This paper presents the requirements of a nuclear amplifier of short resolving time, designed to accept pulses of widely varying amplitudes. Data are given which show that a proportional ionization chamber loaded with a 1,000-ohm resistor develops pulses of 0.5 microsecond duration and several volts amplitude. Results indicate that seven basic requirements are imposed on the amplifier when counting soft beta and gamma radiation in the presence of alpha particles, without absorbers. It should, (1) have a fast recovery time, (2) have a relatively good low frequency response, (3) accept pulses of widely varying heights without developing spurious pulsed, (4) have a limiting output stage, (5) preserve the inherently short rise time of the chamber, (6) minimize pulse integration, and (7) have sufficient gain to detect the weak pulses well below the chamber voltage at which continuous discharge takes place. The results obtained with an amplifier which meets these requirements is described. A formula is derived which indicates that redesign of the proportional ionization chamber might eliminate the need for an amplifier. This may be possible if the radioactive particles are collimated parallel to the collecting electrode.

Atomized U powder was produced by forming an electric arc between two U electrodes in an inert atmosphere and sending a high velocity stream of inert gas through the arc. Uranium particles obtained by this method were of spherical shape; smaller particles contained mostly small grains, and larger particles wore characterizcd by larger grains. The particles were ductile and could be hotpressed to a compact of high density. The temporary equipment used for those preliminary tests on atomization was not adequate to control particle size. Suggestions for the production of atomized U powder of controllable quality are included. (arth)

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This report presents decontamination and corrosion resistance data on various industrial materials tested on a laboratory scale to aid in the section of materials for the construction and maintenance of radiochemical laboratories at Oak Ridge National Laboratory.

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Progress is reported by the Mechanical Development group and by the Plant Assistance group. The Mechanical Development group reports on the thimble removal program, special pile measurements and instruments, graphite sampling, and the ruptured slug problem. The Plant Assistance group reports on technical information on the B, D, F, and H piles, special request container slug, exposure of P-10 fuel slugs, slug corrosion studies, front tube corrosion, and flow laboratory experiments.

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This is a progress report of the production reactors on the Hanford Reservation for the month of July 1950. This report takes each division (e.g., manufacturing, medical, accounting, occupational safety, security, reactor operations, etc.) of the site and summarizes its accomplishments and employee relations for that month.

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The slow neutron transmission of a sample of enriched uranium containing 3.193 gm/cm{sup2} has been investigated with a resolution width of 1 microsec/m (1 microsec/m is the full width of the triangular resolution function at the base) and with points spaced 1/3 microsec/m. The results of these transmission measurements are shown in Fig. 1. The solid line represents the new measurements while the dashed line represents the previous measurements (CUD-4) on this sample using a resolution width of 1.4 microsec/m and with points spaced 2/3 microsec/m.

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This document discusses a meeting held to inform members of the Biology Division of the status of P-10 problems, to exchange ideas on methods of attacking these problems, and to consider new problems.

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This HAPO report documents the design criteria for the P-10 air monitor at the 300 Area. Minimum reliable readings and accompanying remarks document testing of four different monitors.

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In November, 1949, an industrial hygiene study was made of the operations conducted in the Bio-Assay Laboratory, 706 Building, 700 Area. This study was conducted by W.E. Gill and reported in HW-15654. One of the potential health hazards investigated was the use of benzol in laboratory procedures. An evaluation of this problem where the solvent was employed for cleaning glassware indicated that the solvent vapor was present in the workers` breathing zone in concentrations occasionally as high as 170 ppM. Five samples collected at this washing operation showed an average concentration of over 100 ppM; all samples being over the maximum allowable concentration (MAC) of 35 ppM. As a result of the findings of this study several recommendations were made, one of which was the advisability of instituting a program for urine sulfate determinations for the laboratory personnel exposed to benzol. It was felt that this test would demonstrate more precisely than air sampling the actual inhalation and absorption of solvent vapors experienced by the operators and exemplifying such factors as variations in individual respiratory rates and care in the use of solvent during washing.

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The relative stopping powers for 300 Mev protons of H, Li, Be, C, Al, Fe, Cu, Ag, Sn, W, Pb, and U have been measured. The results are shown in Table I. The energy spent per ion-pair production in the gases H{sub 2}, He, N{sub 2}, O{sub 2}, and A at 340 Mev proton energy has also been measured. The results are shown in Table II.

The present liquid third safety is considered undesirable for the piles at their present power levels. Any increase in power level and graphite temperature makes the need for an alternative third safety increasingly imperative. The use of the third safety is envisioned under conditions where the supply of cooling water to an operating pile is interrupted and concurrently the safety rods full to enter the pile because of slight shifting of the top shield or larger shifting of the winches, relative to the pile proper. Under these conditions, undesirable properties of a liquid third safety are present and are discussed in this memorandum.