ANNUAL REPORT Two work packages: WP4.1 - Linear cathode arc coating WP4.2 - Planar cathode arc coating. CARE Annual Meeting

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1 ANNUAL REPORT 2004 CARE- JRA1-SRF WP4 - Thin film cavity production The main aim: : To develop a new method of thin film coating by means of arc discharges under ultra-high vacuum conditions. Instead of RF cavities made of bulk Nb one could apply a Cu-cavity coated with a thin Nb-layer. In contrary to the sputtering technique (used at CERN) the e UHV arc technology promises superior properties of the superconducting ng film. Two work packages: WP4.1 - Linear cathode arc coating WP4.2 - Planar cathode arc coating coordinated by M.J. Sadowski (IPJ, Swierk, Poland) CARE Annual Meeting

2 Work Package WP4.1 Linear cathode arc coating J. Langner et al. The A. Soltan Institute for Nuclear Studies Otwock-Swierk Swierk,, Poland CARE Annual Meeting

3 List of institutions participating in WP4.1 - University of Rome Tor Vergata (Italy) - I N F N -Roma2 (Italy) - I N F N - LNF (Italy) Substantial support through exchange of scientific staff and information, supply of selected components, by partners from: - DESY (Germany) - INFM Naples (Italy) - INFN Milano (Italy) - Institute for High Current Electronics (Tomsk, Russia) is also gratefully acknowledged. CARE Annual Meeting

4 Coating a cavity by means of a high-vacuum linear-arc arc discharge CARE Annual Meeting

5 WP4.1 Linear arc cathode coating (first 18 months) A prototype with a cylindrical (linear) cathode was constructed at IPJ-Swierk in Within the CARE project some modifications of this device were planned for 2004: - an exchange of the old pumping system, - the installation of a gas analyzer, - changes of the old baking system, - an improvement of the control unit. Optimization of triggering system was also planed Prototype facility should be ready on 30 July 2004 Study of the arc current reduction and stabilization Optimization of the powering system & start of coating, apparatus atus ready on 31 Dec CARE Annual Meeting

6 WP4.1 Linear arc cathode coating realization (Nov ) Modification of a prototype facility for a single cell has been delayed due to the delay in transfer of founds,, it was a delay in buying and installation of the necessary durable equipment, new system was ready on October 11, Within the frame of the modification an exchange of the pumping system has been performed: - a TMU 26 turbo-molecular pump has been installed - new UHV gauges have been applied - a new baking system has been installed - a QMS200-Prisma gas analyzer been installed - improvements of the control unit have been performed - a new power supply should be delivered in December 2004 Optimization of the triggering system has been finished (3 different trigger systems are ready for the operation). A prototype of a high-current pulse generator has been commissioned. Studies of the arc current reduction and stabilization are in progress as well as optimization of the powering system. The modified prototype facility for coating of a single cell should be ready by the end of February CARE Annual Meeting

7 Prototype linear-arc arc facility (2003) CARE Annual Meeting

8 Modified UHV linear-arc arc system (schemes) CARE Annual Meeting

9 Triggering systems for UHV linear-arc arc Mechanical HV trigger system Ruby laser, 600 mj,, 60 ns, 0.02 Hz A new Nd:YAG laser, 100 mj,, 8 ns, 20 Hz CARE Annual Meeting

10 Mechanical trigger for linear-arc arc initiation CARE Annual Meeting

11 Modified UHV linear-arc arc facility for single cell coating CARE Annual Meeting

12 Vacuum conditions in a new UHV system CARE Annual Meeting

13 Linear arc discharge - base vacuum 4x10-11 Tr - minimum arc current - 40 A - one hot spot - stable action ~ 1 min CARE Annual Meeting

14 Work Package WP4.2 Planar cathode arc coating S. Tazzari et al. University of Rome Tor Vergata & INFN-Roma2 Rome, Italy CARE Annual Meeting

15 List of institutions participating in WP4.2 - INFN-Roma2 (Italy) - The A. Soltan Institute for Nuclear Studies (Poland) Substantial support through scientific staff exchange, transfer of know how and information, sample measurements, supply of services and components, etc., by partners from: - CERN - Cornell University, Phys. Dept. (USA) - DESY (Germany) - INFM Naples (Italy) - INFN- LNF (Italy) - INFN Milano (Italy) - Institute for High Current Electronics (Tomsk, Russia) - University of Rome Tor Vergata, Chemistry Dept. (Italy) - University of Rome Tor Vergata, Physics Dept. (Italy) is also gratefully acknowledged. CARE Annual Meeting

16 UHV planar cathode arc design water cooling CARE Annual Meeting

17 Work plan for the first 18 months CARE Annual Meeting

18 UHV Planar arc system Sample holders The UHV chamber is pumped down to Torr by an oil-free pumping system consisting of a membrane pump on the fore line and a drag turbo molecular pump. Focusing Trigger window shutter coils Laser box C a t h o d e CARE Annual Meeting

19 Laser triggering system CARE Annual Meeting

20 Prototype filtered arc system sample holder on this s i d e CARE Annual Meeting

21 Optimization of ion current CARE Annual Meeting

22 Ion currents as a function of time B e hav iou r of sev e ra l io n sp ec ies cu rr e nt s vs ti me as reco r de d b y R GA. W hen th e ar c s ta r ts all io n c urre nt s in crea s e but, aft er abo ut o ne minut e op era tio n, t hos e of gas e s ot he r tha n hy droge n are re du ced by m ore th an 2 or der s of m a gnitud e. The mos t im po r ta nt cont amina nts (wa t er, CO and li gh t h ydr ocar bid es ) ar e f oun d in t he hpa ra nge and th eir par t ia l pre s s ure s co nti nu e t o decr e ase wit h time, exc e pt t ha t of hy d roge n tha t re ma ins con st a nt at abo ut 2 x h Pa. CARE Annual Meeting

23 RRR measurements The electrical resistivity has been measured using the standard 4 point method. RRR values are in the for samples deposited at room temperature and thickness of 1 µm. CARE Annual Meeting

24 Measurements of critical temperatures Superconducting critical temperatures, T c, have been measured using and inductive method. A 1KHz current is sent in a coil in contact with the sample surface. The 3 rd harmonic induced voltage, only present during transition to the SC, is measured and recorded. CARE Annual Meeting

25 X-ray diffraction analysis Niobium films, on both Cu and s a p p h i r e substrates, have been characterized by x- ray diffraction under different conditions CARE Annual Meeting

26 Film structure studies a) Ge rm s of cr ys talli t es at t he bo t tom of a c r at e r le f t af t er re moval of a dr opl e t f ro m a c opp e r s ub s tr at e s amp l e. b) C olu m na r c r y st allit e s as hig h as t he 1,5 mm fil m ar e vi s ibl e on t he w all of a de e p c r at e r. CARE Annual Meeting

27 Preliminary RF-measuring system INFM Napoli Schematic drawing (no t to sca le) of the 20 GHz dielectrical ly loa ded resona tor : coupli ng por ts (1), sapphire puck ( 2 ), s uperconducting sample(s) under test (3), Cu-Be spri ngs (4), cavity (5) CARE Annual Meeting

28 Preliminary RF measurements INFM Napoli Com p a ri s on b e t w e e n t h e qu al i t y f act o rs o f bul k N b a n d o f o u r f ilm sa mpl e s. CARE Annual Meeting

29 Summary of WP4.1 A delay by 2 months (may be less) has been induced by a delay in the money transfer from Brussels. A modified prototype linear-arc arc facility for single cavity coating (the first milestone) was ready on 11 October 2004 and parameters of the new system are very good. Some changes in a timetable are needed: - a shift of the start of single cavity coating (the second milestone) until the end of February 2005; - a shift of the droplet filter hardware operation (the third milestone) at least by 6 months (preferably until the end of February 2006). CARE Annual Meeting

30 Summary of WP4.2 Modifications for a prototype planar-cathode facility were performed and the optimization of the laser triggering system was carried out. A prototype planar-arc arc facility for single cavity coating (the first milestone) was ready according to the time-schedule (before September 3, 2004). Characterization of samples coated at different conditions was performed and some preliminary results of Nb-Coated sapphire samples have been collected. Characterization of Nb-coated copper samples are planned for the next year and a report on the planar-cathode arc-facility tests (the third milestone) should be prepared in May CARE Annual Meeting

31 Publications within WP4 framework 1. S. Tazzari, A. Cianchi, R. Russo, L. Catani, F. Tazzioli, J. Langner, M.J. Sadowski, UHV arc deposition for RF superconducting cavity, Proc. 11th Workshop on RF-Superconductivity SFR- 2003, Lubeck/Travemunde, Germany, September 8-12, 2003( published in Travemunde, 2004). 2. R. Russo, A. Cianchi, R. Polini, S. Tazzari, L. Catani, F. Tazzioli, J. Langner, N.N. Koval; UHV arc for superconducting niobium film deposition, Proc. 11th Workshop on RF-Superconductivity SFR- 2003, Lubeck/Travemunde, Germany, September 8-12, 2003 (published in Travemunde, 2004). 3. J. Langner, M.J. Sadowski, K. Czaus, R. Mirowski, J. Witkowski, L. Catani, A. Cianchi, R. Russo, S. Tazzari, F. Tazzioli, D. Proch, N.N. Koval, Y.H. Akhmadeev; Super-conducting niobium films produced by means of ultra-high vacuum arc, Proc. 21st SPPT in Prague, Czech Rep.; Czech. J. Phys. Vol. 54, Suppl. C (2004) C914-C J. Langner, M.J. Sadowski, K. Czaus, R. Mirowski, J. Witkowski, L. Catani, A. Cianchi, R. Russo, S. Tazzari, F. Tazzioli, D. Proch, N.N. Koval, Y.H.Akhmadeev; Status of research on deposition of superconducting films for RF accelerating cavities, Proc. 7th International Conference on Modification of Materials with Particle Beams and Plasma Flows, Tomsk, Russia, July 25-30, 2004, pp J. Langner, M.J. Sadowski, K. Czaus, R. Mirowski, J. Witkowski, L. Catani, A.Cianchi, R. Russo, F. Tazzioli, S. Tazzari, D. Proch, N.N. Koval, Y.H.Akhmadeev; UHV arc deposition of superconducting niobium films, Proc. 10th International Conference and School on Plasma Physics and Controlled Fusion, Alushta (Crimea), Ukraine, September 13-18, 2004; Problems of Atom. Sci. & Techn. (2004) in print. CARE Annual Meeting

32 JRA1-SFR SFR-WP4. WP4.1 Costs Estimated budget for the first 18 months (January 1, 2004, to June 30, 2005) JRA 1- S F R WP 4.1 P e r m a- a nent Staff inclu- ding Parti- cipant ( model) Consum - ables and Proto- typing Additional Staff Durable Equip - ment Travel inclu- ding Sub - con- tract Expected s Direct I n- n direct Requested funding 13 I PJ (AC) Executed budget for the first 9 months (January 1, 2004, to September 30, 2004) JRA 1- S F R WP 4.1 P e r m a- a nent Staff inclu- ding Parti- cipant ( model) Consum - ables and Proto- typing Additional Staff Durable Equip - ment Travel inclu- ding Sub - con- tract Ex ecuted s Direct I n- n direct Received funding 13 IPJ (AC) CARE Annual Meeting

33 Executed budget for the first 12 months (January 1, 2004, to December ember 31,2004)* JRA 1- S F R WP 4.1 P e r m a- a nent Staff inclu- ding Parti- cipant ( model) Consum - ables and Proto- typing Additional Staff Durable Equip - ment Travel inclu- ding Sub - con- tract Expected s Direct I n- n direct Received funding 13 I PJ (AC) * Extrapolated Budget for the next 18 months (January 1, 2005, to June 30, 2006) JRA 1- S F R WP 4.1 P e r m a- a nent Staff inclu- ding Parti- cipant ( model) Consum - ables and Proto- typing Additional Staff Durable Equip - ment Travel inclu- ding Sub - con- tract Executed s Direct I n- n direct Received funding 13 I PJ (AC) CARE Annual Meeting

34 JRA1-SFR SFR-WP4.2 Costs Estimated budget for the first 18 months (January 1, 2004, to June 30, 2005) JRA 1- S F R WP 4.2 P e r m a- a nent Staff inclu- ding Parti- cipant ( model) Consum - ables and Proto- typing Additional Staff Durable Equip - ment Travel inclu- ding Sub - con- tract Expected s Direct I n- n direct Requested funding 10 INFN - R o 2 (AC) Executed budget for the first 9 months (January 1, 2004, to September 30, 2004) JRA 1- S F R WP 4.2 P e r m a- a nent Staff inclu- ding Parti- cipant ( model) Consum - ables and Proto- typing Additional Staff Durable Equip - ment Travel inclu- ding Sub - con- tract Ex ecuted s Direct I n- n direct Received funding 10 INFN - R o 2 (AC) CARE Annual Meeting

35 Executed budget for the first 121 months (January 1, 2004, to December 31,2004)* JRA 1- S F R WP 4.2 P e r m a- a nent Staff inclu- ding Parti- cipant ( model) Consum - ables and Proto- typing Additional Staff Durable Equip - ment Travel inclu- ding Sub - con- tract Expected s Direct I n- n direct R e ceived funding 10 INFN - R o 2 (AC) * Extrapolated Budget for the next 18 months (January 1, 2005, to June 30, 2006) JRA 1- S F R WP 4.2 P e r m a- a nent Staff inclu- ding Parti- cipant ( model) Consum - ables and Proto- typing Additional Staff Durable Equip - ment Travel inclu- ding Sub - con- tract Ex ecuted s Direct I n- n direct Received funding 10 INFN - R o 2 (AC) CARE Annual Meeting

36 Single cell RF cavity during installation at the UHV arc coating stand CARE Annual Meeting