| Title |
First Commissioning of Vacuum System of Positron Damping Ring for SuperKEKB |
| Authors |
- K. Shibata, H. Hisamatsu, T. Ishibashi, K. Kanazawa, M. Shirai, Y. Suetsugupresenter, S. Terui
KEK, Ibaraki, Japan
|
| Abstract |
To satisfy the requirements of high beam quality for positron injection into the SuperKEKB main ring, a new damping ring (DR) is constructed in an upgraded injector system. The DR is a racetrack-shaped storage ring with a circumference of 135.5 m, in which the 1.1 GeV positron beam is stored for 40 ms to damp the emittance. The maximum stored beam current is 70.8 mA. Required beam lifetime due to residual gas scattering is longer than 1000 s and the average pressure should be lower than 10⁻⁵ Pa. Non-evaporable getter (NEG) pumps are mainly used, and the average effective pumping speed for CO is expected to be 0.013 m3s^{−1}m-1 immediately after NEG activation. The beam pipes are made of aluminum alloy, and have antechambers to deal with synchrotron radiation (critical energy 0.8-0.9 keV, total power 7.2 kW) in arc sections, which are effective in reducing the electron cloud and the impedance of the beam pipes. As additional countermeasures against the electron cloud effect, TiN coating and grooved surfacing are also adopted. The commissioning of the DR will commence at the beginning of 2018. The status of the vacuum system of the DR during the first commissioning will be reported.
|
| Paper |
download WEPML057.PDF [1.440 MB / 4 pages] |
| Export |
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| Conference |
IPAC2018, Vancouver, BC, Canada |
| Series |
International Particle Accelerator Conference (9th) |
| Proceedings |
Link to full IPAC2018 Proccedings |
| Session |
MC7 Poster Session |
| Date |
02-May-18 16:00–17:30 |
| Main Classification |
07 Accelerator Technology |
| Sub Classification |
T14 Vacuum Technology |
| Keywords |
photon, vacuum, MMI, operation, positron |
| Publisher |
JACoW Publishing, Geneva, Switzerland |
| Editors |
Shane Koscielniak (TRIUMF, Vancouver, BC, Canada); Todd Satogata (JLab, Newport News, VA, USA); Volker RW Schaa (GSI, Darmstadt, Germany); Jana Thomson (TRIUMF, Vancouver, BC, Canada) |
| ISBN |
978-3-95450-184-7 |
| Published |
June 2018 |
| Copyright |
|
