http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
Mokhtari Oranj, L.,Jung, N.S.,Oh, J.H.,Lee, H.S. North-Holland Physics Pub 2016 Nuclear instruments & methods in physics research. Vol.375 No.-
The proton beam intensity of a 100-MeV proton linac at the Korea Multi-purpose Accelerator Complex (KOMAC) was measured by an Au activation analysis using <SUP>197</SUP>Au(p,pn)<SUP>196</SUP>Au and <SUP>197</SUP>Au(p,p3n)<SUP>194</SUP>Au reactions to determine the accuracy and precision of beam intensity measurement using Gafchromic film dosimetry method. The target, irradiated by 100-MeV protons, was arranged in a stack consisting of Au, Al foils and Pb plates. The yields of produced radio-nuclei in Au foils were obtained by gamma-ray spectroscopy. The FLUKA code was employed to calculate the energy spectrum of protons onto the front surface of Au foils located at three different depth points of the target and also to investigate the condition of incident beam on the target. A good agreement was found between the beam intensity measurements using the activation analysis method at three different depth points of the target. An excellent agreement was also observed between the beam intensity measurements using the Au activation analysis method and the dosimetry method using Gafchromic film.
Cross sections of proton-induced nuclear reactions on bismuth and lead up to 100 MeV
Mokhtari Oranj, L.,Jung, N. S.,Bakhtiari, M.,Lee, A.,Lee, H. S. American Physical Society 2017 Physical review. C Vol.95 No.4
<P>Production cross sections of Bi-209(p, xn)Po-207,Po-206,Po-205,Po-204,Po-203, Bi-209(p, pxn)Bi-207,Bi-206,Bi-205,Bi-204,Bi-203,Bi-202, and Pb-nat(p, xn)Bi-206,Bi-205,Bi-204,Bi-203,Bi-202,Bi-201 reactions weremeasured to fill the gap in the excitation functions up to 100 MeV as well as to figure out the effects of different nuclear properties on proton-induced reactions including heavy nuclei. The targets were arranged in two different stacks consisting ofBi, Pb, Al, Au foils and Pb plates. The proton beam intensity was determined by the activation analysis method using Al-27(p, 3pn)Na-24, Au-197(p, pn)Au-196, and Au-197(p, p3n)Au-194 monitor reactions in parallel as well as the Gafchromic film dosimetry method. The activities of produced radionuclei in the foils were measured by the HPGe spectroscopy system. Over 40 new cross sections were measured in the investigated energy range. A satisfactory agreement was observed between the present experimental data and the previously published data. Excitation functions of mentioned reactions were calculated by using the theoretical model based on the latest version of the TALYS code and compared to the new data as well as with other data in the literature. Additionally, the effects of various combinations of the nuclear input parameters of different level density models, optical model potentials, and gamma-ray strength functions were considered. It was concluded that if certain level density models are used, the calculated cross sections could be comparable to the measured data. Furthermore, the effects of optical model potential and gamma-ray strength functions were considerably lower than that of nuclear level densities.</P>
Leila Mokhtari Oranj,이희석,Mario Santana Leitner 한국물리학회 2017 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.71 No.11
In Korea, a heavy ion accelerator facility (RAON) has been designed for production of rare isotopes. The 90 bending section of this accelerator includes a 1.3-μm-carbon stripper followed by two dipole magnets and other devices. An incident beam is 18.5 MeV/n 238U33+,34+ ions passing through the carbon stripper at the beginning of the section. The two dipoles are tuned to transport 238U ions with specific charge states of 77+, 78+, 79+, 80+ and 81+. Then other ions will be deflected at the bends and cause beam losses. These beam losses are a concern to the devices of transport/beam line. The absorbed dose in devices and prompt dose in the tunnel were calculated using the FLUKA code in order to estimate radiation damage of such devices located at the 90 bending section and for the radiation protection. A novel method to transport multi-charged 238U ions beam was applied in the FLUKA code by using charge distribution of 238U ions after the stripper obtained from LISE++ code. The calculated results showed that the absorbed dose in the devices is influenced by the geometrical arrangement. The maximum dose was observed at the coils of first, second, fourth and fifth quadruples placed after first dipole magnet. The integrated doses for 30 years of operation with 9.5 pμA 238U ions were about 2 MGy for those quadrupoles. In conclusion, the protection of devices particularly, quadruples would be necessary to reduce the damage to devices. Moreover, results showed that the prompt radiation penetrated within the first 60 - 120 cm of concrete.
Study on Radiation Production in the Charge Stripping Section of the RISP Linear Accelerator
오주희,Leila Mokhtari Oranj,이희석,고승국 한국물리학회 2015 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.66 No.3
The linear accelerator of the Rare Isotope Science Project (RISP) accelerates 200 MeV/nucleon238U ions in a multi-charge states. Many kinds of radiations are generated while the primarybeam is transported along the beam line. The stripping process using thin carbon foil leads tocomplicated radiation environments at the 90-degree bending section. The charge distribution of238U ions after the carbon charge stripper was calculated by using the LISE++ program. Theestimates of the radiation environments were carried out by using the well-proved Monte Carlocodes PHITS and FLUKA. The tracks of 238U ions in various charge states were identified usingthe magnetic field subroutine of the PHITS code. The dose distribution caused by U beam lossesfor those tracks was obtained over the accelerator tunnel. A modified calculation was applied fortracking the multi-charged U beams because the fundamental idea of PHITS and FLUKA was totransport fully-ionized ion beam. In this study, the beam loss pattern after a stripping sectionwas observed, and the radiation production by heavy ions was studied. Finally, the performanceof the PHITS and the FLUKA codes was validated for estimating the radiation production at thestripping section by applying a modified method.