Radioactive (a, n) neutron sources include Ra-Be, PuF4, and four PuBe13 sources. Comparative neutron emission rates were determined by two separate methods: (1) the manganese sulfate bath with appropriate corrections made for fast neutron escape or capture and for thermal neutron capture by the source; and (2) long counter measurements corrected for energy response and so rce anisotropy. Agreement to within 1 percent was obtained by the two independent methods. A Ra-Be source calibrated against the NBS neutron standard was used as a primary reference Spectral measurements of PuBe13 and PuF4 neutron sources were made with nuclear emulsions. By the use of cylindrical plastic and lead absorbers, an effort was made to moderate the PuBe13 spectrum and thereby obtain additional calibration points for instrument response studies. Spectral changes were initially studied with the doublemoderator technique, followed by later measurements with nuclear emulsions. From flux and spectral measurements of the primary and moderated radioactive sources, the first collision tissue dose was calculated and, in turn, compared to experimental measurements of absorbed dose with proportional counters designed according to the Bragg-Gray principle. (Author).

This book provides a comprehensive and up-to-date introduction to the fundamental theory and applications of slow-neutron scattering.

Radiation Dosimetry, Second Edition, VOLUME III: Sources, Fields, Measurements, and Applications covers the significant aspects of radiation dosimetry. The book discusses dosimetry relating to x rays and teleisotope gamma rays, discrete and distributed alpha-, beta-, and gamma-ray sources, electron beams, and heavy charged particle beams. The text also describes dosimetry relating to reactors, neutron and mixed n-gamma fields, neutrons from accelerators and radioactive sources, initial and residual ionizing radiation from nuclear weapons, natural and man-made background radiation, radiation in space, ultra-high energy radiation, and uncommon types of particles. Dosimetry relating to health physics, diobiology, radiotherapy, implant and intracavitary therapy, ""transition-zones"" (especially at bone-tissue interfaces), and radiation processing is also considered. Physicists, biophysicists, and people involved in radiological science will find the book invaluable.

This publication addresses recent developments in neutron generator (NG) technology. It presents information on compact instruments with high neutron yield to be used for neutron activation analysis (NAA) and prompt gamma neutron activation analysis in combination with high count rate spectrometers. Traditional NGs have been shown to be effective for applications including borehole logging, homeland security, nuclear medicine and the on-line analysis of aluminium, coal and cement. Pulsed fast thermal neutron analysis, as well as tagged and timed neutron analysis, are additional techniques which can be applied using NG. Furthermore, NG can effectively be used for elemental analysis and is also effective for analysis of hidden materials by neutron radiography. Useful guidelines for developing NG based research laboratories are also provided in this publication.