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Tritium effects on germ cells and fertility (open access)

Tritium effects on germ cells and fertility

Primordial oocytes in juvenile mice show acute gamma-ray LD/sub 50/ as low as 6 rad. This provides opportunities for determining dose-response relations at low doses and chronic exposure in the intact animal - conditions of particular interest for hazard evaluation. Examined in this way, /sup 3/HOH in body water is found to kill murine oocytes exponentially with dose, the LD/sub 50/ level for chronic exposure being only 2..mu..Ci/ml (delivering 0.4 rad/day). At very low doses and dose rates, where comparisons between tritium and other radiations are of special significance for radiological protection, the RBE of tritium compared with /sup 60/Co gamma radiation reaches approximately 3. Effects on murine fertility from tritium-induced oocyte loss have been quantified by reproductive capacity measurements. Chronic low-level exposure has been examined also in three primate species - squirrel, rhesus, and bonnet monkeys. In squirrel monkeys the ovarian germ-cell supply is 99% destroyed by the time of birth from prenatal exposure to body-water levels of /sup 3/HOH (administered in maternal drinking water) of only 3 ..mu..Ci/ml, the LD/sub 50/ level being 0.5 ..mu..Ci/ml (giving 0.1 rad/day), one fourth that in mice. Though not completely ruled out, similar high sensitivity of female germ cells has not been …
Date: November 19, 1982
Creator: Dobson, R.L.; Kwan, T.C. & Straume, T.
System: The UNT Digital Library
Acceleration of magnetized plasma rings (open access)

Acceleration of magnetized plasma rings

One scheme is considered, acceleration of a ring between coaxial electrodes by a B/sub theta/ field as in a coaxial rail-gun. If the electrodes are conical, a ring accelerated towards the apex of the cone undergoes self-similar compression (focussing) during acceleration. Because the allowable acceleration force F/sub a/ = kappa U/sub m//R (kappa < 1) increases as R/sup -2/, the accelerating distance for conical electrodes is considerably shortened over that required for coaxial electrodes. In either case however, since the accelerating flux can expand as the ring moves, most of the accelerating field energy can be converted into kinetic energy of the ring leading to high efficiency.
Date: November 16, 1982
Creator: Hartman, D.; Eddleman, J. & Hammer, J. H.
System: The UNT Digital Library
High-explosive-driven delay line pulse generator (open access)

High-explosive-driven delay line pulse generator

The inclusion of a delay line circuit into the design of a high-explosive-driven generator shortens the time constant of the output pulse. After a brief review of generator concepts and previously described pulse-shortening methods, a geometry is presented which incorporates delay line circuit techcniques into a coil generator. The circuit constants are adjusted to match the velocity of the generated electromagnetic wave to the detonation velocity of the high explosive. The proposed generator can be modeled by adding a variable inductance term to the telegrapher's equation. A particular solution of this equation is useful for exploring the operational parameters of the generator. The duration of the electromagnetic pulse equals the radial expansion time of the high-explosive-driven armature until it strikes the coil. Because the impedance of the generator is a constant, the current multiplication factor is limited only by nonlinear effects such as voltage breakdown, diffusion, and compression at high energies.
Date: November 15, 1982
Creator: Shearer, J.W.
System: The UNT Digital Library
Dynamic gas flow during plasma operation in TMX-U (open access)

Dynamic gas flow during plasma operation in TMX-U

Control of the neutral density outside of the plasma radius is essential for proper operation of the various plasma configurations in TMX-U. TMX-U excess-beam, stream-gun, gas-box, and beam-reflux gases are pumped internally in regions defined by 73/sup 0/ Ti-gettered liners and warm Ti-gettered plasma liners. The array of fast and slow ion gauges - a large TMX-U diagnostic - has been used to measure the dynamic pressure in many of the liner-defined regions on three time scales. The natural divertor action, or plasma pump effect, of mirror plasmas has been measured using the ion gauge diagnostics on a fast time scale during operation of TMX-U with ECRH start-up. Routine operation of TMX-U is enhanced by the ability to verify the effectiveness of gettering and to locate leaks using pressure data collected on the two slow time scales. A computer code, DYNAVAC 6, which treats TMX-U as a set of conductance-coupled regions with pumping and sources in each region, has been used to successfully model the overall gas dynamics during all phases of TMX-U operation.
Date: November 12, 1982
Creator: Pickles, W. L.; Carter, M. R.; Clower, C. A.; Drake, R. P.; Hunt, A. L.; Simonen, T. C. et al.
System: The UNT Digital Library
Airborne-temperature-survey maps of heat-flow anomalies for exploration geology (open access)

Airborne-temperature-survey maps of heat-flow anomalies for exploration geology

Precise airborne temperature surveys depicted small predawn surface temperature differences related to heat flow anomalies at the Long Valley, California, KGRA. Zones with conductive heat flow differences of 45 +- 16 ..mu..cal/cm/sup 2/(s) has predawn surface temperature differences of 1.4 +- 0.3/sup 0/C. The warmer zones had hot water circulating in a shallow (less than 60-m-deep) aquifer. Hot water is a useful geochemical indicator of geothermal and mineral resource potential. The precise airborne temperature survey method recorded redundant infrared scanner signals at two wavelengths (10 to 12 ..mu..m and 4.5 to 5.5 ..mu..m) and two elevations (0.3 km and 1.2 km). Ground thermistor probes recorded air and soil temperatures during the survey overflights. Radiometric temperatures were corrected for air-path and reflected-sky-radiation effects. Corrected temperatures were displayed in image form with color-coded maps which depicted 0.24/sup 0/C temperature differences. After accounting for surficial features on the corrected predawn thermal imagery, there remained several anomalous zones. These zones had high temperature gradients at depths from 6 to 30 m, compared to the temperature gradients in nearby areas.
Date: November 10, 1982
Creator: Del Grande, N.K.
System: The UNT Digital Library
34th Geothermal Coordinating Group Meeting (open access)

34th Geothermal Coordinating Group Meeting

Chairman William Ogle said the overall purpose of the meeting was to consider how the US government, and the Division of Geothermal Energy in particular, might apply its geothermal effort more effectively. Given the present situation, how does Uncle Sam make the best possible effort? On this theme, there are 4 main subquestions: (1) what government support is needed? (2) how can we improve cooperation between industry, the national laboratories, universities, and industries, and does it matter? (3) how do we transfer technology to industry? (4) What should the technical aims be for the next year or so?
Date: November 9, 1982
Creator: unknown
System: The UNT Digital Library
Towards a systematic format for (seismic) equipment qualification standards (open access)

Towards a systematic format for (seismic) equipment qualification standards

As part of technical assistance to the US Nuclear Regulatory Commission (NRC, 1), a systematic format for seismic equipment qualification (EQ) was initiated. This format consists of thirty issues associated with seismic EQ. Each issue was considered as a Category of Possible Seismic EQ Requirements and Criteria. That is, seismic EQ standards might be (but presently are not formulated in terms of requirements and criteria that address each of the thirty issues. Each of the thirty issues was ranked and a minimum set identified. The current requirements in existing NRC and national standards were also evaluated against this common set of issues, and they were estimated to score 60 out of 100 overall. It is believed that the systematic format exhibited in this paper can be of assistance in obtaining a broader and more complete perspective on seismic EQ issues. This format (but especially the technique) may also be of interest in non-seismic EQ since many of the issues are common.
Date: November 9, 1982
Creator: Smith, P.D.
System: The UNT Digital Library
Division of Materials Science (DMS) meeting presentation (open access)

Division of Materials Science (DMS) meeting presentation

Materials preparation techniques are listed. Materials preparation capabilities are discussed for making BeF/sub 2/ glasses and other materials. Materials characterization techniques are listed. (DLC)
Date: November 8, 1982
Creator: Cline, C. F. & Weber, M. J.
System: The UNT Digital Library
Multi-megawatt neutral beams for MFTF-B (open access)

Multi-megawatt neutral beams for MFTF-B

Multi-megawatt neutral-beam sources have successfully made the transition from prototype to commercial production, with some operational improvements due to the commercialization. Long pulse source operation results will be available soon.
Date: November 8, 1982
Creator: Kerr, R. G.
System: The UNT Digital Library
Radioactive ions beams for studying astrophysical nuclear reactions (open access)

Radioactive ions beams for studying astrophysical nuclear reactions

Beams of radioactive ions can be produced as secondary beams following the interaction of conventional accelerator beams with suitable targets. For example we have used beams of /sup 7/Li and /sup 12/C from an EN Tandem Van de Graaff accelerator to produce beams of /sup 7/Be and /sup 13/N via the (p,n) and (d,n) reactions respectively. These beams are focused by a system of magnetic quadrupole lenses to a secondary target. Reactions of such nuclides, especially proton capture and (p,..cap alpha..) reactions, are of interest in solar physics and in the CNO multi-cycle in massive stars. Progress toward the measurement of these reactions is discussed.
Date: November 4, 1982
Creator: Haight, R. C.; Mathews, G. J.; White, R. M.; Aviles, L. A. & Woodard, S. E.
System: The UNT Digital Library
Application of magnetic pulse compression to the grid system of the ETA/ATA accelerator (open access)

Application of magnetic pulse compression to the grid system of the ETA/ATA accelerator

During the past year, several magnetic pulse compression systems have been built and applied to the ETA accelerator. In view of their excellent performance, a non-linear magnetic system has been adopted for the ATA grid drive in place of the spark gap driven Blumlein. The magnetic system will give us a much higher reliability and greater flexibility by being independent of the high pressure gas blown system. A further advantage of this system will be the capability of achieving higher rep-rates in case of a future upgrade. System design and performance under burst mode will be described.
Date: November 2, 1982
Creator: Birx, D. L.; Cook, E. G.; Reginato, L. L.; Schmidt, J. A. & Smith, M. W.
System: The UNT Digital Library
Fast pressure measurements for the TMX-U fusion experiment (open access)

Fast pressure measurements for the TMX-U fusion experiment

The pressure on the boundary of the Lawrence Livermore National Laboratory's (LLNL) tandem mirror (TMX-U) plasma experiment is difficult to trace for several reasons: (1) the TMX-U boundary is in the high vacuum range (10/sup -5/ to 10/sup -6/ Pa) and requires an ionization gauge; (2) the boundary includes high-energy neutral particles and radiation, so the gauge must be optically baffled from the plasma; (3) the gauge must be shielded from the magnetic flux density of 0.03 T; (4) maximum conductance to the gauge must be preserved so that the time response remains about 1 ms; (5) a fast electrical circuit is required to measure the small ion-current changes at a rate consistent with the geometrical and experimental time constant of 1 ms. We have developed solutions to these limitations, including fast ionization gauge (FIG) circuitry for the remote gauge operation and the CAMAC system for recording the pressure-time history in the TMX-U computer data base. We also give some examples of actual fast pressure histories during plasma operation.
Date: November 2, 1982
Creator: Hunt, A.L.; Coffield, F.E. & Pickles, W.L.
System: The UNT Digital Library
3 mm Anisotropy Measurement: On the Quadrupole Component in theCosmic Background Radiation (open access)

3 mm Anisotropy Measurement: On the Quadrupole Component in theCosmic Background Radiation

We have mapped the large-scale anisotropy in the cosmic background radiation at 3 mm wavelength using a liquid-helium-cooled balloon-borne radiometer sensitive enough to detect the dipole in one gondola rotation (1 minute). Statistical errors on the dipole and quadrupole components are below 0.1 mK with less than 0.1 m K galactic contribution. We find a dipole consistent with previous measurements but disagree with recent quadrupole reports. The measurement is also useful in searching for spectral distortions.
Date: November 1, 1982
Creator: Lubin, Philip M.; Epstein, Gerald L. & Smoot, George F.
System: The UNT Digital Library
Advanced medical accelerator design (open access)

Advanced medical accelerator design

This report describes the design of an advanced medical facility dedicated to charged particle radiotherapy and other biomedical applications of relativistic heavy ions. Project status is reviewed and some technical aspects discussed. Clinical standards of reliability are regarded as essential features of this facility. Particular emphasis is therefore placed on the control system and on the use of technology which will maximize operational efficiency. The accelerator will produce a variety of heavy ion beams from helium to argon with intensities sufficient to provide delivered dose rates of several hundred rad/minute over large, uniform fields. The technical components consist of a linac injector with multiple PIG ion sources, a synchrotron and a versatile beam delivery system. An overview is given of both design philosophy and selected accelerator subsystems. Finally, a plan of the facility is described.
Date: November 1, 1982
Creator: Alonso, J. R.; Elioff, T. & Garren, A.
System: The UNT Digital Library
Advanced test accelerator: a high-current induction linac (open access)

Advanced test accelerator: a high-current induction linac

The Advanced Test Accelerator (ATA) is a linear induction accelerator being built at Lawrence Livermore National Laboratory. The aim of the ATA, together with its associated physics program is the research and development necessary to resolve whether particle-beam propagation is possible. Since the accelerator is the tool needed to do the basic propagation experiment, many of its design parameters are specified by the physics. The accelerator parameters are: 50 MeV, 10 kA, 70 ns pulse width (FWHM), and a 1 kHz rep-rate during a ten-pulse burst. In addition, beam quality and pulse-to-pulse repeatability must be excellent. The unique features of the accelerator are the 10 kA beam and the 1 kHz burst frequency.
Date: November 1, 1982
Creator: Cook, E.G.; Birx, D.L. & Reginato, L.L.
System: The UNT Digital Library
Betatrons with kiloampere beams (open access)

Betatrons with kiloampere beams

Although the magnetic-induction method of acceleration used in the betatron is inherently capable of accelerating intense particle beams to high energy, many beam-instability questions arise when beams in the kilo-ampere range are considered. The intense electromagnetic fields produced by the beam, and by the image currents and charges induced in the surrounding walls, can produce very disruptive effects. Several unstable modes of collective oscillation are possible; the suppression of any one of them usually involves energy spread for Landau damping and careful design of the electrical character of the vacuum chamber. The various design criteria are often mutually incompatible. Space-charge detuning can be severe unless large beam apertures and high-energy injection are used. In order to have an acceptably low degree of space-charge detuning in the acceleration of a 10-kilo-ampere electron beam, for example, an injection energy on the order of 50 MeV seems necessary, in which case the forces due to nearby wall images can have a larger effect than the internal forces of the beam. A method of image compensation was invented for reducing the net image forces; it serves also to decrease the longitudinal beam impedance and thus helps alleviate the longitudinal instability as well. In order …
Date: November 1, 1982
Creator: Peterson, J. M.
System: The UNT Digital Library
Brownian-Dynamics Computer Simulations of a One-Dimensional Polymer Model. I. Simple Potentials (open access)

Brownian-Dynamics Computer Simulations of a One-Dimensional Polymer Model. I. Simple Potentials

Brownian Dynamics computer simulation results are presented on a simple one-dimensional polymer model which contains the essential features of rotational angle flexibility. Comparison is made with analytical treatments of the model.
Date: November 1982
Creator: Cook, Robert & Livornese, Lawrence L.
System: The UNT Digital Library
Challenge of ultra-high energies: ultimate limits, possible directions of technology, an approach to collective acceleration (open access)

Challenge of ultra-high energies: ultimate limits, possible directions of technology, an approach to collective acceleration

At the request of Panel Chairman Amaldi, the oral version of this rpeort was largely devoted to a recapitulation and critique of the various methods of collective acceleration, including plasma-laser methods, which had been presented at the meeting.
Date: November 1, 1982
Creator: Keefe, D.
System: The UNT Digital Library
Charge collection in silicon strip detectors (open access)

Charge collection in silicon strip detectors

The use of position sensitive silicon detectors as very high resolution tracking devices in high energy physics experiments has been a subject of intense development over the past few years. Typical applications call for the detection of minimum ionizing particles with position measurement accuracy of 10 ..mu..m in each detector plane. The most straightforward detector geometry is that in which one of the collecting electrodes is subdivided into closely spaced strips, giving a high degree of segmentation in one coordinate. Each strip may be read out as a separate detection element, or, alternatively, resistive and/or capacitive coupling between adjacent strips may be exploited to interpolate the position via charge division measrurements. With readout techniques that couple several strips, the numer of readout channels can, in principle, be reduced by large factors without sacrificing the intrinsic position accuracy. The testing of individual strip properties and charge division between strips has been carried out with minimum ionizing particles or beams for the most part except in one case which used alphs particless scans. This paper describes the use of a highly collimated MeV proton beam for studies of the position sensing properties of representative one dimensional strip detectors.
Date: November 1, 1982
Creator: Kraner, H. W.; Beuttenmuller, R.; Ludlam, T.; Hanson, A. L.; Jones, K. W.; Radeka, V. et al.
System: The UNT Digital Library
Charge-exchange products of BEVALAC projectiles (open access)

Charge-exchange products of BEVALAC projectiles

There is a substantial production of fragments of all masses lighter than the projectile, such fragments being centered in a narrow region of velocity space around the beam velocity. The exciting studies about anomalons deal with the curious enhanced reactivity of some of these secondary fragments. I direct attention here to the rather rare fragments of the same mass number as the projectile but differing in charge by one unit. We also keep track, as a frame of reference, of the products that have lost one neutron from the projectile.
Date: November 1, 1982
Creator: Rasmussen, J.
System: The UNT Digital Library
Contribution of twist-4 to the Q/sup 2/ evolution of F/sub 2/ and xF/sub 3/: an experimental review (open access)

Contribution of twist-4 to the Q/sup 2/ evolution of F/sub 2/ and xF/sub 3/: an experimental review

The status of the theoretical and experimental study of higher twist contributions to the nucleon structure functions is reviewed. After noting the dangers of combining experiments with widely different <Q/sup 2/> and targets, emphasis is placed on those results coming from a single experiment. The values of ..lambda.., the twist-2 scale factor, and h/sub 4/, the coefficient of x/Q/sup 2/(1-x), are restricted by: ..lambda.. <0.44 GeV and -0.2 <h/sub 4/<0.5 GeV/sup 2/.
Date: November 1, 1982
Creator: Morfin, J.G.
System: The UNT Digital Library
Cost of high-field Nb/sub 3/Sn and NbTi accelerator dipole magnets (open access)

Cost of high-field Nb/sub 3/Sn and NbTi accelerator dipole magnets

Future high-energy proton accelerators will likely require very high magnetic fields if the size of the accelerator and associated experimental areas are to be limited to dimensions that can be accomodated by the terrain at convenient sites. Two commercially available superconductors can be used to produce magnetic fields of 10T or more. The first is Nb/sub 3/Sn, which can operate in pool boiling helium at 4.4 K. The second is NbTi, which must be cooled to about 1.9 K in superfluid helium. In this paper the costs of 5-cm-bore, 6-m-long magnets made of these materials and operating at fields from 5 to 11 T are compared. At 10 T the capital cost of a NbTi coil operating in superfluid helium is 35% less than the cost of a Nb/sub 3/Sn coil. The cost of the NbTi coil is still 10% less after the differential operating costs that will be incurred over the life of the accelerator are included. The results presented here are a summary of a detailed analysis of these costs given in a separate report.
Date: November 1, 1982
Creator: Hassenzahl, W.V.
System: The UNT Digital Library
Damage and in-situ annealing during ion implantation (open access)

Damage and in-situ annealing during ion implantation

Formation of amorphous (..cap alpha..) layers in Si during ion implantation in the energy range 100 keV-11 MeV and temperature range liquid nitrogen (LN)-100/sup 0/C has been investigated. Cross-sectional transmission electron microscopy (XTEM) shows that buried amorphous layers can be created for both room temperature (RT) and LN temperature implants, with a wider 100 percent amorphous region for the LN cooled case. The relative narrowing of the ..cap alpha.. layer during RT implantation is attributed to in-situ annealing. Implantation to the same fluence at temperatures above 100/sup 0/C does not produce ..cap alpha.. layers. To further investigate in situ annealing effects, specimens already containing buried ..cap alpha.. layers were further irradiated with ion beams in the temperature range RT-400/sup 0/C. It was found that isolated small ..cap alpha.. zones (less than or equal to 50 diameter) embedded in the crystalline matrix near the two ..cap alpha../c interfaces dissolved into the crystal but the thickness of the 100 percent ..cap alpha.. layer was not appreciably affected by further implantation at 200/sup 0/C. A model for in situ annealing during implantation is presented.
Date: November 1, 1982
Creator: Sadana, D. K.; Washburn, J.; Byrne, P. F. & Cheung, N. W.
System: The UNT Digital Library
Design of a 10-T superconducting dipole magnet using niobium-tin conductor (open access)

Design of a 10-T superconducting dipole magnet using niobium-tin conductor

In order to minimize the size and cost of conventional facilities - land, tunneling, shielding, cryogenic and vacuum system - the dipole magnets for the next generation of particle accelerators must produce as strong a magnetic field as possible. Ten tesla seems to be a reasonable goal, and can be attained by using either niobium-tin conductor at 4.2 K or niobium-titanium at 1.8 K. The beam diameter in a multi-TeV accelerator, can in principle, be quite small, say 20 mm, depending on the design of the injection and extraction systems, and on beam-cooling technology. Magnet cost is strongly dependent on bore diameter, so there is a strong incentive to minimize that. We believe that a 40-mm bore diameter - about 60-mm winding inside diameter is feasible and is a reasonable goal for initial research and development. For such a high field and small bore, there is an incentive to achieve a high overall current density in order to minimize the amount of superconductor. Our design is based on an overall current density of 400 A/sq mm. LBL has undertaken the development of a magnet using niobium-tin conductor intended to meet the above specifications. The conductor is a Rutherford-type cable consisting …
Date: November 1, 1982
Creator: Taylor, C.; Meuser, R.; Caspi, S.; Gilbert, W.; Hassenzahl, W.; Peters, C. et al.
System: The UNT Digital Library