Bryon D. Anderson

Improved computer simulation of the detection process in NE-102 and NE-213 scintillators for 0 to 4.8 MeV neutrons☆

Abstract A description is given of a FORTRAN subroutine which, in conjunction with a Monte-Carlo main program, accurately simulates the experimentally observed variation of detector efficiency with neutron energy throughout the discriminator cut-off region. With absolute C(n, n) and H(n, n) cross sections supplied, the program permits determination of the absolute detection efficiency from measurements of relative detection efficiency in this cut-off region. Variations of detector efficiency with incident neutron entry point and direction are also obtainable.

Testing and calibration of a Faraday cup and other intensity monitors for the external proton beam at LAMPF

Abstract Three different methods of measuring beam intensities have been tested in the external proton beam at the Los Alamos Meson Physics Facility (LAMPF) over a wide range of beam currents. A 700 kg Faraday cup was constructed and has been demonstrated to be capable of absolute measurements with an error lower than 1%. A high gain ArCO2 ion chamber was built for low beam intensity monitoring (down to a few pA) and provided an independent check of the Faraday cup calibration to better than 3%. A secondary emission monitor was also tested and calibrated relative to the Faraday cup. This secondary emission monitor provides reliable relative data for beams greater than about 50 pA.

Investigation of some properties of multiware proportional chambers with planar cathodes

Abstract This article reports a systematic study of the pulse heights, efficiency, and plateau width of a multiwire proportional chamber with planar cathodes. It is shown that the chamber performs identically to a chamber with wire cathodes when the same electric field exists in the neighborhood of the anode signal wires. A chamber with planar cathodes may thus be operated at higher field strengths and consequently higher pulse-height amplification than a chamber with wire cathodes, which have a tendency to draw current due to field emission of electrons. Data are presented on the time jitter of a chamber with planar cathodes as a function of voltage. The observed performance of such chambers in experimental conditions, with high radiation fields, is described.