Cadmium-Lined In-Core Irradiation Tube (CLICIT)

Image

Description

Just like the ICIT, the Cadmium-Lined in-Core Irradiation Tube (CLICIT) is an internally dry tube designed to irradiate samples in the reactor core at the highest neutron flux region.  The CLICIT is a 1.25 inch aluminum tube that runs from the reactor to the B-1 core position, near the center of the core.  The CLICIT differs from the ICIT in that it has a 0.0200 inch layer of cadmium within the tube wall over the vertical length of the core.  An offset bend, designed to limit radiation streaming, limits the sample size to a length of 4 inches.The CLICIT is arguably the most “popular” facility at the OSTR and is primarily used for ⁴⁰Ar/³⁹Ar age dating, as the necessary reaction of ³⁹K(n,p)³⁹Ar is a threshold reaction that takes place in the fast neutron energy spectrum. Irradiating samples in the CLICIT removes most of the “noise” from thermal neutron reactions.

The CLICIT facility has been calibrated for neutron damage studies using the methodologies outlined in ASTM E 721, Standard Guide for Determining Neutron Energy Spectra from Neutron Sensors for Radiation-Hardness Testing of Electronics, and ASTM E 722, Standard Practice for Characterizing Neutron Energy Spectra in Terms of an Equivalent Monoenergetic Neutron Fluence for Radiation-Hardness Testing of Electronics. The CLICIT facility is equipped to handle biased components (i.e., real-time measurements) in both steady-state and pulse reactor modes with an established 1 MeV-equivalent damage flux in silicon of 6.3E9 n kW^-1 s^-1.