IPAC2018 - List of Authors (Duperrex, P.-A.)

Paper	Title	Page
WEPAL067	Number of Turn Measurements on the HIPA Cyclotrons at PSI	2334
	P.-A. Duperrex, A. Facchetti PSI, Villigen PSI, Switzerland
	The number of turns is an important parameter for the tuning of a cyclotron; it is even more important for high intensity machines such as the 1.4 MW High Intensity Proton Accelerator (HIPA) facility. Up to recently, the number of turns had to be measured using radial probes, which cannot be performed during user operation but only during beam development shifts. For user shifts, the estimate of the number of turns was based on the acceleration voltage measurements, with the inherent limited precision of RF measurements. A new scheme based on the time of flight (ToF) measurements has been deployed on the two cyclotrons of HIPA. It is based on the cross-correlation of fast sampled data from pickups located at the entrance and at the exit of the cyclotrons. For the first cyclotron, called Injector 2 (accelerating the beam from 870 keV to 72MeV), the beam had to be externally modulated whereas, for the Ring Cyclotron (72 MeV to 590 MeV), no external modulation was necessary. This paper will present the details of both implementations, their limitations and the quality of the results that can be obtained with the ToF techniques.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-WEPAL067
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WEPAL068	Improving Machine and Target Protection in the SINQ Beam Line at PSI-HIPA	2337
	D. Reggiani, P.-A. Duperrex, R. Dölling, D.C. Kiselev, J. Welte, M. Wohlmuther PSI, Villigen PSI, Switzerland
	With a nominal beam power of nearly 1.4 MW, the PSI High Intensity Proton Accelerator (HIPA) facility is currently at the forefront of the high intensity frontier of particle accelerators. A key issue of this facility is to ensure safe operation of the SINQ spallation source. In particular, too large beam current density and/or inaccurate beam steering can seriously compromise the integrity of the spallation target. Recently, a campaign has been launched in order to improve the fast detection of improper beam delivery and therefore the reliability of the system. New beam diagnostics elements such as an absolute intensity monitor, a beam ellipticity monitor and additional loss monitors have been installed during the 2017 shutdown. In 2018 a new SINQ target will be installed featuring a system of thermocouples which will keep track of the beam position. Moreover, an additional monitor is currently under study which should reliably detect small beam fractions accidentally bypassing the muon production target TE and which are intrinsically dangerous for the SINQ spallation target. This contribution reviews the all efforts to increase the efficiency of the SINQ protection system.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-WEPAL068
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WEPAL069	Reentrant Cavity Resonator for Low Intensities Proton Beam Measurements	2341
	S. Srinivasan, P.-A. Duperrex PSI, Villigen PSI, Switzerland
	A non-interceptive beam current monitor has been developed to investigate the measurement possibilities of low-intensity beams down to 1 nA for proton therapy machines without the drawback of interceptive monitors. This works on the principle of a reentrant cavity resonator such that its fundamental mode resonance frequency of 145.7 MHz matches the second harmonic of the pulse repetition rate of the cyclotron beam i.e. 72.85 MHz. The Driven Modal analysis from the simulation tool ANSYS HFSS was used for parametric model development and to optimize design parameters such as e.g. the position of the inductively coupled pick-ups. A ceramic plate has been inserted in the resonator gap to relax the precision required during manufacturing. A test bench has been designed and constructed for the characterization tests of the prototype. Comparison of the simulated and the experimental scattering parameter from the test bench shows a good agreement.
DOI •	reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-WEPAL069
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Paper

Title

Page

Number of Turn Measurements on the HIPA Cyclotrons at PSI

2334

P.-A. Duperrex, A. Facchetti
PSI, Villigen PSI, Switzerland

The number of turns is an important parameter for the tuning of a cyclotron; it is even more important for high intensity machines such as the 1.4 MW High Intensity Proton Accelerator (HIPA) facility. Up to recently, the number of turns had to be measured using radial probes, which cannot be performed during user operation but only during beam development shifts. For user shifts, the estimate of the number of turns was based on the acceleration voltage measurements, with the inherent limited precision of RF measurements. A new scheme based on the time of flight (ToF) measurements has been deployed on the two cyclotrons of HIPA. It is based on the cross-correlation of fast sampled data from pickups located at the entrance and at the exit of the cyclotrons. For the first cyclotron, called Injector 2 (accelerating the beam from 870 keV to 72MeV), the beam had to be externally modulated whereas, for the Ring Cyclotron (72 MeV to 590 MeV), no external modulation was necessary. This paper will present the details of both implementations, their limitations and the quality of the results that can be obtained with the ToF techniques.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-WEPAL067

Export •

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

WEPAL068

Improving Machine and Target Protection in the SINQ Beam Line at PSI-HIPA

2337

D. Reggiani, P.-A. Duperrex, R. Dölling, D.C. Kiselev, J. Welte, M. Wohlmuther
PSI, Villigen PSI, Switzerland

With a nominal beam power of nearly 1.4 MW, the PSI High Intensity Proton Accelerator (HIPA) facility is currently at the forefront of the high intensity frontier of particle accelerators. A key issue of this facility is to ensure safe operation of the SINQ spallation source. In particular, too large beam current density and/or inaccurate beam steering can seriously compromise the integrity of the spallation target. Recently, a campaign has been launched in order to improve the fast detection of improper beam delivery and therefore the reliability of the system. New beam diagnostics elements such as an absolute intensity monitor, a beam ellipticity monitor and additional loss monitors have been installed during the 2017 shutdown. In 2018 a new SINQ target will be installed featuring a system of thermocouples which will keep track of the beam position. Moreover, an additional monitor is currently under study which should reliably detect small beam fractions accidentally bypassing the muon production target TE and which are intrinsically dangerous for the SINQ spallation target. This contribution reviews the all efforts to increase the efficiency of the SINQ protection system.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-WEPAL068

Export •

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

WEPAL069

Reentrant Cavity Resonator for Low Intensities Proton Beam Measurements

2341

S. Srinivasan, P.-A. Duperrex
PSI, Villigen PSI, Switzerland

A non-interceptive beam current monitor has been developed to investigate the measurement possibilities of low-intensity beams down to 1 nA for proton therapy machines without the drawback of interceptive monitors. This works on the principle of a reentrant cavity resonator such that its fundamental mode resonance frequency of 145.7 MHz matches the second harmonic of the pulse repetition rate of the cyclotron beam i.e. 72.85 MHz. The Driven Modal analysis from the simulation tool ANSYS HFSS was used for parametric model development and to optimize design parameters such as e.g. the position of the inductively coupled pick-ups. A ceramic plate has been inserted in the resonator gap to relax the precision required during manufacturing. A test bench has been designed and constructed for the characterization tests of the prototype. Comparison of the simulated and the experimental scattering parameter from the test bench shows a good agreement.

DOI •

reference for this paper ※ https://doi.org/10.18429/JACoW-IPAC2018-WEPAL069

Export •

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