Electrostatic Matching of a High Current Proton Beam to a RFQ

Journal Article · Tue Dec 13 04:00:00 EST 2011 · AIP Conference Proceedings

DOI:https://doi.org/10.1063/1.3665291· OSTI ID:22003912

Becker, R ^[1]; Hamm, R W ^[2]; Pearce-Percy, H ^[3]

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1. Scientific Software Service, Kapellenweg 2a, D-63571 Gelnhausen (Germany)
2. R and M Technical Enterprises, 4725 Arlene Pl., Pleasanton CA 94566 (United States)
3. CPAC, 6336B Patterson Pass Road, Livermore, CA 94550 (United States)

In order to demonstrate the operation of a prototype DWA (dielectric wall accelerator), it was necessary to modify the LEBT of a commercially procured proton RFQ (Radio Frequency Quadrupole) injector linac. The relatively high output current (35 mA) of the duoplasmatron ion source at the low injection energy of 35 keV to the RFQ presented a matching problem in the beam transport due to the high space charge, the fixed transport length, and the small beam size required at the RFQ. In addition, only the use of electrostatic lenses was considered in order to minimize the size of the system. The standard AccSys design using one decel-accel einzel lens proved to be insufficient, so three new solutions were proposed, each using a pair of decelerating einzel lenses. The tool used to optimize these designs was a newly developed feature of the program IGUN. The RFQ acceptance ellipse is plotted on top of the phase space data of the transport calculation together with an ellipse with the same Twiss parameters which just encloses all the trajectories. The quality of matching is then given as the ratio of the areas of these two ellipses, making optimization easy. This paper will present the results of this optimization and the performance of the actual equipment built and tested.

• OSTI ID: 22003912
• Journal Information: AIP Conference Proceedings, Journal Name: AIP Conference Proceedings Journal Issue: 1 Vol. 1412; ISSN APCPCS; ISSN 0094-243X
• Country of Publication: United States
• Language: English

Related Subjects

43 PARTICLE ACCELERATORS
BEAM ACCEPTANCE
BEAM CURRENTS
BEAM PRODUCTION
BEAM TRANSPORT
DESIGN
DUOPLASMATRONS
ELECTROSTATIC ACCELERATORS
ELECTROSTATIC LENSES
KEV RANGE
LINEAR ACCELERATORS
OPTIMIZATION
PERFORMANCE
PHASE SPACE
PROTON BEAMS
RADIOWAVE RADIATION
SPACE CHARGE
TOOLS