Joint PSP/Taskforce minutes for 13 Feb 2020
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http://beamdocs.fnal.gov/AD-public/DocDB/ShowDocument?docid=8012

(a) Updates from Tan for both PS and Task force
   (i) Status of PSP projects
      (1) Penning source mechanical work to add flange has
   started. Arc modulator wiring cleaned up. Improved turn off time of
   test stand source, but no improvement for source A.
      (2) Inserted 750 keV collimator. Lowered losses overall in Booster.
      (3) Flat injection porch. Good data collected that agreed with
   theory. Measurements showed that because L3 corrector is at the
   "wrong" position caused orbit distortions. By using correction to S5
   corrector reduced oscillations. Kiyomi will show flat injection
   results at next meeting.
      (4) 2nd harmonic. Being repaired.   
      (5) Wide bore cavity. Low power tests complete. Still waiting
   for high power test.
     (6) Collimators. Meeting on 21 Jan. Preliminary engineering
   design. More simulations to calculate collimation efficiency continues.
     (7) Injection girder tests. E4R cleaned up. Girder was to be
   moved today but postponed because of snow.
     (8) Garnet LDRD. Preliminary mechanical design and solenoid done.
     (9) Mode 2 damper. Will try to use existing RF cavity 8 to do
   mode 2 damping. Studies to be done on 18 Feb.
     (10) Kickers. R&D to improve longevity of kickers have
   started. (07 Jan). This is necessary for 15 Hz and 20 Hz operations.
     (11) GMPS LDRD. Work continues with pair of Rogowskii coil to see
   whether by differencing the signals from the coils, a less noisy current
   measurement can be made.
     (12) Digital paraphase. Very close to working. Studies on 18 Feb
     to see whether the digital paraphase module can be made operational.
     (13) LLRF room cleanup. Remove deprecated systems and
   cables. Will do this during operations so that the modules can be
   put back if things go wrong.
  (ii) Task force
       (1) 20 Hz infrastructure meeting be held in about 2 weeks.
       (2) Tall aperture magnets. First pass says D magnet aperture
   should be increased by +/-5 mm. Valery Kapin will be verifying this .
       (3)  50 kV in situ cavity test.
     	  (a) BRF11 and 12 run at higher voltage. BRF11 failed in 2.5
           days because of short in high voltage cable. Repaired on 05
           Feb. BRF12 failed on brick supply in bad modulator after 10
           days.
	   (b) It will be necessary to replace/improve location of the
           high voltage cable in all the RF cavities. Perhaps during shutdown
           2020.
	   (c) All west gallery cavities voltages were raised on 05
	      Feb. But had to be lowered on 07 Feb because quad damper was
   	      saturating anode voltage. Question arose as to whether the higher
   	      voltage caused the quadrupole mode to be more unstable.
	   (d) Large +/10 deg phase seen between fan out and fan back
   	   of mode 2. The plan is to try to damp mode 2 with one
   	   cavity than using all the cavities.
     (7) BTL to L11 changes.
     	 (a) collimators in BTL are required to clean up tails of beam
   	 before injection into Booster. PIPII will have meeting to
         discuss how to do this.

(b) Paul talked about how the RFsum shape can be derived semi-analytically.
   (1) For the Booster, the energy ramp is modeled as a cosine curve.
   (2) For zero intensity, emittance beam, the peak voltage for
   accelerating from 400 MeV to 8GeV is 595 kV.
   (3) However, acceleraing real beam requires an accelerating phase,
   and a finite bucket area to contain it.
   (4) Using the bucket area for an accelerating bucket and the
   required bucket area, then both required accelerating voltage and
   phase can be calculated.
   (5) The result can be compared to the operational RFsum curve and
   they have the same shape.
   (6) Paul found that for PIPII that the required peak voltage is
   1.22 MV
       (i) The result compared well with Chandra's curve made by 100%
   efficient accelerating the beam using ESME.

(c) Jeff summarized the 1/2 integer correction study done on 22 Jan
    (1) The goal is to scan the two groups of quad long circuits, A & B, to
    find the best efficiency. Efficiency was measured with B:CHGA
    measured at 4 ms after TCLK.
    (2) IPM measurements were made concurrently.
    (3) Losses were measured at S06 and 026.
    (4) Scans were done with group A and B circuits
    	 (i) The as found efficiency of 90% was improved to 92%.
	 (ii) But in operations, the efficiency is 93%.
	 (iv) Best efficiency was close to A,B settings predicted by MADX.
    (5) Beam loss at BLMS06 and BLMS026 (note error in slides) showed
    strong effect from A&B circuit settings. (Purple is good, yellow
    is bad in the plots)
    (6) IPM measurements were measured for turns 1000, 1500, 2500
    	(i) Horz emittance shows clearly that it is smallest near
    where losses are the smallest.
    	  (ii( Vert emittance size has more of a gradient than a
    blob. over the scan region.
    (7) Results show that vertical 1/2 integer not the entire story.
    	     (i) Horz 1/2 integer will need to considered as well.
    (8)  Tan suggested that the IPM measurements be plotted as a 3D
    plot, i.e. with a time axis. Might be useful to see where the blow
    up starts.
    (9) Yuri says that for the next study he will produce skew quad
    settings to decouple the machine better.
    (10) Next study will try higher intensity. Attempt 1/2 integer
    horz corrections and also look at multiwire data because it is
    real time compared to IPM data.