Comparison of Pulse Train Recorder Module (PTR) and Shift Register Multiplicity Measurements Using the Large Volume Active Well Coincidence Counter (LV-AWCC)

摘要

The Pulse Train Recorder Module, designated PTR-32, recently was authorized for use by the International Atomic Energy Agency as an alternative, in some applications, to shift-register-based neutron correlation counting data acquisition modules. In addition to system characterization and state of health diagnostics benefits, the use of list mode data acquisition with neutron coincidence counting systems such as the Large Volume Active Well Coincidence Counter (LV-AWCC) has the potential to provide additional assay information such as die-away time for each item assayed. The PTR-32 is both source tagged and time tagged, providing 32 input channels that can be subdivided into convenient geometric groupings, facilitating acquisition of coincident ring ratios without the need for multiple shift-register modules. This additional information ultimately may be useful for determination of the moderator content or average neutron emission energy for the item, which then can be used to help verify declaration or to estimate appropriate response correction factors. Comparison testing of the PTR-32 with a commonly used commercial multiplicity shift register was performed using Oak Ridge National Laboratory's LV-AWCC. In this paper, we present basic performance comparisons, such as count rates and dead time parameters obtained from ~(252)Cf point sources as well as results from a typical ~(235)U calibration, for both the PTR-32 Pulse Train Recorder and the JSR-15 Multiplicity Shift Register.