Accurate activity determination of a californium neutron source.
Appl Radiat Isot
; 194: 110712, 2023 Apr.
Article
in En
| MEDLINE
| ID: mdl-36764223
ABSTRACT
Accurately counting analog events requires constructing an electronics chain that produces one count for each input pulse. In this work we review the use of Nuclear Instrumentation Module electronic units for counting neutron capture events in a 3He tube. We identify two unique types of false trigger events in a leading-edge discriminator and show how a dual timer module can be used to produce a veto window to exclude these events. We use the constructed electronics chain to build an apparatus to measure neutron pulses from a 252Cf neutron source. We compare the measurements with a Monte Carlo N-Particle (MCNP) model to determine the activity of the neutron source. Furthermore, by making additional measurements with borated polyethylene attenuators between the source and detector, we are able to determine the boron concentration of the polyethylene. This technique provides accurate determination of the source activity to a precision of 2.8% at the k = 1 level. The method used is simple, inexpensive, and requires no additional calibrated instruments.
Full text:
1
Collection:
01-internacional
Database:
MEDLINE
Language:
En
Journal:
Appl Radiat Isot
Journal subject:
MEDICINA NUCLEAR
/
SAUDE AMBIENTAL
Year:
2023
Document type:
Article