Cyclotrons2013 - List of Keywords (TRIUMF)

Paper	Title	Other Keywords	Page
MOPPT024	Radial-Sector Cyclotrons with Different Hill and Valley Field Profiles	cyclotron, focusing, proton, betatron	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.

TUPPT005	Temperature Stability of the TRIUMF Cyclotron RF Controls	controls, feedback, cyclotron, monitoring	162
	M.P. Laverty, K. Fong, Q. Zheng TRIUMF, Canada's National Laboratory for Particle and Nuclear Physics, Vancouver, Canada
	Factors which contribute to ambient temperature sensitivity in the TRIUMF cyclotron RF control system are examined and characterized. Seasonal temperature variations together with air conditioning system limitations can give rise to unwanted temperature variations in the rack space housing the control system. If these are large enough, they can cause excursions in the cyclotron accelerating voltage. The critical components responsible are characterized and some possible remedies outlined.

TUPPT011	Measurement of Turn Structure in the Central Region of TRIUMF Cyclotron	resonance, cyclotron, feedback, extraction	177
	T. Planche, R.A. Baartman, Y.-N. Rao TRIUMF, Canada's National Laboratory for Particle and Nuclear Physics, Vancouver, Canada
	To get the most out of the existing beam diagnostics in the TRIUMF cyclotron, we started in 2011 to developed new data processing and visualization tools. The main advantage of these Matlab-based tools, compared to old VMS-based tools, is that they can benefit from a much larger library of modern data processing and visualization algorithms. This effort has already shown itself very useful to highlight essential features of the beam dynamics which remained unnoticed before. In this paper we present measurements results displaying beam dynamics process, and in particular space charge related process, happening in the central region of the TRIUMF cyclotron.
	Poster TUPPT011 [32.212 MB]

TUPPT022	A 20 mA H⁻ Ion Source with Accel-Accel-Decel Extraction System at TRIUMF	extraction, ion-source, ion, emittance	198
	K. Jayamanna, I. Aguilar, I.V. Bylinskii, G. Cojocaru, R.L. Dube, R.K. Laplante, W. L. Louie, M. Lovera, M. Minato, M. Mouat, S. Saminathan, T.M. Tateyama, E. Tikhomolov TRIUMF, Canada's National Laboratory for Particle and Nuclear Physics, Vancouver, Canada
	During the last three decades, TRIUMF has developed H⁻ cusp ion sources for the 500 MeV, TR30, TR13 cyclotrons, as well as many other machines. These ion sources can be categorized as high current versions, producing up to 20mA of CW H⁻ beam within a normalized emittance (4RMS) of 0.6 π-mm-mrad. A new accel-accel-decel extraction system is being developed in order to run the source at optimum source extraction voltage for a large range of beam energies with minimal impact on beam properties. With this extraction system, beam energy can be as low as ~1keV and as high as 60keV while source extraction voltage can be at its optimum within 90kV. The source performances, as well as relevant emittance measurements, are discussed.

TU3PB04	TRIUMF Extraction Foil Developments and Contamination Reduction	electron, extraction, scattering, simulation	269
	Y.-N. Rao, R.A. Baartman, I.V. Bylinskii, V.A. Verzilov TRIUMF, Canada's National Laboratory for Particle and Nuclear Physics, Vancouver, Canada J.M. Schippers PSI, Villigen PSI, Switzerland
	Funding: TRIUMF receives funding via a contribution agreement through the National Research Council of Canada. We made important developments on the extraction probes and stripping foils at TRIUMF. One of the issues we had was the ⁷Be contamination being observed near the 1A stripper, and relatedly, stripping foils warped or even broke during use. This was deemed due to over-heating in the foil and the frame. Another issue was related to the beam spills. Beam spills are primarily caused by the large angle scattering from the stripping foil. It was thus suggested that thinner foils be used to minimize the scattering. In view of these 2 issues, improvements were made such that (1) highly-orientated pyrolytic graphite foils, of thickness around 2 mg/cm², are now used; (2) Tantalum frame is now used in place of the previous stainless steel. These changes, plus additional heat relief features introduced, have resulted in 4 times longer lifetime with the foil, and 5 to 10 times reduction to the tank contamination level around the extraction probe. Also, these improvements have led to significantly reduced amount of beam spill monitor trips. This paper presents these developments and outcomes, including the simulations and calculations performed.
	Slides TU3PB04 [4.798 MB]

WE2PB01	Space Charge Limit in Separated Turn Cyclotrons	space-charge, cyclotron, emittance, extraction	305
	R.A. Baartman TRIUMF, Canada's National Laboratory for Particle and Nuclear Physics, Vancouver, Canada
	A review will be given of the intensity limits of cyclotrons due to space charge, both longitudinal and transverse.
	Slides WE2PB01 [1.513 MB]

WE3PB02	Improvement of the Current Stability from the TRIUMF Cyclotron	cyclotron, injection, space-charge, focusing	414
	T. Planche, R.A. Baartman, Y.-N. Rao TRIUMF, Canada's National Laboratory for Particle and Nuclear Physics, Vancouver, Canada
	The ν_r=3/2 resonance, driven by the third harmonic of the magnetic gradient errors, causes modulation of the radial beam density in the TRIUMF cyclotron. Since extraction is by H^- stripping, this modulation induces unwanted fluctuations of the current split between the two high-energy beam lines. To compensate field imperfections, the cyclotron has sets of harmonic correction coils at different radii, each set constituted of 6 pairs of coils placed in a 6-fold symmetrical manner. The 6-fold symmetry of this layout cannot create a third harmonic of arbitrary phase, and so a single set of harmonic coils cannot provide a full correction of third harmonic errors driving the ν_r=3/2 resonance. However, the outermost two sets of harmonic correction coils are azimuthally displaced. We took advantage of it to achieve a full correction of the resonance. This greatly improved the beam current stability in the high-energy beam lines. To further improve the current stability in the high-energy beam lines, we implemented an active feedback system. This feedback system acts on the amplitude of the first harmonic Bz correction produced by outermost set of harmonic coils.
	Slides WE3PB02 [1.007 MB]

WE4PB01	Tracking in a Cyclotron with Geant4	cyclotron, simulation, proton, acceleration	423
	F.W. Jones, T. Planche, Y.-N. Rao TRIUMF, Canada's National Laboratory for Particle and Nuclear Physics, Vancouver, Canada
	Building on its precursor GEANT, the tracking and simulation toolkit Geant4 has been conceived and realised in a very general fashion, with much attention given to the modeling of electric and magnetic fields and the accuracy of tracking charged particles through them. As evidenced by the G4Beamline application, Geant4 offers a unique simulation approach to beam lines and accelerators, in a 3D geometry and without some of the limitations posed by conventional optics and tracking codes. Here we apply G4Beamline to the TRIUMF cyclotron, describing the generation and input of the field data, accuracy of closed orbits, stability of multi-turn tracking, tracking accelerated orbits, and phase acceptance. Geant4's 3D visualization tools allow detailed examination of trajectories as well as a particle's-eye view of the acceleration process.
	Slides WE4PB01 [4.146 MB]

FR2PB02	Cyclotron Production of Tc-99m	target, cyclotron, vacuum, proton	482
	K.R. Buckley TRIUMF, Canada's National Laboratory for Particle and Nuclear Physics, Vancouver, Canada
	Concern over past and impending shortages of Tc-99m have led to renewed interest in the cyclotron production of Tc-99m - the most used radionuclide in Nuclear Medicine. TRIUMF has led a collaboration to implement the irradiation of Mo-100 solid targets on cyclotrons previously only used for the production of PET radionuclides. The technology and irradiation conditions that are critical parameters affecting the purity of the Tc-99m will be presented.
	Slides FR2PB02 [9.058 MB]

Paper

Title

Other Keywords

Page

MOPPT024

Radial-Sector Cyclotrons with Different Hill and Valley Field Profiles

cyclotron, focusing, proton, betatron

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.

TUPPT005

Temperature Stability of the TRIUMF Cyclotron RF Controls

controls, feedback, cyclotron, monitoring

162

M.P. Laverty, K. Fong, Q. Zheng
TRIUMF, Canada's National Laboratory for Particle and Nuclear Physics, Vancouver, Canada

Factors which contribute to ambient temperature sensitivity in the TRIUMF cyclotron RF control system are examined and characterized. Seasonal temperature variations together with air conditioning system limitations can give rise to unwanted temperature variations in the rack space housing the control system. If these are large enough, they can cause excursions in the cyclotron accelerating voltage. The critical components responsible are characterized and some possible remedies outlined.

TUPPT011

Measurement of Turn Structure in the Central Region of TRIUMF Cyclotron

resonance, cyclotron, feedback, extraction

177

T. Planche, R.A. Baartman, Y.-N. Rao
TRIUMF, Canada's National Laboratory for Particle and Nuclear Physics, Vancouver, Canada

To get the most out of the existing beam diagnostics in the TRIUMF cyclotron, we started in 2011 to developed new data processing and visualization tools. The main advantage of these Matlab-based tools, compared to old VMS-based tools, is that they can benefit from a much larger library of modern data processing and visualization algorithms. This effort has already shown itself very useful to highlight essential features of the beam dynamics which remained unnoticed before. In this paper we present measurements results displaying beam dynamics process, and in particular space charge related process, happening in the central region of the TRIUMF cyclotron.

Poster TUPPT011 [32.212 MB]

TUPPT022

A 20 mA H⁻ Ion Source with Accel-Accel-Decel Extraction System at TRIUMF

extraction, ion-source, ion, emittance

198

K. Jayamanna, I. Aguilar, I.V. Bylinskii, G. Cojocaru, R.L. Dube, R.K. Laplante, W. L. Louie, M. Lovera, M. Minato, M. Mouat, S. Saminathan, T.M. Tateyama, E. Tikhomolov
TRIUMF, Canada's National Laboratory for Particle and Nuclear Physics, Vancouver, Canada

During the last three decades, TRIUMF has developed H⁻ cusp ion sources for the 500 MeV, TR30, TR13 cyclotrons, as well as many other machines. These ion sources can be categorized as high current versions, producing up to 20mA of CW H⁻ beam within a normalized emittance (4RMS) of 0.6 π-mm-mrad. A new accel-accel-decel extraction system is being developed in order to run the source at optimum source extraction voltage for a large range of beam energies with minimal impact on beam properties. With this extraction system, beam energy can be as low as ~1keV and as high as 60keV while source extraction voltage can be at its optimum within 90kV. The source performances, as well as relevant emittance measurements, are discussed.

TU3PB04

TRIUMF Extraction Foil Developments and Contamination Reduction

electron, extraction, scattering, simulation

269

Y.-N. Rao, R.A. Baartman, I.V. Bylinskii, V.A. Verzilov
TRIUMF, Canada's National Laboratory for Particle and Nuclear Physics, Vancouver, Canada
J.M. Schippers
PSI, Villigen PSI, Switzerland

Funding: TRIUMF receives funding via a contribution agreement through the National Research Council of Canada.
We made important developments on the extraction probes and stripping foils at TRIUMF. One of the issues we had was the ⁷Be contamination being observed near the 1A stripper, and relatedly, stripping foils warped or even broke during use. This was deemed due to over-heating in the foil and the frame. Another issue was related to the beam spills. Beam spills are primarily caused by the large angle scattering from the stripping foil. It was thus suggested that thinner foils be used to minimize the scattering. In view of these 2 issues, improvements were made such that (1) highly-orientated pyrolytic graphite foils, of thickness around 2 mg/cm², are now used; (2) Tantalum frame is now used in place of the previous stainless steel. These changes, plus additional heat relief features introduced, have resulted in 4 times longer lifetime with the foil, and 5 to 10 times reduction to the tank contamination level around the extraction probe. Also, these improvements have led to significantly reduced amount of beam spill monitor trips. This paper presents these developments and outcomes, including the simulations and calculations performed.

Slides TU3PB04 [4.798 MB]

WE2PB01

Space Charge Limit in Separated Turn Cyclotrons

space-charge, cyclotron, emittance, extraction

305

R.A. Baartman
TRIUMF, Canada's National Laboratory for Particle and Nuclear Physics, Vancouver, Canada

A review will be given of the intensity limits of cyclotrons due to space charge, both longitudinal and transverse.

Slides WE2PB01 [1.513 MB]

WE3PB02

Improvement of the Current Stability from the TRIUMF Cyclotron

cyclotron, injection, space-charge, focusing

414

T. Planche, R.A. Baartman, Y.-N. Rao
TRIUMF, Canada's National Laboratory for Particle and Nuclear Physics, Vancouver, Canada

The ν_r=3/2 resonance, driven by the third harmonic of the magnetic gradient errors, causes modulation of the radial beam density in the TRIUMF cyclotron. Since extraction is by H^- stripping, this modulation induces unwanted fluctuations of the current split between the two high-energy beam lines. To compensate field imperfections, the cyclotron has sets of harmonic correction coils at different radii, each set constituted of 6 pairs of coils placed in a 6-fold symmetrical manner. The 6-fold symmetry of this layout cannot create a third harmonic of arbitrary phase, and so a single set of harmonic coils cannot provide a full correction of third harmonic errors driving the ν_r=3/2 resonance. However, the outermost two sets of harmonic correction coils are azimuthally displaced. We took advantage of it to achieve a full correction of the resonance. This greatly improved the beam current stability in the high-energy beam lines. To further improve the current stability in the high-energy beam lines, we implemented an active feedback system. This feedback system acts on the amplitude of the first harmonic Bz correction produced by outermost set of harmonic coils.

Slides WE3PB02 [1.007 MB]

WE4PB01

Tracking in a Cyclotron with Geant4

cyclotron, simulation, proton, acceleration

423

F.W. Jones, T. Planche, Y.-N. Rao
TRIUMF, Canada's National Laboratory for Particle and Nuclear Physics, Vancouver, Canada

Building on its precursor GEANT, the tracking and simulation toolkit Geant4 has been conceived and realised in a very general fashion, with much attention given to the modeling of electric and magnetic fields and the accuracy of tracking charged particles through them. As evidenced by the G4Beamline application, Geant4 offers a unique simulation approach to beam lines and accelerators, in a 3D geometry and without some of the limitations posed by conventional optics and tracking codes. Here we apply G4Beamline to the TRIUMF cyclotron, describing the generation and input of the field data, accuracy of closed orbits, stability of multi-turn tracking, tracking accelerated orbits, and phase acceptance. Geant4's 3D visualization tools allow detailed examination of trajectories as well as a particle's-eye view of the acceleration process.

Slides WE4PB01 [4.146 MB]

FR2PB02

Cyclotron Production of Tc-99m

target, cyclotron, vacuum, proton

482

K.R. Buckley
TRIUMF, Canada's National Laboratory for Particle and Nuclear Physics, Vancouver, Canada

Concern over past and impending shortages of Tc-99m have led to renewed interest in the cyclotron production of Tc-99m - the most used radionuclide in Nuclear Medicine. TRIUMF has led a collaboration to implement the irradiation of Mo-100 solid targets on cyclotrons previously only used for the production of PET radionuclides. The technology and irradiation conditions that are critical parameters affecting the purity of the Tc-99m will be presented.

Slides FR2PB02 [9.058 MB]