Reduction of waveguide vacuum trips in CEBAF accelerating cavities with a combination ion pump and non-evaporable getter pump
| Autor: | M. Stutzman, John Fischer, M. Drury, S. Suhring, Gianluigi Ciovati |
|---|---|
| Rok vydání: | 2020 |
| Předmět: |
Physics
Superconductivity Nuclear and High Energy Physics Hydrogen business.industry Physics::Optics chemistry.chemical_element Non-Evaporable Getter law.invention Power (physics) chemistry Ion pump law Getter Cryomodule Physics::Accelerator Physics Optoelectronics business Nonlinear Sciences::Pattern Formation and Solitons Instrumentation Waveguide |
| Zdroj: | Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment. 964:163788 |
| ISSN: | 0168-9002 |
| DOI: | 10.1016/j.nima.2020.163788 |
| Popis: | Pressure spikes in the fundamental power coupler waveguide are a significant source of trips during the operation of both original and refurbished superconducting radio-frequency cavities installed in the CEBAF accelerator. In its original configuration, two waveguides from a cavity-pair are connected to a single 32 l/s ion pump. In 2017 a new cavity-pair was installed in a refurbished cryomodule in which a NEXTorr® D200-5 combination ion pump and non-evaporable getter pump was installed for each waveguide. It is shown that hydrogen is the dominant residual gas in the waveguide and simulations with Molflow+ indicated that the new pumping scheme allows reducing the pressure at the end of the waveguide by a factor of ∼ 5 , compared to the original configuration. The new cavity-pair has been operating in CEBAF for a total of 431 days and it only had a total of 3 trips due to vacuum spikes in the waveguide. |
| Databáze: | OpenAIRE |
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