Modified Simpson Methane Flow Proportional Alpha Counter and Fission Counter (open access)

Modified Simpson Methane Flow Proportional Alpha Counter and Fission Counter

Abstract: This technical report consists of series of drawings of the instrument with the following explanation. The modification of the Simpson Methane flow proportional counter consists of a means for inserting and replacing samples into the chamber through an air-lock device which avoids the introduction of even a small quantity of air into the active volume of the chamber. This is accompanied by sweeping out the small volume of the air-lock containing the sample with methane gas before the sample is introduced into the chamber -- this sweeping out requiring only a few seconds. The mechanical construction is somewhat simplified over that employed in the Simpson counter design, although the electrical and counting characteristics are essentially duplicates of those employed in the Simpson version. Voltage plateaus about 400 volts long, flat within 1% per 100 volts are obtained with the counter, with the operating point at about 2500 volts for methane at one atmosphere pressure. A plateau extending over a range of about 40% variation in amplification factor is obtained. Standard samples have been checked to standard deviation of +/-0.3% over a period of one year. The counter is rather gas-tight and is ready for use within about ten minutes …
Date: July 9, 1947
Creator: Freedman, M. S.
System: The UNT Digital Library
Note on the Determination of Lead in Pitchblende (open access)

Note on the Determination of Lead in Pitchblende

Technical report describing a procedure for the determination of lead in pitchblende. The procedure was determined as needed in the course of an investigation of the processing of pitchblende for the production of uranium. Summary: The volumetric dichromate method for the determination of lead was selected from among several methods investigated as being best suited for a rapid determination of lead in pitchblende. The method as described is accurate to within 1% and it does not require the application of an empirical factor as suggested by Willard and Diehl for this determination.
Date: July 1946
Creator: Braddock, T. R.; Martin, G. L. & McCoy, J. R.
System: The UNT Digital Library
The Emf of Cells with Uranium: Uranium Halide Couples in Fused Salt Electrolytes (open access)

The Emf of Cells with Uranium: Uranium Halide Couples in Fused Salt Electrolytes

The emf of galvanic cells at high temperatures was measured using uranium metal in equilibrium with its chloride as one half of the cell, the other half of the cell being some reference electrode such as silver - silver chloride. Several designs of cells tried are described. A value of 2.83 volts/eq. at 1170[degree]K and also at 990[degree]K is considered as the most probably value for the potential of the uranium halide couple.
Date: July 31, 1947
Creator: Eastman, E. D. (Ermon Dwight), 1891-1945.; Campbell, J. A.; Cubicciotti, D. D. & Sienko, Michell J.
System: The UNT Digital Library
Acute Radiotoxicity of Injected Yttrium91 (open access)

Acute Radiotoxicity of Injected Yttrium91

Report describing results of experiments that involved injecting radioactive yttrium into animals: "The excretion, retention, and distribution of the yttrium was measured, and its effect on survival and growth was observed. The average total excretion of Y91 to the time of death (from 76 hours to 24 days) was a little less than 30 per cent of the injected dose" (p. 2).
Date: July 31, 1947
Creator: Anthony, David S.
System: The UNT Digital Library
Test Results on Clinton Alpha Amplifier Used with an Offner Columbia Scaler (open access)

Test Results on Clinton Alpha Amplifier Used with an Offner Columbia Scaler

Technical report describing development of the Clinton alpha amplifier. The circuit for the Clinton alpha amplifier which is used with an Offner scaler is shown attached to the report. It consists of a pre-amplifier mounted in a cylindrical alpha chamber, followed by a three state amplifier and a pulse height selector in a separate cabinet. Pulses are fed from the pulse height selector in the amplifier to the input tube of the Offner scaler. Through the third stage of the amplifier, this circuit is exactly the same as the California circuit now used by the chemical section for alpha counting. A type 961 Offner scaler was used for these tests. None of the latest Offner scalers type961A, were available to us when the tests were made. Method of testing is given, results are tabulated, computations are made, and eight graphs are given. it appears that the Clinton amplifiers used with a Offner scaler will give substantially the same performance as that given by the California circuit.
Date: July 1, 1944
Creator: Ostdahl, H. E.
System: The UNT Digital Library