IPAC2012 - List of Authors (Bollinger, D.S.)

Paper	Title	Page
MOPPD046	Lifetime of the Highly Efficient H⁻ Ion Sources	466
	V.G. Dudnikov Muons, Inc, Batavia, USA D.S. Bollinger Fermilab, Batavia, USA D.C. Faircloth, S.R. Lawrie STFC/RAL/ISIS, Chilton, Didcot, Oxon, United Kingdom
	Funding: Work supported by grant DE-SC0006267, and STFC JAI grant ST/G008531 Factors limiting operating lifetime of Compact Surface Plasma Sources (CSPS) are analyzed and possible treatments for lifetime enhancement are considered. CSPSs have high plasma density (up to 10¹⁴ cm^-3), high emission current density of negative ions (up to 8 A/cm²), small (1–5 mm) gap between cathode emitter, and a small extraction aperture in the anode. They are very simple, have high energy efficiency up to 100 mA/kW of discharge (~100 times higher then modern large Volume RF SPS) and have a high gas efficiency (up to 30%) using pulsed valves. CSPSs are very good for pulsed operation but electrode power density is often too high for dc operation. However, CSPSs were successfully adopted for DC operation with emission current density ~300 mA/cm² in Hollow cathode Penning Discharge and up to 1 A/cm² in Spherical focusing semiplanotron. Flakes from electrodes sputtering and blistering induced by back accelerated positive ions are the main reasons of ion source failure. Suppression of back accelerated positive ions, flakes explosion by pulsed discharges, and flakes gasification by discharge in NF₃ (or XeF₂) can be used for significant increase of operating lifetime of CSPSs.

THPPP065	The FNAL Injector Upgrade Status	3886
	C.-Y. Tan, D.S. Bollinger, K.L. Duel, P.R. Karns, J.R. Lackey, W. Pellico, V.E. Scarpine, R.E. Tomlin Fermilab, Batavia, USA
	Funding: Operated by Fermi Research Alliance, LLC under Contract No. DE-AC02-07CH11359 with the United States Department of Energy. The new FNAL H⁻ injector upgrade is currently being tested before installation in the Spring 2012 shutdown of the accelerator complex. This line consists of an H⁻ source, low energy beam transport (LEBT) and 200 MHz RFQ. Beam measurements have been performed to validate the design before installation. The results of the beam measurements are presented in this paper.

Paper

Title

Page

Lifetime of the Highly Efficient H⁻ Ion Sources

466

V.G. Dudnikov
Muons, Inc, Batavia, USA
D.S. Bollinger
Fermilab, Batavia, USA
D.C. Faircloth, S.R. Lawrie
STFC/RAL/ISIS, Chilton, Didcot, Oxon, United Kingdom

Funding: Work supported by grant DE-SC0006267, and STFC JAI grant ST/G008531
Factors limiting operating lifetime of Compact Surface Plasma Sources (CSPS) are analyzed and possible treatments for lifetime enhancement are considered. CSPSs have high plasma density (up to 10¹⁴ cm^-3), high emission current density of negative ions (up to 8 A/cm²), small (1–5 mm) gap between cathode emitter, and a small extraction aperture in the anode. They are very simple, have high energy efficiency up to 100 mA/kW of discharge (~100 times higher then modern large Volume RF SPS) and have a high gas efficiency (up to 30%) using pulsed valves. CSPSs are very good for pulsed operation but electrode power density is often too high for dc operation. However, CSPSs were successfully adopted for DC operation with emission current density ~300 mA/cm² in Hollow cathode Penning Discharge and up to 1 A/cm² in Spherical focusing semiplanotron. Flakes from electrodes sputtering and blistering induced by back accelerated positive ions are the main reasons of ion source failure. Suppression of back accelerated positive ions, flakes explosion by pulsed discharges, and flakes gasification by discharge in NF₃ (or XeF₂) can be used for significant increase of operating lifetime of CSPSs.

THPPP065

The FNAL Injector Upgrade Status

3886

C.-Y. Tan, D.S. Bollinger, K.L. Duel, P.R. Karns, J.R. Lackey, W. Pellico, V.E. Scarpine, R.E. Tomlin
Fermilab, Batavia, USA

Funding: Operated by Fermi Research Alliance, LLC under Contract No. DE-AC02-07CH11359 with the United States Department of Energy.
The new FNAL H⁻ injector upgrade is currently being tested before installation in the Spring 2012 shutdown of the accelerator complex. This line consists of an H⁻ source, low energy beam transport (LEBT) and 200 MHz RFQ. Beam measurements have been performed to validate the design before installation. The results of the beam measurements are presented in this paper.