Search

A high-sensitivity scintillation β spectrometer was designed to measure the 90Sr contamination of environmental samples against a background of 40K and 137Cs radionuclides. The plastic scintillator detector with a developed surface also acts as the sample container. The volume of the sample being analyzed is 1000 cm3. The minimum detectable specific activity of 90Sr is 3.5 Bq/kg for solid granular samples and 1 Bq/L for water. (The measurement time for both samples and background is 2 h.)

operation of luminescent solar concentrators, and the results of experimental research on concentrators of various designs, and the influence of the spectral and luminescence parameters of the luminescent solar concentrators upon the concentration coefficient of the~light flux. The present review is a generalization of the technological solutions given in theoretical and experimental papers for increasing and efficiency of luminescent solar concentrators by developing optical media with improved spectral and luminescence features and by optimizing the conditions of light collection:in luminescent solar concentrators for the purpose of reducing luminous losses. The review includes the results of the author~' research, part of which is published for the first time.

A new balloon instrument, the advanced thin ionization calorimeter (ATIC), is currently under development by an international collaboration involving researchers in the U.S., Germany, Korea, Russia and the Ukraine. The instrument will be used, in a series of long duration balloon flights, to investigate the charge composition and energy spectra of primary cosmic rays over the energy range from about 1010 to 1014 eV. The ATIC instrument is designed around a new technology, fully active Bismuth Germanate (BGO) ionization calorimeter that is used to measure the energy deposited by the cascades formed by particles interacting in an approximately 1 proton interaction length thick carbon target. The charge module comprises a highly segmented, triply redundant set of detectors (scintillator, silicon matrix and Cherenkov) that together give good incident charge resolution plus rejection of the 'backscattered' particles from the interaction. Trajectory information is obtained both from scintillator layers and from the cascade profile throughout the BGO calorimeter. This instrument is specifically designed to take advantage of the existing NASA long duration balloon flight capability in Antarctica and/or the Northern Hemisphere. The ATIC instrumentation is presented here, while a companion paper at this conference discusses the expected performance.© (1996) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.

An Advanced Thin Ionization Calorimeter (ATIC) will be used to investigate the charge composition and energy spectra of primary cosmic rays over the energy range from about 10 10 to >10 14 eV in a series of long-duration balloon flights. The totally active BGO calorimeter, 22 radiation length thick, will measure the electromagnetic energy ensuing from nuclear interactions in a one interaction length thick carbon target. Trajectory information will be obtained from the location of the cascade axis in the BGO calorimeter and in the segmented scintillator layers of the upstream carbon target. The highly segmented charge module comprised of scintillator strips, a silicon matrix, and a Cherenkov array will minimize the effect of backscattered particles on primary charge measurements. While obtaining new high priority scientific results, the ATIC balloon payload can also serve as a proof of concept, or engineering model, for a BGO calorimeter-based instrument on the International Space Station. We examine the added advantage of locating such an experiment for long durations on a platform such as the Space Station.