OVERVIEW OF THE BEAM DIAGNOSTICS FOR THE DRIVER OF SPIRAL2

Transcription

1 OVERVIEW OF THE BEAM DIAGNOSTICS FOR THE DRIVER OF SPIRAL2 Unité mixte de recherche CNRS-IN2P3 Université Paris-Sud Orsay cedex Tél. : Fax : Patrick AUSSET for the Spiral 2 Diagnostics Team Page

2 Introduction SPIRAL2 Driver and Beam Characteristics Q/A I (ma) Energy (Mev/u) CW max beam Power (KW) Protons 1/ Deuterons 1/ Ions 1/ Ions (option) 1/ Fast chopper in the MEBT line: Selection of 1/5O up to 1/10 5 bunch C.W. mode Low Duty Factor Pulsed Mode of Operation (slow chopper) Page 2

3 Beam Current Measurements in the L.E.B.T. Shared LEBT line LEBT ions LEBT D + Water Cooled Faraday Cup P max: 1,2 kw ( 250 ) P density max: 2120 W/Cm 2 D + source Ions Source Q/A =1/3 D.C.C.T. Shielding : (µ-métal + Armco + copper) B.W.: 0 10 khz ; Noise: 1 µa / Hz ½ C.W. + Low Duty Factor Pulsed Mode Operation Page 3

4 Beam transverse profiles measurement in the L.E.B.T. 5 BP Shared LEBT line 2 BP LEBT D + D + source 5 BP 12 Secondary emission beam profiler in LEBTs LEBT ions Secondary Emission Monitor: - 47 Tungsten wires ø 150 µm - Maximum beam size: 80 mm - Out-gassing rate Pa. m 3. s -1 Ions Source Q/A =1/3 L. D. F. P. M. Operation: Duration = few ms Repetition : ~ few 100 ms up to 1s Page 4

5 Emittancemeter H + V Beam Transverse Emittance Measurements in the L.E.B.T. Shared LEBT line Shielding e- Supressor grid +V s X L g -V eff Farada y cup z Input slit Output slit Dis splacement x LEBT ions LEBT D + D + source Ions Source Q/A =1/3 Emittancemeter: Allison Scanner - Max. diameter beam: 80 mm - Stroke: 120 mm - Max measurable angle: ± 100mrad - H.V. max: 2.8 kv - Max Beam power: 300 W C.W. - Beam Expected emittance: 1.6π mm mrad rms (N) Page 5

6 Diagnostics tests at LPSC and CEA Saclay LEBT 1 E H = 0.25 π.mm.mrad Norm rms E V = 0.14 π.mm.mrad Norm rms Emittance measurement - Beam: 16 O 6+ 53,33 kev (Dec. 2011) ACCT DCCT Saclay Tests in progress -ACCT + DCCT - Faraday cup - Beam profilers - Emittancemeter - Slow Chopper Beam Dump Dipole D11 Page 6

7 H Beam Measurements in the M.E.B.T Emittancemeter: Allison Scanner - Max. diameter beam: 60 mm - Stroke: 120 mm - Max measurable angle: ± 40 mrad Emittancemeter Scanner Allison Slits H V Slits V - H.V. max: ± 4 kv - Max Beam power: 1 kw C.W. DCCT+ACCT khz Part of MPS Slow Faraday cup 3kW CW W/cm 2 max Slits V Buncher 3 Buncher 2 Buncher 1 Slits V Slits H Fast Chopper - F. C. T - BW > 1.5 GHz Scraper - 3 Harp S.E.M beam profilers (built) L. D. F. P. M. operation D = few 100 µs, T: ~ 100 ms up to 1s -Bunch length measurement: -Fast F. C. (B.W. > 1.5 GHz) 400 W max. D= 45 mm Page 7

8 INTERMEDIATE TEST BENCH Beam Characteristics measurement - Test of diagnostics - Injector Commissionning: Transverse profiles and Emittance, Energy, Bunch length, Longitudinal emittance Bunch length Monitor Emittance-meters Horizontal and vertical Slits Beam dump Beam Position Monitor Time of Flight P.U. Beam Position Monitor Residual Gas ionisation Profiler Faraday cup Slow faraday cup DCCT Page 8

9 Beam Position Measurement in the LINAC. Sensor 12 cavities «first type» 7 cavities «second type» 4 x N Feedthrough Capacité (pf) 1,35 1,35 1,36 1,36 Beam Position Monitor: Capacitive probe Inner ø: 48 mm Length : 39 mm Subtented lobe-angle: 60 Delivering 20th BPM sensor: end of first quarter 2012 N sensor Capacitance (pf) Page 9

10 Beam Position Measurement in the LINAC. Electronics First prototype : available July 1st Electronics Signal processing : Position precision: 0,15 mm, phase : 1 Energy measurement (TOF) Input data Kx, Ky, K: BPM sensitivity (X and Y) ellipticity factor Xerror, Y error: (mechanical/electrical) BPM center offset Δ D :triggerdelay N : Number of acquisitions Selection of the harmonic to process thedata:88,0525mhzor176,105mhz On/Off calibration system offset trim between the four channels of the electronic card. Valid position range of the gravity center of the beam (interlock for MPS) Out put data Beam Position of the center of the beam (dynamic range: ± 20 mm). Resolution :150µm Beamphase.Resolution±1 Beam ellipticity (σ 2 x - σ 2 y). Resolution: ~±20% Shape reproduction of the bunch at the output of the 4 electrodes. Post mortem data over 2.5s (after beam break down) Interlocksignal(Incaseofpositionof thecenterofthe beam outofrange) Page 10

11 HEBT LINES: GENERAL CONFIGURATION 5 lignes (total length=88.7m) : LHE1 : From the output of the LINAC to the beam dump (SAFARI ) L=21.3m. LHE2 : From the dipôle LHE2-D11 to the Ucx target (Inside the production building). L=36m. LHNFS : From the dipôle LHNFS-D11 to the neutron convertor. L=8.8m. LHS3N : From the dipôle LHS3N-D11 (inside the LHE2) to the targets of the Super Separator Spectrometer S3. L=12.4m. LHS3S : From the dipôle LHS3S-D11 (inside the LHE2 ). Future option of the project L=9.5m Page 11

12 NFS High Energy Beam Transfert line: diagnostics S3 Towards production 11 Beam Loss monitors: 1l plastic scintillator + Photo multiplier Beam energy measurement: Set of «Time Of Flight P.U.» Beam profile measurement: 22 EMS profilers Production launching: first quarter 2012 Ionization Profile Monitor or BPM 8 Halo monitors ( loss segmented rings ) Beam Intensity measurement: DCCT + ACCT - Part of MPS Location: 1m from beam pipe Response time E B > 5Mev: 10 µs («high» beam losses ) Spatial resolution : 1m Page 12

13 HEBT lines: BLM detectors configurations LINAC: 1 detector per cryomodule along linac HEBT: 11 detectors in HEBT lines Expected output: longitudinal profile of counting rates Simulated profile for 12 MeV deuterons Loss : 1W Distortions factors: - X-ray and activation background - Scattering/absorption on beam line elements - Complex profiles losses Page 13

14 HEBT lines: BLM detectors final design Slide by courtesy of Florin Negoita Plasmol Centring ring Mu-metal interface shield BLM detector Radiation hardness tests at n/cm 2 (~ 1kGy) using d+be reaction at Bucharest cyclotron: no effect on local discriminator strong effect on LED (30 times reduction) replacing the LED the pulse shape was recovered => no effect on PM amplification no effect on optical transmission The results are consistent with expectations and values used in simulations Scintillator Case (duralumin) LED LED wire Spring Local discriminator Page 14

15 Bunch length measurements Diamond detector-x ray monitor Beam : 12 C 60 MeV crosscheck between X ray monitor and fast Faraday cup -Beam : 12 C 60 MeV Fast Faraday Cup : Residual ionisation gaz Monitor, Fast Faraday cup March 2012: X ray monitor in a LINAC diagnostic box crosscheck between X ray monitor and fast Faraday cup - Page 15

16 Spiral2 Control System Diagnostics EPICS framework was chosen for Spiral2 control system Diagnostics control is provided by 3 laboratories: GANIL, IPHC and IRFU Spiral2 EPICS platform provides a homogeneous control EPICS with PCs/Linux and VME/VxWorks 6.8 ADAS VME boards Epics drivers Modbus A software development model used by each EPICS developer Page 16

17 Diagnostics user interface on LEBTs «FAST ACQUISITION» FOR PULSED BEAM (IRFU) ADAS VME ICV108/178 boards (100 KSamples/s up to 1 MSamples/s) synchronized acquisition on the pulse start display and average value for each pulse Compressed data to speed up visualization BEAM PROFILERS EPICS IOC application to configure measurements and calculate average JAVA application using XAL framework Page 17

18 ACKNOWLEDGMENTS Special Thanks to the contributors to SPIRAL2 diagnostics GANIL : Profilers, Faraday cups, Beam Current transformers, phase and energy measurements, Command &Controls. IPNO: Beam Position Monitors. BARC and TIFR (India) : BPM electronics I.P.H.C : Transverse Emittancemetter, Intermediate Testing Bench. C.E.A - IRFU : Command &Controls NIPNE (Romania) : Beam Loss Monitors SOREQ (Israël): test of beam diagnostics on SARAF: MIGR and BPM sensors.and many other people Page 18