Sains
Malaysiana 37(4): 401-404 (2008)
Assessment of Neutron Flux Gradients in Irradiation
Channels at the
TRIGA Reactor by Au-Cr-Mo Monitor Set Based
on k0-INAA
(Penilaian Tentang Kecerunan Fluks Neutron
Dalam Saluran Penyinaran di Reaktor
TRIGA Dengan Set Pemonitor Au-Cr-Mo Berdasarkan
ko-APNI)
Khoo Kok Siong & Ti Kien Leong
Nuclear Science Programme
School of Applied Physics, Faculty of Science and Technology
Universiti Kebangsaan Malaysia, 43600 Bangi, Selangor,
Malaysia
Sukiman Sarmani & Amran Majid
Chemistry Programme, School of Chemical Sciences &
Food Technology
Universiti Kebangsaan Malaysia, 43600 Bangi, Selangor,
Malaysia
Received: 4 January 2008 / Accepted: 4 April 2008
ABSTRACT
A gradient of neutron flux distribution in an irradiation channel
in research reactor is considered to have effect on the k0-instrumental
neutron activation analysis (k0-INAA) measurement.
A study has been carried out to determine: (1) the variation
of the thermal to epithermal neutron flux ratio (f);
(2) the epithermal neutron flux shape factor (α),
and (3) the neutron flux in an irradiation container at four
selected irradiation channels, use being made of an Au-Cr-Mo
monitor set. In this work, f was found to range from
15.5 – 16.3, while α was found to range from 1.52
x 10-2 – 5.58 x 10-2. Additionally, within
the selected irradiation channels the variation in calculated
thermal neutron flux within one irradiation container was found
to vary from 11.8% - 26.7%. The results of analysis have provided
a determination of variation in the neutron parameters, f
and α, and neutron flux between the irradiation
channels and within the irradiation container.
Keywords: k0-INAA; neutron flux distribution; neutron
parameters
ABSTRAK
Kecerunan taburan fluks neutron pada saluran penyinaran dalam reaktor
penyelidikan boleh memberikan kesan kepada pengukuran analisis
pengaktifan neutron instrumentasi k0 (k0-APNI).
Satu kajian telah dilakukan untuk menentukan: (1) variasi nisbah
fluks neutron terma kepada fluks neutron epiterma (f);
(2) faktor pembentukan fluks neutron epiterma (α),
dan (3) fluks neutron dalam satu bekas penyinaran pada empat
saluran penyinaran terpilih dengan menggunakan set pemantau
Au-Cr-Mo. Dalam kerja ini, f adalah dalam julat 15.5
– 16.3 dan α menunjukkan julat di antara 1.52 x
10-2 – 5.58 x 10-2. Tambahan, variasi
fluks neutron terma yang dikira dalam satu bekas penyinaran
mempunyai perbezaan dari 11.8% - 26.7% pada saluran penyinaran
terpilih. Keputusan analisis membuktikan terdapat variasi dalam
parameter neutron, f dan α, serta fluks neutron
di antara saluran penyinaran dan dalam bekas penyinaran.
Kata kunci: k0-APNI; taburan fluks neutron ; parameter
neutron
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