• 제목/요약/키워드: heavy ion beam

검색결과 70건 처리시간 0.029초

Comparison analysis of superconducting solenoid magnet systems for ECR ion source based on the evolution strategy optimization

  • Wei, Shaoqing;Lee, Sangjin
    • 한국초전도ㆍ저온공학회논문지
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    • 제17권2호
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    • pp.36-40
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    • 2015
  • Electron cyclotron resonance (ECR) ion source is an essential component of heavy-ion accelerator. For a given design, the intensities of the highly charged ion beams extracted from the source can be increased by enlarging the physical volume of ECR zone [1]. Several models for ECR ion source were and will be constructed depending on their operating conditions [2-4]. In this paper three simulation models with 3, 4 and 6 solenoid system were built, but it's not considered anything else except the number of coils. Two groups of optimization analysis are presented, and the evolution strategy (ES) is adopted as an optimization tool which is a technique based on the ideas of mutation, adaptation and annealing [5]. In this research, the volume of ECR zone was calculated approximately, and optimized designs for ECR solenoid magnet system were presented. Firstly it is better to make the volume of ECR zone large to increase the intensity of ion beam under the specific confinement field conditions. At the same time the total volume of superconducting solenoids must be decreased to save material. By considering the volume of ECR zone and the total length of solenoids in each model with different number of coils, the 6 solenoid system represented the highest coil performance. By the way, a certain case, ECR zone volume itself can be essential than the cost. So the maximum ECR zone volume for each solenoid magnet system was calculated respectively with the same size of the plasma chamber and the total magnet space. By comparing the volume of ECR zone, the 6 solenoid system can be also made with the maximum ECR zone volume.

Measurement of Neutron Production Double-differential Cross-sections on Carbon Bombarded with 430 MeV/Nucleon Carbon Ions

  • Itashiki, Yutaro;Imahayashi, Youichi;Shigyo, Nobuhiro;Uozumi, Yusuke;Satoh, Daiki;Kajimoto, Tsuyoshi;Sanami, Toshiya;Koba, Yusuke;Matsufuji, Naruhiro
    • Journal of Radiation Protection and Research
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    • 제41권4호
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    • pp.344-349
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    • 2016
  • Background: Carbon ion therapy has achieved satisfactory results. However, patients have a risk to get a secondary cancer. In order to estimate the risk, it is essential to understand particle transportation and nuclear reactions in the patient's body. The particle transport Monte Carlo simulation code is a useful tool to understand them. Since the code validation for heavy ion incident reactions is not enough, the experimental data of the elementary reaction processes are needed. Materials and Methods: We measured neutron production double-differential cross-sections (DDXs) on a carbon bombarded with 430 MeV/nucleon carbon beam at PH2 beam line of HIMAC facility in NIRS. Neutrons produced in the target were measured with NE213 liquid organic scintillators located at six angles of 15, 30, 45, 60, 75, and $90^{\circ}$. Results and Discussion: Neutron production double-differential cross-sections for carbon bombarded with 430 MeV/nucleon carbon ions were measured by the time-of-flight method with NE213 liquid organic scintillators at six angles of 15, 30, 45, 60, 75, and $90^{\circ}$. The cross sections were obtained from 1 MeV to several hundred MeV. The experimental data were compared with calculated results obtained by Monte Carlo simulation codes PHITS, Geant4, and FLUKA. Conclusion: PHITS was able to reproduce neutron production for elementary processes of carbon-carbon reaction precisely the best of three codes.

Evaluation of dose distribution from 12C ion in radiation therapy by FLUKA code

  • Soltani-Nabipour, Jamshid;Khorshidi, Abdollah;Shojai, Faezeh;Khorami, Khazar
    • Nuclear Engineering and Technology
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    • 제52권10호
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    • pp.2410-2414
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    • 2020
  • Heavy ions have a high potential for destroying deep tumors that carry the highest dose at the peak of Bragg. The peak caused by a single-energy carbon beam is too narrow, which requires special measures for improvement. Here, carbon-12 (12C) ion with different energies has been used as a source for calculating the dose distribution in the water phantom, soft tissue and bone by the code of Monte Carlobased FLUKA code. By increasing the energy of the initial beam, the amount of absorbed dose at Bragg peak in all three targets decreased, but the trend for this reduction was less severe in bone. While the maximum absorbed dose per bone-mass unit in energy of 200 MeV/u was about 30% less than the maximum absorbed dose per unit mass of water or soft tissue, it was merely 2.4% less than soft tissue in 400 MeV/u. The simulation result showed a good agreement with experimental data at GSI Darmstadt facility of biophysics group by 0.15 cm average accuracy in Bragg peak positioning. From 200 to 400 MeV/u incident energy, the Bragg peak location increased about 18 cm in soft tissue. Correspondingly, the bone and soft tissue revealed a reduction dose ratio by 2.9 and 1.9. Induced neutrons did not contribute more than 1.8% to the total energy deposited in the water phantom. Also during 12C ion bombardment, secondary fragments showed 76% and 24% of primary 200 and 400 MeV/u, respectively, were present at the Bragg-peak position. The combined treatment of carbon ions with neutron or electron beams may be more effective in local dose delivery and also treating malignant tumors.

Bragg-curve simulation of carbon-ion beams for particle-therapy applications: A study with the GEANT4 toolkit

  • Hamad, Morad Kh.
    • Nuclear Engineering and Technology
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    • 제53권8호
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    • pp.2767-2773
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    • 2021
  • We used the GEANT4 Monte Carlo MC Toolkit to simulate carbon ion beams incident on water, tissue, and bone, taking into account nuclear fragmentation reactions. Upon increasing the energy of the primary beam, the position of the Bragg-Peak transfers to a location deeper inside the phantom. For different materials, the peak is located at a shallower depth along the beam direction and becomes sharper with increasing electron density NZ. Subsequently, the generated depth dose of the Bragg curve is then benchmarked with experimental data from GSI in Germany. The results exhibit a reasonable correlation with GSI experimental data with an accuracy of between 0.02 and 0.08 cm, thus establishing the basis to adopt MC in heavy-ion treatment planning. The Kolmogorov-Smirnov K-S test further ascertained from a statistical point of view that the simulation data matched the experimentally measured data very well. The two-dimensional isodose contours at the entrance were compared to those around the peak position and in the tail region beyond the peak, showing that bone produces more dose, in comparison to both water and tissue, due to secondary doses. In the water, the results show that the maximum energy deposited per fragment is mainly attributed to secondary carbon ions, followed by secondary boron and beryllium. Furthermore, the number of protons produced is the highest, thus making the maximum contribution to the total dose deposition in the tail region. Finally, the associated spectra of neutrons and photons were analyzed. The mean neutron energy value was found to be 16.29 MeV, and 1.03 MeV for the secondary gamma. However, the neutron dose was found to be negligible as compared to the total dose due to their longer range.

Albino 담배 변이체의 기내 생장과 기내 분화의 특성 (Characterization of in vitro Growth and Differentiation of an Albino Mutant of Nicotiana tobacum L.)

  • 배창휴;이영일;김동철;민경수;김종홍;정재성;;이효연
    • 식물조직배양학회지
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    • 제26권3호
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    • pp.197-203
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    • 1999
  • 수분후 담배의 배에 중이온 beam ($^{14}$ N)을 조사하여 얻은 종자로부터 albino식물체를 분리하여 기내 생장과 분화의 특성을 검토하였다. 기내에서 생장시킨 albino식물체는 엽록소함량이 급격한 감소를 나타내었고 기공수는 잎의 이면 및 표면 표피에서 녹색 식물체 보다 많았다 연속광 조건하의 탄소원을 첨가한 MS배지에서 albino개체는 절간이 신장하지 않았으나 10.0mg/L 의 GA$_3$처리로 절간신장이 회복되었다. 잎절편 배양시 albino식물체는 1.0 mg/L 의 BAP와 kinetin의 단용처리로 다수의 신초를 형성하였고, 1.0mg/L의 2,4-D와 NAA의 단용처리로 다량의 캘러스를 형성하였다. 잎절편에서 유도된 albino 캘러스에 1.0mg/L BAP+0.1mg/L NAA를 혼용처리하면 다수의 식물체가 재분화 되었다. 이와같이 albino 식물체는 다경줄기 형성, 캘러스 형성, 캘러스로부터 재분화율 등이 녹색 식물체와 차이가 없었다. 또한 NAA와 BAP를 혼용처리 하였을 때 잎절편으로부터 기관분화의 유형도 정상주와 비슷하였다. 이러한 결과는 본 albino담배 변이체가 색소체 함량의 급감과 같은 광합성과 관련된 기능에서는 결손을 보이고 있음에도 불구하고 조직수준의 기관분화계에는 이상이 없다는 것을 시사한다.

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A real-time sorting algorithm for in-beam PET of heavy-ion cancer therapy device

  • Ke, Lingyun;Yan, Junwei;Chen, Jinda;Wang, Changxin;Zhang, Xiuling;Du, Chengming;Hu, Minchi;Yang, Zuoqiao;Xu, Jiapeng;Qian, Yi;She, Qianshun;Yang, Haibo;Zhao, Hongyun;Pu, Tianlei;Pei, Changxu;Su, Hong;Kong, Jie
    • Nuclear Engineering and Technology
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    • 제53권10호
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    • pp.3406-3412
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    • 2021
  • A real-time digital time-stamp sorting algorithm used in the In-Beam positron emission tomography (In-Beam PET) is presented. The algorithm is operated in the field programmable gate array (FPGA) and a small amount of registers, MUX and memory cells are used. It is developed for sorting the data of annihilation event from front-end circuits, so as to identify the coincidence events efficiently in a large amount of data. In the In-Beam PET, each annihilation event is detected by the detector array and digitized by the analog to digital converter (ADC) in Data Acquisition Unit (DAQU), with a resolution of 14 bits and sampling rate of 50 MS/s. Test and preliminary operation have been implemented, it can perform a sorting operation under the event count rate up to 1 MHz per channel, and support four channels in total, count rate up to 4 MHz. The performance of this algorithm has been verified by pulse generator and 22Na radiation source, which can sort the events with chaotic order into chronological order completely. The application of this algorithm provides not only an efficient solution for selection of coincidence events, but also a design of electronic circuit with a small-scale structure.

Estimation of Nuclear Interaction for $^{11}C$ Cancer Therapy

  • Maruyama, Koichi;Kanazawa, Mitsutaka;Kitagawa, Atsushi;Suda, Mitsuru;Mizuno, Hideyuki;Iseki, Yasushi
    • 한국의학물리학회:학술대회논문집
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    • 한국의학물리학회 2002년도 Proceedings
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    • pp.199-201
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    • 2002
  • Cancer therapy using high-energy $^{12}$ C ions is successfully under way at HIMAC, Japan. An alternative beam to $^{12}$ C is $^{11}$ C ions. The merit of $^{11}$ C over $^{12}$ C is its capability for monitoring spatial distribution of the irradiated $^{11}$ C by observing the $\beta$$^{+}$ decay with a good position resolution. One of the several problems to be solved before its use for therapy is the amount of nuclear interaction that deteriorates the dose concentration owing to the Bragg curve. Utilizing the dedicated secondary beam course for R&D studies at HIMAC, we measured the total energy loss of $^{11}$ C ions in a scintillator block that simulates the soft tissue in human bodies. In addition to the total absorption $^{11}$ C peak, non-negligible bump-shaped contribution is observed in the energy spectrum. The origin of the bump contribution can be nuclear interaction of the incident $^{11}$ C ions with hydrogen and carbon atoms. Further studies to reduce the ambiguity in dose distribution are mentioned.

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몬테칼로 시뮬레이션을 활용한 양성자가속기 단기사용 시 구성품의 방사화 평가 (A Study on the Radioactive Products of Components in Proton Accelerator on Short Term Usage Using Computed Simulation)

  • 배상일;김정훈
    • 대한방사선기술학회지:방사선기술과학
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    • 제43권5호
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    • pp.389-395
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    • 2020
  • The evaluation of radioactivated components of heavy-ion accelerator facilities affects the safety of radiation management and the exposure dose for workers. and this is an important issue when predicting the disposal cost of waste during maintenance and dismantling of accelerator facilities. In this study, the FLUKA code was used to simulate the proton treatment device nozzle and classify the radio-nuclides and total radioactivity generated by each component over a short period of time. The source term was evaluated using NIST reference beam data, and the neutron flux generated for each component was calculated using the evaluated beam data. Radioactive isotopes caused by generated neutrons were compared and evaluated using nuclide information from the International Radiation Protection Association and the Korea Radioisotope association. Most of the nuclides produced form of beta rays and electron capture, and short-lived nuclides dominated. However, In the case of 54Mn, which is a radioactive product of iron, the effect of gamma rays should be considered. In the case of tritium generated from a material with a low atomic number, it is considered that handling care should be taken due to its long half-life.

Design of muon production target system for the RAON μSR facility in Korea

  • Jeong, Jae Young;Kim, Jae Chang;Kim, Yonghyun;Pak, Kihong;Kim, Kyungmin;Park, Junesic;Son, Jaebum;Kim, Yong Kyun;Lee, Wonjun;Lee, Ju Hahn
    • Nuclear Engineering and Technology
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    • 제53권9호
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    • pp.2909-2917
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    • 2021
  • Following the launch of Rare Isotope Science Project in December 2011, a heavy ion accelerator complex in South Korea, named RAON, has since been designed. It includes a muon facility for muon spin rotation, relaxation, and resonance. The facility will be provided with 600 MeV and 100 kW (one-fourth of the maximum power) proton beam. In this study, the graphite target in RAON was designed to have a rotating disk shape and was cooled by radiative heat transfer. This cool-down process has the following advantages: a low-temperature gradient in the target and the absence of a liquid coolant cooling system. Monte Carlo simulations and ANSYS calculations were performed to optimize the target system in a thermally stable condition when the 100 kW proton beam collided with the target. A comparison between the simulation and experimental data was also included in the design process to obtain reliable results. The final design of the target system will be completed within 2020, and its manufacturing is in progress. The manufactured target system will be installed at the RAON in the Sindong area near Daejeon-city in 2021 to carry out verification experiments.

Heavy ion fragment beam test of Silicon Charge Detector

  • Kim, Mi-Yeong;Nam, Sin-U;Park, Na-Hui;Park, Il-Hong;Bok, Jeong-Beom;Yang, Jong-Man;Lee, Jae-Geum;Han, Ji-Hye;Hyeon, Hyo-Jeong
    • 한국우주과학회:학술대회논문집(한국우주과학회보)
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    • 한국우주과학회 2004년도 한국우주과학회보 제13권1호
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    • pp.100-100
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    • 2004
  • Silicon Charge Detector is to measure the charge of incident cosmic-ray nuclei with a resolution of 0.2 charge unit for atomic number, Z=1-30 with energy range from 1 to 1000 TeV. It is one of detectors for CREAM (Cosmic Ray Energetics And Mass) experiment to test current models of source and acceleration mechanisms of ultra high energy cosmic rays. It's first flight will be with a NASA zero pressure balloon planned to be launched from McMurdo Station, Antarctica in December 2004. (omitted)

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