a robust and novel dosimetry method.

Glaser, Adam K.; Davis, Scott C.; McClatchy, David M.; Zhang, Rongxiao; Pogue, Brian W.; Gladstone, David J. [Thayer School of Engineering, Dartmouth College, Hanover, New Hampshire 03755 (United States); Department of Physics and Astronomy, Dartmouth College, Hanover, New Hampshire 03755 (United States); Thayer School of Engineering and Department of Physics and Astronomy, Dartmouth College, Hanover, New Hampshire 03755 (United States); Norris Cotton Cancer Center, Dartmouth-Hitchcock Medical Center, Lebanon, New Hampshire 03766 (United States)

2013-01-15T23:59:59.000Z

304

Simple Low-Frequency Beam Pickup  

SciTech Connect

Detection of the field induced by a beam outside of the beam pipe can be used as a beam diagnostic. Wires placed in longitudinal slots in the outside wall of the beam pipe can be used as a beam pickup. This has a very small beam-coupling impedance and avoids complications of having a feedthrough. The signal can be reasonably high at low frequencies. We present a field waveform at the outer side of a beam pipe, obtained as a result of calculations and measurements. We calculate the beam-coupling impedance due to a long longitudinal slot in the resistive wall and the signal induced in a wire placed in such a slot and shielded by a thin screen from the beam. These results should be relevant for impedance calculations of the slot in an antechamber and for slots in the PEP-II distributed ion pump screens. The design of the low-frequency beam position monitor is very simple. It can be used in storage rings, synchrotron light sources, and free electron lasers, like LINAC coherent light source.

Novokhatski, A.; Heifets, S.; /SLAC; Aleksandrov, A.; /Oak Ridge

2011-10-12T23:59:59.000Z

305

Beam heating studies on an early model is a superconducting cosine theta magnet  

Science Conference Proceedings (OSTI)

Superconducting magnets for accelerators can be accidentally quenched by heat resulting from beam losses in the magnet. The threshold for such quenches is determined by the time structure of the beam loss and by details of the magnet application, construction and cooling. A 4.25 m long superconducting cosine theta dipole magnet, MARK VI, constructed during the research and development phase of the ISABELLE Project at BNL was installed in the 28.5 GeV/c primary proton beam line from the AGS. By energizing the magnet, the proton beam could be deflected into the magnet. The beam intensity required to quench the magnet was observed for different beam sizes and at several values of magnet current up to 2400 A or approximately 70% of the highest magnet operating current. The maximum current was limited by the gas-cooled power lead flow available using pool-boiling helium rather than single phase forced-flow helium at 5 atm for which the magnet system was designed. Details of the experimental setup including the magnet and cryogenic system, the beam-monitoring equipment and instrumentation are described. The measurements are discussed and compared with beam heating measurements made on another superconducting magnet and interpreted using the Cascade Simulation Program, CASIM.

Bozoki, G; Bunce, G; Danby, G; Foelsche, H; Jackson, J; Prodell, A; Soukas, A; Stevens, A; Stoehr, R; Weisenbloom, J

1980-01-01T23:59:59.000Z

306

PROGRESS IN BEAM FOCUSING AND COMPRESSION FOR WARM-DENSE MATTER EXPERIMENTS  

SciTech Connect

The Heavy-Ion Fusion Sciences Virtual National Laboratory is pursuing an approach to target heating experiments in the Warm Dense Matter regime, using spacecharge-dominated ion beams that are simultaneously longitudinally bunched and transversely focused. Longitudinal beam compression by large factors has beendemonstrated in the Neutralized Drift Compression Experiment (NDCX) with controlledramps and forced neutralization. Using an injected 30-mA K+ ion beam with initialkinetic energy 0.3 MeV, axial compression leading to ~;;50-fold current amplification andsimultaneous radial focusing to beam radii of a few mm have led to encouraging energy deposition approaching the intensities required for eV-range target heating experiments. We discuss the status of several improvements to our Neutralized Drift Compression Experiment and associated beam diagnostics that are under development to reach the necessary higher beam intensities, including: (1) greater axial compression via a longer velocity ramp using a new bunching module with approximately twice the available voltseconds; (2) improved centroid control via beam steering dipoles to mitigate aberrations in the bunching module; (3) time-dependent focusing elements to correct considerable chromatic aberrations; and (4) plasma injection improvements to establish a plasma density always greater than the beam density, expected to be>1013 cm-3.

Seidl, P.A.; Anders, A.; Bieniosek, F.M.; Barnard, J.J.; Calanog, J.; Chen, A.X.; Cohen, R.H.; Coleman, J.E.; Dorf, M.; Gilson, E.P.; Grote, D.P.; Jung, J.Y.; Leitner, M.; Lidia, S.M.; Logan, B.G.; Ni, P.; Roy, P.K.; Van den Bogert, K.; Waltron, W.L.; Welch, D.R.

2008-09-25T23:59:59.000Z

307

Low Emittance Electron Beam Studies  

Science Conference Proceedings (OSTI)

We have studied the properties of a low emittance electron beam produced by laser pulses incident onto an rf gun photocathode. The experiments were carried out at the A0 photoinjector at Fermilab. Such beam studies are necessary for fixing the design of new Linear Colliders as well as for the development of Free Electron Lasers. An overview of the A0 photoinjector is given in Chapter 1. In Chapter 2 we describe the A0 photoinjector laser system. A stable laser system is imperative for reliable photoinjector operation. After the recent upgrade, we have been able to reach a new level of stability in the pulse-to-pulse fluctuations of the pulse amplitude, and of the temporal and transverse profiles. In Chapter 3 we present a study of transverse emittance versus the shape of the photo-cathode drive-laser pulse. For that purpose a special temporal profile laser shaping device called a pulse-stacker was developed. In Chapter 4 we discuss longitudinal beam dynamics studies using a two macro-particle bunch; this technique is helpful in analyzing pulse compression in the magnetic chicane, as well as velocity bunching effects in the rf-gun and the 9-cell accelerating cavity. In Chapter 5 we introduce a proposal for laser acceleration of electrons. We have developed a laser functioning on the TEM*{sub 01} mode, a mode with a longitudinal electric field component which is suitable for such a process. Using this technique at energies above 40 MeV, one would be able to observe laser-based acceleration.

Tikhoplav, Rodion; /Rochester U.

2006-04-01T23:59:59.000Z

308

Cylindrical target Li-beam-driven hohlraum experiments  

SciTech Connect

The authors performed a series of experiments on the Particle Beam Fusion Accelerator II (PBFA II) in May, 1994, and obtained a brightness temperature of 61 {+-} 2 eV for an ion-beam heated hohlraum. The hohlraum was a 4-mm-diameter, right-circular cylinder with a 1.5-mm-thick gold wall, a low-density CH foam fill, and a 1.5- or 3-mm-diameter diagnostic aperture in the top. The nominal parameters of the radially-incident PBFA II Li ion beam were 9 MeV peak energy ({approximately}10 MeV at the gas cell) at the target at a peak power of 2.5 {+-} 0.3 TW/cm{sup 2} and a 15 ns pulse width. Azimuthal variations in intensity of a factor of 3, with respect to the mean, were observed. Nonuniformities in thermal x-ray emission across the area of the diagnostic hole were also observed. Time-dependent hole-closure velocities were measured: the time-averaged velocity of {approximately}2 cm/{micro}s is in good agreement with sound speed estimates. Unfolded x-ray spectra and brightness temperatures as a function of time are reported and compared to simulations. Hole closure corrections are discussed with comparisons between XRD and bolometer measurements. Temperature scaling with power on target is also presented.

Derzon, M.S.; Aubert, J.; Chandler, G.A. [and others

1998-06-01T23:59:59.000Z

309

Monte Carlo methods of neutron beam design for neutron capture therapy at the MIT Research Reactor (MITR-II)  

Science Conference Proceedings (OSTI)

Monte Carlo methods of coupled neutron/photon transport are being used in the design of filtered beams for Neutron Capture Therapy (NCT). This method of beam analysis provides segregation of each individual dose component, and thereby facilitates beam optimization. The Monte Carlo method is discussed in some detail in relation to NCT epithermal beam design. Ideal neutron beams (i.e., plane-wave monoenergetic neutron beams with no primary gamma-ray contamination) have been modeled both for comparison and to establish target conditions for a practical NCT epithermal beam design. Detailed models of the 5 MWt Massachusetts Institute of Technology Research Reactor (MITR-II) together with a polyethylene head phantom have been used to characterize approximately 100 beam filter and moderator configurations. Using the Monte Carlo methodology of beam design and benchmarking/calibrating our computations with measurements, has resulted in an epithermal beam design which is useful for therapy of deep-seated brain tumors. This beam is predicted to be capable of delivering a dose of 2000 RBE-cGy (cJ/kg) to a therapeutic advantage depth of 5.7 cm in polyethylene assuming 30 micrograms/g 10B in tumor with a ten-to-one tumor-to-blood ratio, and a beam diameter of 18.4 cm. The advantage ratio (AR) is predicted to be 2.2 with a total irradiation time of approximately 80 minutes. Further optimization work on the MITR-II epithermal beams is expected to improve the available beams. 20 references.

Clement, S.D.; Choi, J.R.; Zamenhof, R.G.; Yanch, J.C.; Harling, O.K. (Massachusetts Institute of Technology, Cambridge (USA))

1990-01-01T23:59:59.000Z

310

Proton beam therapy control system  

DOE Patents (OSTI)

A tiered communications architecture for managing network traffic in a distributed system. Communication between client or control computers and a plurality of hardware devices is administered by agent and monitor devices whose activities are coordinated to reduce the number of open channels or sockets. The communications architecture also improves the transparency and scalability of the distributed system by reducing network mapping dependence. The architecture is desirably implemented in a proton beam therapy system to provide flexible security policies which improve patent safety and facilitate system maintenance and development.

Baumann, Michael A. (Riverside, CA); Beloussov, Alexandre V. (Bernardino, CA); Bakir, Julide (Alta Loma, CA); Armon, Deganit (Redlands, CA); Olsen, Howard B. (Colton, CA); Salem, Dana (Riverside, CA)

2008-07-08T23:59:59.000Z

311

Protective laser beam viewing device  

SciTech Connect

A protective laser beam viewing system or device including a camera selectively sensitive to laser light wavelengths and a viewing screen receiving images from the laser sensitive camera. According to a preferred embodiment of the invention, the camera is worn on the head of the user or incorporated into a goggle-type viewing display so that it is always aimed at the area of viewing interest to the user and the viewing screen is incorporated into a video display worn as goggles over the eyes of the user.

Neil, George R.; Jordan, Kevin Carl

2012-12-18T23:59:59.000Z

312

Proton beam therapy control system  

DOE Patents (OSTI)

A tiered communications architecture for managing network traffic in a distributed system. Communication between client or control computers and a plurality of hardware devices is administered by agent and monitor devices whose activities are coordinated to reduce the number of open channels or sockets. The communications architecture also improves the transparency and scalability of the distributed system by reducing network mapping dependence. The architecture is desirably implemented in a proton beam therapy system to provide flexible security policies which improve patent safety and facilitate system maintenance and development.

Baumann, Michael A. (Riverside, CA); Beloussov, Alexandre V. (San Bernardino, CA); Bakir, Julide (Alta Loma, CA); Armon, Deganit (Longmeadow, MA); Olsen, Howard B. (Irvine, CA); Salem, Dana (Riverside, CA)

2010-09-21T23:59:59.000Z

313

Proton beam therapy control system  

SciTech Connect

A tiered communications architecture for managing network traffic in a distributed system. Communication between client or control computers and a plurality of hardware devices is administered by agent and monitor devices whose activities are coordinated to reduce the number of open channels or sockets. The communications architecture also improves the transparency and scalability of the distributed system by reducing network mapping dependence. The architecture is desirably implemented in a proton beam therapy system to provide flexible security policies which improve patent safety and facilitate system maintenance and development.

Baumann, Michael A; Beloussov, Alexandre V; Bakir, Julide; Armon, Deganit; Olsen, Howard B; Salem, Dana

2013-06-25T23:59:59.000Z

314

Proton beam therapy control system  

SciTech Connect

A tiered communications architecture for managing network traffic in a distributed system. Communication between client or control computers and a plurality of hardware devices is administered by agent and monitor devices whose activities are coordinated to reduce the number of open channels or sockets. The communications architecture also improves the transparency and scalability of the distributed system by reducing network mapping dependence. The architecture is desirably implemented in a proton beam therapy system to provide flexible security policies which improve patent safety and facilitate system maintenance and development.

Baumann, Michael A; Beloussov, Alexandre V; Bakir, Julide; Armon, Deganit; Olsen, Howard B; Salem, Dana

2013-12-03T23:59:59.000Z

315

Ultrafast electron beam imaging of femtosecond laser-induced plasma  

NLE Websites -- All DOE Office Websites (Extended Search)

Ultrafast electron beam imaging of femtosecond laser-induced plasma Ultrafast electron beam imaging of femtosecond laser-induced plasma dynamics Title Ultrafast electron beam imaging of femtosecond laser-induced plasma dynamics Publication Type Journal Article Year of Publication 2010 Authors Li, Junjie, Xuan Wang, Zhaoyang Chen, Richard Clinite, Samuel S. Mao, Pengfei Zhu, Zhengming Sheng, Jie Zhang, and Jianming Cao Journal Journal of Applied Physics Volume 107 Issue 8 Date Published 03/2010 Keywords copper, electron beam applications, high-speed optical techniques, laser ablation, plasma diagnostics, plasma production by laser Abstract Plasma dynamics in the early stage of laser ablation of a copper target are investigated in real time by making ultrafast electron shadow images and electron deflectometry measurements. These complementary techniques provide both a global view and a local perspective of the associated transient electric field and charge expansion dynamics. The results reveal that the charge cloud above the target surface is composed predominantly of thermally ejected electrons and that it is self-expanding, with a fast front-layer speed exceeding 107 m/s. The average electric field strength of the charge cloud induced by a pump fluence of 2.2 J/cm2 is estimated to be ∼ 2.4×105 V/m.

316

An Improved Beam Screen for the LHC Injection Kickers  

E-Print Network (OSTI)

The two LHC injection kicker magnet systems must produce a kick of 1.3 T.m with a flattop duration variable up to 7860 ns, and rise and fall times of less than 900 ns and 3000 ns, respectively. Each system is composed of two resonant charging power supplies (RCPSs) and four 5 WW transmission line kicker magnets with matched terminating resistors and pulse forming networks (PFNs). A beam screen is placed in the aperture of the magnets: the screen consists of a ceramic tube with conductors on the inner wall. The conductors provide a path for the image current of the, high intensity, LHC beam and screen the ferrite against Wake fields. The conductors initially used gave adequately low beam coupling impedance however inter-conductor discharges occurred during pulsing of the magnet: an alternative design was discharge free at the nominal operating voltage but the impedance was too high for the ultimate LHC beam. This paper presents the results of a new development undertaken to meet the often conflicting requireme...

Barnes, M J; Ducimetière, L; Garrel, N; Kroyer, T

2007-01-01T23:59:59.000Z

317

Construction of Industrial Electron Beam Plant for Wastewater Treatment  

Science Conference Proceedings (OSTI)

A pilot plant for treating 1,000 m3/day of dyeing wastewater with e-beam has been constructed and operated since 1998 in Daegu, Korea together with the biological treatment facility. The wastewater from various stages of the existing purification process has been treated with electron beam in this plant, and it gave rise to elaborate the optimal technology of the electron beam treatment of wastewater with increased reliability at instant changes in the composition of wastewater. Installation of the e-beam pilot plant resulted in decolorizing and destructive oxidation of organic impurities in wastewater, appreciable to reduction of chemical reagent consumption, in reduction of the treatment time, and in increase in flow rate limit of existing facilities by 30-40%. Industrial plant for treating 10,000 m3/day, based upon the pilot experimental result, is under construction and will be finished by 2005. This project is supported by the International Atomic Energy Agency (IAEA) and Korean Government.

Han, B.; Kim, J.; Kim, Y.; Kim, S.; Lee, M.; Choi, J.; Ahn, S.; Makarov, I.E.; Ponomarev, A.V.

2004-10-06T23:59:59.000Z

318

Levy-Student distributions for halos in accelerator beams  

SciTech Connect

We describe the transverse beam distribution in particle accelerators within the controlled, stochastic dynamical scheme of stochastic mechanics (SM) which produces time reversal invariant diffusion processes. This leads to a linearized theory summarized in a Schroedinger-like (SL) equation. The space charge effects have been introduced in recent papers by coupling this S-L equation with the Maxwell equations. We analyze the space-charge effects to understand how the dynamics produces the actual beam distributions, and in particular we show how the stationary, self-consistent solutions are related to the (external and space-charge) potentials both when we suppose that the external field is harmonic (constant focusing), and when we a priori prescribe the shape of the stationary solution. We then proceed to discuss a few other ideas by introducing generalized Student distributions, namely, non-Gaussian, Levy infinitely divisible (but not stable) distributions. We will discuss this idea from two different standpoints: (a) first by supposing that the stationary distribution of our (Wiener powered) SM model is a Student distribution; (b) by supposing that our model is based on a (non-Gaussian) Levy process whose increments are Student distributed. We show that in the case (a) the longer tails of the power decay of the Student laws and in the case (b) the discontinuities of the Levy-Student process can well account for the rare escape of particles from the beam core, and hence for the formation of a halo in intense beams.

Cufaro Petroni, Nicola; De Martino, Salvatore; De Siena, Silvio; Illuminati, Fabrizio [Dipartimento di Matematica dell'Universita di Bari and INFN Sezione di Bari, via E. Orabona 4, 70125 Bari (Italy); Dipartimento di Fisica dell'Universita di Salerno, INFM Unita di Salerno, and INFN Sezione di Napoli Gruppo collegato di Salerno, Via S. Allende, I-84081 Baronissi (Saudi Arabia) (Italy)

2005-12-15T23:59:59.000Z

319

Heavy Ion Beam in Resolution of the Critical Point Problem for Uranium and Uranium Dioxide  

E-Print Network (OSTI)

Important advantages of heavy ion beam (HIB) irradiation of matter are discussed in comparison with traditional sources - laser heating, electron beam, electrical discharge etc. High penetration length (~ 10 mm) is of primary importance for investigation of dense matter properties. This gives an extraordinary chance to reach the uniform heating regime when HIB irradiation is being used for thermophysical property measurements. Advantages of HIB heating of highly-dispersive samples are claimed for providing free and relatively slow quasi-isobaric heating without fast hydrodynamic expansion of heated sample. Perspective of such HIB application are revised for resolution of long-time thermophysical problems for uranium and uranium-bearing compounds (UO2). The priorities in such HIB development are stressed: preferable energy levels, beam-time duration, beam focusing, deposition of the sample etc.

Igor Iosilevskiy; Victor Gryaznov

2010-05-23T23:59:59.000Z

320

A Stripline Fast Faraday Cup for measuring GHz structure of ion beams  

DOE Patents (OSTI)

The Stripline Fast Faraday Cup is a device which is used to quantitatively and qualitatively measure gigahertz time structure characteristics of ion beams with energies up to at least 30 Mev per nucleon. A stripline geometry is employed in conjunction with an electrostatic screen and a Faraday cup to provide for analysis of the structural characteristics of an ion beam. The stripline geometry allows for a large reduction in the size of the instrument while the electrostatic screen permits measurements of the properties associated with low speed ion beams.

Bogaty, J.M.

1990-01-01T23:59:59.000Z

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321

Beam losses due to abrupt crab cavity failures in the LHC  

SciTech Connect

A major concern for the implementation of crab crossing in a future High-Luminosity LHC (HL-LHC) is machine protection in an event of a fast crab-cavity failure. Certain types of abrupt crab-cavity amplitude and phase changes are simulated to characterize the effect of failures on the beam and the resulting particle-loss signatures. The time-dependent beam loss distributions around the ring and particle trajectories obtained from the simulations allow for a first assessment of the resulting beam impact on LHC collimators and on sensitive components around the ring. Results for the nominal LHC lattice is presented.

Baer, T.; Barranco, J.; Calaga, R.; Tomas, R.; Wenninger, B.; Yee, B.; Zimmermann, F.

2011-03-28T23:59:59.000Z

322

Nano-electron beam induced current and hole charge dynamics through uncapped Ge nanocrystals  

Science Conference Proceedings (OSTI)

Dynamics of hole storage in spherical Ge nanocrystals (NCs) formed by a two step dewetting/nucleation process on an oxide layer grown on an n-doped silicon substrate is studied using a nano-electron beam induced current technique. Carrier generation is produced by an electron beam irradiation. The generated current is collected by an atomic force microscope--tip in contact mode at a fixed position away from the beam spot of about 0.5 {mu}m. This distance represents the effective diffusion length of holes. The time constants of holes charging are determined and the effect of the NC size is underlined.

Marchand, A.; El Hdiy, A.; Troyon, M. [Laboratoire de Recherche en Nanosciences, Bat. 6, case no 15, UFR Sciences, Universite de Reims Champagne Ardenne, 51687 Reims Cedex 2 (France); Amiard, G.; Ronda, A.; Berbezier, I. [IM2NP, Faculte des Sciences et Techniques, Campus de Saint Jerome - Case 142, Avenue Escadrille Normandie Niemen, 13397 Marseille Cedex 20 (France)

2012-04-16T23:59:59.000Z

323

Yuan T. Lee's Crossed Molecular Beam Experiment  

NLE Websites -- All DOE Office Websites (Extended Search)

Yuan T. Lee's Crossed Molecular Beam Experiment Yuan T. Lee's Crossed Molecular Beam Experiment Home | Staff | Search | Advisory Committee | User Facilities | Laboratories | Congress | Budget Yuan T. Lee's Crossed Molecular Beam Experiment http://web.archive.org/web/20000902074635/www.er.doe.gov/production/bes/YuanLee_Exp.html (1 of 4)4/7/2006 2:46:13 PM Yuan T. Lee's Crossed Molecular Beam Experiment The above illustration was drawn by Professor Yuan T. Lee, who shared the 1986 Nobel Prize in Chemistry. It shows the design for his crossed molecular beam experiment described in the story beginning on page 27 of "Basic Energy Sciences: Summary of Accomplishments" (DOE/ER-0455P, May 1990); the story is also copied below. The purpose of this experiment was to study the chemical reaction of sodium atoms with oxygen molecules. In the experiment, a beam of sodium atoms (green,

324

Rippled beam free electron laser amplifier  

DOE Patents (OSTI)

A free electron laser amplifier provides a scalloping annular electron beam that interacts with the axial electric field of a TM.sub.0n mode. A waveguide defines an axial centerline and, a solenoid arranged about the waveguide produces an axial constant magnetic field within the waveguide. An electron beam source outputs a annular electron beam that interacts with the axial magnetic field to have an equilibrium radius and a ripple radius component having a variable radius with a ripple period along the axial centerline. An rf source outputs an axial electric field that propagates within the waveguide coaxial with the electron beam and has a radial mode that interacts at the electron beam at the equilibrium radius component of the electron beam.

Carlsten, Bruce E. (Los Alamos, NM)

1999-01-01T23:59:59.000Z

325

Rippled beam free electron Laser Amplifier  

DOE Patents (OSTI)

A free electron laser amplifier provides a scalloping annular electron beam that interacts with the axial electric field of a T{sub 0n} mode. A waveguide defines an axial centerline and . A solenoid arranged about the waveguide produces an axial constant magnetic field within the waveguide. An electron beam source outputs a annular electron beam that interacts with the axial magnetic field to have an equilibrium radius and a ripple radius component having a variable radius with a ripple period along the axial centerline. An rf source outputs an axial electric field that propagates within the waveguide coaxial with the electron beam and has a radial mode that interacts at the electron beam at the equilibrium radius component of the electron beam.

Carlsten, Bruce E.

1998-04-21T23:59:59.000Z

326

Radiation beam calorimetric power measurement system  

DOE Patents (OSTI)

A radiation beam calorimetric power measurement system for measuring the average power of a beam such as a laser beam, including a calorimeter configured to operate over a wide range of coolant flow rates and being cooled by continuously flowing coolant for absorbing light from a laser beam to convert the laser beam energy into heat. The system further includes a flow meter for measuring the coolant flow in the calorimeter and a pair of thermistors for measuring the temperature difference between the coolant inputs and outputs to the calorimeter. The system also includes a microprocessor for processing the measured coolant flow rate and the measured temperature difference to determine the average power of the laser beam.

Baker, John (Livermore, CA); Collins, Leland F. (Pleasanton, CA); Kuklo, Thomas C. (Ripon, CA); Micali, James V. (Dublin, CA)

1992-01-01T23:59:59.000Z

327

PEP-II injection timing and controls  

SciTech Connect

Hardware has been built and software written and incorporated in the existing SLC accelerator control system to control injection of beam pulses from the accelerator into the PEP-II storage rings currently under construction. Hardware includes a CAMAC module to delay the machine timing fiducial in order that a beam pulse extracted from a damping ring will be injected into a selected group of four 476 MHz buckets in a PEP-II ring. Further timing control is accomplished by shifting the phase of the bunches stored in the damping rings before extraction while leaving the phase of the PEP-II stored beam unchanged. The software which drives timing devices on a pulse-to-pulse basis relies on a dedicated communication link on which one scheduling microprocessor broadcasts a 128-bit message to all distributed control microprocessors at 360 Hz. PEP-II injection will be driven by the scheduling microprocessor according to lists specifying bucket numbers in arbitrary order, and according to scheduling constraints maximizing the useful beam delivered to the SLC collider currently in operation. These lists will be generated by a microprocessor monitoring the current stored per bucket in each of the PEP-II rings.

Bharadwaj, V.; Browne, M.; Crane, M.; Gromme, T.; Himel, T.; Ross, M.; Stanek, M. [Stanford Linear Accelerator Center, Menlo Park, CA (United States); Ronan, M. [Lawrence Berkeley National Lab., CA (United States)

1997-07-01T23:59:59.000Z

328

The use of intensity-modulated radiation therapy photon beams for improving the dose uniformity of electron beams shaped with MLC  

Science Conference Proceedings (OSTI)

Electrons are ideal for treating shallow tumors and sparing adjacent normal tissue. Conventionally, electron beams are collimated by cut-outs that are time-consuming to make and difficult to adapt to tumor shape throughout the course of treatment. We propose that electron cut-outs can be replaced using photon multileaf collimator (MLC). Two major problems of this approach are that the scattering of electrons causes penumbra widening because of a large air gap, and available commercial treatment planning systems (TPSs) do not support MLC-collimated electron beams. In this study, these difficulties were overcome by (1) modeling electron beams collimated by photon MLC for a commercial TPS, and (2) developing a technique to reduce electron beam penumbra by adding low-energy intensity-modulated radiation therapy (IMRT) photons (4 MV). We used blocks to simulate MLC shielding in the TPS. Inverse planning was used to optimize boost photon beams. This technique was applied to a parotid and a central nervous system (CNS) clinical case. Combined photon and electron plans were compared with conventional plans and verified using ion chamber, film, and a 2D diode array. Our studies showed that the beam penumbra for mixed beams with 90 cm source to surface distance (SSD) is comparable with electron applicators and cut-outs at 100 cm SSD. Our mixed-beam technique yielded more uniform dose to the planning target volume and lower doses to various organs at risk for both parotid and CNS clinical cases. The plans were verified with measurements, with more than 95% points passing the gamma criteria of 5% in dose difference and 5 mm for distance to agreement. In conclusion, the study has demonstrated the feasibility and potential advantage of using photon MLC to collimate electron beams with boost photon IMRT fields.

Mosalaei, Homeira, E-mail: homeira.mosalaei@lhsc.on.ca [London Regional Cancer Program, London Health Science Centre, Ontario (Canada); Karnas, Scott [London Regional Cancer Program, London Health Science Centre, Ontario (Canada); University of Waterloo, Waterloo, Ontario (Canada); Shah, Sheel [University of Western Ontario, London, Ontario (Canada); Van Doodewaard, Sharon [McMaster University, Hamilton, Ontario (Canada); Foster, Tim [University of Western Ontario, London, Ontario (Canada); Chen, Jeff [London Regional Cancer Program, London Health Science Centre, Ontario (Canada); University of Waterloo, Waterloo, Ontario (Canada)

2012-04-01T23:59:59.000Z

329

Modeling the beam characterization system  

DOE Green Energy (OSTI)

The Beam Characterization System (BCS) recently developed for heliostat evaluation at the Central Receiver Test Facility at Sandia Laboratories, measures, digitizes, records, and analyzes a flux-density pattern in a beam of reflected sunlight. Since the BCS collects data with a given set of conditions (geometry, weather, etc.) to determine optical specifications which can predict heliostat behavior under other sets of conditions, it is necessary to use a theoretical model of the system to interpret results. This model serves as an aid to define specifications, analyze measurements, calculate performance, and answer other questions about the heliostat. A statistical method is used to handle stochastic variables such as sun-tracking errors and surface-slope errors. A cone-optics technique is used to incorporate the statistics into a consistent model of the optical behavior of a heliostat. An overview of this model is given. Use of the model is unfolding slope-error distributions and sun-tracking statistics is described for measurements both in and out of the focal plane. The importance of auxiliary input information such as the sunshape (angular distribution of sun rays) to the analysis of BCS measurements is discussed. Finally, the role of the BCS in validating heliostats against acceptance criteria is summarized.

Biggs, F.; Vittitoe, C.N.; King, D.L.

1979-01-01T23:59:59.000Z

330

Reaction Dynamics with Exotic Beams  

E-Print Network (OSTI)

We review the new possibilities offered by the reaction dynamics of asymmetric heavy ion collisions, using stable and unstable beams. We show that it represents a rather unique tool to probe regions of highly Asymmetric Nuclear Matter ($ANM$) in compressed as well as dilute phases, and to test the in-medium isovector interaction for high momentum nucleons. The focus is on a detailed study of the symmetry term of the nuclear Equation of State ($EOS$) in regions far away from saturation conditions but always under laboratory controlled conditions. Thermodynamic properties of $ANM$ are surveyed starting from nonrelativistic and relativistic effective interactions. In the relativistic case the role of the isovector scalar $\\delta$-meson is stressed. The qualitative new features of the liquid-gas phase transition, "diffusive" instability and isospin distillation, are discussed. The results of ab-initio simulations of n-rich, n-poor, heavy ion collisions, using stochastic isospin dependent transport equations, are analysed as a function of beam energy and centrality. The isospin dynamics plays an important role in all steps of the reaction, from prompt nucleon emissions to the final fragments. The isospin diffusion is also of large interest, due to the interplay of asymmetry and density gradients. In relativistic collisions, the possibility of a direct study of the covariant structure of the effective nucleon interaction is shown. Results are discussed for particle production, collective flows and iso-transparency. Perspectives of further developments of the field, in theory as well as in experiment, are presented.

V. Baran; M. Colonna; V. Greco; M. Di Toro

2004-12-15T23:59:59.000Z

331

Coherence delay augmented laser beam homogenizer  

SciTech Connect

The geometrical restrictions on a laser beam homogenizer are relaxed by ug a coherence delay line to separate a coherent input beam into several components each having a path length difference equal to a multiple of the coherence length with respect to the other components. The components recombine incoherently at the output of the homogenizer, and the resultant beam has a more uniform spatial intensity suitable for microlithography and laser pantogography. Also disclosed is a variable aperture homogenizer, and a liquid filled homogenizer.

Rasmussen, Paul (Livermore, CA); Bernhardt, Anthony (Berkeley, CA)

1993-01-01T23:59:59.000Z

332

Velocity distribution measurements in atomic beams generated using laser induced back-ablation  

E-Print Network (OSTI)

We present measurements of the velocity distribution of calcium atoms in an atomic beam generated using a dual-stage laser back-ablation apparatus. Distributions are measured using a velocity selective Doppler time-of-flight technique. They are Boltzmann-like with rms velocities corresponding to temperatures above the melting point for calcium. Contrary to a recent report in the literature, this method does not generate a sub-thermal atomic beam.

Denning, A; Lee, S; Ammonson, M; Bergeson, S D

2008-01-01T23:59:59.000Z

333

Novel Sources for Focused-ion Beams  

Science Conference Proceedings (OSTI)

... production techniques. This new technique uses a variety of atomic sources to produce highly focused ion beams, with tightly controlled energy. ...

2012-08-14T23:59:59.000Z

334

Beam buckling on random elastic foundations.  

E-Print Network (OSTI)

??This thesis explores the impact of the seafloor on the buckling load of an undersea pipeline via beam on elastic foundation buckling theory. Undersea pipelines… (more)

Bee, Geoffrey

2013-01-01T23:59:59.000Z

335

High power, high beam quality regenerative amplifier  

DOE Patents (OSTI)

A regenerative laser amplifier system generates high peak power and high energy per pulse output beams enabling generation of X-rays used in X-ray lithography for manufacturing integrated circuits. The laser amplifier includes a ring shaped optical path with a limited number of components including a polarizer, a passive 90 degree phase rotator, a plurality of mirrors, a relay telescope, and a gain medium, the components being placed close to the image plane of the relay telescope to reduce diffraction or phase perturbations in order to limit high peak intensity spiking. In the ring, the beam makes two passes through the gain medium for each transit of the optical path to increase the amplifier gain to loss ratio. A beam input into the ring makes two passes around the ring, is diverted into an SBS phase conjugator and proceeds out of the SBS phase conjugator back through the ring in an equal but opposite direction for two passes, further reducing phase perturbations. A master oscillator inputs the beam through an isolation cell (Faraday or Pockels) which transmits the beam into the ring without polarization rotation. The isolation cell rotates polarization only in beams proceeding out of the ring to direct the beams out of the amplifier. The diffraction limited quality of the input beam is preserved in the amplifier so that a high power output beam having nearly the same diffraction limited quality is produced.

Hackel, Lloyd A. (Livermore, CA); Dane, Clifford B. (Livermore, CA)

1993-01-01T23:59:59.000Z

336

High power, high beam quality regenerative amplifier  

DOE Patents (OSTI)

A regenerative laser amplifier system generates high peak power and high energy per pulse output beams enabling generation of X-rays used in X-ray lithography for manufacturing integrated circuits. The laser amplifier includes a ring shaped optical path with a limited number of components including a polarizer, a passive 90 degree phase rotator, a plurality of mirrors, a relay telescope, and a gain medium, the components being placed close to the image plane of the relay telescope to reduce diffraction or phase perturbations in order to limit high peak intensity spiking. In the ring, the beam makes two passes through the gain medium for each transit of the optical path to increase the amplifier gain to loss ratio. A beam input into the ring makes two passes around the ring, is diverted into an SBS phase conjugator and proceeds out of the SBS phase conjugator back through the ring in an equal but opposite direction for two passes, further reducing phase perturbations. A master oscillator inputs the beam through an isolation cell (Faraday or Pockels) which transmits the beam into the ring without polarization rotation. The isolation cell rotates polarization only in beams proceeding out of the ring to direct the beams out of the amplifier. The diffraction limited quality of the input beam is preserved in the amplifier so that a high power output beam having nearly the same diffraction limited quality is produced.

Hackel, L.A.; Dane, C.B.

1993-08-24T23:59:59.000Z

337

Laser Beam Delivery [Laser Applications Laboratory] - Nuclear...  

NLE Websites -- All DOE Office Websites (Extended Search)

Laser Glazing of Railroad Rails High Power Laser Beam Delivery Decontamination and Decommissioning Refractory Alloy Welding Robots Applications Other Facilities Other Capabilities...

338

High Flux Beam Reactor | Environmental Restoration Projects ...  

NLE Websites -- All DOE Office Websites (Extended Search)

Reports HFBR Waste Loading Area, Soil Remediation (PDF) - July 2009 HFBR Decommissioning Project, Removal of the Control Rod Blades and Beam Plugs (PDF) - January 2010...

339

Electron Beam Imaging - Programmaster.org  

Science Conference Proceedings (OSTI)

Sep 14, 2009 ... 13th International Conference on Defects--Recognition, Imaging and Physics in Semiconductors: Electron Beam Imaging Program Organizers: ...

340

Electron Beam Ion Trap (EBIT) Facility  

Science Conference Proceedings (OSTI)

... At these temperatures, even the heaviest atoms shed most of their electrons. ... The ions are probed with an intense electron beam, and the emitted ...

2013-06-06T23:59:59.000Z

Note: This page contains sample records for the topic "beam time esaf" 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

Produced by Selective Electron Beam Melting  

Science Conference Proceedings (OSTI)

The development of processing TiAl by additive manufacturing by using the selective electron beam melting (SEBM) provides a new approach to reach near

342

Focused Ion beam source method and Apparatus  

DOE Patents (OSTI)

A focused ion beam having a cross section of submicron diameter, a high ion current, and a narrow energy range is generated from a target comprised of particle source material by laser ablation. The method involves directing a laser beam having a cross section of critical diameter onto the target, producing a cloud of laser ablated particles having unique characteristics, and extracting and focusing a charged particle beam from the laser ablated cloud. The method is especially suited for producing focused ion beams for semiconductor device analysis and modification.

Pellin, Michael J.; Lykke, Keith R.; Lill, Thorsten B.

1998-08-17T23:59:59.000Z

343

Plasma formed ion beam projection lithography system  

DOE Patents (OSTI)

A plasma-formed ion-beam projection lithography (IPL) system eliminates the acceleration stage between the ion source and stencil mask of a conventional IPL system. Instead a much thicker mask is used as a beam forming or extraction electrode, positioned next to the plasma in the ion source. Thus the entire beam forming electrode or mask is illuminated uniformly with the source plasma. The extracted beam passes through an acceleration and reduction stage onto the resist coated wafer. Low energy ions, about 30 eV, pass through the mask, minimizing heating, scattering, and sputtering.

Leung, Ka-Ngo (Hercules, CA); Lee, Yung-Hee Yvette (Berkeley, CA); Ngo, Vinh (San Jose, CA); Zahir, Nastaran (Greenbrae, CA)

2002-01-01T23:59:59.000Z

344

Beam Characterization at the Neutron Radiography Facility  

SciTech Connect

The quality of a neutron imaging beam directly impacts the quality of radiographic images produced using that beam. Fully characterizing a neutron beam, including determination of the beam’s effective length-to-diameter ratio, neutron flux profile, energy spectrum, image quality, and beam divergence, is vital for producing quality radiographic images. This project characterized the east neutron imaging beamline at the Idaho National Laboratory Neutron Radiography Reactor (NRAD). The experiments which measured the beam’s effective length-to-diameter ratio and image quality are based on American Society for Testing and Materials (ASTM) standards. An analysis of the image produced by a calibrated phantom measured the beam divergence. The energy spectrum measurements consist of a series of foil irradiations using a selection of activation foils, compared to the results produced by a Monte Carlo n-Particle (MCNP) model of the beamline. Improvement of the existing NRAD MCNP beamline model includes validation of the model’s energy spectrum and the development of enhanced image simulation methods. The image simulation methods predict the radiographic image of an object based on the foil reaction rate data obtained by placing a model of the object in front of the image plane in an MCNP beamline model.

Sarah Morgan; Jeffrey King

2013-01-01T23:59:59.000Z

345

Method and apparatus for laser-controlled proton beam radiology  

DOE Patents (OSTI)

A proton beam radiology system provides cancer treatment and proton radiography. The system includes an accelerator for producing an H{sup {minus}} beam and a laser source for generating a laser beam. A photodetachment module is located proximate the periphery of the accelerator. The photodetachment module combines the H{sup {minus}} beam and laser beam to produce a neutral beam therefrom within a subsection of the H{sup {minus}} beam. The photodetachment module emits the neutral beam along a trajectory defined by the laser beam. The photodetachment module includes a stripping foil which forms a proton beam from the neutral beam. The proton beam is delivered to a conveyance segment which transports the proton beam to a patient treatment station. The photodetachment module further includes a laser scanner which moves the laser beam along a path transverse to the cross-section of the H{sup {minus}} beam in order to form the neutral beam in subsections of the H{sup {minus}} beam. As the scanning laser moves across the H{sup {minus}} beam, it similarly varies the trajectory of the proton beam emitted from the photodetachment module and in turn varies the target location of the proton beam upon the patient. Intensity modulation of the proton beam can also be achieved by controlling the output of the laser. 9 figs.

Johnstone, C.J.

1998-06-02T23:59:59.000Z

346

Method and apparatus for laser-controlled proton beam radiology  

DOE Patents (OSTI)

A proton beam radiology system provides cancer treatment and proton radiography. The system includes an accelerator for producing an H.sup.- beam and a laser source for generating a laser beam. A photodetachment module is located proximate the periphery of the accelerator. The photodetachment module combines the H.sup.- beam and laser beam to produce a neutral beam therefrom within a subsection of the H.sup.- beam. The photodetachment module emits the neutral beam along a trajectory defined by the laser beam. The photodetachment module includes a stripping foil which forms a proton beam from the neutral beam. The proton beam is delivered to a conveyance segment which transports the proton beam to a patient treatment station. The photodetachment module further includes a laser scanner which moves the laser beam along a path transverse to the cross-section of the H.sup.- beam in order to form the neutral beam in subsections of the H.sup.- beam. As the scanning laser moves across the H.sup.- beam, it similarly varies the trajectory of the proton beam emitted from the photodetachment module and in turn varies the target location of the proton beam upon the patient. Intensity modulation of the proton beam can also be achieved by controlling the output of the laser.

Johnstone, Carol J. (Warrenville, IL)

1998-01-01T23:59:59.000Z

347

Simulations of coherent beam-beam effects with head-on compensation  

SciTech Connect

Electron lenses are under construction for installation in RHIC in order to mitigate the head-on beam-beam effects. This would allow operation with higher bunch intensity and result in a significant increase in luminosity. We report on recent strong-strong simulations and experiments that were carried out using the RHIC upgrade parameters to assess the impact of coherent beam-beam effects in the presence of head-on compensation.

White S.; Fischer, W.; Luo. Y.

2012-05-20T23:59:59.000Z

348

Energy Spread Reduction of Electron Beams Produced via Laser Wake  

Science Conference Proceedings (OSTI)

Laser wakefield acceleration of electrons holds great promise for producing ultra-compact stages of GeV scale, high quality electron beams for applications such as x-ray free electron lasers and high energy colliders. Ultra-high intensity laser pulses can be self-guided by relativistic plasma waves over tens of vacuum diffraction lengths, to give >1 GeV energy in cm-scale low density plasma using ionization-induced injection to inject charge into the wake at low densities. This thesis describes a series of experiments which investigates the physics of LWFA in the self-guided blowout regime. Beginning with high density gas jet experiments the scaling of the LWFA-produced electron beam energy with plasma electron density is found to be in excellent agreement with both phenomenological theory and with 3-D PIC simulations. It is also determined that self-trapping of background electrons into the wake exhibits a threshold as a function of the electron density, and at the densities required to produce electron beams with energies exceeding 1 GeV a different mechanism is required to trap charge into low density wakes. By introducing small concentrations of high-Z gas to the nominal He background the ionization-induced injection mechanism is enabled. Electron trapping is observed at densities as low as 1.3 x 10{sup 18} cm{sup -3} in a gas cell target, and 1.45 GeV electrons are demonstrated for the first time from LWFA. This is currently the highest electron energy ever produced from LWFA. The ionization-induced trapping mechanism is also shown to generate quasi-continuous electron beam energies, which is undesirable for accelerator applications. By limiting the region over which ionization-induced trapping occurs, the energy spread of the electron beams can be controlled. The development of a novel two-stage gas cell target provides the capability to tailor the gas composition in the longitudinal direction, and confine the trapping process to occur only in a limited, defined region. Using this technique a 460 MeV electron beam was produced with an energy spread of 5%. This technique is directly scalable to multi-GeV electron beam generation with sub-percent energy spreads.

Pollock, B

2012-03-19T23:59:59.000Z

349

An Improved Time Interpolation for Three-Dimensional Doppler Wind Analysis  

Science Conference Proceedings (OSTI)

A temporal interpolation is required for three-dimensional Doppler wind analysis when the precise measurement time is counted for each radar beam position. The time interpolation is traditionally done by a linear scheme either in the measurement ...

Shun Liu; Chongjian Qiu; Qin Xu; Pengfei Zhang

2004-10-01T23:59:59.000Z

350

Reaction Dynamics with Exotic Beams  

E-Print Network (OSTI)

We review the new possibilities offered by the reaction dynamics of asymmetric heavy ion collisions, using stable and unstable beams. We show that it represents a rather unique tool to probe regions of highly Asymmetric Nuclear Matter ($ANM$) in compressed as well as dilute phases, and to test the in-medium isovector interaction for high momentum nucleons. The focus is on a detailed study of the symmetry term of the nuclear Equation of State ($EOS$) in regions far away from saturation conditions but always under laboratory controlled conditions. Thermodynamic properties of $ANM$ are surveyed starting from nonrelativistic and relativistic effective interactions. In the relativistic case the role of the isovector scalar $\\delta$-meson is stressed. The qualitative new features of the liquid-gas phase transition, "diffusive" instability and isospin distillation, are discussed. The results of ab-initio simulations of n-rich, n-poor, heavy ion collisions, using stochastic isospin dependent transport equations, are ...

Baran, V; Greco, V; Di Toro, M

2004-01-01T23:59:59.000Z

351

Status of Jefferson Lab's Load Locked Polarized Electron Beam  

DOE Green Energy (OSTI)

A new 100 kV load locked polarized electron gun has been built at Jefferson Lab. The gun is installed in a test stand on a beam line that resembles the first few meters of the CEBAF nuclear physics photoinjector. With this gun, a GaAs photocathode can be loaded from atmosphere, hydrogen cleaned, activated and taken to high voltage in less than 8 hours. The gun is a three chamber design, with all of the moving parts remaining at ground potential during gun operation. Studies of gun performance, photocathode life times, transverse emittance at high bunch charge, helicity correlated effects and beam polarizations from new photocathode samples will all be greatly facilitated by the use of this load locked gun.

M.L. Stutzman; P. Adderley; M. Baylac; J. Clark; A. Day; J. Grames; J. Hansknecht; M. Poelker

2002-09-01T23:59:59.000Z

352

Use of a large time-compensated scintillation detector in neutron time-of-flight measurements  

DOE Patents (OSTI)

A scintillator for neutron time-of-flight measurements is positioned at a desired angle with respect to the neutron beam, and as a function of the energy thereof, such that the sum of the transit times of the neutrons and photons in the scintillator are substantially independent of the points of scintillations within the scintillator. Extrapolated zero timing is employed rather than the usual constant fraction timing. As a result, a substantially larger scintillator can be employed that substantially increases the data rate and shortens the experiment time.

Goodman, Charles D. (Oak Ridge, TN)

1979-01-01T23:59:59.000Z

353

LCDETxxxxxxx Improved TESLA Optics and Beam Induced  

E-Print Network (OSTI)

LC­DET­xxxx­xxx Improved TESLA Optics and Beam Induced Backgrounds Update Karsten BË?uÃ?er, DESY and Olivier Napoly, CEA/Saclay LCWS 2002, Jeju, Korea Abstract A new tesla optics with l*=5m is under development. An update is given on the simulation of the beam induced backgrounds in the TESLA detector. 1

354

In-line beam current monitor  

SciTech Connect

An intense relativistic electron beam current monitor for a gas neutralized beam transport line includes a first foil for conducting plasma current to the wall where it is measured as it traverses an inductive loop formed by a cavity in the wall. An insulator foil separates the first foil from a second conducting foil which returns the current to the plasma environment.

Ekdahl, Jr., Carl A. (Albuquerque, NM); Frost, Charles A. (Albuquerque, NM)

1986-01-01T23:59:59.000Z

355

Focused helium ion beam milling and deposition  

Science Conference Proceedings (OSTI)

The use of a helium ion microscope with an integrated gas injection system for nanofabrication is explored by demonstrating the milling of fine features into single layered graphene and the controlled deposition of tungsten and platinum wires from gaseous ... Keywords: Beam-induced deposition, Focused ion beam, Gas injection system, Graphene, Helium ion microscope

S. A. Boden; Z. Moktadir; D. M. Bagnall; H. Mizuta; H. N. Rutt

2011-08-01T23:59:59.000Z

356

Design of periodic beam-transport systems  

SciTech Connect

Periodic beam-transport systems have several advantages including insensitivity to errors, minimum magnet apertures, and use of standardized components. A simple procedure is given for the design of modules, with and without bending magnets, that have the same matched beam properties. These modules can be combined in certain ways to produce systems that are achromatic and require a minimum number of matching elements.

Farrell, J.A.

1983-01-01T23:59:59.000Z

357

Policy Issues for Retail Beamed Power Transmission  

E-Print Network (OSTI)

it possible to deliver electric power to off-grid locations using millimeter-wave beams and compact, efficient of very large utility-scale power plants, serving given areas in a hub-and-spoke arrangement. GridPolicy Issues for Retail Beamed Power Transmission Girish Chowdhary, Rajeev Gadre, Narayanan

358

Emittance growth from electron beam modulation  

SciTech Connect

In linac ring colliders like MeRHIC and eRHIC a modulation of the electron bunch can lead to a modulation of the beam beam tune shift and steering errors. These modulations can lead to emittance growth. This note presents simple formulas to estimate these effects which generalize some previous results.

Blaskiewicz, M.

2009-12-01T23:59:59.000Z

359

Fast Beam-Based BPM Calibration  

Science Conference Proceedings (OSTI)

The Alignment Diagnostic System (ADS) of the LCLS undulator system indicates that the 33 undulator quadrupoles have extremely high position stability over many weeks. However, beam trajectory straightness and lasing efficiency degrade more quickly than this. A lengthy Beam Based Alignment (BBA) procedure must be executed every two to four weeks to re-optimize the X-ray beam parameters. The undulator system includes RF cavity Beam Position Monitors (RFBPMs), several of which are utilized by an automatic feedback system to align the incoming electron-beam trajectory to the undulator axis. The beam trajectory straightness degradation has been traced to electronic drifts of the gain and offset of the BPMs used in the beam feedback system. To quickly recover the trajectory straightness, we have developed a fast beam-based procedure to recalibrate the BPMs. This procedure takes advantage of the high-precision monitoring capability of the ADS, which allows highly repeatable positioning of undulator quadrupoles. This report describes the ADS, the position stability of the LCLS undulator quadrupoles, and some results of the new recovery procedure.

Bertsche, K.; Loos, H.; Nuhn, H.-D.; Peters, F.; /SLAC

2012-10-15T23:59:59.000Z

360

A TOMOGRAPHIC TECHNIQUE FOR MAGNETIZED BEAM MATCHING.  

Science Conference Proceedings (OSTI)

To maintain low electron beam temperatures in the proposed RHIC electron cooler, careful matching of the magnetized beam from the source to the cooler solenoid is mandatory. We propose a tomographic technique to diagnose matching conditions. First simulation results will be presented.

MONTAG,C.ET AL.

2004-07-05T23:59:59.000Z

Note: This page contains sample records for the topic "beam time esaf" 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

Beam characterization at the Neutron Radiography Reactor  

Science Conference Proceedings (OSTI)

The quality of a neutron-imaging beam directly impacts the quality of radiographic images produced using that beam. Fully characterizing a neutron beam, including determination of the beam's effective length-to-diameter ratio, neutron flux profile, energy spectrum, potential image quality, and beam divergence, is vital for producing quality radiographic images. This paper provides a characterization of the east neutron imaging beamline at the Idaho National Laboratory Neutron Radiography Reactor (NRAD). The experiments which measured the beam's effective length-to-diameter ratio and potential image quality are based on American Society for Testing and Materials (ASTM) standards. An analysis of the image produced by a calibrated phantom measured the beam divergence. The energy spectrum measurements consist of a series of foil irradiations using a selection of activation foils, compared to the results produced by a Monte Carlo n-Particle (MCNP) model of the beamline. The NRAD has an effective collimation ratio greater than 125, a beam divergence of 0.3 +_ 0.1 degrees, and a gold foil cadmium ratio of 2.7. The flux profile has been quantified and the facility is an ASTM Category 1 radiographic facility. Based on bare and cadmium covered foil activation results, the neutron energy spectrum used in the current MCNP model of the radiography beamline over-samples the thermal region of the neutron energy spectrum.

Sarah W. Morgan; Jeffrey C. King; Chad L. Pope

2013-12-01T23:59:59.000Z

362

Simulating relativistic beam and plasma systems using an optimal boosted frame  

E-Print Network (OSTI)

beam; (b) the average energy history of the electron beams.frame. The average beam energy history reveals agreement at

Vay, J.-L.

2009-01-01T23:59:59.000Z

363

Studies of space-charge-dominated multispecies beam in a solenoid based beam transport line  

Science Conference Proceedings (OSTI)

A self-consistent particle-in-cell (PIC) simulation is used to study the transport properties of a space-charge-dominated multispecies beam propagating through a solenoid-based low energy beam transport line. The evolution of the beam radius and emittance growth of each species arising due to the nonlinear space-charge forces has been investigated. The self-consistent PIC simulation shows the formation of hollow density profiles of subdominant unwanted species around the primary beam, downstream of the transport line. We have utilized this effect for efficient removal of unwanted species by making use of a slit at a suitable location in the beam line.

Sing Babu, P.; Goswami, A.; Pandit, V. S. [Variable Energy Cyclotron Centre, 1/AF, Bidhannagar, Kolkata-700064 (India)

2012-11-15T23:59:59.000Z

364

Power beaming: Mission enabling for lunar exploration  

SciTech Connect

This paper explores several beam power concepts proposed for powering either lunar base or rover vehicles. At present, power requirements to support lunar exploration activity are met by integral self-contained power system designs. To provide requisite energy flexibility for human expansion into space, an innovative approach to replace on-board self-contained power systems is needed. Power beaming provides an alternative approach to supplying power that would ensure increased mission flexibility while reducing total mass launched into space. Providing power to the moon presents significant design challenges because of the duration of the lunar night. Power beaming provides an alternative to solar photovoltaic systems coupled with battery storage, radioisotope thermoelectric generation, and surface nuclear power. The Synthesis Group describes power beaming as a technology supporting lunar exploration. In this analysis beam power designs are compared to conventional power generation methods.

Bamberger, J.A.

1992-01-01T23:59:59.000Z

365

Beam discharge excited by distributed virtual cathode  

Science Conference Proceedings (OSTI)

A new type of beam discharge, i.e., beam discharge with a distributed virtual cathode (VC) is proposed and considered by numerical simulation. The discharge is established during counter motion of high-current electron beams in a gas-filled equipotential cavity and is characterized by a state of hot dense electron plasma of primary electrons. The discharge temporal dynamics is studied. It is shown that the VC lifetime depends linearly from this sum in a wide range of the sum of beam currents, from the boundary current of two-beam instability to the critical current of Pierce instability. Generation of nonlinear electrostatic structures shaped as phase bubbles in the discharge is detected, and their dynamics is studied. The parameters are determined, at which the multiple coexistence of phase bubbles and their coalescence during collisions is observed.

Barabanov, V. N.; Dubinov, A. E.; Loiko, M. V.; Saikov, S. K.; Selemir, V. D. [All-Russia Research Institute of Experimental Physics, Russian Federal Nuclear Center (Russian Federation); Tarakanov, V. P. [Russian Academy of Sciences, Joint Institute for High Temperatures (Russian Federation)

2012-02-15T23:59:59.000Z

366

Soft beams: when capillarity induces axial compression  

E-Print Network (OSTI)

We study the interaction of an elastic beam with a liquid drop in the case where bending and extensional effects are both present. We use a variational approach to derive equilibrium equations and constitutive relation for the beam. This relation is shown to include a term due to surface energy in addition of the classical Young's modulus term, leading to a modification of Hooke's law. At the triple point where solid, liquid, and vapor phases meet we find that the external force applied on the beam is parallel to the liquid-vapor interface. Moreover, in the case where solid-vapor and solid-liquid interface energies do not depend on the extension state of the beam, we show that the extension in the beam is continuous at the triple point and that the wetting angle satisfy the classical Young-Dupr\\'e relation.

Sébastien, Neukirch; Jean-Jacques, Marigo

2013-01-01T23:59:59.000Z

367

Soft beams: when capillarity induces axial compression  

E-Print Network (OSTI)

We study the interaction of an elastic beam with a liquid drop in the case where bending and extensional effects are both present. We use a variational approach to derive equilibrium equations and constitutive relation for the beam. This relation is shown to include a term due to surface energy in addition of the classical Young's modulus term, leading to a modification of Hooke's law. At the triple point where solid, liquid, and vapor phases meet we find that the external force applied on the beam is parallel to the liquid-vapor interface. Moreover, in the case where solid-vapor and solid-liquid interface energies do not depend on the extension state of the beam, we show that the extension in the beam is continuous at the triple point and that the wetting angle satisfy the classical Young-Dupr\\'e relation.

Neukirch Sébastien; Antkowiak Arnaud; Marigo Jean-Jacques

2013-09-11T23:59:59.000Z

368

Microwave accelerator E-beam pumped laser  

DOE Patents (OSTI)

A device and method for pumping gaseous lasers by means of a microwave accelerator. The microwave accelerator produces a relativistic electron beam which is applied along the longitudinal axis of the laser through an electron beam window. The incident points of the electron beam on the electron beam window are varied by deflection coils to enhance the cooling characteristics of the foil. A thyratron is used to reliably modulate the microwave accelerator to produce electron beam pulses which excite the laser medium to produce laser pulse repetition frequencies not previously obtainable. An aerodynamic window is also disclosed which eliminates foil heating problems, as well as a magnetic bottle for reducing laser cavity length and pressures while maintaining efficient energy deposition.

Brau, Charles A. (Los Alamos, NM); Stein, William E. (Los Alamos, NM); Rockwood, Stephen D. (Los Alamos, NM)

1980-01-01T23:59:59.000Z

369

Carbon Fiber Damage in Particle Beam  

E-Print Network (OSTI)

Carbon fibers are commonly used as moving targets in beam wire scanners. The heating of the fiber due to energy loss of the particles travelling through is simulated with Geant4. The heating induced by the beam electromagnetic field is estimated with ANSYS. The heat transfer and sublimation processes are modelled. Due to the model nonlinearity, a numerical approach based on discretization of the wire movement is used to solve it for particular beams. Radiation damage to the fiber is estimated with SRIM. The model is tested with available SPS and LEP data and a dedicated damage test on the SPS beam is performed followed by a post-mortem analysis of the wire remnants. Predictions for the LHC beams are made.

Dehning, B; Kroyer, T; Meyer, M; Sapinski, M

2011-01-01T23:59:59.000Z

370

BEAM TRANSVERSE ISSUES AT THE SNS LINAC  

Science Conference Proceedings (OSTI)

The Spallation Neutron Source (SNS) linac system is designed to deliver 1 GeV pulsed H- beams up to 1.56 MW. As beam power was increased from 10 kW to 680 kW in less than three years, beam loss in the accelerator systems C particularly in the superconducting linac (SCL), became more critical. In the previous studies, beam loss in the SCL was mainly attributed to longitudinal problems. However, our most recent simulations have focused on the transverse issues. These include multipole components from magnet imperfections and from dipole corrector windings of the SNS linac quadrupoles. The effects of these multipoles coupled with other transverse errors and a new possible cause of beam loss will be discussed.

Zhang, Yan [ORNL; Allen, Christopher K [ORNL; Holmes, Jeffrey A [ORNL; Galambos, John D [ORNL; Wang, Jian-Guang [ORNL

2010-01-01T23:59:59.000Z

371

Particle beam dynamics | Princeton Plasma Physics Lab  

NLE Websites -- All DOE Office Websites (Extended Search)

Particle beam dynamics Particle beam dynamics Subscribe to RSS - Particle beam dynamics The study of the physics of charged particle beams and the accelerators that produce them. This cross-disciplinary area intersects with fields such as plasma physics, high-energy density science, and ultra-fast lasers. Premiere issue of "Quest" magazine details PPPL's strides toward fusion energy and advances in plasma science Quest Magazine Summer 2013 Welcome to the premiere issue of Quest, the annual magazine of the U.S. Department of Energy's Princeton Plasma Physics Laboratory (PPPL). Read more about Premiere issue of "Quest" magazine details PPPL's strides toward fusion energy and advances in plasma science Ronald C Davidson Ronald Davidson heads PPPL research on charged particle beam dynamics and

372

Proton beam on lithium film experiment for the FRIB stripper - Laser  

NLE Websites -- All DOE Office Websites (Extended Search)

Engineering Engineering Experimentation > High Power Accelerator Components > Proton beam on lithium film experiment... Capabilities Engineering Experimentation Reactor Safety Testing and Analysis High Power Accelerator Components Proton beam on lithium film experiment for the FRIB stripper Aerosol Experiments System Components Laser Applications Robots Applications Other Facilities Other Capabilities Work with Argonne Contact us For Employees Site Map Help Join us on Facebook Follow us on Twitter NE on Flickr Proton beam on lithium film experiment for the FRIB stripper 1 2 Argonne National Laboratory has developed a liquid lithium charge stripper for use in the Facility for Rare Isotope Beams (FRIB) located at Michigan State University. FRIB will provide intense beams of rare isotopes that can not be handled by ordinary means, creating a challenge to find a workable concept for the charge stripper and to test it in a beamline environment. Argonne's experiment showed, for the first time, the operation of a liquid lithium stripper under realistic conditions of beam-deposited power, and verified that the liquid lithium film was not perturbed by a high power density beam.

373

Ion-beam apparatus and method for analyzing and controlling integrated circuits  

DOE Patents (OSTI)

An ion-beam apparatus and method for analyzing and controlling integrated circuits. The ion-beam apparatus comprises a stage for holding one or more integrated circuits (ICs); a source means for producing a focused ion beam; and a beam-directing means for directing the focused ion beam to irradiate a predetermined portion of the IC for sufficient time to provide an ion-beam-generated electrical input signal to a predetermined element of the IC. The apparatus and method have applications to failure analysis and developmental analysis of ICs and permit an alteration, control, or programming of logic states or device parameters within the IC either separate from or in combination with applied electrical stimulus to the IC for analysis thereof. Preferred embodiments of the present invention including a secondary particle detector and an electron floodgun further permit imaging of the IC by secondary ions or electrons, and allow at least a partial removal or erasure of the ion-beam-generated electrical input signal.

Campbell, Ann N. (Albuquerque, NM); Soden, Jerry M. (Placitas, NM)

1998-01-01T23:59:59.000Z

374

Real time Faraday spectrometer  

DOE Patents (OSTI)

This invention is comprised of a charged particle spectrometer that contains a detection system which embodies the benefits of both foil-light emissions and faraday cups, yet it does not interfere with the particle beam. 5 Figs. (GHH)

Smith, T.E. Jr.; Struve, K.W.; Colella, N.J.

1990-12-31T23:59:59.000Z

375

Beam Loss Studies for the 2-MW LBNE Proton Beam Line  

SciTech Connect

Severe limits are put on allowable beam loss during extraction and transport of a 2.3 MW primary proton beam for the Long Baseline Neutrino Experiment (LBNE) at Fermilab. Detailed simulations with the STRUCT and MARS codes have evaluated the impact of beam loss of 1.6 x 10{sup 14} protons per pulse at 120 GeV, ranging from a single pulse full loss to sustained small fractional loss. It is shown that loss of a single beam pulse at 2.3 MW will result in a catastrophic event: beam pipe destruction, damaged magnets and very high levels of residual radiation inside and outside the tunnel. Acceptable beam loss limits have been determined and robust solutions developed to enable efficient proton beam operation under these constraints.

Drozhdin, A.I.; Childress, S.R.; Mokhov, N.V.; Tropin, I.S.; Zwaska, R.; /Fermilab

2012-05-01T23:59:59.000Z

376

Collimation of a Circulating Beam in the U_70 Synchrotron by Use of Reflections in Axially - Oriented Crystals  

E-Print Network (OSTI)

The possibilities of the extraction and collimation of a circulating beam by a new method due to the reflection of particles in crystals with axial orientation were experimentally investigated in the Fall-2010 run at the U_70 synchrotron. Such crystals have positive features, because the axial potential is five times larger than the planar potential. It has been shown that the collimation efficiency can reach 90% due to axial effects in the crystal. Losses of the circulating beam on a collimator have been reduced by several times; this makes it possible to suppress the muon jet near the steel collimator of the circulating beam.

Afonin, A G; Bulgakov, M K; Voinov, I S; Gorlov, V N; Ivanova, I V; Krylov, D M; Lunn'kov, A N; Maisheev, V A; Reshetnikov, S F; Savin, D A; Syshchikov, E A; Terekhov, V I; Chesnokov, Yu A; Chirkov, P N; Yazynin, I A

2011-01-01T23:59:59.000Z

377

Initial Results of Transverse Beam Profile Measurements Using a LYSO:Ce Crystal  

Science Conference Proceedings (OSTI)

A prototype transverse beam profile monitor for eventual use at the Advanced Superconducting Test Accelerator (ASTA) has been tested at the Fermilab A0 Photoinjector. Results from low-charge (20 pC) studies indicate that a LYSO:Ce scintillator will be a viable alternative to a YAG:Ce scintillator when using intercepting radiation convertor screens for beam profiling. We will also describe the planned implementation of LYSO:Ce crystals to mitigate the coherent optical transition radiation due to the microbunching instability through the use of band-pass filters and specially timed cameras. Based upon tests conducted at the A0PI, we can conclude that the LYSO:Ce crystal will be a suitable alternative to the YAG:Ce crystal for beam imaging. The YAG:Ce and LYSO:Ce crystals both offer similar performance characteristics for low charge beam, but LYSO:Ce combined with a violet bandpass filter has the added benefit of mitigating the COTR due to themicrobunching instability in beam images. The OTR screen can also be used to avoid the scintillator saturation at high areal charge density and the thin foils generate less beam scattering. If the use of bandpass filters, CCD shutter timing and LYSO:Ce are not enough to reduce the COTR due to the microbunching instability, we could use a gated, intensified camera.

Wendt, M.; /Fermilab; Johnson, A.S.; Lumpkin, A.H.; Ruan, J.; Santucci, J.K.; Tan, C.C.; Thurman-Keup, R.M.; /Fermilab; Maxwell, T.J.; /Fermilab

2012-05-01T23:59:59.000Z

378

Manipulation of the micro and macro-structure of beams extracted from cyclotrons  

SciTech Connect

It is standard practice in cyclotrons to alter the extracted micro-pulse width by using center-region slits and/or by chopping the beam before injection. The macro-structure can also be varied by means of pulsed or sinusoidal deflection devices before injection and/or after extraction. All above methods, however, involve cutting away the unwanted beam, thus reducing the time-averaged intensity. This paper will focus on some methods used to alter the time structure of extracted beams without significant beam loss. For example radial gradients in the accelerating fields from rf cavities can be utilized to compress, expand or even split longitudinally the circulating particle bunches. The macro-structure of the extracted beam can be altered by employing resonant extraction methods and replacing the static magnetic bump with either a pulsed or a sinusoidal transverse perturbation. The methods are most suitable for H cyclotrons but may also be considered in a limited scope for cyclotrons using direct extraction. Results of computer simulations and beam tests on the TRIUMF 500 MeV H{sup {minus}} cyclotron will be presented.

Laxdal, R.E.

1995-09-01T23:59:59.000Z

379

World record neutron beam at Los Alamos National Laboratory  

NLE Websites -- All DOE Office Websites (Extended Search)

World record neutron beam at LANL World record neutron beam at Los Alamos National Laboratory Scientists have created the largest neutron beam ever made by a short-pulse laser,...

380

Two-beam detuned-cavity electron accelerator structure  

SciTech Connect

Progress has been made in the theory, development, cavity design and optimization, beam dynamics study, beam transport design, and hardware construction for studies of a detuned two-beam electron accelerator structure.

Jiang, Y.; Hirshfield, J. L. [Beam Physics Laboratory, Yale University, New Haven, CT 06511 (United States); Beam Physics Laboratory, Yale University, New Haven, CT 06511 (United States) and Omega-P, Inc., New Haven, CT 06510 (United States)

2012-12-21T23:59:59.000Z

Note: This page contains sample records for the topic "beam time esaf" 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

A VERY HIGH LEVEL NEUTRAL BEAM CONTROL SYSTEM  

E-Print Network (OSTI)

Level Neutial Beam Control System we have elucidated theseHigh Level Neutral Beam Control System 8!. References 1. V.High-Level Neutral-Beam Control System Victor Elischer Van

Elischer, V.

2010-01-01T23:59:59.000Z

382

Plasma ion sources and ion beam technology in microfabrications  

E-Print Network (OSTI)

5 Ion source for metallic ion beam generation and thin filmnew plasma source for metallic ion beam generation and metal5: Ion source for metallic ion beam generation and thin film

Ji, Lili

2007-01-01T23:59:59.000Z

383

Evaluation of Three-Beam and Four-Beam Profiler Wind Measurement Techniques Using a Five-Beam Wind Profiler and Collocated Meteorological Tower  

Science Conference Proceedings (OSTI)

In this paper a five-beam wind profiler and a collocated meteorological tower are used to estimate the accuracy of four-beam and three-beam wind profiler techniques in measuring horizontal components of the wind. In the traditional three-beam ...

Ahoro Adachi; Takahisa Kobayashi; Kenneth S. Gage; David A. Carter; Leslie M. Hartten; Wallace L. Clark; Masato Fukuda

2005-08-01T23:59:59.000Z

384

Microsoft Word - LCC-0135 Machine Protection Issues in the Beam Delivery System.doc  

NLE Websites -- All DOE Office Websites (Extended Search)

5 5 SLAC-TN-04-039 November 2003 Abstract This note documents a set of expressions used to explore the issue of whether or not it is reasonable to consider a conventional positron source for a Tesla formatted beam. The critical issue is that of energy deposition in the conversion target and the comparison of the induced stress with the ultimate tensile strength of the target material. Since the length of the incident beam pulse is large in comparison to the ratio of beam size to the speed of sound, the concurrent pressure pulse dissipates in a time short compared to the overall pulse duration and one is left with only the Machine Protection Issues in the Beam Delivery System L. Keller and T. Markiewicz Stanford Linear Accelerator Center

385

Intense ion beam research at Los Alamos  

SciTech Connect

Two new interdisciplinary programs are underway at Los Alamos involving the physics and technology of intense light ion beams. In contrast to high-power ICF applications, the LANL effort concentrates on the development of relatively low-voltage (50 to 800 kV) and long-pulsewidth (0.1 to 1 {mu}s) beams. The first program involves the 1.2 MV, 300-kJ Anaconda generator which has been fitted with an extraction ion diode. Long pulsewidth ion beams have been accelerated, propagated, and extracted for a variety of magnetic field conditions. The primary application of this beam is the synthesis of novel materials. Initial experiments on the congruent evaporative deposition of metallic and ceramic thin films are reported. The second program involves the development of a 120-keV, 50-kA, 1-{mu}s proton beam for the magnetic fusion program as an ion source for an intense diagnostic neutral beam. Ultra-bright, pulsed neutral beams will be required to successfully measure ion temperatures and thermalized alpha particle energy distributions in large, dense, ignited tokamaks such as ITER.

Rej, D.J.; Bartsch, R.R.; Davis, H.A.; Faehl, R.J.; Gautier, D.C.; Greenly, J.B.; Henins, I.; Linton, T.W.; Muenchausen, R.E.; Waganaar, W.J.

1992-07-01T23:59:59.000Z

386

Intense ion beam research at Los Alamos  

Science Conference Proceedings (OSTI)

Two new interdisciplinary programs are underway at Los Alamos involving the physics and technology of intense light ion beams. In contrast to high-power ICF applications, the LANL effort concentrates on the development of relatively low-voltage (50 to 800 kV) and long-pulsewidth (0.1 to 1 {mu}s) beams. The first program involves the 1.2 MV, 300-kJ Anaconda generator which has been fitted with an extraction ion diode. Long pulsewidth ion beams have been accelerated, propagated, and extracted for a variety of magnetic field conditions. The primary application of this beam is the synthesis of novel materials. Initial experiments on the congruent evaporative deposition of metallic and ceramic thin films are reported. The second program involves the development of a 120-keV, 50-kA, 1-{mu}s proton beam for the magnetic fusion program as an ion source for an intense diagnostic neutral beam. Ultra-bright, pulsed neutral beams will be required to successfully measure ion temperatures and thermalized alpha particle energy distributions in large, dense, ignited tokamaks such as ITER.

Rej, D.J.; Bartsch, R.R.; Davis, H.A.; Faehl, R.J.; Gautier, D.C.; Greenly, J.B.; Henins, I.; Linton, T.W.; Muenchausen, R.E.; Waganaar, W.J.

1992-01-01T23:59:59.000Z

387

Physics with Rare Isotope Beams  

Science Conference Proceedings (OSTI)

Using stable and radioactive beams provided by ATLAS nuclear reactions of special interest in astrophysics have been studied with emphasis on breakout from the hot CNO cycle to the rp-process. The masses of nuclear fragments provided by a strong fission source have been measured in order to help trace the path of the r process. 8Li ions produced by the d(7Li,8Li)n reaction have been trapped and the electrons and alphas emitted in the ensuing beta-decay measured. The neutrino directions were therefore determined, which leads to a measurement of the electron-neutrino correlation. The energies and kinematics are such that a sensitive search for any tensor admixture could be performed and an upper limit of 0.6% was placed on any such admixture. Earlier work on the electromagnetic form factors of the proton was extended. Graduate students were active participants in all of these eperiments, which formed the basis for six PhD theses.

Segel, Ralph E. [Northwestern University

2013-11-08T23:59:59.000Z

388

Shock Timing Technique for the NIF  

Science Conference Proceedings (OSTI)

Among the final shots at the Nova laser was a series testing the VISAR technique that will be the primary diagnostic for timing the shocks in a NIF ignition capsule. At Nova, the VISAR technique worked over the range of shock strengths and with the precision required for the NIF shock timing job--shock velocities in liquid D{sub 2} from 12 {micro}m/ns to 65 {micro}m/ns with better than 2% accuracy. VISAR images showed stronger shocks overtaking weaker ones, which is the basis of the plan for setting the pulse shape for the NIF ignition campaign. The technique is so precise that VISAR measurements may also play a role in certifying beam-to-beam and shot-to-shot repeatability of NIF laser pulses.

Munro, D.H.; Celliers, P.M.; Collins, G.W.; Gold, D.M.; DaSilva, L.B.; Haan, S.W.; Cauble, R.C.; Hammel, B.A.; Hsing, W.W.

2000-10-03T23:59:59.000Z

389

Building Energy Software Tools Directory: I-BEAM  

NLE Websites -- All DOE Office Websites (Extended Search)

I-BEAM provides comprehensive guidance for managing and assessing IAQ in offices, schools, universities and various public and institutional facilities. I-BEAM features...

390

Transient Melt Pool Response in Wire Feed Electron Beam Direct ...  

Science Conference Proceedings (OSTI)

Presentation Title, Transient Melt Pool Response in Wire Feed Electron Beam Direct ... Abstract Scope, Wire feed electron beam direct digital manufacturing ...

391

NIST Puts a New Twist on the Electron Beam  

Science Conference Proceedings (OSTI)

... This method produces several electron beams fanning out in different directions, with each beam made of electrons that orbit around the direction ...

2011-01-19T23:59:59.000Z

392

PHYSICAL REVIEW SPECIAL TOPICS ACCELERATORS AND BEAMS, VOLUME  

NLE Websites -- All DOE Office Websites (Extended Search)

Argonne Wakefield Accelerator facility are reported. In this regime, the relativistic electron beam is denser than the plasma, causing the beam channel to completely rarefy, and...

393

Ion Beam Experiment to Simulate Simultaneous Molten Salt ...  

Science Conference Proceedings (OSTI)

Experiments to expose candidate materials to simultaneous molten salt corrosion and ion-beam damage are staged at the Ion Beam Materials Laboratory at Los ...

394

Progress in the MITICA beam source design  

SciTech Connect

In the framework of the development of the ITER neutral beam (NB) system, a test facility is planned to be built in Padova. A full size prototype of the ITER heating NB injector (MITICA) shall be built and tested at full beam power (17 MW) as per ITER requirements. The design of the MITICA beam source has further progressed following updated optimization and overall integration criteria. In the paper, the major design choices and revisions are presented, together with some results of numerical analyses carried out in order to assess the electrostatic and thermo-mechanical behaviour of the source.

Zaccaria, P.; Agostinetti, P.; Marcuzzi, D.; Pavei, M.; Pilan, N.; Rizzolo, A.; Sonato, P.; Spada, F.; Trevisan, L. [Consorzio RFX, Euratom-ENEA Association, Corso Stati Uniti 4, I-35127 Padova (Italy)

2012-02-15T23:59:59.000Z

395

Collected abstracts on particle beam diagnostic systems  

SciTech Connect

This report contains a compilation of abstracts on work related to particle beam diagnostics for high temperature plasmas. The abstracts were gathered in early 1978 and represent the status of the various programs as of that date. It is not suggested that this is a comprehensive list of all the work that is going on in the development of particle beam diagnostics, but it does provide a representative view of the work in this field. For example, no abstracts were received from the U.S.S.R. even though they have considerable activity in particle beam diagnostics.

Hickok, R.L.

1979-01-01T23:59:59.000Z

396

Energy-beam-driven rapid fabrication system  

DOE Patents (OSTI)

An energy beam driven rapid fabrication system, in which an energy beam strikes a growth surface to form a molten puddle thereon. Feed powder is then injected into the molten puddle from a converging flow of feed powder. A portion of the feed powder becomes incorporated into the molten puddle, forcing some of the puddle contents to freeze on the growth surface, thereby adding an additional layer of material. By scanning the energy beam and the converging flow of feed powder across the growth surface, complex three-dimensional shapes can be formed, ready or nearly ready for use. Nearly any class of material can be fabricated using this system.

Keicher, David M. (Albuquerque, NM); Atwood, Clinton L. (Albuquerque, NM); Greene, Donald L. (Corrales, NM); Griffith, Michelle L. (Albuquerque, NM); Harwell, Lane D. (Albuquerque, NM); Jeantette, Francisco P. (Albuquerque, NM); Romero, Joseph A. (Albuquerque, NM); Schanwald, Lee P. (Albuquerque, NM); Schmale, David T. (Albuquerque, NM)

2002-01-01T23:59:59.000Z

397

Coating thermal noise for arbitrary shaped beams  

E-Print Network (OSTI)

Advanced LIGO's sensitivity will be limited by coating noise. Though this noise depends on beam shape, and though nongaussian beams are being seriously considered for advanced LIGO, no published analysis exists to compare the quantitative thermal noise improvement alternate beams offer. In this paper, we derive and discuss a simple integral which completely characterizes the dependence of coating thermal noise on shape. The derivation used applies equally well, with minor modifications, to all other forms of thermal noise in the low-frequency limit.

Richard O'Shaughnessy

2006-07-10T23:59:59.000Z

398

Beam instrumentation for the SSC RFQ  

SciTech Connect

A detailed description of the SSC RFQ beam instrumentation is presented. Most of the instrumentation is located in the RFQ end walls. The upstream end wall contains a segmented Faraday cup, a segmented aperture and a wire scanner. The down stream end wall contains a segmented aperture and wire scanner. Two current toroids are used to measure the transmission through the RFQ. The output of the RFQ is a low emittance, pulsed 2.5 Mev H{sup {minus}} beam with peak current of 25 mA and maximum pulse length of 35 {mu}s. Typical beam data are shown with the emphasis being on instrumentation performance.

Datte, P.; Jamieson, G.; Aiello, R.; Beechy, D.; Jones, A.; Martin, D.; Riordon, J.; Webber, R.; Wood, F.

1993-05-01T23:59:59.000Z

399

Impurity beam-trapping instability in tokamaks  

SciTech Connect

The sensitivity of neutron energy production to the impurity trapping of injected neutral beams is considered. This process is affected by inherent low-Z contamination of the tritium pre-heat plasma, by the species composition of the neutral beam, and by the entrance angle of the beam. The sensitivities of the process to these variables, and to the variation of wall material are compared. One finds that successful use of a low-Z, low-sputtering material can appreciably lengthen the useful pulse length. (auth)

Hogan, J.T.; Howe, H.C.

1976-01-01T23:59:59.000Z

400

Intense steady state electron beam generator  

DOE Patents (OSTI)

An intense, steady state, low emittance electron beam generator is formed by operating a hollow cathode discharge plasma source at critical levels in combination with an extraction electrode and a target electrode that are operable to extract a beam of fast primary electrons from the plasma source through a negatively biased grid that is critically operated to repel bulk electrons toward the plasma source while allowing the fast primary electrons to move toward the target in the desired beam that can be successfully transported for relatively large distances, such as one or more meters away from the plasma source. 2 figs.

Hershcovitch, A.; Kovarik, V.J.; Prelec, K.

1990-07-17T23:59:59.000Z

Note: This page contains sample records for the topic "beam time esaf" 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

Fusion Induced by Radioactive Ion Beams  

E-Print Network (OSTI)

The use of radioactive beams opens a new frontier for fusion studies. The coupling to the continuum can be explored with very loosely bound nuclei. Experiments were performed with beams of nuclei at or near the proton and neutron drip-lines to measure fusion and associated reactions in the vicinity of the Coulomb barrier. In addition, the fusion yield is predicted to be enhanced in reactions involving very neutron-rich unstable nuclei. Experimental measurements were carried out to investigate if it is feasible to use such beams to produce new heavy elements. The current status of these experimental activities is given in this review.

J. F. Liang; C. Signorini

2005-04-26T23:59:59.000Z

402

Press Pass - Press Release - U.S. LHC first beam  

NLE Websites -- All DOE Office Websites (Extended Search)

8-15 8-15 Aug. 8, 2008 For immediate release Media Contacts: Brookhaven National Laboratory - Kendra Snyder, ksnyder@bnl.gov, 631-344-8191 Fermilab - Judy Jackson, 630-840-3351, jjackson@fnal.gov Lawrence Berkeley National Laboratory - Dan Krotz, dakrotz@lbl.gov, (510) 486-4019 and Paul Preuss, paul_preuss@lbl.gov, 510-486-6249 CERN - James Gillies, james.gillies@cern.ch, +41 22 767 4101 Photos and graphics of the Large Hadron Collider are available at: http://multimedia-gallery.web.cern.ch/multimedia-gallery/PhotoGallery_Main.aspx and http://www.uslhc.us/Images. U.S. scientists count down to LHC startup Batavia, IL, Berkeley, CA and Upton, NY - On September 10, scientists at the Large Hadron Collider will attempt for the first time to send a proton beam zooming around the 27-kilometer-long accelerator. The LHC, the world's most powerful particle accelerator, is located at CERN in Geneva, Switzerland. Journalists are invited to attend LHC first beam events at CERN and several locations within the United States. Information about the CERN event and accreditation procedures is available at . A list of LHC startup events in the U.S. and contact information for each is available at http://www.uslhc.us/first_beam.

403

The electron beam cure of epoxy paste adhesives  

Science Conference Proceedings (OSTI)

Recently developed epoxy paste adhesives were electron beam cured and experimentally explored to determine their suitability for use in an aerospace-quality aircraft component. There were two major goals for this program. The first was to determine whether the electron beam-curable past adhesives were capable of meeting the requirements of the US Air Force T-38 supersonic jet trainer composite windshield frame. The T-38 windshield frame`s arch is currently manufactured by bonding thin stainless steel plies using an aerospace-grade thermally-cured epoxy film adhesive. The second goal was to develop the lowest cost hand layup and debulk process that could be used to produce laminated steel plies with acceptable properties. The laminate properties examined to determine adhesive suitability include laminate mechanical and physical properties at room, adhesive tack, out-time capability, and the debulk requirements needed to achieve these properties. Eighteen past adhesives and four scrim cloths were experimentally examined using this criteria. One paste adhesive was found to have suitable characteristics in each of these categories and was later chosen for the manufacture of the T-38 windshield frame. This experimental study shows that by using low-cost debulk and layup processes, the electron beam-cured past adhesive mechanical and physical properties meet the specifications of the T-38 composite windshield frame.

Farmer, J.D. [Air Force Advanced Composites Program office, McClellan AFB, CA (United States); Janke, C.J. [Oak Ridge National Lab., TN (United States). Oak Ridge Centers for Manufacturing Technology; Lopata, V.J. [Atomic Energy of Canada Ltd., Pinawa, Manitoba (Canada). Whiteshell Labs.

1998-07-01T23:59:59.000Z

404

Intensity Effects of the FACET Beam in the SLAC Linac  

SciTech Connect

The beam for FACET (Facility for Advanced aCcelerator Experimental Tests) at SLAC requires an energy-time correlation ('chirp') along the linac, so it can be compressed in two chicanes, one at the midpoint in sector 10 and one W-shaped chicane just before the FACET experimental area. The induced correlation has the opposite sign to the typical used for BNS damping, and therefore any orbit variations away from the center kick the tail of the beam more than the head, causing a shear in the beam and emittance growth. Any dispersion created along the linac has similar effects due to the high (>1.2% rms) energy spread necessary for compression. The initial huge emittances could be reduced by a factor of 10, but were still bigger than expected by a factor of 2-3. Normalized emittance of 3 {micro}m-rad in Sector 2 blew up to 150 {micro}m-rad in Sector 11 but could be reduced to about 6-12 {micro}m-rad, for the vertical plane although the results were not very stable. Investigating possible root causes for this, we found locations where up to 10 mm dispersion was created along the linac, which were finally verified with strong steering and up to 7 mm settling of the linac accelerator at these locations.

Decker, F.-J.; Lipkowitz, N.; Sheppard, J.; White, G.R.; Wienands, U.; Woodley, M.; Yocky, G.; /SLAC

2012-07-03T23:59:59.000Z

405

Low Beam Voltage, 10 MW, L-Band Cluster Klystron  

SciTech Connect

Conceptual design of a multi-beam klystron (MBK) for possible ILC and Project X applications is presented. The chief distinction between this MBK design and existing 10-MW MBK's is the low operating voltage of 60 kV. There are at least four compelling reasons that justify development at this time of a low-voltage MBK, namely (1) no pulse transformer; (2) no oil tank for high-voltage components and for the tube socket; (3) no high-voltage cables; and (4) modulator would be a compact 60-kV IGBT switching circuit. The proposed klystron consists of four clusters containing six beams each. The tube has common input and output cavities for all 24 beams, and individual gain cavities for each cluster. A closely related optional configuration, also for a 10 MW tube, would involve four totally independent cavity clusters with four independent input cavities and four 2.5 MW output ports, all within a common magnetic circuit. This option has appeal because the output waveguides would not require a controlled atmosphere, and because it would be easier to achieve phase and amplitude stability as required in individual SC accelerator cavities.

Teryaev, V.; /Novosibirsk, IYF; Yakovlev, V.P.; /Fermilab; Kazakov, S.; /KEK, Tsukuba; Hirshfield, J.L.; /Yale U. /Omega-P, New Haven

2009-05-01T23:59:59.000Z

406

Pitfalls of tungsten multileaf collimator in proton beam therapy  

Science Conference Proceedings (OSTI)

Purpose: Particle beam therapy is associated with significant startup and operational cost. Multileaf collimator (MLC) provides an attractive option to improve the efficiency and reduce the treatment cost. A direct transfer of the MLC technology from external beam radiation therapy is intuitively straightforward to proton therapy. However, activation, neutron production, and the associated secondary cancer risk in proton beam should be an important consideration which is evaluated. Methods: Monte Carlo simulation with FLUKA particle transport code was applied in this study for a number of treatment models. The authors have performed a detailed study of the neutron generation, ambient dose equivalent [H*(10)], and activation of a typical tungsten MLC and compared with those obtained from a brass aperture used in a typical proton therapy system. Brass aperture and tungsten MLC were modeled by absorber blocks in this study, representing worst-case scenario of a fully closed collimator. Results: With a tungsten MLC, the secondary neutron dose to the patient is at least 1.5 times higher than that from a brass aperture. The H*(10) from a tungsten MLC at 10 cm downstream is about 22.3 mSv/Gy delivered to water phantom by noncollimated 200 MeV beam of 20 cm diameter compared to 14 mSv/Gy for the brass aperture. For a 30-fraction treatment course, the activity per unit volume in brass aperture reaches 5.3 x 10{sup 4} Bq cm{sup -3} at the end of the last treatment. The activity in brass decreases by a factor of 380 after 24 h, additional 6.2 times after 40 days of cooling, and is reduced to background level after 1 yr. Initial activity in tungsten after 30 days of treating 30 patients per day is about 3.4 times higher than in brass that decreases only by a factor of 2 after 40 days and accumulates to 1.2 x 10{sup 6} Bq cm{sup -3} after a full year of operation. The daily utilization of the MLC leads to buildup of activity with time. The overall activity continues to increase due to {sup 179}Ta with a half-life of 1.82 yr and thus require prolonged storage for activity cooling. The H*(10) near the patient side of the tungsten block is about 100 {mu}Sv/h and is 27 times higher at the upstream side of the block. This would lead to an accumulated dose for therapists in a year that may exceed occupational maximum permissible dose (50 mSv/yr). The value of H*(10) at the upstream surface of the tungsten block is about 220 times higher than that of the brass. Conclusions: MLC is an efficient way for beam shaping and overall cost reduction device in proton therapy. However, based on this study, tungsten seems to be not an optimal material for MLC in proton beam therapy. Usage of tungsten MLC in clinic may create unnecessary risks associated with the secondary neutrons and induced radioactivity for patients and staff depending on the patient load. A careful selection of material for manufacturing of an optimal MLC for proton therapy is thus desired.

Moskvin, Vadim; Cheng, Chee-Wai; Das, Indra J. [Department of Radiation Oncology, Indiana University School of Medicine, Indianapolis, Indiana 46202 (United States) and Indiana University Health Proton Therapy Center (Formerly Midwest Proton Radiotherapy Institute), Bloomington, Indiana 47408 (United States)

2011-12-15T23:59:59.000Z

407

Mechanical and thermal design of the CEBAF Hall a beam calorimeter  

SciTech Connect

A calorimeter is being fabricated to provide 0.5% - 1.0% absolute measurement of the beam current in the Hall A end station of the Continuous Electron Beam Accelerator Facility (CEBAF) at Jefferson Lab (JLAB). Modern powder metallurgy processes have produced high density, high thermal conductivity tungsten-copper composite materials that minimize electromagnetic and hadronic energy loss while maintaining a rapid thermal response time. Heat leaks are minimized by mounting the mass in vacuum on glass ceramic mounts. A conduction cooling scheme utilizes an advanced carbon fiber compliant thermal interface material. Transient finite difference and finite element models were developed to estimate heat leaks and thermal response times.

M. Bevins; A. Day; P. Degtiarenko; L.A. Dillon-Townes; A. Freyberger; R. Gilman; A. Saha; S. Slachtouski

2005-05-16T23:59:59.000Z

408

Tests of timing properties of silicon photomultipliers  

Science Conference Proceedings (OSTI)

Timing measurements of Silicon Photomultipliers (SiPM) [1] and [2] at the picosecond level were performed at Fermilab. The core timing resolution of the electronic measurement technique is approximately 2 ps. The single photoelectron time resolution (SPTR) was measured for the signals coming from the SiPM's. A SPTR of about one hundred picoseconds was obtained for SiPM's illuminated by laser pulses. The dependence of the SPTR on applied bias voltage and on the wavelength of the light was measured. A simple model is proposed to explain the difference in the SPTR for blue and red light. A time of flight system based on the SiPM's, with quartz Cherenkov radiators, was tested in a proton beam at Fermilab. The time resolution obtained is 35 ps per SiPM. Finally, requirements for the SiPM's temperature and bias voltage stability to maintain the time resolution are discussed.

Ronzhin, A.; Albrow, M.; /Fermilab; Byrum, K.; /Argonne; Demarteau, M.; Los, S.; /Fermilab; May, E.; /Argonne; Ramberg, A.; /Fermilab; Va'vra, J.; /SLAC; Zatserklyaniy, A.; /Puerto Rico U., Mayaguez

2010-03-01T23:59:59.000Z

409

Levy-Student Distributions for Halos in Accelerator Beams  

E-Print Network (OSTI)

We describe the transverse beam distribution in particle accelerators within the controlled, stochastic dynamical scheme of the Stochastic Mechanics (SM) which produces time reversal invariant diffusion processes. This leads to a linearized theory summarized in a Shchr\\"odinger--like (\\Sl) equation. The space charge effects have been introduced in a recent paper~\\cite{prstab} by coupling this \\Sl equation with the Maxwell equations. We analyze the space charge effects to understand how the dynamics produces the actual beam distributions, and in particular we show how the stationary, self--consistent solutions are related to the (external, and space--charge) potentials both when we suppose that the external field is harmonic (\\emph{constant focusing}), and when we \\emph{a priori} prescribe the shape of the stationary solution. We then proceed to discuss a few new ideas~\\cite{epac04} by introducing the generalized Student distributions, namely non--Gaussian, L\\'evy \\emph{infinitely divisible} (but not \\emph{stable}) distributions. We will discuss this idea from two different standpoints: (a) first by supposing that the stationary distribution of our (Wiener powered) SM model is a Student distribution; (b) by supposing that our model is based on a (non--Gaussian) L\\'evy process whose increments are Student distributed. We show that in the case (a) the longer tails of the power decay of the Student laws, and in the case (b) the discontinuities of the L\\'evy--Student process can well account for the rare escape of particles from the beam core, and hence for the formation of a halo in intense beams.

N. Cufaro Petroni; S. De Martino; S. De Siena; F. Illuminati

2005-10-12T23:59:59.000Z

410

14th international symposium on molecular beams  

SciTech Connect

This report discusses research being conducted with molecular beams. The general topic areas are as follows: Clusters I; reaction dynamics; atomic and molecular spectroscopy; clusters II; new techniques; photodissociation & dynamics; and surfaces.

Not Available

1992-09-01T23:59:59.000Z

411

14th international symposium on molecular beams  

Science Conference Proceedings (OSTI)

This report discusses research being conducted with molecular beams. The general topic areas are as follows: Clusters I; reaction dynamics; atomic and molecular spectroscopy; clusters II; new techniques; photodissociation dynamics; and surfaces.

Not Available

1992-01-01T23:59:59.000Z

412

Solar Power Beaming: From Space to Earth  

Science Conference Proceedings (OSTI)

Harvesting solar energy in space and power beaming the collected energy to a receiver station on Earth is a very attractive way to help solve mankind's current energy and environmental problems. However, the colossal and expensive 'first step' required in achieving this goal has to-date stifled its initiation. In this paper, we will demonstrate that recent advance advances in laser and optical technology now make it possible to deploy a space-based system capable of delivering 1 MW of energy to a terrestrial receiver station, via a single unmanned commercial launch into Low Earth Orbit (LEO). Figure 1 depicts the overall concept of our solar power beaming system, showing a large solar collector in space, beaming a coherent laser beam to a receiving station on Earth. We will describe all major subsystems and provide technical and economic discussion to support our conclusions.

Rubenchik, A M; Parker, J M; Beach, R J; Yamamoto, R M

2009-04-14T23:59:59.000Z

413

SolBeam Inc | Open Energy Information  

Open Energy Info (EERE)

California Zip 92677 Product California-based startup developing concentrator photovoltaics. References SolBeam Inc1 LinkedIn Connections CrunchBase Profile No CrunchBase...

414

Compact high precision adjustable beam defining aperture  

DOE Patents (OSTI)

The present invention provides an adjustable aperture for limiting the dimension of a beam of energy. In an exemplary embodiment, the aperture includes (1) at least one piezoelectric bender, where a fixed end of the bender is attached to a common support structure via a first attachment and where a movable end of the bender is movable in response to an actuating voltage applied to the bender and (2) at least one blade attached to the movable end of the bender via a second attachment such that the blade is capable of impinging upon the beam. In an exemplary embodiment, the beam of energy is electromagnetic radiation. In an exemplary embodiment, the beam of energy is X-rays.

Morton, Simon A; Dickert, Jeffrey

2013-07-02T23:59:59.000Z

415

Flow-through ion beam source  

DOE Patents (OSTI)

A method and an apparatus for forming a charge neutral ion beam which is useful in producing thin films of material on electrically conductive or non-conductive substrates are provided.

Springer, Robert W. (Los Alamos, NM)

1997-01-01T23:59:59.000Z

416

Energy flow analysis for curved beams  

Science Conference Proceedings (OSTI)

This paper presents an energy model for the medium- and high-frequency analysis of Love–Kirchhoff curved beams. This model introduced by Nefske and Sung [Statistical Energy Analysis NCA 3

A. Le Bot; M. N. Ichchou; L. Jezequel

1997-01-01T23:59:59.000Z

417

The Radioactive Beam Program at Argonne  

E-Print Network (OSTI)

In this talk I will present selected topics of the ongoing radioactive beam program at Argonne and discuss the capabilities of the CARIBU radioactive ion production facility as well as plans for construction of a novel superconducting solenoid spectrometer.

B. B. Back

2006-06-06T23:59:59.000Z

418

Laboratory Measurements of Electrostatic Solitary Structures Generated by Beam Injection  

SciTech Connect

Electrostatic solitary structures are generated by injection of a suprathermal electron beam parallel to the magnetic field in a laboratory plasma. Electric microprobes with tips smaller than the Debye length ({lambda}{sub De}) enabled the measurement of positive potential pulses with half-widths 4 to 25{lambda}{sub De} and velocities 1 to 3 times the background electron thermal speed. Nonlinear wave packets of similar velocities and scales are also observed, indicating that the two descend from the same mode which is consistent with the electrostatic whistler mode and result from an instability likely to be driven by field-aligned currents.

Lefebvre, Bertrand; Chen, Li-Jen [Space Science Center, University of New Hampshire, Durham, New Hampshire 03824 (United States); Gekelman, Walter; Pribyl, Patrick; Vincena, Stephen [Basic Plasma Science Facility, University of California, Los Angeles, California 90095 (United States); Kintner, Paul [School of Electrical and Computer Engineering, Cornell University, Ithaca, New York 14853 (United States); Pickett, Jolene [Department of Physics and Astronomy, University of Iowa, Iowa City, Iowa 52242 (United States); Chiang, Franklin; Judy, Jack [Electrical Engineering Department, University of California, Los Angeles, California 90095 (United States)

2010-09-10T23:59:59.000Z

419

ENERGY DISTRIBUTION OF FAST NEUTRON BEAM  

DOE Green Energy (OSTI)

Experimental techniques are described for the spectral measurement of a collimated fast-neutron beam. A H/sub 2-/ filled cloud chamber, proton-recording nuclear plates, and threshold fission foils were used as neutron detectors in the measurements. As an application of these techniques, the energy distribution and absolute flux of the fast neutron beam emerging from the Los Alamos fast reactor was measured from 0.1 to 18 Mev. (D.E.B.)

Nereson, N.; Allison, E.; Carlson, J.; Norwood, P.; Squires, D.

1951-02-15T23:59:59.000Z

420

Ion beam processing of advanced electronic materials  

SciTech Connect

This report contains research programs discussed at the materials research society symposia on ion beam processing of advanced electronic materials. Major topics include: shallow implantation and solid-phase epitaxy; damage effects; focused ion beams; MeV implantation; high-dose implantation; implantation in III-V materials and multilayers; and implantation in electronic materials. Individual projects are processed separately for the data bases. (CBS)

Cheung, N.W.; Marwick, A.D.; Roberto, J.B. (eds.) (California Univ., Berkeley, CA (USA); International Business Machines Corp., Yorktown Heights, NY (USA). Thomas J. Watson Research Center; Oak Ridge National Lab., TN (USA))

1989-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "beam time esaf" 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

Diffraction smoothing aperture for an optical beam  

SciTech Connect

The disclosure is directed to an aperture for an optical beam having an irregular periphery or having perturbations imposed upon the periphery to decrease the diffraction effect caused by the beam passing through the aperture. Such apertures are particularly useful with high power solid state laser systems in that they minimize the problem of self-focusing which frequently destroys expensive components in such systems.

Judd, O' Dean P. (Los Alamos, NM); Suydam, Bergen R. (Los Alamos, NM)

1976-01-01T23:59:59.000Z

422

BEAM DYNAMICS ISSUES IN THE SNS LINAC  

Science Conference Proceedings (OSTI)

A review of the Spallation Neutron Source (SNS) linac beam dynamics is presented. It describes transverse and longitudinal beam optics, losses, activation, and comparison between the initial design and the existing accelerator. The SNS linac consists of normal conducting and superconducting parts. The peculiarities in operations with the superconducting part of the SNS linac (SCL), estimations of total losses in SCL, the possible mechanisms of these losses, and the progress in the transverse matching are discussed.

Shishlo, Andrei P [ORNL

2011-01-01T23:59:59.000Z

423

Status of the START neutral beam project  

DOE Green Energy (OSTI)

A major advantage of spherical tokamaks is their potential for achieving high beta and high plasma density in modest sized plasmas using low magntic field. Given this combination of low field and high density, neutral beam injection can provide effective auxiliary heating for the next generation of spherical tokamaks. A neutral beam injector, shipped recently from Oak Ridge National Laboratory as part of an ongoing collaboration on spherical tokamak research, has now been installed onto the START (Small Tight Aspect Ratio Tokamak) experiment at Culham Laboratory. This should provide the first experimental test of neutral injectino into spherical tokamak plasmas, and allow the effects of neutral beam heating on energy confinement and beta values to be assessed at low aspect ratios. This experiment also extends the data base of confinement scaling for tokamaks in general. Modifications to START have included in-situ machining of a new 31 cm diameter port for NBI, plus the installation of a new graphite neutral beam stop equipped with thermocouples to provide beam profile and shinethrough diagnosis. The major modification to the NBI beamline has been the installation of an optical fiber coupled control and instrumentation system. The injector will be operated without cryopumps in a 'volume pumped' configuration, and should provide 0.5 MW of injected hydrogen neutral power at a beam energy of 40 keV for 20 ms pulses. The status of the installation and commissioning program is reported.

Nightingale, M. P. S. [Association EURATOM-CCFE, Abingdon, UK; Peng, Yueng Kay Martin [ORNL

1995-01-01T23:59:59.000Z

424

Coherent beam-beam effects observation and mitigation at the RHIC collider  

SciTech Connect

In polarized proton operation in RHIC coherent beam-beam modes are routinely observed with beam transfer function measurements in the vertical plane. With the existence of coherent modes a larger space is required in the tune diagram than without them and stable conditions can be compromised for operation with high intensity beams as foreseen for future luminosity upgrades. We report on experiments and simulations carried out to understand the existence of coherent modes in the vertical plane and their absence in the horizontal plane, and investigate possible mitigation strategies.

White S.; Fischer, W.; Luo, Y.

2012-05-20T23:59:59.000Z

425

A laser-wire beam-energy and beam-profile monitor at the BNL linac  

SciTech Connect

In 2009 a beam-energy monitor was installed in the high energy beam transport (HEBT) line at the Brookhaven National Lab linac. This device measures the energies of electrons stripped from the 40mA H{sup -} beam by background gas. Electrons are stripped by the 2.0x10{sup -7}torr residual gas at a rate of {approx}1.5x10{sup -8}/cm. Since beam electrons have the same velocities as beam protons, the beam proton energy is deduced by multiplying the electron energy by m{sub p}/m{sub e}=1836. A 183.6MeV H{sup -} beam produces 100keV electrons. In 2010 we installed an optics plates containing a laser and scanning optics to add beam-profile measurement capability via photodetachment. Our 100mJ/pulse, Q-switched laser neutralizes 70% of the beam during its 10ns pulse. This paper describes the upgrades to the detector and gives profile and energy measurements.

Connolly, R.; Degen, C.; DeSanto, L.; Meng, W.; Michnoff, R.; Minty, M.; Nayak, S.

2011-03-28T23:59:59.000Z

426

Particle beam fusion progress report for 1989  

Science Conference Proceedings (OSTI)

This report summarizes the progress on the pulsed power approach to inertial confinement fusion. In 1989, the authors achieved a proton focal intensity of 5 TW/cm{sup 2} on PBFA-II in a 15-cm-radius applied magnetic-field (applied-B) ion diode. This is an improvement by a factor of 4 compared to previous PBFA-II experiments. They completed development of the three-dimensional (3-D), electromagnetic, particle-in-cell code QUICKSILVER and obtained the first 3-D simulations of an applied-B ion diode. The simulations, together with analytic theory, suggest that control of electromagnetic instabilities could reduce ion divergence. In experiments using a lithium fluoride source, they delivered 26 kJ of lithium energy to the diode axis. Rutherford-scattered ion diagnostics have been developed and tested using a conical foil located inside the diode. They can now obtain energy density profiles by using range filters and recording ion images on nuclear track recording film. Timing uncertainties in power flow experiments on PBFA-II have been reduced by a factor of 5. They are investigating three plasma opening switches that use magnetic fields to control and confine the injected plasma. These new switches provide better power flow than the standard plasma erosion switch. Advanced pulsed-power fusion drivers will require extraction-geometry applied-B ion diodes. During this reporting period, progress was made in evaluating the generation, transport, and focus of multiple ion beams in an extraction geometry and in assessing the probable damage to a target chamber first wall.

Sweeney, M.A. [ed.] [Sandia National Labs., Albuquerque, NM (United States). Pulsed Power Sciences Center

1994-08-01T23:59:59.000Z

427

The System of Nanosecond 280-KeV He+ Pulsed Beam  

SciTech Connect

At Fast Neutron Research Facility, the 150 kV-pulses neutron generator is being upgraded to a 280-kV-pulsed-He beam for time-of-flight Rutherford backscattering spectrometry. It involves replacing the existing beam line elements by a multicusp ion source, a 400-kV accelerating tube, 45{sup o}-double focusing dipole magnet and quadrupole lens. The multicusp ion source is a compact filament-driven of 2.6 cm in diameter and 8 cm in length. The current extracted is 20.4 {micro}A with 13 kV of extraction voltage and 8.8 kV of Einzel lens voltage. The beam emittance has found to vary between 6-12 mm mrad. The beam transport system has to be redesigned based on the new elements. The important part of a good pulsed beam depends on the pulsing system. The two main parts are the chopper and buncher. An optimized geometry for the 280 keV pulsed helium ion beam will be presented and discussed. The PARMELA code has been used to optimize the space charge effect, resulting in pulse width of less than 2 ns at a target. The calculated distance from a buncher to the target is 4.6 m. Effects of energy spread and phase angle between chopper and buncher have been included in the optimization of the bunch length.

Junphong, P.; Ano, V.; Lekprasert, B.; Suwannakachorn, D.; Thongnopparat, N.; Vilaithong, T.; /Chiang Mai U.; Wiedemann, H.; /SLAC /SLAC, SSRL

2006-05-01T23:59:59.000Z

428

Ion-beam-driven resonant ion cyclotron instability  

SciTech Connect

The resonant ion-beam-driven electrostatic ion cyclotron instability is identified. Measured dispersion relation and onset vs. beam energy and density agree with numerical calculations based on a theory which includes beam acoustic terms. After amplitude saturation, velocity space diffusion of the beam ions is observed. (auth)

Hendel, H.W.; Yamada, M.; Seiler, S.W.; Ikezi, H.

1975-11-01T23:59:59.000Z

429

Important atomic physics issues for ion beam fusion  

SciTech Connect

This paper suggests several current atomic physics questions important to ion beam fusion. Among the topics discussed are beam transport, beam-target interaction, and reactor design. The major part of the report is discussion concerning areas of research necessary to better understand beam-target interactions. (JDH)

Bangerter, R.O.

1985-03-19T23:59:59.000Z

430

Temporal behavior of neutral particle fluxes in TFTR (Tokamak Fusion Test Reactor) neutral beam injectors  

SciTech Connect

Data from an E {parallel} B charge exchange neutral analyzer (CENA), which views down the axis of a neutral beamline through an aperture in the target chamber calorimeter of the TFTR neutral beam test facility, exhibit two curious effects. First, there is a turn-on transient lasting tens of milliseconds having a magnitude up to three times that of the steady-state level. Second, there is a 720 Hz, up to 20% peak-to-peak fluctuation persisting the entire pulse duration. The turn-on transient occurs as the neutralizer/ion source system reaches a new pressure equilibrium following the effective ion source gas throughput reduction by particle removal as ion beam. Widths of the transient are a function of the gas throughput into the ion source, decreasing as the gas supply rate is reduced. Heating of the neutalizer gas by the beam is assumed responsible, with gas temperature increasing as gas supply rate is decreased. At low gas supply rates, the transient is primarliy due to dynamic changes in the neutralizer line density and/or beam species composition. Light emission from the drift duct corroborate the CENA data. At high gas supply rates, dynamic changes in component divergence and/or spatial profiles of the source plasma are necessary to explain the observations. The 720 Hz fluctuation is attributed to a 3% peak-to-peak ripple of 720 Hz on the arc power supply amplified by the quadratic relationship between beam divergence and beam current. Tight collimation by CENA apertures cause it to accept a very small part of the ion source's velocity space, producing a signal linearly proportional to beam divergence. Estimated fluctuations in the peak power density delivered to the plasma under these conditions are a modest 3--8% peak to peak. The efffects of both phenomena on the injected neutral beam can be ameliorated by careful operion of the ion sources. 21 refs., 11 figs., 2 tabs.

Kamperschroer, J.H.; Gammel, G.M.; Roquemore, A.L.; Grisham, L.R.; Kugel, H.W.; Medley, S.S.; O' Connor, T.E.; Stevenson, T.N.; von Halle, A.; Williams, M.D.

1989-09-01T23:59:59.000Z

431

Dynamic cone beam CT angiography of carotid and cerebral arteries using canine model  

SciTech Connect

Purpose: This research is designed to develop and evaluate a flat-panel detector-based dynamic cone beam CT system for dynamic angiography imaging, which is able to provide both dynamic functional information and dynamic anatomic information from one multirevolution cone beam CT scan. Methods: A dynamic cone beam CT scan acquired projections over four revolutions within a time window of 40 s after contrast agent injection through a femoral vein to cover the entire wash-in and wash-out phases. A dynamic cone beam CT reconstruction algorithm was utilized and a novel recovery method was developed to correct the time-enhancement curve of contrast flow. From the same data set, both projection-based subtraction and reconstruction-based subtraction approaches were utilized and compared to remove the background tissues and visualize the 3D vascular structure to provide the dynamic anatomic information. Results: Through computer simulations, the new recovery algorithm for dynamic time-enhancement curves was optimized and showed excellent accuracy to recover the actual contrast flow. Canine model experiments also indicated that the recovered time-enhancement curves from dynamic cone beam CT imaging agreed well with that of an IV-digital subtraction angiography (DSA) study. The dynamic vascular structures reconstructed using both projection-based subtraction and reconstruction-based subtraction were almost identical as the differences between them were comparable to the background noise level. At the enhancement peak, all the major carotid and cerebral arteries and the Circle of Willis could be clearly observed. Conclusions: The proposed dynamic cone beam CT approach can accurately recover the actual contrast flow, and dynamic anatomic imaging can be obtained with high isotropic 3D resolution. This approach is promising for diagnosis and treatment planning of vascular diseases and strokes.

Cai Weixing; Zhao Binghui; Conover, David; Liu Jiangkun; Ning Ruola [Department of Imaging Sciences, University of Rochester, 601 Elmwood Avenue, Rochester, New York 14642 (United States); Department of Radiology, Shanghai 6th People's Hospital, 600 Yishan Road, Xuhui, Shanghai (China); Koning Corporation, Lennox Tech Enterprise Center, 150 Lucius Gordon Drive Suite 112, West Henrietta, New York 14586 (United States); Department of Imaging Sciences, University of Rochester, 601 Elmwood Avenue, Rochester, New York 14642 (United States); Department of Imaging Sciences, University of Rochester, 601 Elmwood Avenue, Rochester, New York 14642 (United States) and Koning Corporation, Lennox Tech Enterprise Center, 150 Lucius Gordon Drive Suite 112, West Henrietta, New York 14586 (United States)

2012-01-15T23:59:59.000Z

432

Production of high brightness H- beam by charge exchange of hydrogen atom beam in sodium jet  

DOE Green Energy (OSTI)

Production of H{sup -} beam for accelerators applications by charge exchange of high brightness hydrogen neutral beam in a sodium jet cell is experimentally studied in joint BNL-BINP experiment. In the experiment, a hydrogen-neutral beam with 3-6 keV energy, equivalent current up to 5 A and 200 microsecond pulse duration is used. The atomic beam is produced by charge exchange of a proton beam in a pulsed hydrogen target. Formation of the proton beam is performed in an ion source by four-electrode multiaperture ion-optical system. To achieve small beam emittance, the apertures in the ion-optical system have small enough size, and the extraction of ions is carried out from the surface of plasma emitter with a low transverse ion temperature of {approx}0.2 eV formed as a result of plasma jet expansion from the arc plasma generator. Developed for the BNL optically pumped polarized ion source, the sodium jet target with recirculation and aperture diameter of 2 cm is used in the experiment. At the first stage of the experiment H{sup -} beam with 36 mA current, 5 keV energy and {approx}0.15 cm {center_dot} mrad normalized emittance was obtained. To increase H{sup -} beam current ballistically focused hydrogen neutral beam will be applied. The effects of H{sup -} beam space-charge and sodium-jet stability will be studied to determine the basic limitations of this approach.

Davydenko, V.; Zelenski, A.; Ivanov, A.; Kolmogorov, A.

2010-11-16T23:59:59.000Z

433

Positron Beam Propagation in a Meter Long Plasma Channel  

SciTech Connect

Recent experiments and simulations have shown that positron beams propagating in plasmas can be focused and also create wakes with large accelerating gradients. For similar parameters, the wakes driven by positron beams are somewhat smaller compared to the case of an electron beam. Simulations have shown that the wake amplitude can be increased if the positron beam is propagated in a hollow plasma channel (Ref. 1). This paper, compares experimentally, the propagation and beam dynamics of a positron beam in a meter scale homogeneous plasma, to a positron beam hollow channel plasma. The results show that positron beams in hollow channels are less prone to distortions and deflections. Hollow channels were observed to guide the positron beam onto the channel axis. Beam energy loss was also observed implying the formation of a large wake amplitude. The experiments were carried out as part of the E-162 plasma wakefield experiments at SLAC.

Marsh, K.A.; Blue, B.E.; Clayton, C.E.; Joshi, C.; Mori, W.B.; /UCLA; Decker, F.-J.; Hogan, M.J.; Iverson, R.; O' Connell, C.; Raimondi, P.; Siemann, Robert H.; Walz, D.; /SLAC; Katsouleas, T.C.; Muggli, P.; /Southern California U.

2008-03-17T23:59:59.000Z

434

LASER BEAM PROFILE MONITOR DEVELOPMENT AT BNL FOR SNS.  

SciTech Connect

A beam profile monitor for H-beams based on laser photoneutralization is being developed at Brookhaven National Laboratory (BNL) for use on the Spallation Neutron Source (SNS) [l]. An H ion has a first ionization potential of 0.75eV and can be neutralized by light from a Nd:YAG laser (h=1064nm). To measure beam profiles, a narrow laser beam is passed through the ion beam neutralizing a portion of the H-beam struck by the laser. The laser trajectory is stepped across the ion beam. At each laser position, the reduction of the beam current caused by the laser is measured. A proof-of-principle experiment was done earlier at 750keV. This paper reports on measurements made on 200MeV beam at BNL and with a compact scanner prototype at Lawrence Berkeley National Lab on beam from the SNS RFQ.

CONNOLLY,R.; CAMERON,P.; CUPOLO,J.; GASSNER,D.; GRAU,M.; KESSELMAN,M.; PENG,S.; SIKORA,R.

2002-05-06T23:59:59.000Z

435

A Neutral Beam Injector Upgrade for NSTX  

Science Conference Proceedings (OSTI)

The National Spherical Torus Experiment (NSTX) capability with a Neutral Beam Injector (NBI) capable of 80 kiloelectronvolt (keV), 5 Megawatt (MW), 5 second operation. This 5.95 million dollar upgrade reused a previous generation injector and equipment for technical, cost, and schedule reasons to obtain these specifications while retaining a legacy capability of 120 keV neutral particle beam delivery for shorter pulse lengths for possible future NSTX experiments. Concerns with NBI injection included power deposition in the plasma, aiming angles from the fixed NBI fan array, density profiles and beam shine through, orbit losses of beam particles, and protection of the vacuum vessel wall against beam impingement. The upgrade made use of the beamline and cryo panels from the Neutral Beam Test Stand facility, existing power supplies and controls, beamline components and equipment not contaminated by tritium during DT [deuterium-tritium] experiments, and a liquid Helium refrigerator plant to power and cryogenically pump a beamline and three ion sources. All of the Tokamak Fusion Test Reactor (TFTR) ion sources had been contaminated with tritium, so a refurbishment effort was undertaken on selected TFTR sources to rid the three sources destined for the NSTX NBI of as much tritium as possible. An interconnecting duct was fabricated using some spare and some new components to attach the beamline to the NSTX vacuum vessel. Internal vacuum vessel armor using carbon tiles was added to protect the stainless steel vacuum vessel from beam impingement in the absence of plasma and interlock failure. To date, the NBI has operated to 80 keV and 5 MW and has injected requested power levels into NSTX plasmas with good initial results, including high beta and strong heating characteristics at full rated plasma current.

T. Stevenson; B McCormack; G.D. Loesser; M. Kalish; S. Ramakrishnan; L. Grisham; J. Edwards; M. Cropper; G. Rossi; A. von Halle; M. Williams

2002-01-18T23:59:59.000Z

436

Transient Self-Amplified Cerenkov Radiation with a Short Pulse Electron Beam  

SciTech Connect

An analytic and numerical examination of the slow wave Cerenkov free electron maser is presented. We consider the steady state amplifier configuration as well as operation in the selfamplified spontaneous emission (SASE) regime. The linear theory is extended to include electron beams that have a parabolic radial density inhomogeneity. Closed form solutions for the dispersion relation and modal structure of the electromagnetic field are determined in this inhomogeneous case. To determine the steady state response, a macro-particle approach is used to develop a set of coupled nonlinear ordinary differential equations for the amplitude and phase of the electromagnetic wave, which are solved in conjunction with the particle dynamical equations to determine the response when the system is driven as an amplifier with a time harmonic source. We then consider the case in which a fast rise time electron beam is injected into a dielectric loaded waveguide. In this case, radiation is generated by SASE, with the instability seeded by the leading edge of the electron beam. A pulse of radiation is produced, slipping behind the leading edge of the beam due to the disparity between the group velocity of the radiation and the beam velocity. Short pulses of microwave radiation are generated in the SASE regime and are investigated using particle-in-cell (PIC) simulations. The nonlinear dynamics are significantly more complicated in the transient SASE regime when compared with the steady state amplifier model due to the slippage of the radiation with respect to the beam. As strong self-bunching of the electron beam develops due to SASE, short pulses of superradiant emission develop with peak powers significantly larger than the predicted saturated power based on the steady state amplifier model. As these superradiant pulses grow, their pulse length decreases and forms a series of soliton-like pulses. Comparisons between the linear theory, macro-particle model, and PIC simulations are made in the appropriate regimes.

Poole, B R; Blackfield, D T; Camacho, J F

2009-01-22T23:59:59.000Z

437

Last Revised: 7/23/10 (Gades  

NLE Websites -- All DOE Office Websites (Extended Search)

Revised: 7/23/10 (Gades) Revised: 7/23/10 (Gades) Instructions for Requesting Dry Ice at the APS Dry Ice requests are handled by APS Detector Pool staff. Dry ice should be requested through the Detector Pool database, similar to how detectors are requested. Dry ice is only available during normal business hours. Since dry ice must be obtained from a building other than the APS, requests must be made in advance to ensure availability of a government vehicle for transporting dry ice. Access the Detector Pool database via the link below. Requestors will be taken to a log-in page similar to the log-in page for the ESAF system. https://beam.aps.anl.gov/pls/apsweb/wam0002.dds_main_menu The page can also be found on the Optics and Detector Group homepage (the "Submit a Detector

438

Polarization of fast particle beams by collisional pumping  

DOE Patents (OSTI)

The invention relates to method and apparatus for polarizing a fast beam of particles by collisional pumping, including generating a fast beam of particles, and generating a thick electron-spin-polarized medium positioned as a target for said beam, said medium being sufficiently thick to allow said beam to interact with said medium to produce collisional pumping whereby said particle beam becomes highly polarized.

Stearns, J.W.; Kaplan, S.N.; Pyle, R.V.; Anderson, L.W.; Schlachter, A.S.; Ruby, L.

1984-10-19T23:59:59.000Z

439

Laser power beaming to extend lives of GSO NiCd satellites  

DOE Green Energy (OSTI)

It is proposed that a ground-based laser can beam power to commercial communication satellites in geosynchronous orbit and reduce battery depth-of-discharge during eclipses. Two laser system designs are presented which have the capability of reducing battery discharge by 100%. Both utilize a steerable beam director, with a mirror diameter of 4 meters in one case and 8 meters in the other. Both also use an adaptive optics unit within the beam train to provide real-time corrections for wavefront distortions caused by atmospheric turbulence. The required system power output is in the range of 100 to 200 kW for a transmitted wavelength just under 900 nm. Laser power beaming can nearly double the remaining lifetime of a satellite that uses NiCd batteries. However, by the time such lasers become available, nearly all NiCd satellites will be replaced by NiH{sub 2} satellites, which stand to benefit much less from power beaming.

Monroe, D.K.

1993-12-31T23:59:59.000Z

440

Fermilab PXIE Beam Diagnostics Development and Testing at the HINS Beam Facility  

Science Conference Proceedings (OSTI)

Fermilab is planning the construction of a prototype front end of the Project X linac. The Project X Injector Experiment (PXIE) is expected to accelerate 1 mA CW H- beam up to 30 MeV. Some of the major goals of the project are to test a CW RFQ and H- source, a broadband bunch-by-bunch beam chopper and a low-energy superconducting linac. The successful characterization and operation of such an accelerator place stringent requirements on beamline diagnostics. These crucial beam measurements include bunch currents, beam orbit, beam phase, bunch length, transverse profile and emittance and beam halo and tails, as well as the extinction performance of the broadband chopper. This paper presents PXIE beam measurement requirements and instrumentation development plans. Presented are plans to test key instruments at the Fermilab High Intensity Neutrino Source (HINS) beam facility. Since HINS is already an operational accelerator, utilizing HINS for instrumentation testing will allow for quicker development of the required PXIE diagnostics.

Lebedev, V.A.; Shemyakin, A.V.; Steimel, J.; Wendt, M.; /Fermilab; Hanna, B.M.; Prost, L.R.; Scarpine, V.E.; /Fermilab

2012-05-01T23:59:59.000Z

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441

BEAM STOP DESIGN METHODOLOGY AND DESCRIPTION OF A NEW SNS BEAM STOP  

Science Conference Proceedings (OSTI)

The design of accelerator components such as magnets, accelerator cavities and beam instruments tends to be a fairly standardized and collective effort within the particle accelerator community with well established performance, reliability and, in some cases, even budgetary criteria. Beam stop design, by contrast, has been comparatively subjective historically with much more general goals. This lack of rigor has lead to a variety of facility implementations with limited standardization and minimal consensus on approach to development within the particle accelerator community. At the Spallation Neutron Source (SNS), for example, there are four high power beam stops in use, three of which have significantly different design solutions. This paper describes the design of a new off-momentum beam stop for the SNS. The technical description of the system will be complemented by a discussion of design methodology. This paper presented an overview of the new SNS HEBT off-momentum beam stop and outlined a methodology for beam stop system design. The new beam stop consists of aluminium and steel blocks cooled by a closed-loop forced-air system and is expected to be commissioned this summer. The design methodology outlined in the paper represents a basic description of the process, data, analyses and critical decisions involved in the development of a beam stop system.

Polsky, Yarom [ORNL; Plum, Michael A [ORNL; Geoghegan, Patrick J [ORNL; Jacobs, Lorelei L [ORNL; Lu, Wei [ORNL; McTeer, Stephen Mark [ORNL

2010-01-01T23:59:59.000Z

442

Indirectly sensing accelerator beam currents for limiting maximum beam current magnitude  

DOE Patents (OSTI)

A beam current limiter is disclosed for sensing and limiting the beam current in a particle accelerator, such as a cyclotron or linear accelerator, used in scientific research and medical treatment. A pair of independently operable capacitive electrodes sense the passage of charged particle bunches to develop an RF signal indicative of the beam current magnitude produced at the output of a bunched beam accelerator. The RF signal produced by each sensing electrode is converted to a variable DC voltage indicative of the beam current magnitude. The variable DC voltages thus developed are compared to each other to verify proper system function and are further compared to known references to detect beam currents in excess of pre-established limits. In the event of a system malfunction, or if the detected beam current exceeds pre-established limits, the beam current limiter automatically inhibits further accelerator operation. A high Q tank circuit associated with each sensing electrode provides a narrow system bandwidth to reduce noise and enhance dynamic range. System linearity is provided by injecting, into each sensing electrode, an RF signal that is offset from the bunching frequency by a pre-determined beat frequency to ensure that subsequent rectifying diodes operate in a linear response region. The system thus provides a large dynamic range in combination with good linearity. 6 figs.

Bogaty, J.M.; Clifft, B.E.; Bollinger, L.M.

1995-08-08T23:59:59.000Z

443

Indirectly sensing accelerator beam currents for limiting maximum beam current magnitude  

DOE Patents (OSTI)

A beam current limiter for sensing and limiting the beam current in a particle accelerator, such as a cyclotron or linear accelerator, used in scientific research and medical treatment. A pair of independently operable capacitive electrodes sense the passage of charged particle bunches to develop an RF signal indicative of the beam current magnitude produced at the output of a bunched beam accelerator. The RF signal produced by each sensing electrode is converted to a variable DC voltage indicative of the beam current magnitude. The variable DC voltages thus developed are compared to each other to verify proper system function and are further compared to known references to detect beam currents in excess of pre-established limits. In the event of a system malfunction, or if the detected beam current exceeds pre-established limits, the beam current limiter automatically inhibits further accelerator operation. A high Q tank circuit associated with each sensing electrode provides a narrow system bandwidth to reduce noise and enhance dynamic range. System linearity is provided by injecting, into each sensing electrode, an RF signal that is offset from the bunching frequency by a pre-determined beat frequency to ensure that subsequent rectifying diodes operate in a linear response region. The system thus provides a large dynamic range in combination with good linearity.

Bogaty, John M. (Lombard, IL); Clifft, Benny E. (Park Forest, IL); Bollinger, Lowell M. (Downers Grove, IL)

1995-01-01T23:59:59.000Z

444

Laser-driven relativistic electron beam interaction with solid dielectric  

SciTech Connect

The multi-frames shadowgraphy, interferometry and polarimetry diagnostics with sub-ps time resolution were used for an investigation of ionization wave dynamics inside a glass target induced by laser-driven relativistic electron beam. Experiments were done using the 50 TW Leopard laser at the UNR. For a laser flux of {approx}2 Multiplication-Sign 10{sup 18}W/cm{sup 2} a hemispherical ionization wave propagates at c/3. The maximum of the electron density inside the glass target is {approx}2 Multiplication-Sign 10{sup 19}cm{sup -3}. Magnetic and electric fields are less than {approx}15 kG and {approx}1 MV/cm, respectively. The electron temperature has a maximum of {approx}0.5 eV. 2D interference phase shift shows the 'fountain effect' of electron beam. The very low ionization inside glass target {approx}0.1% suggests a fast recombination at the sub-ps time scale. 2D PIC-simulations demonstrate radial spreading of fast electrons by self-consistent electrostatic fields.

Sarkisov, G. S.; Ivanov, V. V.; Leblanc, P.; Sentoku, Y.; Yates, K.; Wiewior, P.; Chalyy, O.; Astanovitskiy, A.; Bychenkov, V. Yu.; Jobe, D.; Spielman, R. B. [Raytheon Ktech, 1300 Eubank Blvd, Albuquerque, NM, 87123 (United States); Department of Physics, University of Nevada Reno, 5625 Fox Ave, Reno, NV, 89506 (United States); P.N. Lebedev Physics Institute, RAS, 53 Leninski Prospect, Moscow, 119991 (Russian Federation); Raytheon Ktech, 1300 Eubank Blvd, Albuquerque, NM, 87123 (Russian Federation)

2012-07-30T23:59:59.000Z