1. Cryomodule Test Schedule
M. Drury
11-Nov-2018

2. Outline
Schedule
Staffing
Transition to Operations Review 12 Nov 2018

3. Schedule
The schedule presented addresses the first test of two cryomodules in the LERF
Expect this round of testing to be the worst case in terms of schedule time
Debugging new systems
General lack of familiarity with new controls
Developing new testing procedures.
We can expect to shave
Transition to Operations Review 12 Nov 2018

4. Schedule: Cool Down Cool Down depends on CHL schedule
Need CHL to 4K before u-tube operations
Pump down of the LERF modules coincides with CHL pump down of the linacs to 2K
Start simultaneous Cool downs on 1/3/19 (2nd day back after break)
The modules must be at 4K, stable and full of liquid before 01/14
If all goes well, the modules are ready for pump down by 01/09
Transition to Operations Review 12 Nov 2018

5. Schedule: Pre-checks and prep work
HPRF pre-checks (SSA’s already checked out into shorts etc)
Complete RF Cable calibrations
All GM tubes are in correct locations
Check all waveguide flange connections at couplers and at SSA outputs.
Check all coax cable connections
Field probes
Directional couplers
Arc detectors in place
~ Two shifts to complete 01/15 – 01/16
Transition to Operations Review 12 Nov 2018

6. Schedule: Pre-checks and prep work
Interlock Checks –both cryomodules - 1 shift
PSS to Power Permit
SSA’s - High Voltage On and RF On
Cavities to RF On
Check each interlock to ensure that RF permit is removed
Beamline Vacuum – all eight permits
Coupler Vacuum – all eight permits
Arc detectors
Fire test LED’s – each cavity
Coupler temps
Force trip by lowering trip level below temperature reading for each of two sensors on each coupler.
At end of test, ensure trip levels are correctly set
Stepper Temps
Force trip by lowering trip level below temperature reading for each sensor on each tuner.
At end of test, ensure trip levels are correctly set.
~ Two shifts – complete 01/17
Transition to Operations Review 12 Nov 2018

7. Schedule: Tuners Tuner Tests (both cryomodules)
Set up cavity at low gradient. (No higher than 5 MV/m)
Exercise each mechanical tuner
Verify acceptance criteria for mechanical tuners
Each cavity left at MHz
Exercise piezo tuners
Verify acceptance criteria for piezo tuning (range)
Two piezos per cavity
~ 1 hour per cavity – two shifts of tuning
Budget 3 shifts in case there are issues
Coupler (FPC) tuning
Manual tuning – low power rf with network analyzer locally (in vault)
Tune all couplers to 4x107
~ 2 days
Complete by 01/23
Transition to Operations Review 12 Nov 2018

8. Schedule : Maximum Gradient
Measure Qext’s (FPC, field probe, HOM’s) (at initial gradient ~ 8 MV/m)
Probe calibration
Monitor predetermined signal list using strip tools
Ramp up gradient in SEL Pulsed mode (low duty cycle < 10%)
Automated ramp routine? (if not then gradients raised manually at set increments and intervals)
Ramp from 8 MV/m until gradient limit is reached
Limits include repeatable quenches, admin limits, repeatable trips from interlocks
monitor for field emission
Repeat ramp from (limiting gradient – 3 MV/m) up to limiting gradient in SEL CW mode. Verify CW limiting gradient
One hour run at Usable Gradient
Usable Gradient = (quench gradient – ½ MV/m) or admin limit or field emission limited gradient.
At end of one hour, automated ramp down to collect FE data, frequency vs. gradient
If one hour run fails, lower gradient by ~1/2 MV/m and try again.
Re-measure Qext’s at Usable Gradient and at 16 MV/m
Budget ~ 8 hours per cavity for untested module, ~ 4 hours per cavity for tested module
Complete by 01/31
Transition to Operations Review 12 Nov 2018

9. Schedule : Fast Cool Down and Qo Measurements
Temp Bump / Fast Cool Down
Budget ~5 days to complete both cryomodules
Must be scheduled with input and approval of the Cryo Group and may effect thee schedule.
Qo’s
Mass flow method
Needs procedural development
~ 1 week to develop
Allot ~2 hours per data point at first (after development)
Time required may decrease with experience
~ 8 hours per cavity to start (after development cycle)
Back up plan – dP/dt method
Complete by 02/26
Transition to Operations Review 12 Nov 2018

10. Schedule: Multiple Cavity Operations
In general, set gradients in all cavities in a cryomodule at 16 MV/m or at the “Usable Gradient” if lower than 16 MV/m.
GDR mode operation
Ramp each cavity up to target gradient
Cryo Operator monitors pressure, level in primary
Monitors 5K ckt – adjusts flow as necessary
Adjusts heater power down in LERF modules to compensate for increased dynamic load.
With all cavities at target gradients - soak until coupler temps reach equilibrium temperature ~ 6 – 10 hours
Perform procedure on each cryomodule in turn
Perform procedure with both cryomodules
Budget ~ 3 shifts per operation
Multiple cavity operations must be scheduled with input and approval from the Cryo Group which may affect the schedule.
Complete by 03/05
After completion of these tests – modules can be warmed up with Cryo Group approval
Earliest date – 03/06
Transition to Operations Review 12 Nov 2018

11. Schedule assumes two shifts a day, M-F
This schedule does not account for potential remote operations outside the Test Plan.
Might not fully account for “debugging”
While the schedule is somewhat conservative, will likely run longer.
If testing runs past the end of Winter Physics Run (03/12) could be halted by CHL work.
Transition to Operations Review 12 Nov 2018

12. Overall Schedule
Transition to Operations Review 12 Nov 2018

13. Staffing
Test Operators are initially selected from a list of personnel that have experience testing cryomodules in both the CMTF and in the CEBAF accelerator.
Transition to Operations Review 12 Nov 2018

14. List of Potential Test Operators
Staffing
List of Potential Test Operators
RF Test
Anna Solopova – Lead RF Test Operator
Janice Nelson - SLAC
Bob Legg
Mike Drury
Mike McCaughan
Gigi Ciovati
Steve Dutton
Cryo Test
Naeem Huque – Lead
Frank Humphry
Leonard Page
Peter Owen
Mike Drury
Liang Zhao
Expect that SLAC will contribute Visiting Operators
Expect some help from Ops during Down time
Transition to Operations Review 12 Nov 2018

15. Test Plan is well defined at the top level
Summary
Test Plan is well defined at the top level
Some development work is required to deal with new measurement schemes and new hardware
As currently scheduled, testing is compatible with CEBAF Operations
Any operations that may have an effect on CHL stability will be scheduled with input and approval of the Cryo Group.
Transition to Operations Review 12 Nov 2018