Difference between revisions of "PITMinutes 02-26-2018"

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(New page: == Attendance == R. Bachimanchi, K. Baggett, J. Benesch, A. Freyberger, R. Geng, G. Krafft, A. Kimber, R. Legg, F. Marhauser, R. Nelson, T. Plawski, R. Rimmer, and H. Wang. == Agenda and...)
 
(Attendance)
 
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== Attendance ==
 
== Attendance ==
  
R. Bachimanchi, K. Baggett, J. Benesch, A. Freyberger, R. Geng, G. Krafft, A. Kimber, R. Legg, F. Marhauser, R. Nelson, T. Plawski, R. Rimmer, and H. Wang.
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R. Bachimanchi, K. Baggett, J. Benesch, R. Geng, C. Hovater, G. Krafft, A. Kimber, F. Marhauser, C. Mounts, R. Nelson, T. Plawski, T. Powers, C. Reece, and R. Rimmer.
  
 
== Agenda and Notes ==
 
== Agenda and Notes ==
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1. Operations Status and Summary/Review (Freyberger)
 
1. Operations Status and Summary/Review (Freyberger)
  
Four Hall Ops has started. Beam current has been up to about
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Four Hall Ops has started. Have had a rough couple weeks
300 muA total in both linacs. RF not entirely stable yet, but
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as the beam average current was raised. CEBAF seems to have
no indication of BBU instability yet. Keeping my
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an average current limit around the spec average current of
fingers crossed.
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460 muA 5 pass beam. This current has been briefly achieved,
 +
but steady OPs at around 325 muA. BBU looked for but none
 +
obviously present. Much optics work has cleaned up beam and
 +
made more substantial apertures, but the average current limitation
 +
remains. OPS trip rates now dominated by RF trips.
  
We've had beam loss and lots of separator tuning. Haven't
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C75 Review completed. Will post review report when available.
seen clear hot spots. 5 RF trips/hr and 5 MPS trips/hr. Fluctuating RF?
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Because no hot spots observed, will be increasing current soon.
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RF separators seem to have settled down. circulator loads unstable.
 
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Recovery reboot?
C75 Project and Implementation Review will be held Thursday, Feb. 15. Here is the talk repository.
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[https://www.jlab.org/indico/event/251/ Site for C75 Project and Implementation Review Talks]
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Practice session will be held this Friday, Feb. 9 in this room.
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2. Beam Loading and Q_ext (Krafft)
 
2. Beam Loading and Q_ext (Krafft)
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current limits?
 
current limits?
  
[https://casa.jlab.org/LINACPIT/Optimal_Qext.pptx Presentation on Optimal Qext]
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[https://casa.jlab.org/LINACPIT/Optimal_Qext.ppt Presentation on Optimal Qext]
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[https://casa.jlab.org/LINACPIT/ced_20feb2018.txt CED All Qs list]
 
[https://casa.jlab.org/LINACPIT/ced_20feb2018.txt CED All Qs list]
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[https://casa.jlab.org/LINACPIT/RF_Power_C75.xlsx Xcel with power calculations]
  
 
3. Draft Cryomodule Specification (Benesch)
 
3. Draft Cryomodule Specification (Benesch)

Latest revision as of 18:05, 26 February 2018

Attendance

R. Bachimanchi, K. Baggett, J. Benesch, R. Geng, C. Hovater, G. Krafft, A. Kimber, F. Marhauser, C. Mounts, R. Nelson, T. Plawski, T. Powers, C. Reece, and R. Rimmer.

Agenda and Notes

1. Operations Status and Summary/Review (Freyberger)

Four Hall Ops has started. Have had a rough couple weeks as the beam average current was raised. CEBAF seems to have an average current limit around the spec average current of 460 muA 5 pass beam. This current has been briefly achieved, but steady OPs at around 325 muA. BBU looked for but none obviously present. Much optics work has cleaned up beam and made more substantial apertures, but the average current limitation remains. OPS trip rates now dominated by RF trips.

C75 Review completed. Will post review report when available.

RF separators seem to have settled down. circulator loads unstable. Recovery reboot?

2. Beam Loading and Q_ext (Krafft)

Jay has gathered some data that indicates that perhaps the Q_ext on many cavities is incorrect. This means the RF systems are not matched to the cavities at the highest operating currents, leading to addition power loads on the klystrons. Could this be a contributor to the average current limits?

Presentation on Optimal Qext

CED All Qs list

Xcel with power calculations

3. Draft Cryomodule Specification (Benesch)

Jay has written up a set of goals for the cryomodules: Draft Cryomodule Specification

4. Draft Acceptance Criteria (Legg)

Bob shared the LCLS II module acceptance criteria that the LCLS II project is working under. We should perhaps adopt something similar for C75? (Discuss Pros and Cons)

LCLS II Module Acceptance Criteria

Frank and Gigi (mainly) have written up a C75 performance specification document.

JLAB-TN-17-055: Draft C75 Specification Document

Action Items

Leadership of quenches. Offline discussion.

Complete C75 Module Specifications (Marhauser, Benesch, Krafft)

C100 Refurbishment Project for the future?