NEUTRON AND GAMMA SPECTRUM ANALYSIS OF KARTINI RESEARCH REACTOR FOR BORON NEUTRON CAPTURE THERAPY (BNCT)

NEUTRON AND GAMMA SPECTRUM ANALYSIS OF KARTINI RESEARCH REACTOR
FOR BORON NEUTRON CAPTURE THERAPY (BNCT). MCNPX was used to design a threedimensional
model of Kartini Research Reactor (KRR) as a neutron source and performed criticality
calculation. The criticality calculation of the reactor aims to obtain the neutron and gamma spectrum by
simulating the fission reaction inside the reactor core. Total source histories were 105 per cycle, when the
number of cycle for criticality calcutation was 1000 cycles with 60 skipped cycles. The reactor criticality
according to the simulation result is 1.00179±0.00007. The total neutron flux on ring A, B, C, D, E and F
inside the reactor core are respectively 6.553×1011 n/cm2s, 4.53×1012 n/cm2s, 4.167×1012 n/cm2s,
3.751×1012 n/cm2s, 2.914×1012 n/cm2s and 3.107×1012 n/cm2s. The total gamma flux is 6.956×1011
particles/cm2s, 4.838×1012 particles/cm2s, 4.398×1012 particles/cm2s, 3.962×1012 particles/cm2s,
2.953×1012 particles/cm2s and 2.013×1012 particles/cm2s, respectively for each ring. Thermal neutron
fluxes recorded on the base of radial piercing beamport were 4.678×1010 n/cm2s, with the epithermal
neutron flux of 5.37×109 n/cm2s and fast neutron flux of 4.17×1010 n/cm2s. The gamma flux on that side
reaches 4.22×1012 particles/cm2s. On the 92-cm-ranges from the base inside radial piercing beamport,
both neutron and gamma flux decrease up to 5.11×108 n/cm2s for thermal neutron flux, 4.598×106 n/cm2s
for epithermal neutron flux, 2.55×107 n/cm2s for fast neutron flux and 8.214×1010 particles/cm2s for
gamma flux. In conclusion, the spectrum yield from this study can be use to define the source spectrum of
the simulations and optimations prior to BNCT pre-clinical trial (in vivo/in vitro test) use KRR radial
piercing beamport.