Response of a lithium gadolinium borate scintillator in monoenergetic neutron fields.
Accurate estimation of neutron dose requires knowledge of the neutron energy distribution in the working environment. Existing neutron spectrometry systems, Bonner spheres for example, are large and bulky, and require long data acquisition times. A portable system that could indicate the approximate neutron energy spectrum in a short time would be extremely useful in radiation protection. A composite scintillator, consisting of lithium gadolinium borate crystals in a plastic scintillator matrix, produced by Photogenics is being tested for this purpose. A prototype device based on this scintillator and digital pulse processing electronics has been calibrated using quasi-monoenergetic neutron fields at the low-scatter facility of the UK National Physical Laboratory (NPL). Energies selected were 144, 250, 565, 1400, 2500 and 5000 keV, with correction for scattered neutrons being made using the shadow cone technique. Measurements were also made in the NPL thermal neutron field. Pulse distributions collected with the digitiser in capture-gated mode are presented, and detection efficiency and energy resolution derived. For comparison, neutron spectra were also collected using the commercially available Microspec N-Probe from Bubble Technology Industries, which consists of an NE213 scintillator and a 3He proportional counter.
Williams
A M
AM
Nuclear Department, HMS Sultan, Gosport, PO12 3BY, UK. mbsy52@popex.com
Beeley
P A
PA
Spyrou
N M
NM
D000465:Algorithms; D001822:Body Burden; D001881:Borates / Q000737:chemistry / Q000528:radiation effects*; D004867:Equipment Design; D019544:Equipment Failure Analysis / Q000379:methods*; D005682:Gadolinium / Q000737:chemistry / Q000528:radiation effects*; D006801:Humans; D018499:Linear Energy Transfer; D018020:Lithium Compounds / Q000737:chemistry / Q000528:radiation effects*; D008904:Miniaturization; D009502:Neutrons; D011829:Radiation Dosage; D011835:Radiation Protection / Q000295:instrumentation* / Q000379:methods; D011874:Radiometry / Q000295:instrumentation* / Q000379:methods; D012062:Relative Biological Effectiveness; D015203:Reproducibility of Results; D018570:Risk Assessment / Q000379:methods*; D012307:Risk Factors; D012588:Scintillation Counting / Q000295:instrumentation* / Q000379:methods; D012680:Sensitivity and Specificity; D012815:Signal Processing, Computer-Assisted / Q000295:instrumentation*
D001881:Borates; D018020:Lithium Compounds; C494376:lithium gadolinium borate; D005682:Gadolinium