Bartolini, R.

Borland, M.

Dallin, L.

Kuske, P.

Müller, R.

Nadolski, L.S.

Perez, F.

Safranek, J.A.

Shin, S.

Zhentang, Z.

HZB Repository

SURVEY OF COMMISSIONING OF RECENT STORAGE RING LIGHTSOURCES∗M. Borland, ANL, Argonne, IL 60439, USARiccardo Bartolini, Ian Martin DLS, Oxfordshire, UKLes Dallin, Canadian Light Source, Saskatchewan, CanadaFrancis Perez, CELLS-ALBA Synchrotron, Cerdanyola del Valles, SpainPeter Kuske, Roland Mueller, HZB, Berlin, GermanyLaurent Stanislas Nadolski, SOLEIL, Gif-sur-Yvette, FranceJames A. Safranek, SLAC, Menlo Park, California, USASeunghwan Shin, PAL, Pohang, South KoreaZhao Zhentang, SINAP, Shanghai, ChinaAbstractThe Advanced Photon Source and other existing storagering light sources are contemplating replacing an operat-ing storage ring with a multi-bend achromat lattice [1–6].Existing light sources have large user communities whoare greatly inconvenienced by extended shutdowns. Hence,there will be a premium placed on rapid commissioning ofthe new lattice. To better understand the possibilities, weundertook a survey of recent commissioning experiences atthird-generation light sources. We present a summary ofthat survey here.INTRODUCTIONAPS, ESRF, and other existing synchrotron light sourcefacilities are contemplating replacing their operating stor-age rings. Users and funding agencies insist that “dark time”is minimized. APS, for example, is targeting 12 months forremoval, installation, and commissioning of a new multi-bend achromat replacement ring. Of this 12 month period,only three months are set aside for commissioning. Otherfacilities are facing similarly demanding constraints.As a result, we need to determine how realistic such shortcommissioning intervals are. We also need to determinewhat factors are most likely to prevent successful commis-sioning in such a short time, and what steps can be taken toensure rapid commissioning. Toward this end, we surveyedrecently-commissioned light sources to understand their ex-perience, where “recently-commissioned” was defined aswithin the last 10-15 years.The survey questions were created at APS by M. Bor-land, L. Emery, J. Kerby, and A. Zholents. In the interestof brevity, the questions are paraphrased below. Responsesdirected at the survey questionswere received from seven fa-cilities, namely, ALBA, BESSY-II, DLS, PLS-II, SOLEIL,SSRF, and SPEAR3. Information was also provided byCLS. The co-authors of this paper responded to the surveyfor their respective facilities.∗ Work supported in part by the U.S. Department of Energy, Office of Sci-ence, Office of Basic Energy Sciences, under Contract No. DE-AC02-06CH11357.A potential source of confusion is that commissioningmaymean different things to different people. As part of thesurvey, we suggested the following definition: commission-ing begins when beam is first injected into the ring. It endswhen the ring is capable of supportingmeaningful beamlinecommissioning,which generally requires several conditions1. The ring can routinely store a significant fraction of theplanned initial operating current for periods of 8 hoursor more.2. The lattice and emittance are essentially at the initialdesign configuration and values.3. The lifetime is workable.4. The orbit and beam stability are workable.5. One or more ready-to-use insertion devices are in-stalled and available.Respondents to the survey generally agreed with this defi-nition. In some cases, delivery of beam to “friendly users”was considered the endpoint.QUESTIONS AND ANSWERSQuestion: How was the commissioning schedule de-veloped? This question was intended to ask about the pro-cess for developing the commissioning schedule, but wasn’tvery clear and was misunderstood by several respondents.Common themes in answers included: Basing the sched-ule on experience at other facilities; e.g., PLS-II followedthe SPEAR3 example of 6 month replacement followed by6 month commissioning. In some cases, requirements weredriven by the user community. Also mentionedwere: exten-sive discussions among commissioning team, creation of alist of major milestones, and definition of a phased commis-sioning approach.What was the scheduled duration of commissioningand how was it structured? Scheduled duration ranged be-tween 4 and 12 months, with 6 months being the most com-mon response (five). Other responses (one each) included 3months, 9 months, and 12 months. Hence, in terms of plan-ning, the 3 month commissioning period contemplated byAPS is a factor of two shorter than typically contemplated.WEBD2 Proceedings of IPAC2015, Richmond, VA, USAISBN 978-3-95450-168-72482Copyright©2015CC-BY-3.0andbytherespectiveauthors2: Photon Sources and Electron AcceleratorsA05 - Synchrotron Radiation FacilitiesHow much time would ideally have been required andhow much was actually required? This question was in-tended to determine how much safety margin was built intothe schedule. Five of seven facilities stated that if noth-ing had gone wrong, commissioning would have taken 3months or less (see Fig. 1). Commissioning typically tookmuch less time than scheduled (see Fig. 2). All but onefacility completed commissioning in less than the sched-uled time, with five of seven reporting commissioning inless than 4 months. The median ratio of actual to scheduledtime was 2/3 and no correlation was seen between year ofstart and time required to commission (see Fig. 3).What was the shift schedule? If not 24/7, why not?Most respondents reported using a 24/7 commissioningschedule, but with interruptions for repairs and installationin several cases. Therewas no obvious relationship betweenthe number of hours of shift work per week and the time re-quired for commissioning, as shown in Fig. 4.How many personnel were involved in commission-ing? The reporting in this case was more varied. Between6 and 18 physicists were involved, with a median of 7. Be-tween 5 and 7 operators were involved, with a median of 5.In total, between 15 and 50 personnel were invovled, with amedian of 30.Amusingly enough, the data appear to (weakly) suggestthat having more people is associated with slower commis-sioning, see Fig. 5. However, the responses are hard to com-pare and are incomplete. It may well be that more peoplebecame involved when difficulties (and hence delays) wereencountered.Which factors introduced the largest delays? Variousfactors were cited in the responses, including vacuum ob-struction (4), delivery delays (2), vacuum chamber heat-ing (2), need to understand detailed behavior of hardware(2), vacuum leak (1), machine protection system delayed(1), magnet wiring error (1), operating procedure error (1),catastrophic failure of a unique component (1), and inade-quate simulation of start-up method (1). One of the lessonsto be drawn from the responses is that vacuum system prob-lems are common and that it is advisable to test components(e.g., bellows liners) on an existing accelerator when possi-ble In addition, commissioning interleavedwith installationintroduces delays.Which factors advanced commissioning mostrapidly? The most-cited factor was thorough subsystemcommissioning (7), followed by control system readyand tested (5). Under the latter heading, MATLABMiddle Layer (MML, 3) and model-based tools (2) wereemphasized. Other factors included first-turn BPMs (2),anticipating failures and problems (1), robust rf bellows(1), and sending staff to commission other rings to gainexperience (1).Lessons here are to test hardware carefully ahead of timebefore introducing beam, and use well-tested software.For new ring in next 5-10 years, what factors are mostlikely to introduce delays? With this question, the re-sponses shifted toward more physics-related concerns, withobtaining stored beam with small dynamic and physicalaperture (4) and obtaining sufficient stored beam to performcorrections (3) being the most-cited concerns. Other issuesare familiar, including lack of full subsystem commission-ing (2), vacuum components (2), rf bellows (1), impedance(1), late delivery of components (1), control system notready or not tested (1), unforeseen major failures (1), andaged staff (1).For new ring in next 5-10 years, what are essential fac-tors for rapid progess? Responses here shifted somewhatcompared to the responses to the previous question, theworking, well-understood diagnostics (5) and in particularturn-by-turn BPMs (3) being commonly cited. Thoroughsubsystem commissioning (4) and having control system ap-plications ready (3) was again emphasized. Under the latterheading, MML (2), LOCO (1), and data logging (1) whereall mentioned. Other factors included well trained, experi-enced staff (2); robust lattice design (1); technical documen-tation (1); and reliable magnet measurements (1).The responses evinced some frustationwith technical sys-tem readiness, particularly with respect to BPMs.If commissioning a new ring in the next 5-10 years,what’s your best estimate of the minimum time re-quired? The median estimate was 4 months, which corre-sponds to the median time to actually commission the ringssurveyed. However, there was only a weak correlation be-tween the estimated time and the actual time for the ringsurveyed (see Fig. 6).CONCLUSIONSOur survey of recently-commissioned rings garnered de-tailed responses from 7 facilities. Most recent rings com-missioned in 4 months or less, typically taking only 2/3 ofthe scheduled time. Most respondents estimated that a newring would take the same amount of time, although respon-dents from facilities that commissioned quickly did not nec-essarily feel a new ringwould also be commissioned quickly.Existing rings could have commissioned in about 2/3 thetime if problems had been avoided.Keys to success include thorough subsystem commission-ing without beam and having controls software tested aheadof time. Delays in the commissioning of new rings are mostlikely to be caused by the difficulty of getting (sufficient)stored beam in new lattices, the lack of full subsystem com-missioning, vacuum system issues (heating, obstructions),and delivery delays.Commissioning an upgrade in 3months seems within therealm of possibility with sufficient care and advance prepa-ration.Proceedings of IPAC2015, Richmond, VA, USA WEBD22: Photon Sources and Electron AcceleratorsA05 - Synchrotron Radiation FacilitiesISBN 978-3-95450-168-72483 Copyright©2015CC-BY-3.0andbytherespectiveauthorsFigure 1: Relationship between ideal and actual commis-sioning time.Figure 2: Relationship between actual and scheduled com-missioning time.Figure 3: Relationship between actual commissioning timeand year when commissioning started.Figure 4: Relationship between actual commissioning timeand commissioning hours per week.Figure 5: Relationship between actual commissioning timeand total staff.Figure 6: Relationship between actual commissioning timeand estimated minimum time for a new ring.REFERENCES[1] R. Bartolini and others. Proc. of PAC2013, 24–26 (2013).[2] J. C. Biasci et al. Synchrotron Radiation News, 8–12 (2014).[3] G. Decker. Synchrotron Radiation News, 13–17 (2014).[4] C. Steier. Synchrotron Radiation News, 18–22 (2014).[5] H. Tanaka. Synchrotron Radiation News, 23–26 (2014).[6] L. S. Nadolski and others. Proc. of IPAC2014, 203–205WEBD2 Proceedings of IPAC2015, Richmond, VA, USAISBN 978-3-95450-168-72484Copyright©2015CC-BY-3.0andbytherespectiveauthors2: Photon Sources and Electron AcceleratorsA05 - Synchrotron Radiation Facilities

Survey of Commissioning of Recent Storage Ring Light Sources

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Survey of Commissioning of Recent Storage Ring Light Sources

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