Abstract
Linac surgery is required in radiotherapy activities. However, if Linac operated more than 8 MV can cause additional radiation of neutrons, as well as triggers forming secondary cancer. The study was conducted to determine the distribution of thermal neutron flux and energy responses on the trace. One method to detect neutrons is to use a nuclear trace detector. Measurements were made using a CR-39 detector coated with a Boron radiator. A number of detectors were placed on the surface of the sphere and entered into a 30×30×30 cm 3 fantom. Irradiation is done by placing fantom under Linac gantry with 100cm SSD distance. After irradiation, then etching. The results of the measurements showed that the distribution of thermal neutron fluxes spread in all directions. Linac 10 MV neutron flux value varies, starting at 0° of 1,637×10 3 n/cm 2 .s and decrease at 135°of 1.285×10 3 n/cm 2 s. The highest Linac 15 MV at detector position 0° of 10.723x10 4 n/cm 2 .s and decreased at 135° of 5.142x10 4 n/cm 2 s. This proves that the farther from the source the less the thermal neutron flux value due to the collision process. While Linac 10 MV and 15 MV produce range of diameter ranging from 8.21-16.75 (μm) and 9.21-17.45 (μm), with energy response value 0.5-3.5 MeV. The larger the energy response, the smaller the diameter and vice versa, this is due to the effect of penetration on the depth of the distance resulting in smaller track.
Highlights
Linac surgery is required in radiotherapy activities
if Linac operated more than 8 MV can cause additional radiation
The study was conducted to determine the distribution of thermal neutron flux and energy responses on the trace
Summary
Perkembangan perangkat terapi di bidang radiologi dan kedokteran mengalami kemajuan, salah satunya adalah Linac (linier accelarator) yang biasa digunakan dalam terapi penyakit kanker [1]. Keuntungan perangkat terapi Linac yaitu tidak menggunakan sumber radioaktif secara langsung sehingga aman saat penggunaan dan dijadikan alternatif pengganti alat terapi radiasi kobalt dan cesium [2]. Pendekatan yang cocok untuk melihat sebaran neutron termal yaitu menggunakan detektor jejak nuklir CR-39 dengan penambahan radiator Boron. Tujuannya adalah untuk melihat sebaran yang terdeteksi detektor di masing-masing titik, karena sifat radiasi tidak dapat diamati secara kasat mata, dan hanya bisa terhambur kesegala arah tanpa diketahui daerah mana yang terkena paparan paling besar. Sedangkan untuk mengetahui tanggapan energi dapat dilakukan dengan mengukur diameter bentuk jejak, mengingat masing-masing bentuk jejak mewakili nilai energi yang dipancarkan radiasi, sehingga nilai energi neutron yang terhambur dapat diestimasi. Berdasarkan penelitian yang telah dilakukan sebelumnya, analisis distribusi fluks neutron termal dan tanggapan energi perlu dilakukan untuk mengetahui pengaruh sebaran fluks neutron termal, dan melihat pengaruh bentuk diameter jejak terhadap tanggapan energi radiasi. Sehingga akan dilakukan analisis sebaran fluks pada medium air sebagai pereflektor hamburan
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
