Mondjo Mondjo, Mondjo
Jurusan Teknik Fisika, Fakultas Teknik, Universitas Gadjah Mada

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Program Komputer Berbasis Delphi untuk Analisis Perhitungan Persebaran Dosis Radiasi Pesawat Sinar-X dalam Bentuk Kurva Isodosis Adzdzantyawan, Anggrata; Mondjo, Mondjo; Waseso, Probo
Teknofisika Vol 3, No 1 (2014)
Publisher : Jurusan Teknik Fisika, Fakultas Teknik, Universitas Gadjah Mada

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Abstract

Pada instalasi radiasi seperti instalasi radiologi, aspek keselamatan pekerja radiasi harus diperhatikan. Setiap pekerja radiasi harus mengenali medan tempatnya melakukan pekerjaannya dengan tersedianya informasi yang jelas mengenai tingkat radiasi, terlebih radiasi sekunder. Bentuk informasi medan radiasi tersebut divisualisasikan dalam bentuk kurva isodosis. Analisis persebaran dan besarnya dosis radiasi sekunder di sekitar pesawat sinar-X dilakukan dengan adanya visualisasi informasi tersebut. Pembuatan program komputer sebagai alat bantu peraga bertujuan untuk mempermudah melakukan analisis kurva isodosis. Pada penelitian ini, dilakukan pengukuran laju dosis radiasi sekunder menggunakan phantom air sebagai media penghambur pada sudut hambur 90° dengan tabung pesawat sinar-X diarahkan ke bawah tegak lurus meja pasien pada 7 arah sudut di sekeliling phantom air, di setiap arahnya divariasikan 3 jarak titik pengambilan. Selanjutnya data yang sudah terkumpul akan diolah dengan menghitung laju dosis di setiap sudutnya, kemudian menghubungkan laju dosis yang sama antar sudut dan menghitung laju dosis pada titik-titik tertentu. Berdasarkan tahapan tersebut selanjutnya dibuat program komputer berbasis Delphi. Pengujian dilakukan dengan analisa data hasil perhitungan laju dosis radiasi menggunakan program dibandingkan dengan pengukuran sebenarnya. Hasil pengujian program tersebut didapat selisih hasil laju dosis menggunakan perhitungan program dengan pengukuran berkisar pada rentang 10,830-32,050% dan selisih rerata sebesar 17,334%.
PENGARUH FAKTOR IKLIM TERHADAP POLA SEBARAN INTEGRAL KONSENTRASI KONTAMINAN RADIOAKTIF TAHUNAN DARI CEROBONG REAKTOR KARTINI YOGYAKARTA KE UDARA LINGKUNGAN SEKITARNYA Mondjo, Mondjo; Sudibyakto, Sudibyakto
Jurnal Sains & Teknologi Modifikasi Cuaca Vol 1, No 2 (2000): December 2000
Publisher : BPPT

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Abstract

This research is to study the impact of climate factors and environmental risk due tooperation of The Nuclear Reactor of Kartini that is proportional to the annual integratedconcentration of the radioactive contaminant into the air of surrounding areas A research has been done to design a mathematical model to relate the annual integrated concentration of the radioactive contaminant with the radioactive contaminant released from the Reactor of Kartini (the rate the effluents are released, type of the radioactive contaminant, dimension of stack), and climatological factor (wind direction, wind speed, solar radiation percentage) . The result shown that the maximum of annual integrated concentration of the radioactive contaminant of Argon-41 had been on the decrease but variation of the annual climatological factor was not significant with the distribution of it. The map of the annual integrated concentration of Argon-41 shown up the maximum of 3 the annual integrated concentration of Argon-41 was 0,6 μ Ci/m . The area where had the 3 value of the annual integrated concentration of Argon-41 of 0,4 – 0,6 μ Ci/m (equal to the -5 3mean concentration of Argon-41 of 4,04 – 6,06 × 10 μ Ci/m ) for the direction of 60° onthe distance of 200 – 1075 m, the direction of 30° on the distance of 200 – 800 m, and the direction of 90° on the distance of 300 – 575 m. The contribution of contaminant released from the stack of the Reactor of Kartini was lower than the natural radioactivity so the operation of the Reactor of Kartini was not significant with the degree of theenvironmental radioactivity.
Calculation of Absorbed Dose Distribution for Breast Brachytherapy Simulation By CS-1 131Cs Seed and ADVANTAGETM 103Pd Seed Using Monte Carlo N Particle Extended Simulator Rahmat, Faisal Reza; Mondjo, Mondjo; Agung, Alexander
Indonesian Journal of Physics and Nuclear Applications Vol 2 No 2 (2017)
Publisher : Fakultas Sains dan Matematika Universitas Kristen Satya Wacana

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Abstract

Simulation using Monte Carlo code has been conducted to determine the distribution of absorbed dose to the breast brachytherapy with 131Cs and 103Pd radionuclide sources. Simulations performed on stage I breast cancer with cancer diameter is 2 cm. Sources of radionuclides simulated in the form of seed is modeled with CS-1 which is made by IsoRay 131Cs and seed ADVANTAGETM103Pd which is made by IsoAID, LLC. Seed was planted in breast cancer cells. Calculation of absorbed dose distribution was performed by varying the distance from the seed. Variations of the distance started from a radius of 0.3 cm to 2 cm with a range of 0.1 cm respectively. In this simulation will also be reviewed the value of absorbed dose for healthy cell like breast, sternum, and lung. The relation between the absorbed dose and the distance from the seed can be described in the form of power law. The results of the calculation show that the maximum absorbed dose is in the target site of the cancer cells (5.791 ± 0.002) Gy per 5 MBq of 131Cs and (2.755 ± 0.009) Gy per 5 MBq for 103Pd. The absorbed dose at sternum (1.514 ± 0.011) x 10-4 Gy per 5 MBq of 131Cs and (7.515 ± 0.633) x 10-7 Gy per 5 MBq for 103Pd. While the absorbed dose in the lungs is and (3.615 ± 0.082) x 10-5 Gy per 5 MBq for 131Cs and (3.972 ± 0.591) x 10-8 Gy per 5 MBq for 103Pd.