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The boundaries of Texas

Description: The boundaries of Texas were the cause of disputes between the French, the Spanish, Mexico, and later the United States of America. The intensity of these disputes threatened to disrupt the Union itself, and caused a war between the United States and Mexico.
Date: August 1937
Creator: Wilkinson, C. A.
Partner: UNT Libraries

Development of a RAMI Program for LANSCE upgrade

Description: Improvement of beam availability is a prime objective of the present LANSCE (Los Alamos Neutron Scattering Center) Upgrade. A RAMI (reliability, availability, maintainability, and inspectability) program is being developed to identify the most cost-effective improvements to achieve the availability goal. The beam-delivery system is divided into subsystems appropriate for the modeling of availability. The availability of each subsystem is determined from operation data and assessment of individual component designs. These availability data are incorporated in an availability model to predict the benefit of improvement projects to achieve cost-benefit prioritization. Examination of the data also identifies a comprehensive list of factors affecting availability. A good understanding of these factors using root-cause analysis is essential for availability improvement. This paper describes the RAMI program and the development of the availability model.
Date: May 1, 1995
Creator: Chan, K.C.D.; Hutson, R.L.; Macek, R.J.; Tallerico, P.J. & Wilkinson, C.A.
Partner: UNT Libraries Government Documents Department

Monte Carlo based formula for radiation shielding assessment in the forward direction

Description: Monte Carlo simulations of 800-MeV proton beam spills in common shielding materials show that neutron dose equivalent rates in the forward direction can be characterized by a Moyer Model-like formula. Particle transport codes were used to determine the neutron flux at depths up to 6 meters and for production angles from 0[degrees] to 30[degrees] for primary proton beam spills on cylindrical beam stops. The flux was then converted to dose equivalent rate as a function of depth and angle. The results for three common shielding materials were combined and the resulting fitted formula provides a quick method for estimating the dose equivalent rates and shielding effectiveness outside thick shielding at forward angles.
Date: January 1, 1993
Creator: Wilkinson, C.A.; Fitzgerald, D.H.; Frankle, S.C.; Hutson, R.L. & Macek, R.J.
Partner: UNT Libraries Government Documents Department

A comparison of analytic models for estimating dose equivalent rates in shielding with beam spill measurements

Description: A comparison of 800-MeV proton beam spill measurements at the Los Alamos Meson Physics Facility (LAMPF) with analytical model calculations of neutron dose equivalent rates (DER) show agreement within factors of 2-3 for simple shielding geometries. The DER estimates were based on a modified Moyer model for transverse angles and a Monte Carlo based forward angle model described in the proceeding paper.
Date: January 1, 1992
Creator: Frankle, S.C.; Fitzgerald, D.H.; Hutson, R.L.; Macek, R.J. & Wilkinson, C.A.
Partner: UNT Libraries Government Documents Department

Application of a simple analytical model to estimate effectiveness of radiation shielding for neutrons

Description: Neutron dose equivalent rates have been measured for 800-MeV proton beam spills at the Los Alamos Meson Physics Facility. Neutron detectors were used to measure the neutron dose levels at a number of locations for each beam-spill test, and neutron energy spectra were measured for several beam-spill tests. Estimates of expected levels for various detector locations were made using a simple analytical model developed for 800-MeV proton beam spills. A comparison of measurements and model estimates indicates that the model is reasonably accurate in estimating the neutron dose equivalent rate for simple shielding geometries. The model fails for more complicated shielding geometries, where indirect contributions to the dose equivalent rate can dominate.
Date: January 1, 1993
Creator: Frankle, S.C.; Fitzgerald, D.H.; Hutson, R.L.; Macek, R.J. & Wilkinson, C.A.
Partner: UNT Libraries Government Documents Department

The status of CYGNUS experiment: Past, present, and future

Description: The CYGNUS experiment, located in Los Alamos, NM, has been continuously operating since April 2, 1986. The experiment consists of an air shower array and an associated 44 m/sup 2/ muon detector; its large size, good angular resolution, muon detection, and low energy threshold make it a unique experiment among those currently operating. The experiment has undergone continuous expansion in several stages since it began operation. The experiment, its expansion, and further plans for the further will be described. 6 refs., 9 figs.
Date: January 1, 1989
Creator: Haines, T.J.; Berley, D.; Chang, C.Y.; Dingus, B.L.; Goodman, J.A.; Stark, M. et al.
Partner: UNT Libraries Government Documents Department

Results from beam tests of MEGA's low-mass, high-rate cylindrical MWPCs

Description: One of the leading experimental projects at LAMPF has been the MEGA experiment. This is an experiment to search for the rare decay {mu} {yields} e{gamma} with a sensitivity of 10{sup {minus}13}. A prime component of this project has been the design and construction of high-rate, low mass MWPCs for the tracking of positrons from muon decay. With rate capabilities of 2 {times} 10{sup 4} e{sup +}/mm{sup 2}/s and a thickness of 3 {times} 10{sup {minus}4} radiation lengths, these chambers are state-of-the-art cylindrical MWPCs. Cylindrical chambers of this size (0.9 m{sup 2}) and thinness have never been previously constructed. The MEGA project at LAMPF has recently succeeded in building chambers with these necessary performance characteristics as demonstrated by data taken from muon decays, cosmic rays, and sources.
Date: January 1, 1991
Creator: Stanislaus, S.; Armijo, V.; Black, J.K.; Bolton, R.D.; Carius, S.; Cooper, M.D. et al.
Partner: UNT Libraries Government Documents Department

Status of the expansion of the CYGNUS array at Los Alamos

Description: The CYGNUS air shower array, located in Los Alamos, New Mexico, has been operating since April, 1986. The expansion of the array from 108 to 200 counters is described along with the increase in muon detection area. The new array, to be fully operational by the end of 1989, will have three times the sensitivity to UHE sources. 5 refs., 2 figs.
Date: January 1, 1989
Creator: Berley, D.; Chang, C.Y.; Dingus, B.L.; Goodman, J.A.; Haines, T.J.; Stark, M. et al.
Partner: UNT Libraries Government Documents Department

Relative muon content of UHE showers associated with Hercules X-1

Description: A further analysis is presented of the muon content associated with the July, 1986 UHE observation of the Hercules X-1 system, previously reported by the CYGNUS collaboration. The probability for observing comparable muon content in a set of background'' showers similar to those of the Hercules burst is given. 3 refs., 2 tabs.
Date: January 1, 1989
Creator: Alexandreas, D.E.; Allen, R.C.; Biller, S.; Dion, G.; Lu, X-Q; Vishwanath, P.R. et al.
Partner: UNT Libraries Government Documents Department