Effects of thermal acoustic oscillations on LCLS-II cryomodule testing
| Autor: | R Wang, Jeremiah Holzbauer, Yu. Pischalnikov, Warren Schappert, Richard Stanek, Joshua Einstein-Curtis, Joseph Hurd, Benjamin Hansen, R Bossert, Arkadiy Klebaner, Joshua Kaluzny, W Hughes, J Makara, O Al Atassi, J. Theilacker, M.J. White |
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| Rok vydání: | 2017 |
| Předmět: | |
| Zdroj: | IOP Conference Series: Materials Science and Engineering. 278:012188 |
| ISSN: | 1757-899X 1757-8981 |
| DOI: | 10.1088/1757-899x/278/1/012188 |
| Popis: | Thermoacoustic Oscillations (TAOs) is a commonly experienced phenomenon in helium cryogenics and in most cases, is an undesirable effect. During LCLS-II prototype Cryomodule (pCM) testing, TAOs were observed in both the Cryogenics Distribution System and in the LCLS-II Cryomodule JT and Cooldown Valves. The TAOs manifested themselves through the usual effect of added heat load to the cryogenic system and ice formation on the oscillating device. However, during cavity testing, the TAOs were also found to significantly contribute to microphonics detuning of the SRF cavities. Systematic studies were carried out and it was discovered that the TAOs could be "turned-off" or substantially decreased by operating at subcritical pressures on the LHe supply. Lastly, various TAO dampening/mitigation techniques were employed to allow operations at supercritical pressure with greatly reduced static heat load and microphonics levels. |
| Databáze: | OpenAIRE |
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