Report for General Research July 10 to October 2, 1950 (Supporting Research Volume)

The efficient prosecution of the research and process development on polonium, radium, actinium, waste disposal, and alpha-neutron sources requires the use of a wide variety of instrumental techniques such as: alpha, beta, gamma, and neutron counters and survey meters; emission, absorption, and mass spectroscopy: x-ray and electron diffraction; microbalances; and calorimeters. The complex and kaleidoscopic aspects of our research program require; (1) The application of standard instruments and techniques to a variety of problems; (2) The development of new techniques for the use of standard instruments; and (3) The development of new or improved Instruments. The sum of the above three categories constitutes the field of supporting research. The amplifier for counting pulses of wide dynamic range which was developed for counting beta particles in the presence of alphas has operated so satisfactorily that it has been decided to attempt to adopt it for neutron counting. Substantial improvement at medium counting rates has already been obtained but results at high counting rates are not as satisfactory. The development of a survey meter for monitoring fast neutrons has been under way for sometime. The attainment of higher efficiency has been attempted by the use of a dual-chambered counter tube. The tube operates with a filling of methane gas at two atmospheres pressure. The achievement of leak-proof seals and highest purity methane has been under investigation as their necessity has been indicated by tests. The development of a scintillation counter for surveying and measuring low levels of alpha activity has been continued. Recent efforts have been directed towards determining the correct voltages to be applied to the photomultiplier tube in order to operate under optimum conditions. Recent tests of the coincidence counter to detect scintillations in water containing alpha-active waste material have indicated the necessity of obtaining photomultiplier tubes with low noise level and a better regulated, noise-free power supply