Speaker
Mr
Baochen Wang
(University of Science and Technology of China)
Description
Prompt gamma neutron activation analysis (PGNAA) is a measurement
technique for nondestructive elemental analysis. The method is used intensively for
on-line and in situ analysis in various fields. It has a short measurement time, usually
only about 120s. In order to ensure the measurement accuracy and get better statistics,
the measurement system requires a high count rate, which is an important indicator of
PGNAA.
Industrial field applications must have large detector sizes to increase the
detection efficiency. A sodium iodide (NaI) detector which size is 6×7 inch is used.
Resistor divider structure is used in conventional PMT base board. At high count
rate condition, the drive current would be insufficient and the output signal would be
distorted, which leaded to the destruction of the linear relationship between the PMT
output signal amplitude and the incident particle energy. The upper limit of energy
spectrum is only 5MeV at 100k count rate.
In this paper, a PMT base board with current amplification design has been
developed. The PNP transistor is used to amplify the drive current. It can avoid the
AC coupling and can achieve small size. The test results show that the design satisfies
the drive current demand at high count rate. The design increases the upper limit of
energy spectrum to 10MeV at 250k count rate, which improves the resolution of
elements.
Primary author
Mr
Baochen Wang
(University of Science and Technology of China)
