Cyclotrons2013 - List of Authors (Winklehner, D.)

Paper

Title

Page

Cyclotron Injection Tests of High-Intensity H²⁺ Beam

372

F.S. Labrecque, B.F. Milton
BCSI, Vancouver, BC, Canada
J.R. Alonso, D. Campo, J.M. Conrad, M. Toups
MIT, Cambridge, Massachusetts, USA
L. Calabretta, L. Celona
INFN/LNS, Catania, Italy
R. Gutierrez-Martinez, L.A. Winslow
UCLA, Los Angeles, USA
D. Winklehner
NSCL, East Lansing, Michigan, USA

Funding: Work funded by NSF agency, contract PHY-1148134
The IsoDAR (sterile neutrino) and DAEδALUS (CP-violation in neutrino sector) experiments will use cyclotrons to deliver high intensity (10 mA peak current) proton beams to neutrino-producing targets. To achieve these very high currents, we plan to inject and accelerate molecular H²⁺ ions. To understand high intensity H²⁺ injection into the central region of a compact cyclotron, and to benchmark space-charge dominated simulation studies, central-region tests are being conducted. The first test was completed this summer; a collaboration of MIT, BEST Cyclotrons and INFN-LNS at the BEST shops in Vancouver. The LNS Versatile Ion Source (VIS) was shipped from Catania to Vancouver, and was mounted, along with HV components and first focusing solenoid, on a test bench. In addition to the bench, BEST provided further beam line elements, instrumentation and a test cyclotron magnet for acceleration to no greater than 1 MeV/amu (to avoid any neutron production). Axial injection studies were conducted with a Catania-designed spiral inflector. Experimental configurations, beam characterization measurements, and phase acceptance and buncher efficiency studies will be reported.

WE3PB03

Space Charge Compensation Measurements in the Injector Beam Lines of the NSCL Coupled Cyclotron Facility

417

D. Winklehner, D.G. Cole, D. Leitner, G. Machicoane, L. Tobos
NSCL, East Lansing, Michigan, USA

Space charge compensation is a well-known phenomenon for high current injector beam lines. For beam lines using mostly magnetic focusing elements and for pressures above 10^-6 mbar, compensation (neutralization) up to 98% has been observed. However, due to the low pressures required for the efficient transport of high charge state ions, ion beams in ECR injector lines are typically only partly neutralized and space charge effects are present. With the dramatic performance increase of the next generation Electron Cyclotron Resonance Ion Sources (ECRIS) it is possible to extract tens of mA of beams from ECR plasmas. Realistic beam transport simulations are important to meet the acceptance criteria of subsequent accelerator systems and have to include non-linear effects from space charge, but also space charge compensation. In this contribution we report on measurements of space charge compensation in the ECRIS low energy beam lines of the Coupled Cyclotron Facility at NSCL using a retarding field analyzer. Results are discussed and compared to simulations.

Slides WE3PB03 [8.833 MB]

Paper	Title	Page
WEPPT026	Cyclotron Injection Tests of High-Intensity H²⁺ Beam	372
	F.S. Labrecque, B.F. Milton BCSI, Vancouver, BC, Canada J.R. Alonso, D. Campo, J.M. Conrad, M. Toups MIT, Cambridge, Massachusetts, USA L. Calabretta, L. Celona INFN/LNS, Catania, Italy R. Gutierrez-Martinez, L.A. Winslow UCLA, Los Angeles, USA D. Winklehner NSCL, East Lansing, Michigan, USA
	Funding: Work funded by NSF agency, contract PHY-1148134 The IsoDAR (sterile neutrino) and DAEδALUS (CP-violation in neutrino sector) experiments will use cyclotrons to deliver high intensity (10 mA peak current) proton beams to neutrino-producing targets. To achieve these very high currents, we plan to inject and accelerate molecular H²⁺ ions. To understand high intensity H²⁺ injection into the central region of a compact cyclotron, and to benchmark space-charge dominated simulation studies, central-region tests are being conducted. The first test was completed this summer; a collaboration of MIT, BEST Cyclotrons and INFN-LNS at the BEST shops in Vancouver. The LNS Versatile Ion Source (VIS) was shipped from Catania to Vancouver, and was mounted, along with HV components and first focusing solenoid, on a test bench. In addition to the bench, BEST provided further beam line elements, instrumentation and a test cyclotron magnet for acceleration to no greater than 1 MeV/amu (to avoid any neutron production). Axial injection studies were conducted with a Catania-designed spiral inflector. Experimental configurations, beam characterization measurements, and phase acceptance and buncher efficiency studies will be reported.

WE3PB03	Space Charge Compensation Measurements in the Injector Beam Lines of the NSCL Coupled Cyclotron Facility	417
	D. Winklehner, D.G. Cole, D. Leitner, G. Machicoane, L. Tobos NSCL, East Lansing, Michigan, USA
	Space charge compensation is a well-known phenomenon for high current injector beam lines. For beam lines using mostly magnetic focusing elements and for pressures above 10^-6 mbar, compensation (neutralization) up to 98% has been observed. However, due to the low pressures required for the efficient transport of high charge state ions, ion beams in ECR injector lines are typically only partly neutralized and space charge effects are present. With the dramatic performance increase of the next generation Electron Cyclotron Resonance Ion Sources (ECRIS) it is possible to extract tens of mA of beams from ECR plasmas. Realistic beam transport simulations are important to meet the acceptance criteria of subsequent accelerator systems and have to include non-linear effects from space charge, but also space charge compensation. In this contribution we report on measurements of space charge compensation in the ECRIS low energy beam lines of the Coupled Cyclotron Facility at NSCL using a retarding field analyzer. Results are discussed and compared to simulations.
	Slides WE3PB03 [8.833 MB]