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Title: QUARTERLY STATUS REPORT OF THE LASL CONTROLLED THERMONUCLEAR RESEARCH PROGRAM FOR PERIOD ENDING AUGUST 20, 1960

Abstract

; : 5 = 8 ; < 8 ; 7 : 9 ; ; plasma density at the input cusp was increased by moving the gun closer to the P.F. and increasing the amount of neutral gas admitted to the gwn. As a result the input cusp was opened to beta = 1 at 2000 gauss and a beta = 1 region contained for approximately 30 mu sec. The contained plasma appeared to be uncomfortably close to the chamber walls. A larger apparatus in the form of a caulked picket fence is being designed to remedy this difficulty. In the skew-trapping experiment, measurements showed complete reflection of the off-axis input beam by the far mirror. A contained beam was not observed. However, there is evidence that projectm- g portions of the vacuum chamber seriously intercept the beam. Potential probes in a hydromagnetic gun were used to measure the induced radial voltage as the sheath sweeps B/sub tt/ past the probe. The plasma velocity deduced from this voltage and the magnitude of B/sub theta / was in excellent agreement with direct measurements. Differential probe measurements showed that the radial voltage drop along the sheath occurs mostly within 3 mm of themore » center electrode, indicating a cathode drop similar to that of classical glow discharges. The large toroidal discharge, Perhapsatron S-5 Zeus, was put into successful operation. Measurements showed that the pinch current agrees approximately with that predicted on the basis of previous experience. Neutron bursts of about 10/sup 8/ were obtained, but tests at voltages higher than 17.5 kv were terminated by failure of the quartz torus. The microwave-scattering experiment was improved by the application of a microwave phase-shift interferometer in order to measure the electron density. The measurements showed that the density attained was too low to produce a detectable scattered signal in the receiver. Steps are being taken, therefore, to improve the r-f ionization system. Parts are being ordered to enable a search for radiation scattered by collective ion oscillations. A technique was developed for measuring the electron temperature as a function of time on a single discharge in Scylla. It was found that the temperature during a given half-cycle of compression field peaks later than B/sub z/, as would be expected from a simple model of adiabatic compression and collisional energy exchange between electrons and ions. With preionized operation, soft x rays were not produced on the first half-cycle for +B/sub 0/, but appeared for zero and negative bias fields. There is thus a striking independence of the soft x-ray and neutron signals, since the latter do not appear for B/sub 0/ = 0. This independence also occurs in crowbarred operation in which the neutron pulse is extended while the x-ray signal is not. A vacuum x-ray spectrometer using beryl diffraction crystals is being put into operation. It will be used for the direct measurement of the Scylla soft x-ray spectrum. The assumption that the Scylla ion and electron temperatures can be accounted for by adiabatic compression was tested by means of a simple mathematical model. It was assumed that the only two processes operating were adiabatic compression and collisional interchange of energy between the ions and electrons. This model can account for the ion and electron temperatures (1.3 kev and 240 ev, respectively) at peak compression only if the electron-ion relaxation time is greater than three times the Spitzer value. In the orthogonal-pinch experiment, magnetic studies of a deuterium discharge were continued with emphasis on external field and flux measurements. Preliminary calculations of plasma radius vs. time are being made using the experimental data. Scaling of the physical dimensions and a reduction in the mirror ratio leads to larger neutron yields extending in time throughout a B/sub z/ zero. The possible causes of the events leading to the onset of field intermixing are considered to be of basic importance. Electrostatic probes were applied in the Ixion experiment to determine the radial potential distribution. The results showed a re« less

Authors:
Publication Date:
Research Org.:
Los Alamos Scientific Lab., N. Mex.
OSTI Identifier:
4129355
Report Number(s):
LAMS-2464
NSA Number:
NSA-14-026323
DOE Contract Number:  
W-7405-ENG-36
Resource Type:
Technical Report
Resource Relation:
Other Information: Orig. Receipt Date: 31-DEC-60
Country of Publication:
United States
Language:
English
Subject:
PHYSICS; ALUMINUM SILICATES- BERYL- BERYLLIUM SILICATES- CONFINEMENT- CRYSTALS- DIFFRACTION- ELECTRIC DISCHARGES- ELECTRONS- INTERACTIONS- IONIZATION- IONS- MAGNETIC FIELDS- MEASURED VALUES- MINERALS- NEUTRONS- PINCH- PLASMA- PRESSURE- PULSES- RARE EARTHS- SCYLLA- SIGNALS- SPECTROMETERS- TEMPERATURE- THERMONUCLEAR DEVICES- VACUUM- X RADIATION; BEAMS- CONFIGURATION- CONFINEMENT- CUSP- CUSPED GEOMETRIES- DENSITY- GASES- MAGNETIC FIELDS- MEASURED VALUES- PARTICLE SOURCES- PLANNING- PLASMA- PRESSURE- SURFACES- THERMODYNAMICS- THERMONUCLEAR DEVICES- VESSELS; BEAMS- CONFINEMENT- MAGNETIC MIRRORS- MEASURED VALUES-

Citation Formats

Glasstone, S. comp. and ed. QUARTERLY STATUS REPORT OF THE LASL CONTROLLED THERMONUCLEAR RESEARCH PROGRAM FOR PERIOD ENDING AUGUST 20, 1960. United States: N. p., 1960. Web.
Glasstone, S. comp. and ed. QUARTERLY STATUS REPORT OF THE LASL CONTROLLED THERMONUCLEAR RESEARCH PROGRAM FOR PERIOD ENDING AUGUST 20, 1960. United States.
Glasstone, S. comp. and ed. Thu . "QUARTERLY STATUS REPORT OF THE LASL CONTROLLED THERMONUCLEAR RESEARCH PROGRAM FOR PERIOD ENDING AUGUST 20, 1960". United States.
@article{osti_4129355,
title = {QUARTERLY STATUS REPORT OF THE LASL CONTROLLED THERMONUCLEAR RESEARCH PROGRAM FOR PERIOD ENDING AUGUST 20, 1960},
author = {Glasstone, S. comp. and ed.},
abstractNote = {; : 5 = 8 ; < 8 ; 7 : 9 ; ; plasma density at the input cusp was increased by moving the gun closer to the P.F. and increasing the amount of neutral gas admitted to the gwn. As a result the input cusp was opened to beta = 1 at 2000 gauss and a beta = 1 region contained for approximately 30 mu sec. The contained plasma appeared to be uncomfortably close to the chamber walls. A larger apparatus in the form of a caulked picket fence is being designed to remedy this difficulty. In the skew-trapping experiment, measurements showed complete reflection of the off-axis input beam by the far mirror. A contained beam was not observed. However, there is evidence that projectm- g portions of the vacuum chamber seriously intercept the beam. Potential probes in a hydromagnetic gun were used to measure the induced radial voltage as the sheath sweeps B/sub tt/ past the probe. The plasma velocity deduced from this voltage and the magnitude of B/sub theta / was in excellent agreement with direct measurements. Differential probe measurements showed that the radial voltage drop along the sheath occurs mostly within 3 mm of the center electrode, indicating a cathode drop similar to that of classical glow discharges. The large toroidal discharge, Perhapsatron S-5 Zeus, was put into successful operation. Measurements showed that the pinch current agrees approximately with that predicted on the basis of previous experience. Neutron bursts of about 10/sup 8/ were obtained, but tests at voltages higher than 17.5 kv were terminated by failure of the quartz torus. The microwave-scattering experiment was improved by the application of a microwave phase-shift interferometer in order to measure the electron density. The measurements showed that the density attained was too low to produce a detectable scattered signal in the receiver. Steps are being taken, therefore, to improve the r-f ionization system. Parts are being ordered to enable a search for radiation scattered by collective ion oscillations. A technique was developed for measuring the electron temperature as a function of time on a single discharge in Scylla. It was found that the temperature during a given half-cycle of compression field peaks later than B/sub z/, as would be expected from a simple model of adiabatic compression and collisional energy exchange between electrons and ions. With preionized operation, soft x rays were not produced on the first half-cycle for +B/sub 0/, but appeared for zero and negative bias fields. There is thus a striking independence of the soft x-ray and neutron signals, since the latter do not appear for B/sub 0/ = 0. This independence also occurs in crowbarred operation in which the neutron pulse is extended while the x-ray signal is not. A vacuum x-ray spectrometer using beryl diffraction crystals is being put into operation. It will be used for the direct measurement of the Scylla soft x-ray spectrum. The assumption that the Scylla ion and electron temperatures can be accounted for by adiabatic compression was tested by means of a simple mathematical model. It was assumed that the only two processes operating were adiabatic compression and collisional interchange of energy between the ions and electrons. This model can account for the ion and electron temperatures (1.3 kev and 240 ev, respectively) at peak compression only if the electron-ion relaxation time is greater than three times the Spitzer value. In the orthogonal-pinch experiment, magnetic studies of a deuterium discharge were continued with emphasis on external field and flux measurements. Preliminary calculations of plasma radius vs. time are being made using the experimental data. Scaling of the physical dimensions and a reduction in the mirror ratio leads to larger neutron yields extending in time throughout a B/sub z/ zero. The possible causes of the events leading to the onset of field intermixing are considered to be of basic importance. Electrostatic probes were applied in the Ixion experiment to determine the radial potential distribution. The results showed a re},
doi = {},
journal = {},
number = ,
volume = ,
place = {United States},
year = {1960},
month = {9}
}

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