Authors: Yadollah Lotfi Gholam Reza Etaati Vahid DoustMohammadi Nima GhalEh
Publish Date: 2014/11/29
Volume: 34, Issue: 2, Pages: 411-421
Abstract
Silveractivated Geiger counters together with a polyethylene layer as neutron moderator are frequently used in pulsed neutron flux measurements in research studies with plasma focus PF devices In this study an array of seven counters was used at seven different angles 0° ±30° ±60° and ±90° to the PFaxis for which a software and a 10channel data acquisition hardware PCT2660 compatible with NIM standards have been designed and fabricated In the proposed PCT2660 the preset timing algorithms are considered as general and they can be programmed for required detector calibrations and neutron flux measurements The calibration constant measurement has been undertaken with a 165 Ci Am–Be source of 35 mm diameter by 70 mm cylindrical active volume located at anode top whilst the neutron flux at zero degree of PF device axis at 135 kV operating voltage and 1354 × 10−2 PSI pressure is measured as 288 ± 029 × 108 neutrons per shot Accordingly the studies on the angular distribution of the PF neutron emission within the pressure range of 773 × 10−2–1547 × 10−2 PSI confirm an anisotropy ranging from 153 ± 009 to 295 ± 024 and a symmetry of angular distribution around the anode axisThe authors would like to thank the anonymous reviewers for careful reading of the manuscript and their helpful comments Also the authors would like to express their gratitude to Dr N Q Pourdana the CamTESOL certified editor for proofreading of this article
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