Physics of antimatter-matter reactions for interstellar propulsion (open access)

Physics of antimatter-matter reactions for interstellar propulsion

At the stage of the antiproton-nucleon annihilation chain of events relevant to propulsion the annihilation produces energetic charged pions and gamma rays. If annihilation occurs in a complex nucleus, protons, neutrons, and other nuclear fragments are also produced. The charge, number, and energy of the annihilation products are such that annihilation rocket engine concepts involving relatively low specific impulse (I/sub sp/ approx. = 1000 to 2000 s) and very high I/sub sp/ (3 x 10/sup 7/ s) appear feasible and have efficiencies on the order of 50% for annihilation energy to propulsion energy conversion. At I/sub sp/'s of around 15,000 s, however, it may be that only the kinetic energy of the charged nuclear fragments can be utilized for propulsion in engines of ordinary size. An estimate of this kinetic energy was made from known pieces of experimental and theoretical information. Its value is about 10% of the annihilation energy. Control over the mean penetration depth of protons into matter prior to annihilation is necessary so that annihilation occurs in the proper region within the engine. Control is possible by varying the antiproton kinetic energy to obtain a suitable annihilation cross section. The annihilation cross section at low energies is …
Date: August 22, 1986
Creator: Morgan, D.L. Jr.
Object Type: Article
System: The UNT Digital Library
Addition of bromine as a diagnostic gas to inertial confinement fusion target microspheres (open access)

Addition of bromine as a diagnostic gas to inertial confinement fusion target microspheres

Currently, direct fuel rho r measurements on Inertial Confinement Fusion (ICF) targets by neutron activation of the argon tracer gas mixed with the DT fuel would require a 100 fold increase in neutron yield. Bromine, on the other hand, has excellent properties for neutron activation analysis at neutron yields of 10two' to 10/sup 8/, when present at an internal pressure of from 0.1 to 0.2 atmospheres. Bromine addition is accomplished in a 2 furnace system using the dried-gel method of microsphere production. An upper furnace operated at 1500/sup 0/C is separated from a lower furnace by a cooled zone. The lower furnace is filled with bromine gas and operated at approximately 1250/sup 0/C. The upper furnace is the glass production furnace. The cooled zone in between the upper and lower furnace is to prevent the hot bromine gas from rising into the upper furnace. The microspheres pass through the cooled zone and immediately into the 1250/sup 0/C bromine furnace where the bromine permeates into the spheres.
Date: August 22, 1980
Creator: Morrison, R. L.
Object Type: Article
System: The UNT Digital Library
Numerical solution of the Schroedinger integral equation for dt. mu. Progress report (open access)

Numerical solution of the Schroedinger integral equation for dt. mu. Progress report

The Schroedinger Integral Equation is derived for an N-body system, and solutions for required Green's functions are obtained. The initial method of numerical solution has yielded the correct ground states and lower excited states of He (test case) and dt..mu... Steps are being taken to improve the numerical accuracy.
Date: August 22, 1986
Creator: Morgan, D.L. Jr.
Object Type: Report
System: The UNT Digital Library
Antiproton-hydrogen atom rearrangement-annihilation cross section (open access)

Antiproton-hydrogen atom rearrangement-annihilation cross section

For antiproton energies of several eV or less, annihilation in matter occurs through atomic rearrangement processes in which the antiproton becomes bound to a nucleus prior to annihilation. Existing calculations of the antiproton-hydrogen atom rearrangement cross section are semiclassical and employ the Born-Oppenheimer approximation. They also employ various arguments in regard to the behavior of the system when the Born-Oppenheimer approximation breaks down at small antiproton-proton separations. These arguments indicate that rearrangement is essentially irreversible. In the present study, a detailed investigation was made of the antiproton-hydrogen atom system when the Born-Oppenheimer approximation breaks down. The results of this study indicate that the previous arguments were approximately correct, but that there is a significant probability for rearrangement reversing prior to annihilation. This probability is estimated to be about 20%. 8 refs., 4 figs., 2 tabs.
Date: August 22, 1986
Creator: Morgan, D.L. Jr.
Object Type: Article
System: The UNT Digital Library
Microscopic approach to the generator coordinate method (open access)

Microscopic approach to the generator coordinate method

In this paper, we solve different theoretical problems associated with the calculation of the kernel occurring in the Hill-Wheeler integral equations within the framework of generator coordinate method. In particular, we extend the Wick's theorem to nonorthogonal Bogoliubov states. Expressions for the overlap between Bogoliubov states and for the generalized density matrix are also derived. These expressions are valid even when using an incomplete basis, as in the case of actual calculations. Finally, the Hill-Wheeler formalism is developed for a finite range interaction and the Skyrme force, and evaluated for the latter. 20 refs., 1 fig., 4 tabs.
Date: August 22, 1989
Creator: Haider, Q.; Gogny, D. & Weiss, M.S.
Object Type: Report
System: The UNT Digital Library
Fuel debris assessment for Three Mile Island Unit 2 (TMI-2) reactor recovery by gamma-ray and neutron dosimetry (open access)

Fuel debris assessment for Three Mile Island Unit 2 (TMI-2) reactor recovery by gamma-ray and neutron dosimetry

As a result of the accident on March 28, 1979, fuel debris was dispersed into the primary coolant system of the Three Mile Island Unit 2 (TMI-2) reactor. Location and quantification of fuel debris is essential for TMI-2 recovery. TMI-2 fuel debris assessments can be carried out nondestructively by neutron and gamma-ray dosimetry. Efforts to date have been directed toward fuel debris characterization of the makeup and purification demineralizers, will maintain reactor coolant water purity. Two highly specialized dosimetry methods were applied: solid state track recorder (SSTR) neutron dosimetry and continuous gamma-ray spectrometry. The most recent dosimetry results are reviewed and compared. To reduce the intense background radiation from /sup 137/Cs, the Si(Li) detector was surrounded by a 5.5 diameter lead shield 8'' shield in length. The spectral data were used to determine the intensity of the 2.18 MeV gamma ray from the fission product /sup 144/Ce. Assuming this fission product does not migrate out of the fuel, the quantity of /sup 144/Ce is directly related to the quantity of fuel present. Based on the observed source geometry and the measured flux of the /sup 144/Ce 2.18 MeV gamma rays, the fuel content of the A demineralizer was calculated to …
Date: August 22, 1983
Creator: Gold, R.; Roberts, J. H.; McNeece, J. P.; Kaiser, B. J.; Ruddy, F. H.; Preston, C. C. et al.
Object Type: Article
System: The UNT Digital Library
Electron impact ionization of heavy ions: some surprises (open access)

Electron impact ionization of heavy ions: some surprises

This paper reports the results of calculations of electron impact ionization cross sections for a variety of heavy ions using a distorted wave Born-exchange approximation. The target is described by a Hartree-Fock wavefunction. The scattering matrix element is represented by a triple partial wave expansion over incident, scattered, and ejected (originally bound) continuum states. These partial waves are computed in the potentials associated with the initial target (incident and scattered waves) and the residual ion (ejected waves). A Gauss integration was performed over the distribution of energy between the two final state continuum electrons. For ionization of closed d- and f-subshells, the ejected f-waves were computed in frozen-core term-dependent Hartree-Fock potentials, which include the strong repulsive contribution in singlet terms which arises from the interaction of an excited orbital with an almost closed shell. Ground state correlation was included in some calculations of ionization of d/sup 10/ subshells.
Date: August 22, 1986
Creator: Younger, S.M.
Object Type: Article
System: The UNT Digital Library
Physics considerations for tandem-mirror magnet design (open access)

Physics considerations for tandem-mirror magnet design

This lecture describes the physics considerations entering the magnet design of a quadrupole-stabilized, tandem-mirror system.
Date: August 22, 1983
Creator: Baldwin, D.E.
Object Type: Article
System: The UNT Digital Library
Time variations of fields in superconducting magnets and their effects on accelerators (open access)

Time variations of fields in superconducting magnets and their effects on accelerators

A report on the time dependence of magnetic fields in the superconducting magnets of the Fermilab Tevatron has been published. A field variation of order 1 gauss at the aperture radius is observed. Studies on both full sized Tevatron, dipoles and prototype magnets have been used to elucidate these effects. Explanations based on eddy currents in the coil matrix or on flux creep in the superconducting filaments are explored with these tests. Measurement results and techniques for controlling the effect based on new laboratory tests and the latest accelerator operation are presented. 9 refs., 4 figs.
Date: August 22, 1988
Creator: Herrup, D. A.; Syphers, M. J.; Johnson, D. E.; Johnson, R. P.; Tollestrup, A. V.; Hanft, R. W. et al.
Object Type: Article
System: The UNT Digital Library
Design and modelling of a 5 MeV radio frequency electron gun (open access)

Design and modelling of a 5 MeV radio frequency electron gun

The Accelerator Test Facility (ATF) at Brookhaven National Laboratory is a linac-laser complex for research into laser acceleration and for the generation of coherent radiation from electron beams. In order to achieve the design 50 MeV output emittance (..gamma..sigma/sub x/sigma/sub x/') of less than 3 /times/ 10/sup /minus/5/ m rad a high brightness electron gun is required. This paper describes computations and measurements made on a full scale brass model of a 1-1/2 cell, ..pi..-mode, resonant, disc loaded, radiofrequency gun structure which has been designed for this purpose. 7 refs., 9 figs., 6 tabs.
Date: August 22, 1988
Creator: Batchelor, K.; Sheehan, J. & Woodle, M.
Object Type: Report
System: The UNT Digital Library
Remedial measures plan for a spill of solvent refined coal liquid at the SRC pilot plant, Ft. Lewis, Washington. Final Report (open access)

Remedial measures plan for a spill of solvent refined coal liquid at the SRC pilot plant, Ft. Lewis, Washington. Final Report

On December 19, 1979, a spill of SRC liquid occurred during transfer of the liquid from a storage tank to sample drums. Approximately 2,300 gallons of fluid flowed into the floor of the tank farm and infiltrated into the porous and permeable gravels at the site. Because of concern for the possible impact of the SRC fluid on the quality of ground water, surface water, and water supply sources at and near the site, GMRC commissioned Radian to evaluate the problem and recommend specific measures to mitigate any known or anticipated impacts. This report presents the results of Radian's investigations. Although ground-water contamination apparently has occurred as a result of the December 19 spill, the contamination plume is localized to the vicinity of the SRC plant and Lake Sequalitchew. A contamination plume apparently is presently moving toward Lake Sequalitchew, but the two pump wells included in the Remedial Measures Plan will arrest this movement. These wells will be pumped until phenol concentrations in the groundwater fall to acceptable levels. The source of contamination at the spill is being cut off by excavation of the contaminated soil and sealing of the floor of the tank farm. No public water supplies are …
Date: August 22, 1980
Creator: Grimshaw, T.W. & Little, W.M.
Object Type: Report
System: The UNT Digital Library
Induction-linac based free-electron laser amplifiers for plasma heating (open access)

Induction-linac based free-electron laser amplifiers for plasma heating

We describe an induction-linac based free-electron laser amplifier that is presently under construction at the Lawrence Livermore National Laboratory. It is designed to produce up to 2 MW of average power at a frequency of 250 GHz for plasma heating experiments in the Microwave Tokamak Experiment. In addition, we shall describe a FEL amplifier design for plasma heating of advanced tokamak fusion devices. This system is designed to produce average power levels of about 10 MW at frequencies ranging form 280 to 560 GHz. 7 refs., 1 tab.
Date: August 22, 1988
Creator: Jong, R.A.
Object Type: Article
System: The UNT Digital Library
Training in test samples of superconducting cables for accelerator magnets (open access)

Training in test samples of superconducting cables for accelerator magnets

In the critical current measurement of some high current NbTi cables, the samples have to be ''trained'' by repeated quenching in order to obtain a usable voltage-current curve for I/sub c/ determination. This training behavior is most pronounced when the applied field is perpendicular to the wide face of the conductor and is strongly dependent on the copper-to-superconductor ratio and the clamping pressure. Data are given for SSC prototype cables as well as for HERA production conductors. Although a quantitative understanding of the experimental data is still lacking, some speculations regarding stability are presented. 8 refs., 7 figs.
Date: August 22, 1988
Creator: Ghosh, A. K.; Garber, M.; Robins, K. E. & Sampson, W. B.
Object Type: Article
System: The UNT Digital Library
Energy spread in SLC linac with Landau damping (open access)

Energy spread in SLC linac with Landau damping

The possibility of using Landau damping to reduce the growth of the beam size due to transverse wake fields has been known for some time. Recently K. Bane has calculated the effects of Landau damping for the SLC. The energy spread is then slowly removed so that at the end of the linac it has returned to the SLC specification of less than +0.5%. The purpose of the energy spread is to reduce the resonant driving of the tail of the bunch by the head. In this note the expected energy spreads within the beam are tabulated at various positions along the linac for use by those people designing momentum dependent equipment and for those interested in Landau damping.
Date: August 22, 1984
Creator: Seeman, John
Object Type: Report
System: The UNT Digital Library
Texas Register, Volume 11, Number 63, Pages 3708-3767, August 22, 1986 (open access)

Texas Register, Volume 11, Number 63, Pages 3708-3767, August 22, 1986

A weekly publication, the Texas Register serves as the journal of state agency rulemaking for Texas. Information published in the Texas Register includes proposed, adopted, withdrawn and emergency rule actions, notices of state agency review of agency rules, governor's appointments, attorney general opinions, and miscellaneous documents such as requests for proposals. After adoption, these rulemaking actions are codified into the Texas Administrative Code.
Date: August 22, 1986
Creator: Texas. Secretary of State.
Object Type: Journal/Magazine/Newsletter
System: The Portal to Texas History
Texas Register, Volume 5, Number 63, Pages 3433-3462, August 22, 1980 (open access)

Texas Register, Volume 5, Number 63, Pages 3433-3462, August 22, 1980

A weekly publication, the Texas Register serves as the journal of state agency rulemaking for Texas. Information published in the Texas Register includes proposed, adopted, withdrawn and emergency rule actions, notices of state agency review of agency rules, governor's appointments, attorney general opinions, and miscellaneous documents such as requests for proposals. After adoption, these rulemaking actions are codified into the Texas Administrative Code.
Date: August 22, 1980
Creator: Texas. Secretary of State.
Object Type: Journal/Magazine/Newsletter
System: The Portal to Texas History
Texas Attorney General Opinion: JM-537 (open access)

Texas Attorney General Opinion: JM-537

Document issued by the Office of the Attorney General of Texas in Austin, Texas, providing an interpretation of Texas law. It provides the opinion of the Texas Attorney General, Jim Mattox, regarding a legal question submitted for clarification; Payment of attorneys' fees, investigation costs, and expert witness fees under article 26.055 of the Texas Code of Criminal Procedure
Date: August 22, 1986
Creator: Texas. Attorney-General's Office.
Object Type: Text
System: The Portal to Texas History
Texas Attorney General Opinion: JM-538 (open access)

Texas Attorney General Opinion: JM-538

Document issued by the Office of the Attorney General of Texas in Austin, Texas, providing an interpretation of Texas law. It provides the opinion of the Texas Attorney General, Jim Mattox, regarding a legal question submitted for clarification; Duties and liabilities of a police officer who is also a firefighter emergency medical technician
Date: August 22, 1986
Creator: Texas. Attorney-General's Office.
Object Type: Text
System: The Portal to Texas History
Texas Attorney General Opinion: JM-943 (open access)

Texas Attorney General Opinion: JM-943

Document issued by the Office of the Attorney General of Texas in Austin, Texas, providing an interpretation of Texas law. It provides the opinion of the Texas Attorney General, Jim Mattox, regarding a legal question submitted for clarification; Construction of V.T.C.S. art.320f(RQ-14-34).
Date: August 22, 1988
Creator: Texas. Attorney-General's Office.
Object Type: Text
System: The Portal to Texas History
Studies of time dependence of fields in TEVATRON superconducting dipole magnets (open access)

Studies of time dependence of fields in TEVATRON superconducting dipole magnets

The time variation in the magnetic field of a model Tevatron dipole magnet at constant excitation current has been studied. Variations in symmetry allowed harmonic components over long time ranges show a log t behavior indicative of ''flux creep.'' Both short time range and long time range behavior depend in a detailed way on the excitation history. Similar effects are seen in the remnant fields present in full-scale Tevatron dipoles following current ramping. Both magnitudes and time dependences are observed to depend on details for the ramps, such as ramp rate, flattop duration, and number of ramps. In a few magnets, variations are also seen in symmetry unallowed harmonics. 9 refs., 10 figs.
Date: August 22, 1988
Creator: Hanft, R. W.; Brown, B. C.; Herrup, D. A.; Lamm, M. J.; McInturff, A. D. & Syphers, M. J.
Object Type: Article
System: The UNT Digital Library
D-Zero End Cap Calorimeter Annular Piping Analysis (open access)

D-Zero End Cap Calorimeter Annular Piping Analysis

In accoradnce with the ASME Code for Pressure Piping, B31 version of Chemical Plant and Petroleum Refinery Piping, ANSI/ASME B31.3-1984 Edition, the maximum allowable stress for 304 stainless steel piping is 25,500 psi. This 'Allowable Displacement Stress Range' value was calculated using equation (1a) found on page 16 of the above mentioned reference. Each of the lines that comprise the End Cap Calorimeter (BC) piping were modeled on ANSYS and the appropriate constraints were applied. This was done using the Piping Stress Analysis Module of ANSYS. The bending stresses and displacements due to the thermal contraction that occurs in cooling the piping from 300 K to 77 K were calculated by ANSYS. The seven lines involved and their maximum bending stresses are as follows: (1) Rupture Disc - Maximum bending stress is 8335 psi; (2) Argon Relief - Maximum bending stress is 12,619 psi; (3) Gaseous Argon Supply - Maximum bending stress is 5399 psi; (4) Liquid Nitrogen Cooldown Supply - Maximum bending stress is 7049 psi; (5) Liquid Nitrogen Operating Supply - Maximum bending stress is 5774 psi; (6) Nitrogen Exhaust - Maximum bending stress is 1826 psi; and (7) Argon/Nitrogen Vent - Maximum bending stress is 48,364 psi. …
Date: August 22, 1988
Creator: Kurita, C. H.
Object Type: Report
System: The UNT Digital Library
Limits on likesign dilepton production in. nu. /sub. mu. / interactions (open access)

Limits on likesign dilepton production in. nu. /sub. mu. / interactions

We have searched for the production of likesign dilepton events (nu/sub ..mu../ + Ne ..-->.. ..mu../sup -/ + e/sup -/ + ...) in a wideband neutrino beam at Fermilab using the 15-ft bubble chamber. We observe no signal above the background arising from conventional sources. We set 90% confidence level upper limits for the production rates of (nu/sub ..mu../ + Ne ..-->.. ..mu../sup -/ + e/sup -/ + ...)/ (nu/sub ..mu../ + Ne ..-->.. ..mu../sup -/ + ...) < 0.76 x 10/sup -4/ and (nu/sub ..mu../ + Ne ..-->.. ..mu../sup -/ + e/sup -/ + ...)/ (nu/sub ..mu../ + Ne ..-->.. ..mu../sup -/ + e/sup +/ + ...) < 5.3 x 10/sup -2/.
Date: August 22, 1985
Creator: Baker, N.J.
Object Type: Article
System: The UNT Digital Library
Compact Torus plasma ring accelerator: a new type driver for inertial confinement fusion (open access)

Compact Torus plasma ring accelerator: a new type driver for inertial confinement fusion

We discuss the acceleration of magnetically-confined plasma rings to provide a driver for ICF. The acceleration of plasma rings is predicted to be efficient and following focusing, to generate ion-bombardment power in the range 10/sup 15/ to 10/sup 16/ W/cm/sup 2/ at a total deposition energy of multimegajoules. The simplicity of plasma ring accelerator suggests that a 5 MJ (on target) driver would cost in the range 1 to 5 $/joule. First experimental tests of the accelerator are described.
Date: August 22, 1986
Creator: Hartman, C. W.; Eddleman, J. L.; Hammer, J. H. & Meeker, D. L.
Object Type: Article
System: The UNT Digital Library
Flux creep in a TEVATRON cable (open access)

Flux creep in a TEVATRON cable

We have measured the slow magnetization decay of a short sample (2.3 cm) of Tevatron cable in fields up to 0.3 T. The special susceptometer in development for these measurements is based on a commercial SQUID and is described in detail. The observed decay is logarithmic in time as expected from flux creep in the NbTi filaments. A strong correlation was found between the decay and the magnetization status of the sample. It is too early yet to present a quantitative correlation between what we observed and the decay observed in the sextupole component of Tevatron dipoles. The detailed understanding of this phenomenon may be instrumental in guiding the search for efficient superconducting synchrotron operational procedures. 3 refs., 5 figs.
Date: August 22, 1988
Creator: Kuchnir, M. & Tollestrup, A.V.
Object Type: Article
System: The UNT Digital Library