Characterization and use of the new NIST rapid pneumatic tube irradiation facility |
| |
Authors: | D A Becker |
| |
Institution: | (1) Nuclear Methods Group, Analytical Chemistry Division/CSTL, National Institute of Standards and Technology, 20899-0001 Gaithersburg, MD, USA |
| |
Abstract: | Recently a new rapid pneumatic tube facility was inserted into a long unused location in the NIST 20 MW nuclear reactor. This
facility was designed and constructed specifically for rapid INAA using short lived activation products. Included is a computer
controlled console which uses fast sensors to accurately measure the irradiation capsule flight time, and a loss-free counting
system connected to a 32% efficient PHGe detector with a transistor reset preamplifier. Measurement of travel, times from
end-of-irradiation to detector were 473±8 ms. Measurement of the thermal neutron fluence rate was 5.0·1013 n·cm−2·s−1. The other three pneumatic tubes in the NIST reactor have transfer times of 3 to 15 seconds, and no timing capability more
accurate than human response. This new facility substantially improves our ability to accurately determine activation products
with half-lives from 1 to 100 seconds. Characterization information reported on this new irradiation facility includes absolute
fluence measurements, fluence rate variations within the capsule and variations with time, and determination of analytical
sensitivities for fluorine-20 selenium-77m, and silver-110g. |
| |
Keywords: | |
本文献已被 SpringerLink 等数据库收录! |
|