Recent performance of and plasma outage studies with the SNS H{sup −} source
- Spallation Neutron Source, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37830 (United States)
Spallation Neutron Source ramps to higher power levels that can be sustained with high availability. The goal is 1.4 MW despite a compromised radio frequency quadrupole (RFQ), which requires higher radio frequency power than design levels to approach the nominal beam transmission. Unfortunately at higher power the RFQ often loses its thermal stability, a problem apparently enhanced by beam losses and high influxes of hydrogen. Delivering as much H{sup −} beam as possible with the least amount of hydrogen led to plasma outages. The root cause is the dense 1-ms long ∼55-kW 2-MHz plasma pulses reflecting ∼90% of the continuous ∼300 W, 13-MHz power, which was mitigated with a 4-ms filter for the reflected power signal and an outage resistant, slightly detuned 13-MHz match. Lowering the H{sub 2} gas also increased the H{sup −} beam current to ∼55 mA and increased the RFQ transmission by ∼7% (relative)
- OSTI ID:
- 22482960
- Journal Information:
- Review of Scientific Instruments, Vol. 87, Issue 2; Other Information: (c) 2015 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA); ISSN 0034-6748
- Country of Publication:
- United States
- Language:
- English
Similar Records
Characterization of the CW starter plasma RF matching network for operating the SNS H{sup −} ion source with lower H{sub 2} flows
Recent performance and ignition tests of the pulsed SNS H{sup −} source for 1-MW neutron production