1. HIE-ISOLDE Project Status Report
Yacine KADI
CERN
HIE-ISOLDE Project

2. OUTLINE Status of the Technical Infrastructure
Results from the Machine Commissioning
Future Plans
Conclusions
HIE-PCG meeting, Y. Kadi, 21 Sep. 2015

3. Technical Infrastructure (E. Siesling)
ISOLDE target zone
Compressor building 198
Water station B197
ISOLDE Low Energy
Cold Box building 199
HIE SC Linac
Equipment platform
Installation of the HIE-ISOLDE technical infrastructure (red boxes) has been completed with minor disruptions to the parallel running of the Low-Energy physics programs at the ISOLDE facility.
All the services are by now fully operational.
High Energy Beam Transfer lines HEBT

4. Cryogenic Plant Cryo System: fully commissioned. Liquid He made.
The overhauled ALEPH compressor units and cold box together with the new cryogenic distribution line have been commissioned and supplying LHe at 4.5K since June 2015
Cryo System: fully commissioned. Liquid He made.

5. Cryo Distribution Line
Cryogenic distribution line feeding the SC linac with liquid He at 4.5K is in steady operation since June 2015
Cryo Cold Line & all 6 Jumper Boxes: installed and instrumented
Pressure tests done on Cold Line.

6. HEBT Lines MiniBall Scattering Chamber
Elements of the SC linac and the first two High-Energy Beam Transfer lines (XT01 and XT02) have all been installed.
The quadrupole, H/V corrector and dipole magnets and associated beam diagnostic boxes have all been tested and commissioned.
The first two experiments (Miniball and the Scattering chamber) are being installed in view of the first physics run this coming Fall.

7. SC Linac Cryo-Module 1 installed on Saturday 2nd May.
The first high-beta cryomodule (CM1) was transported to the HIE-ISOLDE linac tunnel in May and after a dense installation campaign, CM1 was ready for cryogenic cool-down a month later. The installation and commissioning of the second high-beta cryomodule (CM2) is scheduled for the first quarter of 2016.
Subsystems such as cryogenic instrumentation, vacuum controls, RF interlocks, fire and oxygen deficiency alarms have all been tested.
Cryo-Module 1 installed on Saturday 2nd May.
Cool-down: mid-June to mid-July

8. CM1 HW commissioning: main results (W. Venturini)
Cryogenics: ~100% availability over 2 months, then problems (4 CB stops + incident)
Vacuum: in range of mbar
Cold alignment: ~1.2 mm vertical offset corrected
Cavity conditioning OK, only CAV2 has FE
Cavity tuning OK: all cavities at MHz, mid range
Cavity performance: 6 MV/m/CAV with less than 50 W
Serious issue with power coupler identified
Solenoid performance: OK, “feature” under control
Combined powering cavities and solenoid OK
Static heat load measured within specs ( ~ 10 W)
LLRF loops working well beyond specs at 2 MV/m

9. Issues for phase 1: RF coupler
Observation: RF drifts when driving cavities at high power to initially assumed operational bandwidths thermal effects in the power coupler
Potential showstopper
Actions taken:
Dedicated test in SM18 permanent damage at 200 W
Post mortem analysis
Second test in SM18 OK after 9 hours at 60 W
Test bench at room temperature: no damage with 500 W for 1 hour, or 250 W for 24 hours
Third test in SM18 week 36, testing possible fix
Adapting low level RF loops to reduce bandwidth as much as possible (now 3 Hz 50 W seemed possible)
On Saturday 29th August, CAV4 powered at 14 W (minimum requirement for operation) for 24 h clear signatures of degradation!
80 W !

10. Testing possible fix at SM18 (A. Miyazaki)
Addition of a Thermal Anchor

11. Coupler with the additional thermal anchor (50W 9h)

12. Coupler Powering (A. Miyazaki)
black: without anchor
red: with anchor
Time constant p1 is shorter by factor two with same reflected power

13. Coupler Cooling (A. Miyazaki)
black: without anchor
red: with anchor
Time constant p1 is shorter by factor seven with same reflected power

14. Coupler Temperature (A. Miyazaki)
185
160
135
110 85 60
Cu block temperature [K]
Without Thermal Anchor 65 60 55 50 45 40 35
Cu block temperature [K]
With Thermal Anchor

15. Effect on Eacc (A. Miyazaki)
black: without anchor
red: with anchor

16. Adapting the LLRF (D. Valuch et al.)
On 13/09/2015 all five cavities were successfully powered and locked using an automatic sequence
Relatively stable operation at 2.5MV/m with 3Hz bandwidth
Field quality in per-cent/degree mode. Worse than the specification, with sufficient power we can do much better.
rms power limited to ~20W, saturation set to 40W
Coupler gets damaged at 80W for 24 hours.

17. Adapting the LLRF (D. Valuch et al.)
Microphonics is the limiting factor for low power operation
Low frequency vibrations (1-5Hz), higher frequency vibration (50Hz) in the cryostat not yet understood
Perturbations are seriously affecting the cavity field – operation at high field (>3MV/m) without tightly locked loops is not possible
Cavity 4 coupler collapsed, but cavity operational at >3Hz bandwidth => Field limitation
Cavity 5 coupler motor is not fully operational – bandwidth can not be set to more than 2Hz

18. Adapting the LLRF: next steps (D. Valuch et al.)
Localize the source of vibrations
Measure the microphonics in Generator Mode
Switch off pumps and other equipment, minute cycle time
Deploy new firmware and FESA class to address minor bugs
Implement automatic cavity sequence (new FESA class)
Start preparing the OP interaction (MachineSetpoint property)
Attempt to lock all cavities at higher than 2.5MV/m (yield 6MV/m):
Need to increase the power limit, otherwise not possible.
Closely monitor the Forward power for deposited heat

19. Cryolab Test Set-up (T. Koettig)
First cool-down is planned for this Monday
The goal is to measure the temperature distribution along the coax cable and coupler antenna first w/o RF power
Then start powering with stepwise increase in RF power until we see a thermal runaway
Test set-up will be used also to qualify new RF coupler assembly

20. HIE ISOLDE roadmap 2015 Tests related to RF coupler limitations
Cryo incident Aug 12th
Possible interleaving
The machine commissioning campaign covered the vacuum and cryogenics performance, monitoring and alignment adjustment of the active elements, conditioning and RF measurement of the superconducting cavities, power tests of the superconducting solenoid, and commissioning of the LLRF and of the tuning systems. Cold testing of the first cryomodule started in June 2015.
All 5 superconducting cavities (in CM1) were successfully RF conditioned at cold. The high field multipacting band around 1.5 MV/m was easily processed in 4/5 hours per cavity.
An important milestone was reached when all superconducting elements (cavities and solenoid) were successfully powered at nominal field at the same time.
The fully digital HIE ISOLDE low level RF system was deployed for the first time to control the first cryomodule. It was used to tune the SC QWRs very close to the target linac frequency of MHz.
All HEBT hardware commissioned on schedule
CM1 cooled down and hardware tests complete
Issue with power coupler looking for an operational point
Cryogenics Incident on 12th August

21. Overall Summary Enormous progress since April 2015
Infrastructure in place
HEBT hardware commissioning completed
CM1 installed, cooled and powered. Full test campaign carried out
REX beam commissioning well advanced
Beam commissioning of SC Linac is possible in September
The results of hardware tests (problem on RF couplers) highlighted that CM1 is not fully qualified for sustained operation as planned
Agree with Collaboration on a common scope for 2015 Physics run

22. Thank you for your attention

23. DBoxes commissioning in XT00-XT01
S. Sadovich (BE/BI)

24. DB status in XT00 – XT01 XT01 LBD4 LBD3 LBD1 SBD1 SBD2 SBD3 SBD4 SBD5
All instruments in
LBD2 LBD3 LBD4
are installed and ready to be checked with beam
LBD4
FC; SS; Coll
FC – Faraday Cup
SS – Scanning slit
Coll – Collimator slit
Stripping foils are not installed
All instruments in
LBD1 SBD1 SBD2 SBD3 SBD4 SBD5
are installed and checked with beam (FC)
Problems:
Short cut (cup - repeller) in FC in SBD1
Leak/Broken SS in SBD5
LBD3
FC; SS; Coll
Wall
LBD1
FC; SS; Coll; SD
SBD1
FC; SS; Coll
SBD2
FC; SS; Coll
SBD3
FC; SS; Coll
SBD4
FC; SS; Coll
SBD5
FC; SS; Coll; SD
LBD2
FC; SS; Coll
CM1
XT00

25. Next steps As soon as beam available: As soon as scheduled: Winter SD:
Testing profile measurement in all DBs
Testing emittance measurement option
TOF measurements
As soon as scheduled:
Change SS in SDB5
Winter SD:
Repair FC in SDB1

26. Proposed beam line layout

27. HIE-ISOLDE Roadmap REX Beam phases wk 14/2015 SD 2015/16 I SD 2016/17II
III
The present schedule foresees to deliver beams up to 4.2 MeV/u for the heaviest species this autumn with a single high-beta cryomodule.
A second cryomodule will be installed during the winter shutdown 2015/2016 bringing the energy to 5.5 MeV/u for all the radionuclides available at ISOLDE. This will complete phase 1, making Coulomb excitation studies possible up to A/q=4.5.
A second phase will consist in adding two more high-beta cryomodules during the winter shutdown 2016/2017, thus doubling the available accelerating voltage. The optics of the third beam line, for which the infrastructure has already been installed, will be added during this phase, in order to host the HELIOS detector.
Finally, in phase 3, two low-beta cryomodules would be installed, replacing some normal conducting structures of the present REX-ISOLDE. This would allow varying continuously the energy between 0.45 and 10 MeV/u together with an improved beam quality. This phase has now been removed from the MTP
Legend:
Existing REX-structures:
RFQ, IHS: 20-gap IH-structure, 7GX: 7-gap split-ring cavities, 9GP: 9-gap IH-structure