Approaches to ultrafast neutron detectors (open access)

Approaches to ultrafast neutron detectors

We discuss two approaches to obtain detectors of very high temporal resolution. In the first approach, uranium-coated cathode is used in a streak tube configuration. Secondary electrons accompanying the fission fragments from a neutron-uranium reaction are accelerated, focussed and energy analyzed through a pinhole and streaked. Calculations show that 20 ps time-resolution can be obtained. In the second approach, a uranium-coated cathode is integrated into a transmission line. State-of-the-art technology indicates that time resolution of 20 ps can be obtained by gating the cathode with a fast electric pulse.
Date: October 5, 1984
Creator: Wang, C. L.; Kalibjian, R.; Singh, M. S.; Wiedwald, J. D.; Campbell, D. E.; Campbell, E. M. et al.
Object Type: Article
System: The UNT Digital Library
Assessment of alternatives for long-term management of uranium ore residues and contaminated soils located at DOE's Niagara Falls Storage Site (open access)

Assessment of alternatives for long-term management of uranium ore residues and contaminated soils located at DOE's Niagara Falls Storage Site

About 11,000 m/sup 3/ of uranium ore residues and 180,000 m/sup 3/ of wastes (mostly slightly contaminated soils) are consolidated within a diked containment area at the Niagara Falls Storage Site (NFSS) located about 30 km north of Buffalo, NY. The residues account for less than 6% of the total volume of contaminated materials but almost 99% of the radioactivty. The average /sup 226/Ra concentration in the residues is 67,000 pCi/g. Several alternatives for long-term management of the wastes and residues are being considered, including: improvement of the containment at NFSS, modification of the form of the residues, management of the residues separately from the wastes, management of the wastes and residues at another humid site (Oak Ridge, TN) or arid site (Hanford, WA), and dispersal of the wastes in the ocean. Potential radiological risks are expected to be smaller than the nonradiological risks of occupational and transportation-related injuries and deaths. Dispersal of the slightly contaminated wastes in the ocean is not expected to result in any significant impacts on the ocean environment or pose any significant radiological risk to humans. It will be necessary to take perpetual care of the near-surface burial sites because the residues and wastes will …
Date: November 5, 1984
Creator: Merry-Libby, P.
Object Type: Article
System: The UNT Digital Library
Database requirements for the Advanced Test Accelerator project (open access)

Database requirements for the Advanced Test Accelerator project

The database requirements for the Advanced Test Accelerator (ATA) project are outlined. ATA is a state-of-the-art electron accelerator capable of producing energetic (50 million electron volt), high current (10,000 ampere), short pulse (70 billionths of a second) beams of electrons for a wide variety of applications. Databasing is required for two applications. First, the description of the configuration of facility itself requires an extended database. Second, experimental data gathered from the facility must be organized and managed to insure its full utilization. The two applications are intimately related since the acquisition and analysis of experimental data requires knowledge of the system configuration. This report reviews the needs of the ATA program and current implementation, intentions, and desires. These database applications have several unique aspects which are of interest and will be highlighted. The features desired in an ultimate database system are outlined. 3 references, 5 figures.
Date: November 5, 1984
Creator: Chambers, F.W.
Object Type: Article
System: The UNT Digital Library
Design note about a 75 KVA quiet power distribution system (open access)

Design note about a 75 KVA quiet power distribution system

This note describes a 75KVA quiet power distribution system for X 653 in neutrino Lab D. It is fed from the regular AC distribution which exists in the building and it has no standby power. Its purpose is to remove electrical disturbances which are present on the regular AC distribution.
Date: April 5, 1984
Creator: Visser, A. T.
Object Type: Report
System: The UNT Digital Library
Including the effect of control strategy in solar load ratio calculations (open access)

Including the effect of control strategy in solar load ratio calculations

As originally developed, solar load ratio correlations for performance analysis of passive heating systems were intended for use only with a constant thermostat setpoint. The thermostat setpoint used in the method may be adjusted to account for the effect of heating from internal sources, but setback or shutdown strategies that are frequantly employed in both residential and commercial buildings were not allowed. A procedure for approximating the effect of various control strategies through use of an equivalent constant thermostat setpoint, T/sub ec/, has recently been developed at Los Alamos National Laboratory. The value of T/sub ec/ depends on the level and duration of thermostat settings used during the diurnal cycle and on the characteristic time constant is a function of the diurnal heat capacity of the building and its loss characteristics. The method described in this paper has been applied to a variety of passive solar buildings in two distinct climatic regions and was found to yield good accuracy when compared with detailed thermal network calculations.
Date: June 5, 1984
Creator: Wray, W. O. & Kosiewicz, C. E.
Object Type: Article
System: The UNT Digital Library
Long-pulse beamlines for the mirror fusion test facility (open access)

Long-pulse beamlines for the mirror fusion test facility

We have recently obtained test results indicating that a beam of pure full-energy deuterium particles can be delivered to the plasma targets in MFTF-B. We used a close-coupled separator magnet with the ion source to separate the impurities from the full-energy deuterium particles. Our completed studies show that the usual iron-core sweep magnet and shielding used in neutral beamlines can be eliminated and the gas flow out of the beamline decreased. This design also reduces beam losses. We will use smooth-bore OFHC tube arrays brazed to manifolds for the active heat transfer surfaces. Tests indicate that both burnout and life requirements are met by this design. In this paper, we present test results and discuss the MFTF-B long-pulse beamline configuration.
Date: September 5, 1984
Creator: Stone, R.R.; Goldner, A.I. & P., Poulsen
Object Type: Article
System: The UNT Digital Library
Monte Carlo simulation of the microcanonical ensemble (open access)

Monte Carlo simulation of the microcanonical ensemble

We consider simulating statistical systems with a random walk on a constant energy surface. This combines features of deterministic molecular dynamics techniques and conventional Monte Carlo simulations. For discrete systems the method can be programmed to run an order of magnitude faster than other approaches. It does not require high quality random numbers and may also be useful for nonequilibrium studies. 10 references.
Date: April 5, 1984
Creator: Creutz, M.
Object Type: Article
System: The UNT Digital Library
Muon SR Newsletter, No. 29, April 5, 1984 (open access)

Muon SR Newsletter, No. 29, April 5, 1984

Muon SR stands for Muon Spin Relaxation, Rotation, Resonance, Research, or what have you. The intention of the mnemonic acronym is to draw attention to the analogy with NMR and ESR, the range of whose applications is well known. Any study of the interactions of the muon spin by virtue of the asymmetric decay is considered ..mu..SR, but this definition is not intended to exclude any peripherally related phenomena, especially if relevant to the use of the muon's mganetic moment as a delicate probe of matter. Abstracts of individual items from this issue were prepared separately for the data base.
Date: April 5, 1984
Creator: Crowe, K.M.; Portis, A.M. & Yamazaki, T. (eds.)
Object Type: Report
System: The UNT Digital Library
Operations Security Assessment of the Department of Energy`s Richland Operation Office, Final Report (SAS-4394-HQ) (open access)

Operations Security Assessment of the Department of Energy`s Richland Operation Office, Final Report (SAS-4394-HQ)

None
Date: October 5, 1984
Creator: Merrill, B. J.
Object Type: Report
System: The UNT Digital Library
Radiochemical detector cross section sensitivity studies in the A approx. = 90 mass region (open access)

Radiochemical detector cross section sensitivity studies in the A approx. = 90 mass region

The use of radiochemical detectors in the A approx. = 90 mass region to measure 14 MeV neutron fluences is investigated from the standpoint of cross section sensitivities. Specifically, /sup 90/Zr and /sup 89/Y neutron-induced cascades leading to the production of /sup 89/Zr, /sup 88/Zr, /sup 88/Y, and /sup 87/Y are studied in a one-energy-group approximation, and the sensitivities of the measured ratios R/sub Z/ = /sup 88/Zr//sup 89/Zr and R/sub Y/ = /sup 87/Y//sup 88/Y to the input cross sections are delineated. The most sensitive cross section in each cascade is the cross section that dominates the production of the final isotope in the chain. Only one of the isomeric levels in /sup 90/Zr contributes importantly to the Zr cascade. Burnback (n,..gamma..) and burnup (n,p) reactions are also considered. The (n,..gamma..) effects are small, but (n,p) effects can be substantial due to low energy enhancements of (n,p) cross sections in the neutron-deficient isotopes.
Date: April 5, 1984
Creator: MacGregor, Malcolm H.
Object Type: Report
System: The UNT Digital Library
Reaction cross-section calculations using new experimental and theoretical level structure data for deformed nuclei (open access)

Reaction cross-section calculations using new experimental and theoretical level structure data for deformed nuclei

A technique for modeling quasiparticle excitation energies and rotational parameters in odd-odd deformed nuclei has been used to construct sets of discrete states with energy 0 to 1.5 MeV in /sup 176/Lu and /sup 236/Np. These data were used as part of the input for calculation of isomer production cross-section ratios in the /sup 175/Lu(n,..gamma..)/sup 176/Lu and /sup 237/Np(n,2n)/sup 236/Np reactions. In order to achieve agreement with experiment, it has been found necessary to include in the modeled set many rotational bands (35 to 95), which are comprised of hundreds of levels with their gamma-ray branching ratios. It is essential that enough bands be included to produce a representative selection of K quantum numbers in the de-excitation cascade. 20 refs., 3 figs., 3 tabs.
Date: October 5, 1984
Creator: Hoff, R. W.; Gardner, D. G. & Gardner, M. A.
Object Type: Article
System: The UNT Digital Library
Searching for top, Higgs, and supersymmetry: the minimum invariant mass technique (open access)

Searching for top, Higgs, and supersymmetry: the minimum invariant mass technique

Supersymmetric particls, Higgs mesons, the top quark and other heavy objects are expected to decay frequently into three or more body final states in which at least one particle, such a neutrino or photino, is non-interacting. A method is described for obtaining an excellent estimate of both the mass and the longitudinal momentum of the parent state. The probable longitudinal momenta of the non-interacting particle and of the parent, and the minimum invariant mass of the parent are derived from a minimization procedure. The distributions in these variables are shown to peak sharply at their true values.
Date: March 5, 1984
Creator: Berger, E. L.
Object Type: Article
System: The UNT Digital Library
Sludge composition for each tank and DWPF feed batches (open access)

Sludge composition for each tank and DWPF feed batches

This is a summary of the chemical composition of the sludge on a tank-by-tank basis and the projected chemical composition of the first four feed batches to the DWPF.
Date: July 5, 1984
Creator: Fowler, J. R.
Object Type: Report
System: The UNT Digital Library
Soft x-ray laser experiments at Novette Laser Facility (open access)

Soft x-ray laser experiments at Novette Laser Facility

We discuss the results of and future plans for experiments to study the possibility of producing an x-ray laser. The schemes we have investigated are all pumped by the Novette Laser, operated at short pulse (tau/sub L/ approx. 100 psec) and an incident wavelength of lambda /sub L/ approx. 0.53 ..mu..m. We have studied the possibility of lasing at 53.6, 68.0 to 72.0, 119.0, and 153.0 eV, using the inversion methods of resonant photo-excitation, collisional excitation, and three-body recombination.
Date: March 5, 1984
Creator: Matthews, D.; Hagelstein, P.; Rosen, M.; Kauffman, R.; Lee, R.; Wang, C. et al.
Object Type: Article
System: The UNT Digital Library