论文信息 - REVIEW OF HIGH FIELD Q SLOPE, CAVITY MEASUREMENTS*

REVIEW OF HIGH FIELD Q SLOPE, CAVITY MEASUREMENTS*

One of the most interesting phenomenon occurring in superconducting radio-frequency (SRF) cavities made of bulk niobium is represented by a sharp decrease of the quality factor above peak surface magnetic field of about 90 mT and is referred to as "high field Q-slope" or "Q-drop". This phenomenon was observed first in 1997 and since then some effort was devoted to the understanding of the causes behind it. Still, no clear physical interpretation of the Q-drop has emerged, despite several attempts. In this contribution, I will review the experimental results for various cavities measured in many laboratories and I will try to identify common features and differences related to the Q-drop.

Gianluigi Ciovati | G. Ciovati

[1] H. Padamsee,et al. Temperature mapping results on the high-field Q-slope of 1500 MHz single cell superconducting radiofrequency cavities baked in-situ at 400 C , 2007, 2007 IEEE Particle Accelerator Conference (PAC).

[2] B. Visentin,et al. CAVITY BAKING : A CURE FOR THE HIGH ACCELERATOR FIELD Q0 DROP , 1999 .

[3] H. Preis,et al. Electropolishing and in-situ Baking of 1.3 GHz Niobium Cavities , 1999 .

[4] B. Visentin,et al. A NON - ELECTROPOLISHED NIOBIUM CAVITY REACHED 40 MV/m AT SACLAY , 2002 .

[5] J. Halbritter,et al. Material science of N[lc]b RF accelerator cavities: Where do we stand 2001? , 2001 .

[6] Matthias Liepe,et al. High-Field Slope in Superconducting Cavities Due to Magnetic Field Enhancement at Grain Boundaries , 1999 .

[7] J. Sekutowicz,et al. Preliminary Results From Single Crystal and Very Large Crystal Niobium Cavities , 2005, Proceedings of the 2005 Particle Accelerator Conference.

[8] K. Saito,et al. Performance of 1300 Mhz KEK-type single cell niobium cavities , 1997 .