ABSTRAK
Telah dilakukan penelitian tentang optimasi pemandu berkas neutron dan hasil berkas neutron tersebut diiradiasikan ke phantom untuk dianalisis laju dosis fotonnya. Sebelum dilakukan optimasi, hasil penelitian telah divalidasi, dan diketahui kesalahan relatif penelitian adalah 77,21%. Optimasi pemandu berkas neutron dilakukan dengan penambahan filter neutron di depan apperture. Dari optimasi yang dilakukan diketahui desain pemandu berkas neutron dengan filter AlF3, dengan fluks neutron epitermal sebesar 3,85 ×107 cm-2.s-1. Berkas tersebut diiradiasikan ke phantom dan diperoleh laju dosis foton terbesar diterima oleh sel kanker sebesar 1,19 × 10-5 Gy/s.  Selanjutnya, dosis foton terdistribusi secara berturut- turut pada otak sehat, tengkorak, kulit kepala, tulang belakang bagian atas dan tulang wajah sebesar (8,52, 7,31, 4,24, 2,56 dan 2,42) × 10-6 Gy/s. Pada organ bagian dada, laju dosis foton yang diterima berorde 10-7 Gy/s. Dan terus mengalami penurunan untuk organ di daerah perut dan kaki yaitu berorde 10-8 dan 10-10 Gy/s.
Kata kunci: Laju dosis foton, pemandu berkas neutron, BNCT, GBM, MCNPX
ABSTRACT
Optimation of neutron beam guide with simulation using MCNPX have been done. The results of the neutron beam was irradiated to the phantom, and the photon dose rate have been analyzed. Before the optimization, the results of the research have been validated and known that ratio of the fast neutron dose rate and epihermal neutron flux was decrease with increasing of the fast neutron filter thickness. Optimation of neutron beam guide have been done by adding a neutron filter in front of the aperture. Desaign of neutron beam guide that performed the optimum result have been shown by the neutron beam guide with AlF3 filter and the epithermal neutron flux is 3.85 × 107 cm-2.s-1. The beam have been irradiated to the ORNL-MIRD phantom with glioblastoma multiforme brain cancer (GBM) and the largest photon dose rate received by the cancer cells, 1.19 × 10-5 Gy / s. Furthermore, the dose of photons distributed consecutively in the healthy brain, skull, scalp, upper spine and facial bones, (8.52, 7.31, 4.24, 2.56 and 2.42) × 10- 6 Gy / s. In the internal organs of the chest, the dose rate of photons received about 10-7 Gy / s. And continued to decline for the organs in the abdomen and legs are about 10-8 and 10-10 Gy / s. For exposure time 60 minute, the healty cell received dose that lower than permission.
Key word: photon dose rate, neutron beam’s guide, BNCT, GBM, MCNPX