Widyanti, Kurnia Nur (2018) Studi Distribusi Fluks Neutron Termal Dan Energi Yang Dihasilkan Linac Menggunakan Detektor Cr-39 Pada Medium Air. Magister thesis, Universitas Brawijaya.
Abstract
Operasi Linac diperlukan dalam kegiatan radioterapi. Akan tetapi jika Linac dioperasikan lebih dari 8 MV dapat menimbulkan radiasi tambahan berupa neutron, sekaligus pemicu pembentuk kanker sekunder. Penelitian dilakukan untuk menentukan sebaran fluks neutron termal dan tanggapan energi pada jejak. Salah satu metode untuk mendeteksi neutron yaitu menggunakan detektor jejak nuklir. Pengukuran dilakukan menggunakan detektor CR-39 yang dilapisi radiator Boron. Sejumlah detektor diletakkan pada permukaan fantom bola dan dimasukkan kedalam fantom berukuran 30x30x30cm3. Penyinaran dilakukan dengan menempatkan fantom dibawah gantry Linac dengan jarak SSD 100cm. Setelah penyinaran, kemudian dilakukan etsa. Hasil pengukuran menunjukkan distribusi fluks neutron termal menyebar kesegala arah. Nilai fluks neutron Linac 10 MV bervariasi, mulai tertinggi di kedalaman 00 sebesar 6.637x103 n/cm2.s dan mulai menurun sampai pada kedalaman 1350 sebesar 1.285x103 n/cm2.s, begitu juga Linac 15 MV tertinggi di kedalaman 00 sebesar 10.723x104 n/cm2.s dan menurun sampai kedalaman 1350 sebesar 5.142x104 n/cm2.s, hal ini membuktikan bahwa semakin jauh dari sumber semakin berkurang nilai fluks neutron termal akibat proses tumbukan. Sedangkan Linac 10 MV dan 15 MV menghasilkan rentang diameter berkisar 8.21-16.75 (μm) dan 9.21-17.45 (μm), dengan nilai tanggapan energi 0.5-3.5 MeV. Semakin besar tanggapan energi, semakin kecil diameter begitu juga sebaliknya, hal ini diakibatkan pengaruh penetrasi pada kedalaman jarak yang mengakibatkan jejak semakin kecil
English 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 30x30x30cm3 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 a depth of 00 of 6.637x103 n/cm2.s and starting to decrease to a depth of 1350 of 1.285x103 n/cm2.s, as well as the highest Linac 15 MV at a depth of 00 of 10.723x104 n/cm2.s and decreased to a depth of 1350 of 5.142x104 n/cm2.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.
| Item Type: | Thesis (Magister) |
|---|---|
| Identification Number: | TES/539.733/WID/s/2018/041804763 |
| Uncontrolled Keywords: | LINEAR ACCCELERATORS, NEUTRONS, NEUTRON FLUX |
| Subjects: | 500 Natural sciences and mathematics > 539 Modern physics > 539.7 Atomic and nuclear physics > 539.73 Particle acceleration > 539.733 Resonance accelerators |
| Divisions: | S2/S3 > Doktor Fisika, Fakultas MIPA |
| Depositing User: | Nur Cholis |
| Date Deposited: | 20 Mar 2019 03:28 |
| Last Modified: | 20 Mar 2019 03:28 |
| URI: | http://repository.ub.ac.id/id/eprint/165654 |
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