[BTeam] Fwd: Schedule options
Mike Spata
spata at jlab.org
Mon Apr 21 06:50:06 EDT 2014
Good morning,
The accelerator will remain open during day shifts through Saturday for recovery from the ZA magnet.
A strawman schedule for beam recovery on swing/owl starting on Tuesday is outlined below. Under this
scenario LASO coverage will resume for tomorrow's swing shift with no day coverage until Sunday.
Mike
----- Original Message -----
From: "Arne Freyberger" <freyberg at jlab.org>
To: "Michael Spata" <spata at jlab.org>, "Noel Okay" <okay at jlab.org>, "Paul Vasilauskis" <vasilaus at jlab.org>, "Ken Baggett" <baggett at jlab.org>, "lauze" <lauze at jlab.org>, "Bob May" <may at jlab.org>, "Kelly Mahoney" <mahoney at jlab.org>, "Steve Suhring" <suhring at jlab.org>, rmichaud at jlab.org, "Matt Bickley" <bickley at jlab.org>, "Fulvia Pilat" <pilat at jlab.org>, "Geoffrey Krafft" <krafft at jlab.org>, "Michael Tiefenback" <tiefen at jlab.org>, "Jay Benesch" <benesch at jlab.org>
Sent: Sunday, April 20, 2014 1:53:41 PM
Subject: Schedule options
Last Monday we discussed the end-game and how to proceed. Tuesday the ZA arc event occurred (Risk 2.2.1 Unknown hardware...). Friday a subset of the CPT/B-team met to discuss the schedule options. Tonight, I plan to send a status update email to CAB/lab leadership. The email will be more or less a summary of my journal entry below, with the addition that having explored two paths forward, continue with the 550MeV/linac setup or revert back to the 1000MeV/linac setup from the beginning of April (option 1.2). I will recommend that we stay the course and finish the 5.5pass setup at the 550MeV/linac setting (option 1.1). I think this gives the highest probability of success as it allows the hardware to be fully explored at the lower energy before pushing to 910'ish MeV/linac. In particular this approach provides time for the shunt issued to be worked a bit longer (this is a new risk since last Monday). Both options take about the same amount of time, although the schedule is not that detailed.
If you see anything that should be adjusted, let me know. I plan to transmit the email around 9pm tonight.
Arne
Schedule Options and ACC-II end-game decision flow
1 Beam plans for remaining two weeks OPS
<2014-04-18 Fri 13:33>
1.1 550MeV/linac first option
1.1.1 2014-04-21 Mon
Owl Open Day Open, repair, CHL1 trip/pump down test Swing TBD, PSS certs Hall-D segment
1.1.2 2014-04-22 Tue
Owl TBD Day Open, repair Swing NL02-NL06 tests, Beam to 5R, PSS certs Hall-D segment, restore 550MeV/linac
1.1.3 2014-04-23 Wed
Owl Beam to 5R, restore 550MeV/linac, investigate dispersion/BPM issue, RF calibration Day Open repair Swing Beam to 2R, 550MeV/linac, RF Calibration
1.1.4 2014-04-24 Thu
Owl Beam to 2R, 550MeV/linac, RF Calibration Day Open repair Swing Beam to 2R, 550MeV/linac, RF Calibration
1.1.5 2014-04-25 Fri
Owl Beam to 2R, 550MeV/linac, RF Calibration Day Open repair Swing Beam to 2R, 550MeV/linac, RF Calibration
1.1.6 2014-04-26 Sat
Owl Beam to 5R, 550MeV/linac, ORFP Day Open repair Swing YR repairs complete, beam beyond 5R allowed
1.1.7 2014-04-27 Sun
Owl Push beam beyond 5R, 550 MeV/linac Day Beam to 6R Swing Beam to 7R
1.1.8 2014-04-28 Mon
Owl Push to 8R, 550 MeV/linac Day Push to 8R, pathlength Swing Beam to 8R
1.1.9 2014-04-29 Tue
Owl Push to 10R, 550 MeV/linac Day Push to 10R, authorization to go to D-dump? Swing Beam to 10R
1.1.10 2014-04-30 Wed
Owl Push to 5C dumplet, 550 MeV/linac Day Beam to 5C Swing Beam to 5C, evaluate pathlength and adjust wavelength and/or orbits to minimize dogleg settings.
1.1.11 2014-05-01 Thu
Owl Push to D-dump @ 550MeV/linac Day Push to D-dump Swing Beam to D-dump at 550 MeV/linac
1.1.12 2014-05-02 Fri
Owl Change energy via scaling 550 MeV/linac to 910MeV/linac Day 910 MeV/linac scaling, ORFP Swing 910 MeV/linac scaling, ORFP
1.1.13 2014-05-03 Sat
Owl Demonstrate project goals Day Demonstrate project goals Swing Demonstrate project goals
1.1.14 2014-05-04 Sun
Owl Optics characterization Day Optics characterization Swing Optics characterization
1.1.15 2014-05-05 Mon – 2014-05-09 Fri
Owl Optics characterization Day Optics characterization Swing Optics characterization
1.1.16 2014-05-06 Tues – 2014-05-09 Fri
Owl Schedule Contingency Day Schedule Contingency Swing Schedule Contingency
1.1.17 2014-05-09 Fri
* Beam ends
1.2 1000MeV/linac early option
1.2.1 2014-04-21 Mon
Owl Open Day Open, repair, CHL1 trip/pump down test Swing PSS certs Hall-D segment, TBD
1.2.2 2014-04-22 Tue
Owl TBD Day Open, repair Swing NL02-NL06 tests, Beam to 5R, PSS certs Hall-D segment, restore 550MeV/linac?
1.2.3 2014-04-23 Wed
Owl Beam to 5R, restore 550MeV/linac, investigate dispersion/BPM issue, RF calibration Day Open repair Swing Beam to 2R, 550MeV/linac, RF Calibration
1.2.4 2014-04-24 Thu
Owl Beam to 2R, 550MeV/linac, RF Calibration Day Open repair Swing Beam to 2R, 550MeV/linac, RF Calibration
1.2.5 2014-04-25 Fri
Owl Beam to 2R, 550MeV/linac, RF Calibration Day Open repair Swing RF setup at 1000MeV/linac
1.2.6 2014-04-26 Sat
Owl Beam to 5R, 1000MeV/linac, ORFP Day Open repair Swing YR repairs complete, beam beyond 5R allowed
1.2.7 2014-04-27 Sun
Owl Push beam beyond 5R, 1000 MeV/linac Day Beam to 6R Swing Beam to 7R
1.2.8 2014-04-28 Mon
Owl Push to 8R, 1000 MeV/linac Day Push to 8R, pathlength? Swing Push to 8R
1.2.9 2014-04-29 Tue
Owl Beam to 8R Day Push to 10R, authorization to go to D-dump? Swing Push to 10R
1.2.10 2014-04-30 Wed
Owl Push to 10R, pathlength Day Beam to 10R Swing Push to 5C dumplet, 1000 MeV/linac
1.2.11 2014-05-01 Thu
Owl Push to 5C Day Beam to 5C Swing Push to Hall-D tagger dump
1.2.12 2014-05-02 Fri
Owl Push to Hall-D tagger dump Day Beam to Hall-D tagger dump Swing Demonstrate project Goals
1.2.13 2014-05-03 Sat
Owl Demonstrate project goals Day Demonstrate project goals Swing Optics characterization
1.2.14 2014-05-04 Sun
Owl Optics characterization Day Optics characterization Swing Optics characterization
1.2.15 2014-05-05 Mon
Owl Optics characterization Day Optics characterization Swing Schedule contingency
1.2.16 2014-05-06 Tues – 2014-05-09 Fri
Owl Schedule Contingency Day Schedule Contingency Swing Schedule Contingency
1.2.17 2014-05-09 Fri
Beam ends
2 AccII Decision Tree OPS
<2014-04-11 Fri 11:30> What if things do not go well in the next three weeks? How to make decision on beam operations after [2014-05-02 Fri] .
2.1 Project Milestones
MS-02A-03 Beam delivered to 5C dumplet with energy greater than 10GeV. Project date: 2013-12-31 Tue MS-03P-25 Beam delivered to the Tagger Vault with energy greater than 10GeV. Project Date: on or before 2014-04-14 Mon
2.2 Risk Registry
2.2.1 Unknown hardware issue in remaining beam lines
Likelihood Low , HCO process provides confidence that the hardware will function as designed Impact Medium , a subtle hardware issue that escapes detection by the HCO process can result in a long downtime on the order of days. Mitigation None , continue to emphasize the usefulness of HCO.
2.2.2 Pathlength
Likelihood High , we've already encountered a surprising 2cm pathlength effect with at present an unknown origin. The dog-leg capacity at 10GeV, 5.5pass to D is constrained due to lack of upgrade (planned for Summer2014/Winter2015). Impact High , it can take days to sort out the pathlength and optimize the optics. May take several iterations of dog-leg settings, orbit adjustments and MO frequency changes. Similar to the issues worked through during March 3-pass spin-up. Mitigation Initial spin-up of the machine at low energy (where the dog-legs have sufficient range) will be used to determine the best approach for achieving proper pathlength at 900MeV/linac settings for the 10GeV goal. Impact Post-Mitigation Medium
2.2.3 Synchrotron radiation induced orbit issues in the upper Arcs.
Likelihood High , the synchrotron radiation compensation coils are not ready for operations. Impact Medium , these coils are in the machine to compensate for the loss of energy as the beam traverses the Arc. Without these coils the correctors will need to compensate for a constant field in the Arc Dipoles in passes 6,7,8,9,10. Mitigation Keep the energy as low as possible to achieve the goal. The project goals are 10GeV 5.5 pass, which is 909MeV/linac. Energy loss is proportional to E^4, so for top energy (10/12)^4= 0.48. So energy loss should be about half of the worse case envision (at full energy). Impact Post-Mitigation Low
2.2.4 Shunt current at maximum near 10GeV setting
Likelihood High , the design calls for a peak shunt current at about a 10GeV CEBAF setting. The design shunt currents below and above that energy setting are less. Impact High , without the shunts delivering the requested design currents, off nominal corner steering will have to take place. Some of the shunts presently overheat when operated at the peak design value. Mitigation Engineering and Operability are exploring solutions to this problem. Some options include temporary air-conditioning, forced air flow, lower LCW temperature. One could achieve the project goals by delivery 11GeV beam to Hall-D, instead of 10GeV. This would lower the shunt currents but would adversely impact the synchrotron radiation effects, pathlength capabilities and RF performance. Impact Post-Mitigation Unknown at this time.
2.3 Decision Tree and actions
2.3.1 On 2014-04-21 Mon
2.3.1.1 Has tune beam been transported to the 5C dumplet at 550MeV/linac?
Yes Things maybe slightly late but achieving beam to tagger vault by May-2 still possible GOTO 2.3.4 No Work with CPT to evaluate why progress has been slower than expected. GOTO 2.3.5
2.3.2 On 2014-04-25 Fri
2.3.2.1 Has tune beam at or above 550MeV/linac been transported to the Hall-D Tagger Vault?
Yes Things maybe slightly late but achieving 10GeV beam to the 5C dumplet by 2014-05-02 Fri is still possible. Start the energy scaling as soon as possible. Terminate as soon as goal is reached to avoid lengthy period with the C100s at gradient. GOTO 2.3.3 No Work with CPT to evaluate why progress has been slower than expected. GOTO 2.3.5
2.3.3 On 2014-05-02 Fri
2.3.3.1 Beam with E>10GeV at the 5C dumplet and beam to the Hall-D Tagger Vault?
Yes Great you're done!!!! GOTO PARTY!!! No Work with CPT to evaluate why progress has been slower than expected. GOTO 2.3.5
2.3.4 Hardware/Authorization ready for beam to Tagger Vault?
Yes Commission beam to tagger vault with the 550MeV/linac configuration. No Scale machine to 910MeV/linac, and transport 10GeV beam to the 5C dumplet. After this has been achieved, transport beam to Tagger vault at a convenient energy.
2.3.5 Why are things going much slower than expected?
Issue Unknown An unknown issue is stopping beam commissioning progress. Since the source is unknown it is impossible to estimate the time needed for resolution. This is bad. Work with CPT to develop a plan to determine the root cause of the issue.
* Send email to CAB/Lab/Project Leadership that there are issues and achieving the dumplet goal by May 2nd is unlikely and achieving the beam to the Tagger Vault milestone by May 15th is in jeopardy.
* Follow this up with daily status reports to CAB/Lab/Project Leadership.
* Continue to work the problem until it has been resolved or it is cleared that the expected date for beam to 5C dumplet is after 2014-05-15.
* If expected date for beam to 5C dumplet is after 2014-05-15, GOTO : 2.3.6.2
* Once resolved GOTO : 2.3.6
Issue Known and resolved A resolved issue has caused significant delay. Progress, after resolution, in recent days has been as expected. Tunnel tour during the open house is at risk. email Send email to Lab Leadership on the status of beam operations. Detail the need to go beyond the planned end date of 2014-05-02 Fri and the possible impact on the open house GOTO 2.3.6 Issue known but unresolved In this case a known issue has held up beam commissioning progress. Work with the CPT to determine an estimate for establishing beam to the Tagger Vault that incorporates the time needed to fix the known issue as well as the remaining beam tasks. GOTO 2.3.6
2.3.6 Update Schedule
2.3.6.1 Progress the Schedule
* Using progress accumulated to date and additional information to update the schedule, include all tasks including beam to the tagger Vault.
2.3.6.2 Quit?
* If the expected date for beam with E > 10GeV to 5C dumplet is after 2014-05-15 Thu:
* send an email to Lab/12GeV/CAB leadership explaining the situation.
* Continue beam operations up to 2014-05-02 Fri
* Incorporate the 5C dumplet and Tagger Vault milestone into the 2014Fall beam commissioning plans.
2.3.6.3 Keep at it!
* If the expected end date for beam with E > 10 GeV to the 5C dumplet precedes 2014-05-15 Thu
* send an email to Lab/12GeV/CAB leadership explaining the situation.
* Tunnel tour during the open house is in jeopardy.
* Continue beam operations up to 2014-05-15 Thu, get as far as possible in beam transport up to the drop dead date.
* If needed, incorporate the 5C dumplet and Tagger Vault milestone into the 2014Fall beam commissioning plans.
* Continue to track progress beam commissioning effort
* Send daily updates to Lab/12GeV/CAB Leadership
--
Arne Freyberger
Director of Accelerator Operations
Jefferson Lab
12000 Jefferson Avenue Cell: (757) 876-6289
Postal Suite 19 Email: freyberg at jlab.org Newport News, VA 23606
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