TY  - CONF
AU  - Stockli, M.P.
AU  - Clemmer, M.E.
AU  - Cousineau, S.M.
AU  - Draganic, I.N.
AU  - Dudnikov, V.G.
AU  - Garnett, R.W.
AU  - Han, B.
AU  - Justice, T.A.
AU  - Kang, Y.W.
AU  - Kleinjan, D.
AU  - Murray, S.N.
AU  - Pennisi, T.R.
AU  - Piller, C.
AU  - Rouleau, G.
AU  - Stinson, C.
AU  - Welton, R.F.
ED  - Boland, Mark
ED  - Tanaka, Hitoshi
ED  - Button, David
ED  - Dowd, Rohan
ED  - Schaa, Volker RW
ED  - Tan, Eugene
TI  - Operating the SNS RF H⁻ Ion Source with a 10% Duty Factor
J2  - Proc. of IPAC2019, Melbourne, Australia, 19-24 May 2019
CY  - Melbourne, Australia
T2  - International Particle Accelerator Conference
T3  - 10
LA  - english
AB  - The SNS (Spallation Neutron Source) (radio-frequency) RF-driven, H⁻ ion source injects ~50 mA of H⁻ beam into the SNS accelerator at 60 Hz with a 6% duty factor. It injects up to 7 A·hrs of H⁻ ions during its ~14-week service cycles, which is an unprecedented lifetime for small-emittance, high-current pulsed H⁻ ion sources. The SNS source also features unprecedented low cesium consumption and can be installed and started up in <10 h. Presently, the LANSCE (Los Alamos Neutron Science CEnter) accelerator complex in Los Alamos is fed by a filament-driven, biased converter-type H⁻ source that operates with a high plasma duty factor of 10%. It needs to be replaced every 4 weeks with a ~4 day startup phase. The measured negative beam current of 16-18 mA falls below the desired 21 mA acceptance of LANSCE’s accelerator especially since the beam contains several mA of electrons. LANSCE and SNS are exploring the possibility of using the SNS RF H⁻ source at LANSCE to increase the H⁻ beam current and the ion source lifetime while decreasing the startup time. For this purpose, the SNS H⁻ source has been tested at a 10% duty factor by operating it at 120 Hz with 840 µs plasma pulses generated with ~30 kW of 2 MHz RF power, and extracting ~25 mA around-the-clock for 28 days. This, and additional tests and other considerations are discussed in this paper.
PB  - JACoW Publishing
CP  - Geneva, Switzerland
SP  - 1951
EP  - 1953
KW  - ion-source
KW  - plasma
KW  - electron
KW  - neutron
KW  - LEBT
DA  - 2019/06
PY  - 2019
SN  - 978-3-95450-208-0
DO  - DOI: 10.18429/JACoW-IPAC2019-TUPTS009
UR  - http://jacow.org/ipac2019/papers/tupts009.pdf
ER  - 

TY  - CONF
AU  - Brown, D.L.
AU  - Crofford, M.T.
AU  - Peters, C.C.
ED  - Boland, Mark
ED  - Tanaka, Hitoshi
ED  - Button, David
ED  - Dowd, Rohan
ED  - Schaa, Volker RW
ED  - Tan, Eugene
TI  - Optimizing Room Temperature RF Structures for Accelerator Driven System Operations
J2  - Proc. of IPAC2019, Melbourne, Australia, 19-24 May 2019
CY  - Melbourne, Australia
T2  - International Particle Accelerator Conference
T3  - 10
LA  - english
AB  - Minimizing beam trip rates is one of the key operational goals at the Spallation Neutron Source (SNS). Trip rates are closely monitored, and real-time statistics are kept during beam operations for immediate analysis. Beam trips are automatically binned by the length of the trip along with the cause for each trip. The shortest beam trips occur with the highest frequency and those trip rates are dominated by the room temperature RF structures. There can be many causes for the RF structure malfunctions, but one area that has had a major impact on trip rates is improvement in how RF processing is done on structures after extended maintenance periods. Details about the improvement in RF conditioning will be discussed.
PB  - JACoW Publishing
CP  - Geneva, Switzerland
SP  - 2993
EP  - 2995
KW  - vacuum
KW  - cavity
KW  - operation
KW  - RF-structure
KW  - DTL
DA  - 2019/06
PY  - 2019
SN  - 978-3-95450-208-0
DO  - DOI: 10.18429/JACoW-IPAC2019-WEPRB075
UR  - http://jacow.org/ipac2019/papers/weprb075.pdf
ER  -