CYCLOTRONS 2010 - List of Keywords (beam-losses)

Paper	Title	Other Keywords	Page
MOM2CIO01	Review of High Power Cyclotrons for Heavy Ion Beams	cyclotron, ion, heavy-ion, ion-source	9
	A. Goto RIKEN Nishina Center, Wako, Japan
	Since heavy ion cyclotrons for use in radioactive beam sciences were built in laboratories worldwide in 1980's, a lot of efforts on the upgrade of many such cyclotrons have been made in terms of beam intensity as well as beam energy. This talk describes an overview of such cyclotrons that provide heavy ion beams with the power in kW range or higher. Some technological issues related to high-power heavy ion beams are also discussed based on the experiences of those cyclotrons.
	Slides MOM2CIO01 [8.469 MB]

MOM2CCO03	Progress towards High Intensity Heavy Ion Beams at the AGOR-Facility	ion, vacuum, cyclotron, acceleration	21
	S. Brandenburg, J.P.M. Beijers, M.A. Hevinga, M.A. Hofstee, H.R. Kremers, V. Mironov, J. Mulder, S. Saminathan, A. Sen KVI, Groningen, The Netherlands
	Funding: This work is supported by the European Union through EURONS, contract 506065 and the "Stichting voor Fundamenteel Onderzoek der Materie" (FOM). The on-going upgrade program of the AGOR-facility aiming at intensities beyond 10¹² pps for heavy ion beams up to Pb will be discussed. The progress in the main elements of the program (further development of the ECR-source; improvement of the transmission into and through the cyclotron and protection of equipment agains excessive beam loss) will be reported. Further improvement of the ECR ion source is facilitated by the installation of a second source. Redesign of the LEBT to compensate aberrations is in progress; simulations predict a significant increase in transmission. A new, cooled electrostatic extractor is being commissioned and the beam loss control system has been completed. The main remaining issue is vacuum degradation induced by beam loss caused by charge exchange on the residual gas. Experiments at GSI[1] have shown that scrapers and surface coatings can strongly reduce this effect. Tracking calculations of the distribution of the beam losses over the vacuum chamber to determine the optimum location of scrapers and application of a gold coating to relevant parts of the vacuum chamber are underway. [1] C. Omet, H. Kollmus, H. Reich-Sprenger, P. Spiller; Ion catcher system for the stabilisation of the dynamic pressure in SIS18; http://jacow.org/e08/papers/mopc099.pdf
	Slides MOM2CCO03 [1.532 MB]

MOPCP014	Activation of a 250 MeV SC-cyclotron for Protontherapy	cyclotron, proton, extraction, radioactivity	72
	J.M. Schippers, D.C. Kiselev, R. Lüscher, O. Morath, M. Wohlmuther PSI, Villigen, Switzerland B. Amrein, P. Frey, M. Kostezer, A. Schmidt, G. Steen PSI-LRF, Villigen, PSI, Switzerland
	Dedicated Cyclotrons of 230-250 MeV are used at protontherapy facilities since ~12 years. Beam losses at acceleration and extraction cause buildup of radioactivity in the cyclotron, having consequences for accessibility, service and decommissioning. At PSI a dedicated 250 MeV SC-cyclotron is used for proton therapy since 2007. The machine has been optimized to obtain a high extraction efficiency of over 80%. Apart from these losses, most other losses occur at a pair of phase slits at 21 cm radius. Here we report on a systematic study of the radioactivity at selected locations in the pole, the RF system and of some screws located near the median plane. The spectra of gamma rays emitted from iron plugs in the pole, copper disks in the liner and several screws have been measured with HPGe detectors. From these spectra the isotopic compositions have been derived and compared with activities calculated with the Monte Carlo transport code MCNPX. Dose rate measurements have been made as a function of time. The data and beam history of the cyclotron allow us predictions of the dose rate during service activities shortly after beam interruption as well as after a specified life time.

MOPCP087	Beamloss Monitoring and Control for High Intensity Beams at the AGOR-Facility	cyclotron, pick-up, injection, controls	227
	M.A. Hevinga, S. Brandenburg, T.W. Nijboer, J. Vorenholt KVI, Groningen, The Netherlands
	Funding: This work is supported by the European Union through EURONS, contract 506065 and the "Stichting voor Fundamenteel Onderzoek der Materie" (FOM). The experiments at the AGOR facility require intense heavy ion beams with a beam power up to 500 W. Examples are 6 x 10¹² pps of ²⁰Ne at 23 MeV/A and 10¹² pps ²⁰⁶Pb at 8.5 MeV/A. To prevent damage to components by the beam (power density >100 W/mm³ in unfavorable cases) a modular beam loss monitoring and control system has been developed for the cyclotron and high energy beam lines. The architecture of the system will be described and the considerations for the major design choices discussed. The system uses the CAN-bus for communication and verification of system integrity. The injected beam is chopped at 1 kHz with a variable duty factor up to 90 %. The beam intensity at injection and a number of locations in the high energy beam line is measured by inductive pick-ups. Furthermore localized beam losses on slits and diaphragms are directly measured. When beam loss in any section exceeds the predefined maximum value the duty factor of the beam is automatically reduced. Beam diagnostics are protected by switching off the beam when they are inserted at too high intensity.

WEM2CIO04	Beam Diagnostics for Cyclotrons	cyclotron, diagnostics, ion, simulation	344
	R. Dölling PSI, Villigen, Switzerland
	An overview is given on beam diagnostics used at cyclotrons. The focus is set to devices installed inside the cyclotron with its special "environmental" conditions and limitations and on techniques which cover specific needs of the commissioning and operation of cyclotrons.
	Slides WEM2CIO04 [4.247 MB]

Paper

Title

Other Keywords

Page

MOM2CIO01

Review of High Power Cyclotrons for Heavy Ion Beams

cyclotron, ion, heavy-ion, ion-source

9

A. Goto
RIKEN Nishina Center, Wako, Japan

Since heavy ion cyclotrons for use in radioactive beam sciences were built in laboratories worldwide in 1980's, a lot of efforts on the upgrade of many such cyclotrons have been made in terms of beam intensity as well as beam energy. This talk describes an overview of such cyclotrons that provide heavy ion beams with the power in kW range or higher. Some technological issues related to high-power heavy ion beams are also discussed based on the experiences of those cyclotrons.

Slides MOM2CIO01 [8.469 MB]

MOM2CCO03

Progress towards High Intensity Heavy Ion Beams at the AGOR-Facility

ion, vacuum, cyclotron, acceleration

21

S. Brandenburg, J.P.M. Beijers, M.A. Hevinga, M.A. Hofstee, H.R. Kremers, V. Mironov, J. Mulder, S. Saminathan, A. Sen
KVI, Groningen, The Netherlands

Funding: This work is supported by the European Union through EURONS, contract 506065 and the "Stichting voor Fundamenteel Onderzoek der Materie" (FOM).
The on-going upgrade program of the AGOR-facility aiming at intensities beyond 10¹² pps for heavy ion beams up to Pb will be discussed. The progress in the main elements of the program (further development of the ECR-source; improvement of the transmission into and through the cyclotron and protection of equipment agains excessive beam loss) will be reported. Further improvement of the ECR ion source is facilitated by the installation of a second source. Redesign of the LEBT to compensate aberrations is in progress; simulations predict a significant increase in transmission. A new, cooled electrostatic extractor is being commissioned and the beam loss control system has been completed. The main remaining issue is vacuum degradation induced by beam loss caused by charge exchange on the residual gas. Experiments at GSI[1] have shown that scrapers and surface coatings can strongly reduce this effect. Tracking calculations of the distribution of the beam losses over the vacuum chamber to determine the optimum location of scrapers and application of a gold coating to relevant parts of the vacuum chamber are underway.
[1] C. Omet, H. Kollmus, H. Reich-Sprenger, P. Spiller; Ion catcher system for the stabilisation of the dynamic pressure in SIS18; http://jacow.org/e08/papers/mopc099.pdf

Slides MOM2CCO03 [1.532 MB]

MOPCP014

Activation of a 250 MeV SC-cyclotron for Protontherapy

cyclotron, proton, extraction, radioactivity

72

J.M. Schippers, D.C. Kiselev, R. Lüscher, O. Morath, M. Wohlmuther
PSI, Villigen, Switzerland
B. Amrein, P. Frey, M. Kostezer, A. Schmidt, G. Steen
PSI-LRF, Villigen, PSI, Switzerland

Dedicated Cyclotrons of 230-250 MeV are used at protontherapy facilities since ~12 years. Beam losses at acceleration and extraction cause buildup of radioactivity in the cyclotron, having consequences for accessibility, service and decommissioning. At PSI a dedicated 250 MeV SC-cyclotron is used for proton therapy since 2007. The machine has been optimized to obtain a high extraction efficiency of over 80%. Apart from these losses, most other losses occur at a pair of phase slits at 21 cm radius. Here we report on a systematic study of the radioactivity at selected locations in the pole, the RF system and of some screws located near the median plane. The spectra of gamma rays emitted from iron plugs in the pole, copper disks in the liner and several screws have been measured with HPGe detectors. From these spectra the isotopic compositions have been derived and compared with activities calculated with the Monte Carlo transport code MCNPX. Dose rate measurements have been made as a function of time. The data and beam history of the cyclotron allow us predictions of the dose rate during service activities shortly after beam interruption as well as after a specified life time.

MOPCP087

Beamloss Monitoring and Control for High Intensity Beams at the AGOR-Facility

cyclotron, pick-up, injection, controls

227

M.A. Hevinga, S. Brandenburg, T.W. Nijboer, J. Vorenholt
KVI, Groningen, The Netherlands

Funding: This work is supported by the European Union through EURONS, contract 506065 and the "Stichting voor Fundamenteel Onderzoek der Materie" (FOM).
The experiments at the AGOR facility require intense heavy ion beams with a beam power up to 500 W. Examples are 6 x 10¹² pps of ²⁰Ne at 23 MeV/A and 10¹² pps ²⁰⁶Pb at 8.5 MeV/A. To prevent damage to components by the beam (power density >100 W/mm³ in unfavorable cases) a modular beam loss monitoring and control system has been developed for the cyclotron and high energy beam lines. The architecture of the system will be described and the considerations for the major design choices discussed. The system uses the CAN-bus for communication and verification of system integrity. The injected beam is chopped at 1 kHz with a variable duty factor up to 90 %. The beam intensity at injection and a number of locations in the high energy beam line is measured by inductive pick-ups. Furthermore localized beam losses on slits and diaphragms are directly measured. When beam loss in any section exceeds the predefined maximum value the duty factor of the beam is automatically reduced. Beam diagnostics are protected by switching off the beam when they are inserted at too high intensity.

WEM2CIO04

Beam Diagnostics for Cyclotrons

cyclotron, diagnostics, ion, simulation

344

R. Dölling
PSI, Villigen, Switzerland

An overview is given on beam diagnostics used at cyclotrons. The focus is set to devices installed inside the cyclotron with its special "environmental" conditions and limitations and on techniques which cover specific needs of the commissioning and operation of cyclotrons.

Slides WEM2CIO04 [4.247 MB]