Title: Research and Development on Superconducting Radio-Frequency Technology for Accelerator Application

Transcription

1 D.Proch DESY,2.Nov.04

2 (Joined Research Activity) (coordinated accelerator research in Europe) Title: Research and Development on Superconducting Radio-Frequency Technology for Accelerator Application Acronym: SRF Co-Coordinators: D. Proch, DESY, T.Garvey, CNRS-Orsay Deputy: H.Mais

3 High gradients ( close to the theoretical limit) increase beam energy /shorten linac length High Q value (= low Rf loss) Reduce cryogenic cooling power Allow long pulse operation ( CW) Reliability of cavity and auxiliary components Availability of accelerator system, Robust fabrication, preparation and assembly technology Reproducible component and system performance

4 (integrating infrastructure initiative) TTF (TTF-FEL) is an excellent accelerator test-bed for R&D on SRF accelerator technology Use /modify existing infrastructure (chemistry, clean room treatment, cryogenic installation, materials analysis,...) at partner laboratories to design and prototype new SRF accelerator components Install new components in TTF linac to : increase operational performance of TTF establish improved technology for application at any existing or planned SRF accelerator

5 11 Participating Laboratories and Institutes: Institute (Participating number) Acronym Coordinator DESY (6) DESY D. Proch CEA/DSM/DAPNIA (1) CEA CNRS-IN2P3-Orsay (3) INFN Legnaro (11) R. Aleksan CNRS-Orsay T.Garvey INFN-LNL S. Guiducci INFN Milano (11) INFN-Mi S. Guiducci INFN Roma2 (11) INFN-Ro2 S. Guiducci INFN Frascati (11) Paul Scherrer Institute (21) Technical University of Lodz (14) Warsaw University of Technology (16) INFN-LNF S. Guiducci PSI TUL WUT-ISE V. Schlott A.Napieralski R.Romaniuk IPJ Swierk (15) IPJ M. Sadowski

6 Work packages in JRASRF 2 Improved Standard Cavity Fabrication 3 Seamless Cavity Production 4 Thin Film Cavity Production 5 Surface Preparation : EP, dry ice 6 Material Analysis: Scanning 7 Input coupler 8 Cold tuners 9 Low Level RF (LLRF) 10 Cryostat Integration Tests 11 Beam Diagnostics (BD)

7 Documentation retrieving on Components & Ancillaries from various lab. Ancillaries Cold flanges Stiffening Pick-up HOM Tuners Power coupler conn. Work in progress He tank Tuner Power coupler Pick up connection Preliminary study of deformation of a Al Cold Flanges HOM Stiffening ring

8 Vacuum arc coating by a linear cathode

9 Planar vacuum arc coating with a magnetic droplet filter

10 Schema of hydroforming apparatus Movable Matrix Tube Fixed Matrix Ptube sensor Water Hydr. system Pcyl sensor Oil Hydr system Rsensor Lsensor

11 Double - cell Nb cavity 2H1 hydroformed at DESY from Nb200 deep drown tube no intermediate constraints no intermediate annealing

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15 Analogical signals Electrolytic cell Voltage Supply PLC VOLTAGE CONTROL REGIME the best working point of the I-V characteristic is searched and followed by during the whole EP process Digital Inputoutput PC Automation Software

16 INPUT-OUTPUT channels I-V settings and display of the Polarization curve Tuning of the EP operation point

17 Dry ice cleaning tests Nozzel test in cut NbCu cavity Cleaning the beam tube of Nb cavity

18 Input coupler design with disc rf windows

19 Assembly of coupler test stand in clean room in Orsay

20 CARE meeting November 2004 Vacuum chamber and tools for mounting vertical TiN coating

21 Fast Frequency Tuner An actuator deforms the cavity lengthwise in a fast way, enough to compensate dynamic detuning ACTUATOR: Cryogenic T: 2 K Radiation hardness: 2 MGy/20 y? L at cavity: 3 µm Pass-band: > 20 khz Low termic load for the cryogenic system Some complex mechanical resonances of the system must be compensated DIGITAL FILTER H(s) ACTUATOR ACTUATOR ACTUATOR DRIVER D(s) DAC Plant = D H R G + ( s) H( s) R( s) D( s) F( s) LOOP = F(s) DIGITAL FILTER: AS A SECURITY FOR THE FEEDBACK LOOP STABILITY DIGITAL BLOCK TO GENERATE THE COMPENSATION SIGNAL REFERENCE SIGNAL: NOMINAL FREQUENCY OF THE CAVITY ADC ADC A A 1n A A 2n.. A 1n... A nn FEEDFORWARD PHASE DETECTOR Sample signal linked to RF INPUT Response to a TRIAL PULSE R(s)

22 Test facility for feedback control A different approach: developing of: - digital and analog electronic - compensation filter design A simpler test facility based upon a monocell cavity at room T The goal is to realize a simpler but significant model of the TTF tuning system The actuator is kept in direct mechanical coupling to the resonant cavity. Cu monocell TTF-shaped f0 = 1.3 GHz T = 300 K

23 Coax tuner analysis Stress distribution Von Mises Max displacement for the given rotation δ z δ sum

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25 Radiation effects in electronic devices is summarised in the figure below Work done by our group Linac 2 radiation field as well as 241 Am-Be and 60 Co sources were used Developments: GaAs (COTS) ) Neutron Dosimeter TL Dosimetry for Neutron/Gamma SEU and permanent damage of CMOS & CCD Cameras and FPGA SEU of various Memory chips HVL -Thickness of Gamma and Neutron shielding materials Mitigation Strategy for the Future Plans for the new Electron Linac protection of Electronic devices Identification of all tentative radiation effects Effective Radiation monitoring Implementation of real-time Dosimetry system Radiation Characterisation Implementation of TLD and Bubble Dosimeter Implementation of Shielding Implementation of a Radiation Health Redundancy and Voting databasefor electronic devices Evolutionary algorithm

26 8 ADCs 14 bits, 80 MHz 4 DACs, 14 bits, 125 MHz DSP Board Virtex2 XC2V4000 Optolink GHz

27 FIRST SYSTEM TEST IN A CLIMATIC CHAMBER Prototype designed, built and tested Results: Short term stability (1 min) 0.8 ps Long term stability (day) 5 ps There is a big room for improvements Second system setup prepared Phase noise measurements planned SOME OF DEVELOPED SYSTEM COMPONENTS Temperature controlled oven Laser transmitter System controller interface

28 CryHoLab at Saclay/Orsay

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31 Diffraction Radiation A Collaboration between INFN-LNF and INFN-Roma2 with an interest of Desy A charged particle going through a slit cut in a metallic foil, emits a radiation produced by polarization currents induced by the electromagnetic field on the screen surface. It is exactly the same effect of Transition Radiation, apart from the cut in the emitting surface, from which the radiation name. Interference from the two half foils produce a classical interference pattern in the radiation far field angular distribution.

32 Energy 500 MeV Wavelength 800 nm Filter bandwidth 40 nm Slit width.5 mm Charge 30 nc Emittance 10 mm mrad Vertical beam size 50 µm Vertical angular spread 200 µrad Horizontal angular spread 200 µrad Pixel acceptance 100 µrad

33 Modified "reentrant" cold unit for ACC1

34 Reentrant BPM mounted in cryomodule ACC1 Quadrupole BPM Cavity

35 Beam signals from ACC1 (no electronics)

36 Work package in JRASRF TTF XFEL ILC 2 Improved Standard Cavity Fabrication 3 Seamless Cavity Production?? 4 Thin Film Cavity Production? CW FEL no 5 Surface Preparation : EP, dry ice 6 Material Analysis: Scanning 7 Input coupler 8 Cold tuners 9 Low Level RF (LLRF) 10 Cryostat Integration Tests 11 Beam Diagnostics (BD)

37 Overlap of JRA-SRF activities in accelerator projects ILC SRF X-FEL TTF, VUVFEL

38 Orientation of CARE SRF Technology in the accelerator landscape FEL ILC TTF SRF Physics: New material Pushing Hc ERL CARE SRF XFEL EUROTeV EUROFEL