Improved Kanne tritium monitoring system

A Kanne chamber has been redesigned to reduce its sensitivity to such contaminants as tritium water vapor and tritiated oil. The high voltage electrode has been replaced by a wire cylinder and the collection electrode has been reduced in diameter. The sensitivity to contamination of the chamber has been reduced by about a factor of 40. The design allows for decontamination of the chamber in place. The improved electronics used is also discussed

Wide-range tritium monitor

An ionization chamber consisting of two active volumes in a single enclosure and an auto range changing electrometer covering a dynamic range of 10/sup 8/ are discussed. The tritium monitor is designed to have a reduced sensitivity to tritium contamination, to have a fast response, and to be useful for tritium concentrations of a few ..mu..Ci/m/sup 3/ to 10/sup 8/ ..mu..Ci/m/sup 3/

Tritium monitoring system using a modified Kanne chamber for use in tritium contaminating environments

A Kanne chamber has been redesigned to reduce its sensitivity to such contaminants as tritium water vapor and tritiated oil. The high voltage electrode has been replaced by a wire cylinder and the collection electrode has been reduced in diameter. The sensitivity to contamination of the chamber has been reduced by about a factor of 40. The design allows for decontamination of the chamber in place. The improved electronics used is also discussed

Real-time delay monitor for flow-system cell sorters

For optimum performance in cell sorting, it is critical to assure proper timing in the charging of droplets to be deflected. A method for determining the transit delay time in cell sorters has been devised and applied to daily operation in the Los Alamos sorter systems. This delay monitor relies on detection of either scattered or absorbed light from cells in the fluid stream near the point of droplet breakoff

Pulsed system for obtaining microdosimetric data with high intensity beams

The use of heavy particle accelerators for radiation therapy requires high intensity beams in order to produce useful dose rates. The 800-MeV proton beam at LAMPF passes through different production targets to generate secondary pion beams. Conventional microdosimetric techniques are not applicable under these conditions because exceedingly high count rates result in detector damage, gas breakdown, and saturation effects in the electronics. We describe a new microdosimetric system developed at the Pion Biomedical Channel of LAMPF. The accelerator provides a variable low intensity pulse once every ten high intensity macropulses. The voltage on the detector is pulsed in coincidence with the low intensity pulse so that we were able to operate the detector under optimum data-taking conditions. A low noise two-stage preamplifier was built in connection with the pulsed mode operation. A comparison is made between data obtained in pulsed (high intensity beam) and unpulsed (low intensity beam) modes. The spectra obtained by the two methods agree within the experimental uncertainties

High speed single particle sizing by light scattering in a flow system

Two approaches to rapid, single particle sizing for particles in the 1 to 20 ..mu..m diameter range are presented. One method measures multiangle scattered light over a polar angular range of nearly 360 degrees. A second method is based on the analysis of the pulse shapes from small angle forward scattered light. In both cases the particles in liquid suspension are made to pass one at a time through a focused laser beam for analysis