Dwi Satya Palupi
Kelompok Penelitian Kosmologi, Astrofisika, dan Fisika Matematik (KAM) Jurusan Fisika FMIPA UGM, Yogyakarta

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Persamaan Fokker Planck dan Aplikasinya Dalam Astrofisika

BERKALA FISIKA Vol 13, No 2 (2010): Berkala Fisika, Edisi Khusus
Publisher : BERKALA FISIKA

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Abstract

Abstract It has been established Fokker-Planck equation to obtain the evolution of particle distribution functions that describe the motion of particles in a fluid that can not be described by the Liouville equation. Fokker-Planck equation contains a diffusion component particles and the interaction between the particles will be discussed application of Fokker-Planck equation in astrophysics since the plasma in the form of interstellar space so that there is interaction between the particles making up the plasma.   Keywords: Fokker-Planck, plasma, astrophysics

Konsep Massa Ekonomis Sebagai Ukuran Kelembaman Pelaku Ekonomi Dalam Ruang Harga (Kajian Mekanika Kuantum Dalam Ekonomi Mikro)

BERKALA FISIKA Vol 13, No 2 (2010): Berkala Fisika, Edisi Khusus
Publisher : BERKALA FISIKA

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Abstract

This paper has studied the correlation of economic systems in the market for goods by using the concept of state and the concept of observable in quantum mechanics.Also proposed the concept of economical mass as an economic actor counterparts concept of inertia or inertia in physics. Studied the things that determine the mass of a principal economic economical. Discussed the possibility of applying the model to market goods with commodities and M N economic actors using the concept of Quantum Many Body Problem. Keywords: Ekonofisika, Applied Physics, Massa economical, Quantum many-body problem

OPTIMIZATION OF BIOLOGICAL SHIELD FOR BORON NEUTRON CAPTURE CANCER THERAPY (BNCT) AT KARTINI RESEARCH REACTOR

JURNAL TEKNOLOGI REAKTOR NUKLIR TRI DASA MEGA Vol 19, No 3 (2017): Oktober 2017
Publisher : Pusat Teknologi Dan Keselamatan Reaktor Nuklir (PTKRN)

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Abstract

A study to optimize a model of neutron radiation shielding for BNCT facility in the irradiation room has been performed. The collimator used in this study is a predesigned collimator from earlier studies. The model includes the selection of the materials and the thickness of materials used for radiation shield. The radiation shield is required to absorb leaking radiation in order to protect workers at the threshold dose of 20 mSv/year. The considered materials were barite concrete, paraffin, stainless steel 304 and lead. The leaking neutron radiation dose rates have been determined using Monte Carlo N Particle Version Extended (MCNPX) with a radiation dose limit rate that is less than 10 µSv/hour. This dose limit is in accordance with BAPETEN regulation related the threshold dose for workers, in which the working duration is 8 hours per day and 5 days per week. It is recommended that the best model for the irradiation room has a dimension 30 cm width, 30 cm length, 30 cm height and a main layer of irradiation room shielding made from the material paraffin which is 68 cm thickness on the left side and bottom of the irradiation room, 70 cm thickness on the right side of the iradiation room, 45 cm thickness on the front of the irradiation room and 67 cm thickness on the top of the irradiation room. The additional layers of 15 cm and 10 cm thickness are used along with paraffin in order to reduce the intensity of primary radiation from piercing the beamport after two primary layers. There is no neutron radiation leakage in this model.Keywords: Radiation shielding, BNCT, MCNPX, radiation dose rate, piercing beamport. OPTIMASI PERISAI RADIASI NEUTRON FASILITAS RUANGAN IRADIASI UNTUK BORON NEUTRON CAPTURE CANCER THERAPY (BNCT) DENGAN SUMBER BEAMPORT TEMBUS REAKTOR KARTINI. Telah dilakukan pemodelan perisai radiasi neutron untuk fasilitas Boron Neutron Capture Therapy (BNCT) pada sekeliling ruangan iradiasi. Pemodelan mencakup pemilihan bahan dan tebal yang digunakan untuk perisai radiasi. Perisai diharuskan mampu menahan radiasi yang keluar ruangan sehingga dosis radiasi berada di bawah ambang dosis bagi pekerja radiasi sebesar 20 mSv/tahun. Bahan yang dipertimbangkan adalah beton barit, paraffin, stainless steel 304 dan timbal. Perhitungan laju dosis neutron epitermal dilakukan dengan menggunakan program Monte Carlo N Particle Version Extended (MCNPX) dengan batasan laju dosis radiasi kurang dari 10 µSv/jam, sesuai dengan peraturan Kepala BAPETEN mengenai batas ambang laju dosis pekerja radiasi, dengan asumsi perhitungan waktu kerja 8 jam per hari dan 5 hari per minggu. Desain pertama dari empat desain yang telah dibuat kemudian dipilih sebagai desain yang direkomendasikan dengan laju dosis di bawah batas ambang 10 µSv/jam. Ruangan iradiasi memiliki dimensi panjang 30 cm, lebar 30 cm dan tinggi 30 cm. Lapisan utama perisai pada desain pertama berbahan paraffin setebal 68 cm pada sisi kiri dan bawah ruangan, 70 cm pada sisi kanan ruangan, 45 cm pada sisi depan ruangan dan 67 cm pada sisi atas ruangan. Paraffin setebal 15 cm dan 10 cm ditambahkan sebagai peredam intensitas radiasi primer dari beamport tembus yang masih cukup besar.Kata Kunci: perisai radiasi, BNCT, MCNPX, laju dosis radiasi, beamport tembus.

Dosimetry of In Vivo Experiment for Lung Cancer Based on Boron Neutron Capture Therapy on Radial Piercing Beam Port Kartini Nuclear Reactor by MCNPX Simulation Method

ASEAN Journal on Science and Technology for Development Vol 35 No 3 (2018): Developments in Nuclear Techniques in the Treatment of Cancer
Publisher : Universitas Gadjah Mada

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Abstract

Cancer is one of the leading causes of death globally, with lung cancer being among the most prevalent. Boron Neutron Capture Therapy (BNCT) is a cancer therapy method that uses the interaction between thermal neutrons and boron-10 which produces a decaying boron-11 particle and emits alpha, lithium 7 and gamma particles. A study was carried out to model an in vivo experiment of rat organisms that have lung cancer. Dimensions of a rat’s body were used in Konijnenberg research. Modeling lung cancer type, non-small cell lung cancer, was used in Monte Carlo N Particle-X. Lung cancer was modeled with a spherical geometry consisting of 3 dimensions: PTV, GTV, and CTV. In this case, the neutron source was from the radial piercing beam port of Kartini Reactor, Yogyakarta. The variation of boron concentration was 20, 25, 30, 35, 40, and 40 µg/g cancer. The output of the MCNP calculation was neutron scattering dose, gamma-ray dose and neutron flux from the reactor. A neutron flux was used to calculate the alpha proton and gamma-ray dose from the interaction of tissue material and thermal neutrons. The total dose was calculated from a four-dose component in BNCT. The results showed that the dose rate will increase when the boron concentration is higher, whereas irradiating time will decrease.

Characteristics in Water Phantom of Epithermal Neutron Beam Produced by Double Layer Beam Shaping Assembly

ASEAN Journal on Science and Technology for Development Vol 36 No 1 (2019)
Publisher : Universitas Gadjah Mada

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Abstract

A Double Layer Beam Shaping Assembly (DLBSA) was designed to produce epithermal neutrons for BNCT purposes. The Monte Carlo N-Particle eXtended program was used as the software to design the DLBSA and phantom. Distribution of epithermal neutron and gamma flux in the DLBSA and phantom and absorbed dose in the phantom were computed using the Particle and Heavy Ion Transport code System program. Testing results of epithermal neutron beam irradiation of the water phantom showed that epithermal neutrons were thermalized and penetrated the phantom up to a depth of 12 cm. The maximum value of the absorbed dose was 2 × 10-3 Gy at a depth of 2 cm in the phantom.