Cyclotrons2016 - List of Authors (Röcken, H.)

Paper	Title	Page
THP05	Beam Intensity Modulation Capabilities for Varian's ProBeam® Isochronous Cyclotron	313
	S. Busold, H. Röcken VMS-PT, Troisdorf, Germany
	Varian's ProBeam 250 MeV superconducting proton cyclotron is an isochronous cyclotron for radiological applications using pencil beam scanning mode and thus provides continuous beam (at its fundamental frequency of 72 MHz). In its clinical operation mode up to 800 nA of proton beam are specified and routinely extracted. Even more can be extracted in technical mode. The cold cathode Penning ion source provides enough protons to reach this current, and a layer-to-layer intensity modulation of the scanned beam is realized with an internal electrostatic deflector, which is used to vary the extracted beam current between maximum and zero. However, for research applications there is sometimes the request for higher flexibility, in particular for higher possible beam intensities and faster beam intensity modulation. In order to explore possibilities of the machine for such research modes, experimental investigations have been performed: Pulsed beams with repetition rates of up to 2 kHz and variable pulse lengths down to 4 μs as well as peak currents during pulse of up to 30 μA are in the accessible range with only changes at power supply level.
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

THP06	Recent Ion Source Developments for VARIAN's ProBeam® Cyclotron	316
	S. Busold, H. Röcken VMS-PT, Troisdorf, Germany A.S. Partowidjojo, J.M. Schippers PSI, Villigen PSI, Switzerland
	The cold cathode Penning ionization gauge (PIG) type proton source of the VARIANÂ’s ProBeam® 250 MeV superconducting isochronous cyclotron suffers from the usual cathode/chimney erosion during operation. Furthermore, a relatively high hydrogen gas flow is needed to generate a proton beam in the μA range, which induces conditions for RF operation below optimum. In the quest to increase cathode/chimney life time and thereby directly extend service intervals, thus reducing the total cost of ownership, several experimental investigations have been performed at a dedicated test bench at PSI, Switzerland, including material studies, a detailed operation analysis and switching to a hot cathode design.
Export •	reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

Paper

Title

Page

Beam Intensity Modulation Capabilities for Varian's ProBeam® Isochronous Cyclotron

313

S. Busold, H. Röcken
VMS-PT, Troisdorf, Germany

Varian's ProBeam 250 MeV superconducting proton cyclotron is an isochronous cyclotron for radiological applications using pencil beam scanning mode and thus provides continuous beam (at its fundamental frequency of 72 MHz). In its clinical operation mode up to 800 nA of proton beam are specified and routinely extracted. Even more can be extracted in technical mode. The cold cathode Penning ion source provides enough protons to reach this current, and a layer-to-layer intensity modulation of the scanned beam is realized with an internal electrostatic deflector, which is used to vary the extracted beam current between maximum and zero. However, for research applications there is sometimes the request for higher flexibility, in particular for higher possible beam intensities and faster beam intensity modulation. In order to explore possibilities of the machine for such research modes, experimental investigations have been performed: Pulsed beams with repetition rates of up to 2 kHz and variable pulse lengths down to 4 μs as well as peak currents during pulse of up to 30 μA are in the accessible range with only changes at power supply level.

Export •

reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)

THP06

Recent Ion Source Developments for VARIAN's ProBeam® Cyclotron

316

S. Busold, H. Röcken
VMS-PT, Troisdorf, Germany
A.S. Partowidjojo, J.M. Schippers
PSI, Villigen PSI, Switzerland

The cold cathode Penning ionization gauge (PIG) type proton source of the VARIANÂ’s ProBeam® 250 MeV superconducting isochronous cyclotron suffers from the usual cathode/chimney erosion during operation. Furthermore, a relatively high hydrogen gas flow is needed to generate a proton beam in the μA range, which induces conditions for RF operation below optimum. In the quest to increase cathode/chimney life time and thereby directly extend service intervals, thus reducing the total cost of ownership, several experimental investigations have been performed at a dedicated test bench at PSI, Switzerland, including material studies, a detailed operation analysis and switching to a hot cathode design.

Export •

reference for this paper using ※ BibTeX, ※ LaTeX, ※ Text/Word, ※ RIS, ※ EndNote (xml)