Cyclotrons2013 - List of Keywords (betatron)

Paper	Title	Other Keywords	Page
MOPPT024	Radial-Sector Cyclotrons with Different Hill and Valley Field Profiles	cyclotron, focusing, proton, TRIUMF	82
	M.K. Craddock UBC & TRIUMF, Vancouver, British Columbia, Canada
	A new class of isochronous cyclotron is described in which more general radial field profiles B(r) are allowed than the simple proportionality to total energy found in conventional radial- and spiral-sector cyclotrons. Isochronism is maintained by using different field profiles in the hills and valleys. Suitably chosen profiles will produce high flutter factors and significant alternating-gradient focusing, enabling vertical focusing to be maintained up to 1 GeV or more using radial rather than spiral sectors.

MO4PB03	Advanced FFAG Optics, Design and Experiment	acceleration, emittance, insertion, linac	120
	J.-B. Lagrange, Y. Mori Kyoto University, Research Reactor Institute, Osaka, Japan
	Much progress has been made in the FFAG design with novel ideas, for example, FFAG straight line, FFAG with race track shape, FFAG with vertical orbit excursion, etc. Some of these were demonstrated experimentally. The talk will review the recent progress around the world.
	Slides MO4PB03 [13.272 MB]

TUPSH007	Improvement in Design of 10 MeV AVF Cyclotron Magnet	cyclotron, factory, simulation, magnet-design	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.

WE2PB02	Vlasov Equation Approach to Space Charge Effects in Isochronous Machines	space-charge, simulation, cyclotron, plasma	310
	A.J. Cerfon, O. Bühler, J.V. Guadagni Courant Institute of Mathematical Sciences, New York University, New York, USA J.P. Freidberg, F.I. Parra Diaz MIT/PSFC, Cambridge, Massachusetts, USA
	Starting from the collisionless Vlasov equation, we derive two simple coupled two-dimensional fluid equations describing the radial-longitudinal beam vortex motion associated with space charge effects in isochronous cyclotrons. These equations show that the vortex motion can be intuitively understood as the nonlinear advection of the beam by the ExB velocity field, where E is the electric field due to the space charge and B is the applied magnetic field. This explains why elongated beams develop spiral halos while round beams are always stable. Solving the coupled equations numerically, we find good agreement between our model and 3-D Particle-In-Cell OPAL simulations. J.J. Yang, A.Adelmann, M. Humbel, M. Seidel, and T.J. Zhang, Physical Review Special Topics Accelerators and Beams 13, 062401 (2010)
	Slides WE2PB02 [1.166 MB]

WEPPT008	Correction of Vertical Shifting of Extracted Beam at the Test Operation of DC-110 Cyclotron	cyclotron, extraction, ion, heavy-ion	338
	I.A. Ivanenko, B. Gikal, I.V. Kalagin, N.Yu. Kazarinov, V.I. Mironov, E. Samsonov JINR, Dubna, Moscow Region, Russia
	The specialized heavy ion cyclotron DC-110 has been designed and created by the Flerov Laboratory of Nuclear Reactions of Joint Institute for Nuclear Research for scientifically industrial complex “BETA” placed in Dubna (Russia). DC-110 cyclotron is intended for accelerating the intense Ar, Kr, Xe ion beams with fixed energy of 2.5 MeV/nucleon. The commissioning of DC-110 cyclotron has been carried out at the end of 2012. The project parameters of the ion beams have been achieved. During commissioning of cyclotron the vertical displacement of the beam at the last orbits and at the extraction channel was revealed. The calculations and experiments have shown that the reason of this displacement is the radial component of magnetic field at the median plane of the cyclotron, which appears because of asymmetry of the magnetic yoke. Correction of the vertical displacement of the beam has been achieved by creating an asymmetry of current distribution in the main coils of the electromagnet.

WEPPT011	Measurement of Radial Oscillation and Phase of Accelerating Beam in Kolkata Superconducting Cyclotron	cyclotron, extraction, acceleration, resonance	344
	J. Pradhan, A. Agarwal, U. Bhunia, A. Chakrabarti, J. Debnath, M.K. Dey, A. Dutta, Z.A. Naser, S. Paul, V. Singh VECC, Kolkata, India
	This paper describes various measurements performed on the beam behavior with the help of the main probe and the differential probe to have a clear insight of the accelerating beam and the difficulties of beam -extraction process in the K500 superconducting cyclotron at Kolkata. Beam shadow measurements with three probes at three sectors were done to get the information of beam-centering and radial oscillations. The radial oscillation amplitude is estimated from the measurements. A differential probe was used to measure the turn separation and its modulation due to radial oscillation. With the help of magnetic field detuning method, the beam phase history was also measured.

WEPPT012	Beam Dynamics in Presence of Imperfection Fields Near the Extraction Zone of Kolkata Superconducting Cyclotron	extraction, cyclotron, resonance, simulation	347
	J. Debnath, U. Bhunia, A. Chakrabarti, M.K. Dey, A. Dutta, Z.A. Naser, S. Paul, J. Pradhan, V. Singh VECC, Kolkata, India
	Funding: VECC, DAE The superconducting cyclotron at Kolkata has accelerated the ion beams up to the extraction radius producing neutrons via nuclear reactions. After that the beam extraction process has been tried exhaustively. But rigorous beam extraction trials indicate towards some kind of error field, which was not possible to balance with the trim coil operated in harmonic-coil mode. It is found that the beam is being off-centered by a large amount after crossing the resonance zone and it is not reaching the extraction radius in proper path. This paper will be emphasizing the effect of various kind of error field on the beam. However, the magnetic field is being measured again to know the exact distribution of the field.

WEPPT025	Beam Physics Demonstrations with the Rutgers 12-Inch Cyclotron	cyclotron, ion, focusing, resonance	369
	T.W. Koeth UMD, College Park, Maryland, USA
	The Rutgers 12-Inch Cyclotron is a research grade accelerator dedicated to undergraduate education.[1] From its inception, it has been intended for instruction and has been designed to demonstrate classic beam physics phenomena. The machine is easily reconfigured, allowing experiments to be designed and performed within one academic semester. Our cyclotron gives students a hands-on opportunity to operate an accelerator and directly observe many fundamental beam physics concepts, including axial and radial betatron motion, destructive resonances, weak and azimuthally varying field (AVF) focusing schemes, DEE voltage effects, and more.

Paper

Title

Other Keywords

Page

MOPPT024

Radial-Sector Cyclotrons with Different Hill and Valley Field Profiles

cyclotron, focusing, proton, TRIUMF

82

M.K. Craddock
UBC & TRIUMF, Vancouver, British Columbia, Canada

A new class of isochronous cyclotron is described in which more general radial field profiles B(r) are allowed than the simple proportionality to total energy found in conventional radial- and spiral-sector cyclotrons. Isochronism is maintained by using different field profiles in the hills and valleys. Suitably chosen profiles will produce high flutter factors and significant alternating-gradient focusing, enabling vertical focusing to be maintained up to 1 GeV or more using radial rather than spiral sectors.

MO4PB03

Advanced FFAG Optics, Design and Experiment

acceleration, emittance, insertion, linac

120

J.-B. Lagrange, Y. Mori
Kyoto University, Research Reactor Institute, Osaka, Japan

Much progress has been made in the FFAG design with novel ideas, for example, FFAG straight line, FFAG with race track shape, FFAG with vertical orbit excursion, etc. Some of these were demonstrated experimentally. The talk will review the recent progress around the world.

Slides MO4PB03 [13.272 MB]

TUPSH007

Improvement in Design of 10 MeV AVF Cyclotron Magnet

cyclotron, factory, simulation, magnet-design

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.

WE2PB02

Vlasov Equation Approach to Space Charge Effects in Isochronous Machines

space-charge, simulation, cyclotron, plasma

310

A.J. Cerfon, O. Bühler, J.V. Guadagni
Courant Institute of Mathematical Sciences, New York University, New York, USA
J.P. Freidberg, F.I. Parra Diaz
MIT/PSFC, Cambridge, Massachusetts, USA

Starting from the collisionless Vlasov equation, we derive two simple coupled two-dimensional fluid equations describing the radial-longitudinal beam vortex motion associated with space charge effects in isochronous cyclotrons. These equations show that the vortex motion can be intuitively understood as the nonlinear advection of the beam by the ExB velocity field, where E is the electric field due to the space charge and B is the applied magnetic field. This explains why elongated beams develop spiral halos while round beams are always stable. Solving the coupled equations numerically, we find good agreement between our model and 3-D Particle-In-Cell OPAL simulations*.
* J.J. Yang, A.Adelmann, M. Humbel, M. Seidel, and T.J. Zhang, Physical Review Special Topics Accelerators and Beams 13, 062401 (2010)

Slides WE2PB02 [1.166 MB]

WEPPT008

Correction of Vertical Shifting of Extracted Beam at the Test Operation of DC-110 Cyclotron

cyclotron, extraction, ion, heavy-ion

338

I.A. Ivanenko, B. Gikal, I.V. Kalagin, N.Yu. Kazarinov, V.I. Mironov, E. Samsonov
JINR, Dubna, Moscow Region, Russia

The specialized heavy ion cyclotron DC-110 has been designed and created by the Flerov Laboratory of Nuclear Reactions of Joint Institute for Nuclear Research for scientifically industrial complex “BETA” placed in Dubna (Russia). DC-110 cyclotron is intended for accelerating the intense Ar, Kr, Xe ion beams with fixed energy of 2.5 MeV/nucleon. The commissioning of DC-110 cyclotron has been carried out at the end of 2012. The project parameters of the ion beams have been achieved. During commissioning of cyclotron the vertical displacement of the beam at the last orbits and at the extraction channel was revealed. The calculations and experiments have shown that the reason of this displacement is the radial component of magnetic field at the median plane of the cyclotron, which appears because of asymmetry of the magnetic yoke. Correction of the vertical displacement of the beam has been achieved by creating an asymmetry of current distribution in the main coils of the electromagnet.

WEPPT011

Measurement of Radial Oscillation and Phase of Accelerating Beam in Kolkata Superconducting Cyclotron

cyclotron, extraction, acceleration, resonance

344

J. Pradhan, A. Agarwal, U. Bhunia, A. Chakrabarti, J. Debnath, M.K. Dey, A. Dutta, Z.A. Naser, S. Paul, V. Singh
VECC, Kolkata, India

This paper describes various measurements performed on the beam behavior with the help of the main probe and the differential probe to have a clear insight of the accelerating beam and the difficulties of beam -extraction process in the K500 superconducting cyclotron at Kolkata. Beam shadow measurements with three probes at three sectors were done to get the information of beam-centering and radial oscillations. The radial oscillation amplitude is estimated from the measurements. A differential probe was used to measure the turn separation and its modulation due to radial oscillation. With the help of magnetic field detuning method, the beam phase history was also measured.

WEPPT012

Beam Dynamics in Presence of Imperfection Fields Near the Extraction Zone of Kolkata Superconducting Cyclotron

extraction, cyclotron, resonance, simulation

347

J. Debnath, U. Bhunia, A. Chakrabarti, M.K. Dey, A. Dutta, Z.A. Naser, S. Paul, J. Pradhan, V. Singh
VECC, Kolkata, India

Funding: VECC, DAE
The superconducting cyclotron at Kolkata has accelerated the ion beams up to the extraction radius producing neutrons via nuclear reactions. After that the beam extraction process has been tried exhaustively. But rigorous beam extraction trials indicate towards some kind of error field, which was not possible to balance with the trim coil operated in harmonic-coil mode. It is found that the beam is being off-centered by a large amount after crossing the resonance zone and it is not reaching the extraction radius in proper path. This paper will be emphasizing the effect of various kind of error field on the beam. However, the magnetic field is being measured again to know the exact distribution of the field.

WEPPT025

Beam Physics Demonstrations with the Rutgers 12-Inch Cyclotron

cyclotron, ion, focusing, resonance

369

T.W. Koeth
UMD, College Park, Maryland, USA

The Rutgers 12-Inch Cyclotron is a research grade accelerator dedicated to undergraduate education.[1] From its inception, it has been intended for instruction and has been designed to demonstrate classic beam physics phenomena. The machine is easily reconfigured, allowing experiments to be designed and performed within one academic semester. Our cyclotron gives students a hands-on opportunity to operate an accelerator and directly observe many fundamental beam physics concepts, including axial and radial betatron motion, destructive resonances, weak and azimuthally varying field (AVF) focusing schemes, DEE voltage effects, and more.