1. Recent Results of Vertical Test for S1-Global Project at KEK-STF Y. Yamamoto, H. Hayano, E. Kako, S. Noguchi, H. Sakai, M. Satoh, T. Shishido, K. Umemori, K. Watanabe (KEK, Japan) [SRF2009@Berlin; TUPPO 057] Processing Items at STF Abstract Summary S1-Global project will be carried out at KEK-STF (Superconducting rf Test Facility) in 2010, in which eight L-band cavities are used and tested with ILC (International Linear Collider) specification. Within them, four cavities are delivered from KEK, two from DESY and two from FNAL. A series of vertical tests was started using five cavities (MHI#5-#9) from Dec/2008 and will be finished on Nov/2009. In this report, the recent results are presented in detail. Cavity# of V.T. E acc, max [MV/m] Q 0 at E acc, max Radiation [μSv/h] R res [nΩ] Q t at 2 nd πcomment MHI#51 st 27.33.72x10 9 >100011.05.28x10 12 2 nd 19.71.28x10 10 14311.92.33x10 11 3 rd 27.17.53x10 9 30310.02.23x10 11 Keeping for S1-G MHI#61 st 25.74.61x10 9 >100010.33.08x10 11 2 nd 24.65.06x10 9 >10000013.22.86x10 11 Study of magnetic shield 3 rd 25.97.45x10 9 >1000008.32.81x10 11 Study of magnetic shield 4 th 19.69.14x10 9 010.82.36x10 11 5 th 22.18.33x10 9 877011.73.86x10 11 cable breakdown MHI#71 st 16.52.40x10 9 412012.98.90x10 11 MHI#81 st 16.01.30x10 10 25613.71.66x10 11 MHI#91 st 25.06.48x10 9 >10000013.61.86x10 11 Keeping for S1-G Summary of Vertical Tests for S1-Global Processing Items (1) Inspection by optical camera after delivery (2) Measurement of cavity frequency and field flatness by bead method, and check of cavity dimensions (3) Pre-EP (5μm) (4) EP1 (100μm) (5) Inspection by optical camera after EP1 (6) Measurement of cavity frequency and field flatness by bead method after EP1 (7) Measurement of thickness of cavity (check of consistency for electro-polished amount) (8) Annealing (750 ℃, 3 hours) (9) Inspection by optical camera after annealing (10) Pre-tuning, frequency tuning (f 0 =1297.2MHz, field flatness>96%) and check of cavity dimensions (11) Q in, Q HOM and f HOM measurement (12) EP2 (50 or 20μm) (13) H 2 O 2 or ethanol rinsing with ultrasonic (14) Hot water rinsing with ultrasonic (1 hour) (15) HPR (8-12 hours) (16) Assembly working in clean room and vacuum evacuation (17) Baking (100 ℃, 50 hours) (18) Putting on cavity stand (19) Mounting T-mapping and X-ray-mapping system (20) Vertical test It takes two weeks to do above every process! Excitation of Other Passband Modes Continuous TypeInstant Type DateCavityMeasured ModeExcited ModeType 2008/10/8AES#14π/9π/9continuous 2008/12/18MHI#66π/9π/9, 2π/9, 3π/9continuous 2009/1/22MHI#66π/93π/9continuous 2009/2/26MHI#56π/9π/9, 2π/9, 3π/9continuous 4π/9π/9instant 2009/4/16MHI#5π8π/9continuous 6π/94π/9instant 4π/95π/9, πinstant 2009/6/4MHI#6π6, 7, 8π/9instant 8π/91285.56MHzinstant 6π/95π/9instant 2009/6/25MHI#7π8π/9instant 8π/92, 7π/9instant 5π/91290MHz, 7π/9instant 2009/7/9MHI#87π/9π/9, 2π/9, 8π/9instant 6π/9 4π/9, 5π/9, 7π/9, 8π/9 instant 2009/9/3MHI#91 st π8π/9continuous 1297.39MHz, 7π/9instant CAUSES OF FIELD LIMIT Thermal quenching This is a clear and usual phenomenon which is generated by a defect or contamination. There is a good correlation between the results of T-mapping and the pass-band mode measurement, although any suspicious spot is not almost found at the heating location. Field emission This is a significant problem which cause is not identified. There is no correlation between the results of T-mapping and the pass-band mode measurement. The heating is triggered by the electron bombardment due to the field emission. Multipacting Multipacting is easily overcome in one situation and it takes a longer time to do it in other situation. If the RF conditioning is performed for a longer time, it is possibly overcome in the end. Cavity# of V.T.Q t @1 st πE acc, max @1 st πQ t @2 nd πE acc, max @2 nd πΔ MHI#51 st 5.65x10 12 27.1MV/m5.28x10 12 27.3MV/m-6.5% 2 nd 2.58x10 11 20.4MV/m2.33x10 11 19.7MV/m-9.7% 3 rd 2.46x10 11 27.2MV/m2.23x10 11 27.1MV/m-9.3% MHI#61 st 3.70x10 11 27.1MV/m3.08x10 11 25.7MV/m-16.8% 2 nd 3.32x10 11 28.0MV/m2.86x10 11 24.6MV/m-13.9% 3 rd 3.24x10 11 27.5MV/m2.81x10 11 25.9MV/m-13.3% 4 th 2.60x10 11 19.6MV/m2.36x10 11 19.6MV/m-9.2% MHI#71 st 9.18x10 11 15.4MV/m8.90x10 11 16.5MV/m-3.1% MHI#81 st 1.67x10 11 15.9MV/m1.66x10 11 16.0MV/m-0.6% MHI#91 st 1.94x10 11 26.9MV/m1.86x10 11 25.0MV/m-4.1% Results of MHI#9 cavity 1 st batch2 nd batch3 rd batch The vertical test for S1-Global project is routinely done every two weeks. The MHI#5 and #6 cavities were much improved, compared to MHI#1-#4. However, any cavity dose not reach 35MV/m yet. Recently, many brown stains are attached on the surface of the cavity. This trouble should be solved as the top priority. After that, it is expected that the performance of the MHI cavity will be improved. Brown stains