Joint PSP/Taskforce minutes for 24 Oct 2019
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slides posted to: http://beamdocs.fnal.gov/AD-public/DocDB/ShowDocument?docid=7781

(a) Updates from Tan for both PS and Task force
   (i) PS startup blues
      (1) source A gas pressure is high. Cannot find leak. Will run
   with it for now.
      (2) source B required might Cs boiler temperature (~140 degC) to
   run with enough beam
       	    (i) Suspect that there is a clog.
      (3) Postmortem: End of next shutdown to start both sources
      because they will naturally stagger out.
      (4) LRF4 breaker change. Found wire whisker to be cause of
   problem fo breaker overcurrent problems.
      (5) Booster damper problems. Nathan will continue working on it
   once beam returns.
      (6) Power outages on Wed 23 Oct and Friday 25 Oct doesn't help
   with startup.
   (ii) Status of PSP projects
      (1) Klystron testing has been added to work to be done in
   FY20. This is to identify all viable spares in Linac.
      (2) Flat injection. Many problems were identified. Kiyomi, Howie and
      others will need to look at these problems. Studies are planned.
      (3) 2nd harmonic. Removed from test cave. Getting ready for
   repair.
      (4) Wide bore cavity. In test cave. Low power tests show
   that entire frequency vs bias curve is shifted to lower
   frequency. At bias of 2500 A, fres is 416 kHz lower than the
   required 53.2 MHz. Can reach 52.8 MHz at 2800 A. The remedy is to
   remove some ferrites from the tuners. A simulation will be done
   with the new measurements to determin the number of ferrite rings
   to be removed. In the meantime, cavity tests for gap voltage, HOM
   modes, power loss etc. will continue.
     (5) BTL to Booster. Civil construction is
   considering two ways of getting the beampipe into Booster. Option 1
   is baseline has limited space for instrumentation. Option 2 will
   allow moving the dogleg magnets out of the Booster tunnel, and more
   instruments. However it has a higher cost. A request for more
   penetrations have been given to Steve Dixon.
     (6) Garnet improvements LDRD. There is a preliminary design of
   the test fixture and solenoid. A mechanical engineer is being
   requested to join the group.
     (7) Paraphase upgrade. Brian Schupbach has done measurements
   during the shutdown. Will test the digitial system when we start up.
   (iii) Task force
      (1) Digital LLRF meeting on 18 Oct. Discovered potential
   problems with proposed injection scheme. Not clear any of the
   proposed methods of injection into Booster will work. Need to
   understand how to tie PIPII LLRF to Booster LLRF. No specs for GMPS
   flatness, jitter etc. Studies have been proposed.
     (2)  Wide bore gradient magnets
     	 (a) Mechanical  have gone into L3 to figure out how move
   magnets.
        (b) Valery K., Jeff E. and Salah C. have measured dimensions
   of unused septa.
     (3) 20 Hz cavity tests. See below.
     (4) BTL to L11 changes. See above entry 5.

(b) Victor gave an update on the 20 Hz cavity tests
   (1) Goal is to check whether the bias supplies can cavities can run
   at 20 Hz and to check for other problems, for example
	(i) Power distribution may be under-rated.
	(ii) Do the bus bars get hot in the penetrations.
   (2) New APG, CIG, bias and frequency cuves were generated.
       (symmetric about Bdot=0) during +/-200 us.
     (3) 20 Hz $BA events were used in the timeline.
     (4) RF frequency for 20 Hz tests start at 44.7 MHz and end at 53 MHz.
     (5) RF station 7 was the used guinea pig to test the curves.
       L11
     (6) All the RF stations in the east were used for the test. What
   was found:
     	 (i) yard transformer rated at 1.2 MVA.
	 (ii) Distribution breaker rated at 1600A but 1650A was
         flowing through it. Too much current and not acceptable for normal
         operations. 
      (7) Average bus bar current for 15 Hz is 1100A and at 20 Hz is
   1600A.
	(i) Bus bars do not come into equilibrium in 3 hours. It takes
   over 3 days
   	(ii) For 3 hour test no bus bar exceeded 160F. 248F is melting
   point of polybeads.
   	 (iii) Hottest temperature is inside the penetrations from IR
   thermal measurements.
     (8) Tuner temperatures were measured on a cavity in the test
   cave.
	(i) Temperatures were cooler on the tuner for 20 Hz because
   the bias was higher and the losses from the ferrite was lower.
     (9) The temperature of the cavity was also measured. Critical
   places are at the windows.
   (10) Experiment was done with 22.5kV modulator voltages for PIP
   voltage and 24.0 kV for PIPII.
   (10) Cavity temperatures at 20 Hz were mostly cooler than at 15 Hz.
   (11) Bias supply could regulate but reliabiity is unknown.
   (12) Some possibly remedies for the increased current requirements
   were discussed.
   	(i) Inrease intrinsic cavity resonant frequency.
	(ii) Change tuner configuration: number of  low mu and high mu
   ferrrites can be changed to increase intrinsic resonant frequency.
   	(iii) Buy new bias supplies that are more efficient. Very
   expensive option.
   	(iv) Increase yard power breaker to 1.5MVA. Expensive.