Cyclotrons2013 - List of Authors (Ghergherehchi, M.)

Paper

Title

Page

Heat Transfer Study and Cooling of 10 MeV Cyclotron Cavity

150

S. Saboonchi, H. Afarideh
AUT, Tehran, Iran
M.R. Asadi
PPRC, Tehran, Iran
J.-S. Chai, M. Ghergherehchi
SKKU, Suwon, Republic of Korea

The most important problem in mechanical design of RF cavity of cyclotron is generated heat by RF power loss. An optimized cooling system for cavity is necessary to prevent Dee damaging and minimizing error function of cyclotron created by displacements. Also optimization of water circuit and water flow is essential because it affects unwanted vibrations and manufacturing. In this paper an attempt has been done to design an optimized cooling system for the cavity of a 10 MeV cyclotron with frequency of 69 MHz and 50 KW RF power using ANSYS and CST software.

TUPPT001

Control System of 10 MeV Baby Cyclotron

156

A. Abdorrahman, H. Afarideh, G.R. Aslani, S. Malakzade
AUT, Tehran, Iran
A. Afshar
Amirkabir University of Technology, Tehran, Iran
J.-S. Chai, M. Ghergherehchi
SKKU, Suwon, Republic of Korea

For controlling all the equipment and services required for operating the 10 MeV baby cyclotron and optimizing various parameters, an extensive control system is used. Most of the control systems are located in the control room which is situated outside the biological shield. The control console in the control room has switches for all the power supplies like main magnet, radio frequency system, vacuum system, ion-source, deflector, etc. Several Programmable Logic Controllers (PLC's) which are located near the equipment control the whole system. A technique of Supervisory Control and Data Acquisition (SCADA) is presented to monitor, control, and log actions of the PLC's on a PC through use of I/O communication interface coupled with an Open Process Control/Object Linking and Embedding [OLE] for Process Control (OPC) Server/Client architecture. In order to monitor and control different part of system, OPC data is then linked to a National Instruments (NI) LabVIEW. In this paper, details of the architecture and insight into applicability to other systems are presented.

TUPPT019

Development Study of Penning Ion Source for Compact 9 MeV Cyclotron

195

Y.H. Yeon, J.-S. Chai, T.V. Cong, Kh.M. Gad, M. Ghergherehchi, S.Y. Jung, H.S. Kim, H.W. Kim, S.H. Kim, S.H. Lee, Y.S. Lee, X.J. Mu, S.Y. Oh, S. Shin
SKKU, Suwon, Republic of Korea

Funding: This research was supported by WCU (World Class University) program through the National Research Foundation of Korea funded by the Ministry of Education, Science and Technology (R31-2008-10029).
Penning Ion Gauge(PIG) have been used in internal source for cyclotron. PIG source for internal source of 9 MeV cyclotron produces H⁻ ion. This source consists of cold cathode which discharges electrons for producing H⁻ ion and anode for making plasma wall. Cold cathode material tantalum was used for emitting electrons and tungsten copper alloy was used for anode. The size of PIG source is related to size of cyclotron magnet. Optimization of cathode and anode location and sizing were needed for simplifying this source for reducing the size of compact cyclotron. Transportation of electrons and number of secondary electrons has been calculated by CST particle studio. Motion of H2 gas has been calculated by ANSYS. Calculation of PIG source in 9 MeV cyclotron has been performed by using various chimneys with different size of expansion gap between the plasma boundary and the chimney wall. In this paper design process and experiment result is reported.

TUPPT023

Design and Simulation of Cavity for 10 MeV Compact Cyclotron

200

V. Afzalan, H. Afarideh, R. Azizi
AUT, Tehran, Iran
J.-S. Chai, M. Ghergherehchi
SKKU, Suwon, Republic of Korea

RF system is known as one of the most vital parts to produce the efficient accelerator system. In this paper, the RF system and cavity of 10 MeV AVF ( Azimuthally Varying Field ) Cyclotron for radioisotope production are designed. The Cyclotron works on 4th harmonic with Dee's voltage of 50 KV. In order to supply the expected accelerating voltages RF power coupling and RF tuner has been considered. The RF system is simulated using commercially available simulator, CST Microwave Studio code. In contrast the geometry of cavity is optimized to achieve suitable Q value in desired frequency. Since the factors are non-ideal during the fabrication process, the actual Q value of cavities is estimated.

TUPSH007

Improvement in Design of 10 MeV AVF Cyclotron Magnet

233

R. Solhju, H. Afarideh, B. Mahdian
AUT, Tehran, Iran
J.-S. Chai, M. Ghergherehchi
SKKU, Suwon, Republic of Korea

Design study of a 10 MeV baby cyclotron which accelerates H− ions is started in March, 2012 at Amirkabir University of Technology (AUT). Up to this point, conceptual design of the cyclotron magnet is finished. This process has been done in two steps: initial design and then optimization. After finishing the initial design of the magnet by CST software and adopting hard-edge approximation for finding the pole tip, an optimization process has been followed to smooth the pole edge in order to decrease the tension in sharp edges of the pole. In this paper, we are going to explain about the optimization process in details. Actually, we tried to fit the best curve at the pole edges of the magnet with goal of having minimum magnetic field error. Also a short report of results which was obtained before optimization is provided here. Precision of this design is ensured by checking the magnetic field and beam dynamic parameters during the optimization.

TUPSH008

Conceptual Design of the 100 MeV Separated Sector Cyclotron

236

B. Mahdian, H. Afarideh, R. Solhju
AUT, Tehran, Iran
J.-S. Chai, M. Ghergherehchi
SKKU, Suwon, Republic of Korea

The 100 MeV separated sector cyclotron was designed at Amirkabir University of Technology (AUT), which was aimed for various applications including radioactive ion-beam (RIB) production and proton therapy. It has four separated sector magnets. The cyclotron magnet design was based on an iterative process starting from a simple model that requires the vision of the complete cyclotron and the possibility of integration of all subsystems. By computer simulation with the 3D (CST) and 2D (POSSION) codes, principle parameters of the cyclotron magnet system were estimated (pole radius 180 cm, outer diameter 640 cm, height 300 cm). The results showed that the isochronous deviations between simulated values and the calculation one are smaller than 5 Gauss at most radii and therefore fulfilled the requirements. This work has been done with high accuracy which is proved by particle trajectories and considered mesh range. It has been concluded that it can be possible to design and develop this high energy cyclotron by introducing simple model without using trim and harmonic coils.

TUPSH013

Design Study of 10 MeV H⁻ Cyclotron Magnet

248

H.S. Kim, J.-S. Chai, M. Ghergherehchi, H.W. Kim, S.H. Kim, S.H. Lee
SKKU, Suwon, Republic of Korea

Funding: This work has been supported by National Research Foundation of Korea funded by the Ministry of Science, ICT and Future Planning (NRF-2010-0025952).
For the past decades, PET (positron emission tomography) has been remarkable growth in market. PET using 18F is widely provided for cancer screening and expected to be installed at small and medium hospital for convenience of patients. At Sungkyunkwan University, 10 MeV H⁻ cyclotron, which produces 18F is being developed. In this paper, we demonstrated main magnet design and whole design procedure was explained. The result of design is verified by orbit analysis and single particle tracking. The description of the obtained result is presented in this paper.

WEPPT018

Behavior of Space Charge Dominated Beam Envelope in Central Region of High Current Cyclotron

359

R. Azizi, H. Afarideh, V. Afzalan
AUT, Tehran, Iran
J.-S. Chai, M. Ghergherehchi
SKKU, Suwon, Republic of Korea

In this paper the space charge effect in the two first turn after injection has been investigated. In order to determine beam envelopes, two corresponding equations were chosen. In addition, all steps of calculation were done by MATLAB program. It should be mentioned limiting current and also magnetic, electrical field and edge effect has been considered. As far as, the high current cyclotron with 0.8π mm mrad emittance has been studied and current alters till 10 mA.*
*M. Reiser, Theory and Design of Charged Particle Beams (Wiley, New York, 1994), Chapters.3 and 4.

WEPSH003

Development of New Combined System for Production of FDG and NaF Radiopharmaceuticals

390

F. Dehghan, H. Afarideh, S. Jaloo
AUT, Tehran, Iran
M. Akhlaghi
Tehran University of Medical Sciences, Research Center for Nuclear Medicine, Tehran, Iran
J.-S. Chai, J.-S. Chai, M. Ghergherehchi
SKKU, Suwon, Republic of Korea

In this work, we present a new combined system which produces FDG and NaF in separate runs. The needed for synthesis this radiopharmaceuticals are obtained by bombardment of highly enriched water with proton. The aim is development of routine systems to use with baby cyclotrons. In this study, the various chemical steps and required reagents as well as different reagent delivery methods has been investigated. This evaluation has been done with purpose of optimizing the performance of a conceptually simple device integrated into a fully automated synthesis procedure for radiosynthesis of FDG and NaF. In this system, we have used AVR microcontroller to control the process and LabVIEW software for monitoring the operation of system. Furthermore, Geiger Muller counters have been used to determine the activity to insure the accuracy of the systems operation.

WEPSH006

⁶²Zn Radioisotope Production by Cyclotron

393

M. Ghergherehchi, J.-S. Chai, J.-S. Chai
SKKU, Suwon, Republic of Korea
H. Afarideh
AUT, Tehran, Iran

Natural Cu target was irradiated with proton beam in the energy range of 15 to 30 MeV at a beam current of 100 μA for 15 min. In this irradiation radioisotope of ⁶²Zn produced as a generator and then decay to ⁶²Cu radioisotope. The ⁶²Cu is emitting β+ and known to PET radioisotope. Excitation function of ⁶²Cu via ^natCu (p, 2n) ⁶²Zn, ⁶²Cu and ⁶²Cu (d, 3n) ⁶²Zn reactions were calculated using Alice and Talys codes and then were compared with the reported measurement by experimental data and ENDF-2011 data. Production yield versus target thickness were evaluated with attention to reaction cross section data obtained from Alice and Talys codes, and stopping power and range of protons in target materials using SRIM code. The production yield also examined experimentally and found that the optimum irradiation yield achieved to be 5.9 mci/μAh at protons of 100 μA current and 30 MeV energy. A radiolabeling process also was performed using ⁶²ZnCl₂ and antitumor compound, bleomycin (BLM) as a possible tumor imaging.

FR1PB02

Secondary Particle Dose and RBE Measurements Using High-Energy Proton Beams

464

M. Ghergherehchi, J.-S. Chai
SKKU, Suwon, Republic of Korea
D.H. Shin
NCC, Goyang, Kyeonggi, Republic of Korea

High- and intermediate-energy protons are not able to directly form a track in a CR-39 etch detector (TED). Such detectors, however, can be used for the detection and dosimetry of the beams of these particles through the registration of secondary charged particles with sufficiently high values of linear energy transfer (LET). The studied were realized in a clinical proton beam of the NCC Korea, with primary energy of 72 to 220 MeV (1.1 to 0.4 KeV/ μm). The contribution of the secondary particle dose and the value of RBE both increase with decreasing proton energy. A strong agreement between experimentally obtained results and the predicted total cross sections was verified by the Alice code. Stimulation of the secondary particle dose by the Geant4 code also predicted results in agreement by experimental results. It is clear that higher cross sectional values lead to an increased production of secondary particles. This secondary particle dose is highly important for applications such as radiotherapy, radiobiology, and radiation protection.

Slides FR1PB02 [2.955 MB]

Paper	Title	Page
TU2PB03	Heat Transfer Study and Cooling of 10 MeV Cyclotron Cavity	150
	S. Saboonchi, H. Afarideh AUT, Tehran, Iran M.R. Asadi PPRC, Tehran, Iran J.-S. Chai, M. Ghergherehchi SKKU, Suwon, Republic of Korea
	The most important problem in mechanical design of RF cavity of cyclotron is generated heat by RF power loss. An optimized cooling system for cavity is necessary to prevent Dee damaging and minimizing error function of cyclotron created by displacements. Also optimization of water circuit and water flow is essential because it affects unwanted vibrations and manufacturing. In this paper an attempt has been done to design an optimized cooling system for the cavity of a 10 MeV cyclotron with frequency of 69 MHz and 50 KW RF power using ANSYS and CST software.

TUPPT001	Control System of 10 MeV Baby Cyclotron	156
	A. Abdorrahman, H. Afarideh, G.R. Aslani, S. Malakzade AUT, Tehran, Iran A. Afshar Amirkabir University of Technology, Tehran, Iran J.-S. Chai, M. Ghergherehchi SKKU, Suwon, Republic of Korea
	For controlling all the equipment and services required for operating the 10 MeV baby cyclotron and optimizing various parameters, an extensive control system is used. Most of the control systems are located in the control room which is situated outside the biological shield. The control console in the control room has switches for all the power supplies like main magnet, radio frequency system, vacuum system, ion-source, deflector, etc. Several Programmable Logic Controllers (PLC's) which are located near the equipment control the whole system. A technique of Supervisory Control and Data Acquisition (SCADA) is presented to monitor, control, and log actions of the PLC's on a PC through use of I/O communication interface coupled with an Open Process Control/Object Linking and Embedding [OLE] for Process Control (OPC) Server/Client architecture. In order to monitor and control different part of system, OPC data is then linked to a National Instruments (NI) LabVIEW. In this paper, details of the architecture and insight into applicability to other systems are presented.

TUPPT019	Development Study of Penning Ion Source for Compact 9 MeV Cyclotron	195
	Y.H. Yeon, J.-S. Chai, T.V. Cong, Kh.M. Gad, M. Ghergherehchi, S.Y. Jung, H.S. Kim, H.W. Kim, S.H. Kim, S.H. Lee, Y.S. Lee, X.J. Mu, S.Y. Oh, S. Shin SKKU, Suwon, Republic of Korea
	Funding: This research was supported by WCU (World Class University) program through the National Research Foundation of Korea funded by the Ministry of Education, Science and Technology (R31-2008-10029). Penning Ion Gauge(PIG) have been used in internal source for cyclotron. PIG source for internal source of 9 MeV cyclotron produces H⁻ ion. This source consists of cold cathode which discharges electrons for producing H⁻ ion and anode for making plasma wall. Cold cathode material tantalum was used for emitting electrons and tungsten copper alloy was used for anode. The size of PIG source is related to size of cyclotron magnet. Optimization of cathode and anode location and sizing were needed for simplifying this source for reducing the size of compact cyclotron. Transportation of electrons and number of secondary electrons has been calculated by CST particle studio. Motion of H2 gas has been calculated by ANSYS. Calculation of PIG source in 9 MeV cyclotron has been performed by using various chimneys with different size of expansion gap between the plasma boundary and the chimney wall. In this paper design process and experiment result is reported.

TUPPT023	Design and Simulation of Cavity for 10 MeV Compact Cyclotron	200
	V. Afzalan, H. Afarideh, R. Azizi AUT, Tehran, Iran J.-S. Chai, M. Ghergherehchi SKKU, Suwon, Republic of Korea
	RF system is known as one of the most vital parts to produce the efficient accelerator system. In this paper, the RF system and cavity of 10 MeV AVF ( Azimuthally Varying Field ) Cyclotron for radioisotope production are designed. The Cyclotron works on 4th harmonic with Dee's voltage of 50 KV. In order to supply the expected accelerating voltages RF power coupling and RF tuner has been considered. The RF system is simulated using commercially available simulator, CST Microwave Studio code. In contrast the geometry of cavity is optimized to achieve suitable Q value in desired frequency. Since the factors are non-ideal during the fabrication process, the actual Q value of cavities is estimated.

TUPSH007	Improvement in Design of 10 MeV AVF Cyclotron Magnet	233
	R. Solhju, H. Afarideh, B. Mahdian AUT, Tehran, Iran J.-S. Chai, M. Ghergherehchi SKKU, Suwon, Republic of Korea
	Design study of a 10 MeV baby cyclotron which accelerates H− ions is started in March, 2012 at Amirkabir University of Technology (AUT). Up to this point, conceptual design of the cyclotron magnet is finished. This process has been done in two steps: initial design and then optimization. After finishing the initial design of the magnet by CST software and adopting hard-edge approximation for finding the pole tip, an optimization process has been followed to smooth the pole edge in order to decrease the tension in sharp edges of the pole. In this paper, we are going to explain about the optimization process in details. Actually, we tried to fit the best curve at the pole edges of the magnet with goal of having minimum magnetic field error. Also a short report of results which was obtained before optimization is provided here. Precision of this design is ensured by checking the magnetic field and beam dynamic parameters during the optimization.

TUPSH008	Conceptual Design of the 100 MeV Separated Sector Cyclotron	236
	B. Mahdian, H. Afarideh, R. Solhju AUT, Tehran, Iran J.-S. Chai, M. Ghergherehchi SKKU, Suwon, Republic of Korea
	The 100 MeV separated sector cyclotron was designed at Amirkabir University of Technology (AUT), which was aimed for various applications including radioactive ion-beam (RIB) production and proton therapy. It has four separated sector magnets. The cyclotron magnet design was based on an iterative process starting from a simple model that requires the vision of the complete cyclotron and the possibility of integration of all subsystems. By computer simulation with the 3D (CST) and 2D (POSSION) codes, principle parameters of the cyclotron magnet system were estimated (pole radius 180 cm, outer diameter 640 cm, height 300 cm). The results showed that the isochronous deviations between simulated values and the calculation one are smaller than 5 Gauss at most radii and therefore fulfilled the requirements. This work has been done with high accuracy which is proved by particle trajectories and considered mesh range. It has been concluded that it can be possible to design and develop this high energy cyclotron by introducing simple model without using trim and harmonic coils.

TUPSH013	Design Study of 10 MeV H⁻ Cyclotron Magnet	248
	H.S. Kim, J.-S. Chai, M. Ghergherehchi, H.W. Kim, S.H. Kim, S.H. Lee SKKU, Suwon, Republic of Korea
	Funding: This work has been supported by National Research Foundation of Korea funded by the Ministry of Science, ICT and Future Planning (NRF-2010-0025952). For the past decades, PET (positron emission tomography) has been remarkable growth in market. PET using 18F is widely provided for cancer screening and expected to be installed at small and medium hospital for convenience of patients. At Sungkyunkwan University, 10 MeV H⁻ cyclotron, which produces 18F is being developed. In this paper, we demonstrated main magnet design and whole design procedure was explained. The result of design is verified by orbit analysis and single particle tracking. The description of the obtained result is presented in this paper.

WEPPT018	Behavior of Space Charge Dominated Beam Envelope in Central Region of High Current Cyclotron	359
	R. Azizi, H. Afarideh, V. Afzalan AUT, Tehran, Iran J.-S. Chai, M. Ghergherehchi SKKU, Suwon, Republic of Korea
	In this paper the space charge effect in the two first turn after injection has been investigated. In order to determine beam envelopes, two corresponding equations were chosen. In addition, all steps of calculation were done by MATLAB program. It should be mentioned limiting current and also magnetic, electrical field and edge effect has been considered. As far as, the high current cyclotron with 0.8π mm mrad emittance has been studied and current alters till 10 mA.* *M. Reiser, Theory and Design of Charged Particle Beams (Wiley, New York, 1994), Chapters.3 and 4.

WEPSH003	Development of New Combined System for Production of FDG and NaF Radiopharmaceuticals	390
	F. Dehghan, H. Afarideh, S. Jaloo AUT, Tehran, Iran M. Akhlaghi Tehran University of Medical Sciences, Research Center for Nuclear Medicine, Tehran, Iran J.-S. Chai, J.-S. Chai, M. Ghergherehchi SKKU, Suwon, Republic of Korea
	In this work, we present a new combined system which produces FDG and NaF in separate runs. The needed for synthesis this radiopharmaceuticals are obtained by bombardment of highly enriched water with proton. The aim is development of routine systems to use with baby cyclotrons. In this study, the various chemical steps and required reagents as well as different reagent delivery methods has been investigated. This evaluation has been done with purpose of optimizing the performance of a conceptually simple device integrated into a fully automated synthesis procedure for radiosynthesis of FDG and NaF. In this system, we have used AVR microcontroller to control the process and LabVIEW software for monitoring the operation of system. Furthermore, Geiger Muller counters have been used to determine the activity to insure the accuracy of the systems operation.

WEPSH006	⁶²Zn Radioisotope Production by Cyclotron	393
	M. Ghergherehchi, J.-S. Chai, J.-S. Chai SKKU, Suwon, Republic of Korea H. Afarideh AUT, Tehran, Iran
	Natural Cu target was irradiated with proton beam in the energy range of 15 to 30 MeV at a beam current of 100 μA for 15 min. In this irradiation radioisotope of ⁶²Zn produced as a generator and then decay to ⁶²Cu radioisotope. The ⁶²Cu is emitting β+ and known to PET radioisotope. Excitation function of ⁶²Cu via ^natCu (p, 2n) ⁶²Zn, ⁶²Cu and ⁶²Cu (d, 3n) ⁶²Zn reactions were calculated using Alice and Talys codes and then were compared with the reported measurement by experimental data and ENDF-2011 data. Production yield versus target thickness were evaluated with attention to reaction cross section data obtained from Alice and Talys codes, and stopping power and range of protons in target materials using SRIM code. The production yield also examined experimentally and found that the optimum irradiation yield achieved to be 5.9 mci/μAh at protons of 100 μA current and 30 MeV energy. A radiolabeling process also was performed using ⁶²ZnCl₂ and antitumor compound, bleomycin (BLM) as a possible tumor imaging.

FR1PB02	Secondary Particle Dose and RBE Measurements Using High-Energy Proton Beams	464
	M. Ghergherehchi, J.-S. Chai SKKU, Suwon, Republic of Korea D.H. Shin NCC, Goyang, Kyeonggi, Republic of Korea
	High- and intermediate-energy protons are not able to directly form a track in a CR-39 etch detector (TED). Such detectors, however, can be used for the detection and dosimetry of the beams of these particles through the registration of secondary charged particles with sufficiently high values of linear energy transfer (LET). The studied were realized in a clinical proton beam of the NCC Korea, with primary energy of 72 to 220 MeV (1.1 to 0.4 KeV/ μm). The contribution of the secondary particle dose and the value of RBE both increase with decreasing proton energy. A strong agreement between experimentally obtained results and the predicted total cross sections was verified by the Alice code. Stimulation of the secondary particle dose by the Geant4 code also predicted results in agreement by experimental results. It is clear that higher cross sectional values lead to an increased production of secondary particles. This secondary particle dose is highly important for applications such as radiotherapy, radiobiology, and radiation protection.
	Slides FR1PB02 [2.955 MB]