1. CCC Project at GSI- Update Febin Kurian GSI Helmholtzzentrum für Schwerionenforschung Germany

2. Contents Highlights of the CCC at GSI – from the past Beam current measurement with CCC – Spring 2014 Measurements planned for September 2014 Conceptual schematic of the new CCC system Some hints for a new cryostat design

3. GSI-CCC Cryostat: First Concept Possibility of test measurements offline and also within the beam line. Possibility of complete and easy dismantling of the cryostat and the equipment therein Low liquid helium consumption - Manual filling of LHe is difficult especially when installed in the beam line – one filling should be enough for complete experimental session. Should have a more or less fixed cycle time including (cooling down- experiments- warming up)

4. Existing CCC system at GSI 100 mm 381 mm 352 mm 658 mm 710 mm 1200 mm

5. GSI Facility CCC installation location

6. Beam current measurements with CCC Plan of the measurement Characteristics of the newly installed SQUID sensor system and electronics Noise figure of the CCC system Vibration analysis of the experimental set up Measurement of the beam current Comparison of the measured currents with a different system (in our case, Secondary Electron Monitor)

7. Supracon SQUID + Magnicon Electronics I-V Characteristics 1µA/div 200mv/div V-ɸ Characteristics 50mv/div 200mv/div

8. 50 nA Test pulse signal measured by CCC (noise floor – 2 nA) Current Calibration CCC- pickup coil Low pass filter- Cut off frequency = 170 Hz

9. Noise Spectrum

10. Current Calibration Curve Voltage- Current conversion factor=74.2 nA/V

11. Current Measurement Scheme Oscilloscope/FFT SQUID Amp. T,P,L Current Source SQUID Control Diff. Amplifier SIS18 DCCT CCC SEM Al foils Femto DHPCA 100 transimpedance amplifier. GM cooler unit H.V Measurement room Femto Amp control pc- Remote access

13. Current Measurement-1 Output signal contains, Signal from the DCCT installed in SIS 18 CCC differential output -- blue and red SEM signal Example of a raw output signal shows the beam current of about 3E9 particles of Ni 26+ with energy of 600 MeV extracted from SIS18 over 1 second (Mean current – 12.5 nA)

14. Current Measurement-2 Beam current signal by 7E8 particles of Ni 26+ with energy of 600 MeV extracted from SIS18 over 500 millisecond (Mean current – 5.5 nA)

15. Current Measurement-3 Smallest signal measured by CCC of 2.5E8 particles of Ni 26+ (Mean current – 1.9 nA) at 600 MeV extracted over 500 millisecond

16. Current measurement-CCC and SEM Comparison of the spill structures given by CCC and SEM when measuring the current of 5E9 particles extracted over 64 ms giving an average current of 210 nA DCCT, CCC and SEM signals

17. Current Estimation from plots

18. Current measurements with CCC and SEM-1 SEM result is shown without a multiplication factor to obtain equivalent current (Presently used factor shows discrepancies with the current values measured by CCC) In Smaller range

19. Special Conditions Presence of “Anti-Alias filter” SQUID signal is filtered with a low pass filter at the magnicon amplifier with cut-off frequency of 10KHz Optically isolated differential amplifier Output amplification of 10: 2 differential Differential output Cut-off frequency 200 KHz SEM- Bandwidth depends on amplification factor given at the femto amplifier - 220 kHz at 10 8 to 200 MHz at 10 3.

20. Measurement planned for Sept. 2014 Measurement over wider bandwidth (without the filter at the Magnicon electronics) More measurements on the intrinsic current resolution of the CCC. Wider range of the beam current/ extraction time More set of SQUID adjustment – R f @FLL, GBP combinations More measurements on the zero drift SEM calibration and comparison with CCC

21. Conceptual design of the new CCC-1 Some boundary conditions Limited space available in the beam line for running and more importantly for any repair works once installed. Horizontal design – More stable and compact compared to the vertical solution All the components in the system should be as reachable as possible for any dismantling/repair works and following cleaning up. The system should as independent from the beam line as possible – CCC should not influence beam/other experiments nearby. All installation locations may not be accessible when beam line is in operation – complete remote operation should be foreseen. Any thermal fluctuation/ pressure difference in the cryostat will affect the SQUID measurements – Hence the system should be as “quiet” as possible.

22. Conceptual design of the new CCC-2 Isolation vacuum Disturbing the accelerator vacuum – consequences : CCC is like a cryo-pump when cold -- During warming up, release of several types of gases condensed on the cold CCC Venting and hence any modifications is restricted by the beam line vacuum conditions. Constant thermal load by radiation onto the cryostat from the beam tube – long “warm-hole” is unavoidable without isolation vacuum. With isolation vacuum, one can do a lot more studies during test measurements (more realistic simulation of beam currents).

23. LHe liquefaction plants LHeP18 PT410 GM Based GWR-ATL Liquefaction unit

24. Challenges with Re-cooling systems Purity of the Helium boil-off Mechanical isolation of the CCC cryostat from the cryo-cooler Thermal instabilities causes drastic zero drifts in the SQUID signal Installation and operation space availability in all beam line

25. New CCC Concept Mag. shield incl. pickup coil isolation vacuum chamber Radiation shield Cooling- cold helium boil-off LHe cryostat Bellow – isolation vacuum Ceramic spacer Suspension (3) Mag. shield Suspension (3) LHe cryostat Support - Mag. shield Bellow – LHe cryostat SQUID signal feedthrough Vacuum connection SQUID sensor

27. 1000 mm 657 mm 435 mm 160 mm 550 mm

28. CCC Installed in HTP

43. Thanks for your attention