Klaus Hanke, Stephan Maury(CERN), Thomas Zickler(CERN)
Description
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The Accelerator Technical, Operation & Performance (ATOP) days are held from
4-6 March 2009 in 30-7-018. The meeting covers the whole non-LHC accelerator
complex and reviews the main issues discussed at the ABOC, ATC and APC
committees in 2008. The meeting reports to the BEMB, TEMB and ENMB.
Session 1 - Operation in 2008 and outlook for 2009AT Auditorium
AT Auditorium
CERN
09:00
Introduction10m
Speaker:
Klaus Hanke
09:10
Operations review 2008 and beam status in the different machines30m
We review the beam performance of all the operational machines in the accelerator complex in 2008, look into the problems encountered, and report case by case on the current status and readiness for 2009 beam production.
Speaker:
Django Manglunki
Slides
09:40
Operation scenarios for 2009 - all beams required in 200930m
2009 will be a very challenging year for the CERN accelerator complex. The clear priority will be the LHC with a run through the winter into 2010 scheduled. The implications of this are discussed. The complex will also have to deliver beam in the normal physics schedule to a plethora of other clients. These clients are enumerated and their required beam is detailed. The machine development strategy for the year is elucidated.
Speaker:
Mike Lamont
Slides
10:10
Progress and first experiences with MTE30m
The Multi-Turn Extraction has been commissioned during the 2008 run of the PS. Both single- and multi-bunch beams with a total intensity of up to 1.4×10^13 protons have been extracted with efficiencies up to 98%. Furthermore, injection tests in the SPS were performed, with the beam then accelerated and extracted to produce neutrinos for the CNGS experiments. The detailed measurements performed during the commissioning period are presented. A proposal for the 2009 planning for the start-up will also be discussed.
Speaker:
Simone Gilardoni
Slides
10:40
Coffee break
20m
11:00
Instrumentation status throughout the accelerator complex in 2008 – operation’s point of view30m
A report will be given on the performance and issues of the beam instrumentation available to support machine operation throughout the CERN accelerator complex apart from the LHC. Difficulties of machine operation due to instrumentation problems will be highlighted.
Speaker:
Bettina Mikulec
Slides
11:30
Controls issue in 2008 – operation’s point of view30m
The accelerator chain encountered different problems related to the controls system in the large sense of the word. This presentation will give an overview of the issues concerned together with the applied solutions, where applicable, for the whole accelerator chain apart from the LHC. In the cases where no solutions were found or implemented, the issues will be addressed in more detail in order to urge for a solution prior to the approaching start up.
Speaker:
Rende Steerenberg
Slides
12:00
Do we understand the low pbar production in the AD?30m
During the 2008 startup, the pbar production efficiency was unusually low. Despite several tuning attempts during the run, peak values such as observed in 2007 were never reached and typical beam intensities stayed below numbers of previous years. Here we will discuss the possible causes, what was done in 2008 and what could be done during this years startup in order to improve AD performance.
Speaker:
Tommy Eriksson
Slides
12:30
→
14:00
LUNCH TIME
1h 30m
AT Auditorium
AT Auditorium
CERN
14:00
→
17:20
Session 2 - Accelerator hardware and controlsAT Auditorium
AT Auditorium
CERN
14:00
Mitigation strategies in case of possible magnet failure in the DTL of Linac 230m
Postponed to Friday morning 12:20
Speaker:
Richard Scrivens
14:30
Status and prospects of the PS magnet consolidation program30m
The talk will summarize the findings of the consolidation program implemented on the PS main units, with emphasis on critical aspects which may affect the operation of the PS for up to 10 additional years. An overview of the spare magnet situation for the whole PS complex will also be briefly given, together with a list of proposed actions to complete and consolidate the spare magnet availability.
Speaker:
Davide Tommasini
Slides
15:00
Status and prospects of the SPS magnet consolidation program30m
The 744 main dipole and 216 main quadrupole magnets constitute the bending and focusing system for the SPS ring. These magnet families are among the most populated of the SPS complex with the lowest ratio of spares to magnets in operation. After more than 35 years of operation these magnets need particular attention. Therefore, analysis is continuously performed to detect issues which may lead to poor reliability and adapted consolidation programs are set up to prevent significant down time. The status of the ongoing consolidation programs and update of the results from recent investigations and subsequent consequences will be presented.
Speaker:
Jeremie Bauche
Slides
15:30
Coffee break
20m
15:50
Instrumentation throughout the accelerator complex: prospects for 200930m
During the 2008 run and 2008-9 shutdown several beam instrumentation systems have been upgraded, tested and targeted to be operationally deployed in 2009. In addition, the BI group has been re-organized following the 2009 restructuring. This presentation will present the agreed renovation plan, the corresponding progress and the BI organization put in place. It will also present possible impacts and consequences of a compressed shut-down on BI equipments for operation in 2010.
Speaker:
Jean-Jacques GRAS
Slides
16:20
CERN accelerator controls renovation project30m
This talk will recall the motivations for the Accelerator Controls Renovation Project and the major outcome of the workshop held in December 2008. The project will then be presented with a special focus on how operational objectives will be defined in the light of the new LHC operational planning.
Speaker:
Marc Vanden Eynden
Slides
16:50
New MPS regulation system30m
A new control system for the CPS main power supply (MPS) will be available in 2009. The key features of the new system will be presented and compared to the existing system and the status of the installation and commissioning will be reported.
Session 3 - High intensity beams and radiation issuesAT Auditorium
AT Auditorium
CERN
09:00
Review of the machine protection system in the SPS30m
In the past few years the SPS beam interlock systems have been entirely renovated. The core of the beam and extraction interlock systems are now made with the same electronic components than the LHC. Those system provide flexibility, a high level of safety and excellent post-mortem diagnostics. A new flexible Software Interlock System was designed for the SPS. Although together those two systems provide the SPS with powerful interlocks systems, there are still significant issues for the protection of the SPS ring and of the North transfer line that resulted in two major machine protection incidents in 2007 and 2008. This presentation will provide an overview of the SPS protection systems and highlight some of the issues that still need to be addressed to make the SPS a safer place.
Speaker:
Jorg Wenninger
Slides
09:30
Review of the machine protection system in the PS complex15m
The performance of interlocks and machine protection system in the PS complex machines and experimental areas in 2008 will be briefly reviewed from an operations point of view. In particular, some issues related to the ISOLDE proton request and possible cures will be presented. The implementation of a new BLM into the Linac2 access safety chain to protect the Linac4 work site and the possible consequences for operation in 2009 will be discussed.
Speaker:
Klaus Hanke
Slides
09:45
RF limitations while running at high intensities in the injectors30m
RF limitations at high intensities are related to either the effects of increased beam loading or the passage through certain beam stability limits. The presentation will make an effort to quantify and compare the importance of these different effects in the machines constituting the injector chain (Linac2, PSB, PS, SPS).
Speaker:
Erk Jensen
Slides
10:15
Coffee break
20m
10:35
ISOLDE radioactive air handling30m
The present PSB‐ISOLDE target area is designed to take the maximum possible booster beam of 3.2x1013 protons at 1 GeV per 1.2 seconds (average beam current of 4.3 uA and power 4.3 kW). However, at that the time of the design an average current of about 2 uA had been assumed for normal ISOLDE operation, the radiation levels and radioactivity levels had been calculated for 1013 protons per second, 2x1020 protons per year onto the 2 target stations and 4000 hours of operation per year.
In 2007, operation of ISOLDE had to be restricted to 1uA of proton beam due to an unexplained increase in the measured activated air release to the atmosphere. This presentation will outline the measures taken to restore ISOLDE back to its normal average operation beam current of 2uA.
A potential increase of the average beam intensity of 2uA will need additional studies. Some ideas will be given on the required technical modifications, in particular with view to the HIE‐ISOLDE project.
Speaker:
Richard Catherall
Slides
11:05
Status of RAMSES and ARCON radiation monitoring systems30m
The Safety Commission operates and maintains two different radiation monitoring systems to survey the levels of ionizing radiation at CERN and its environment. Recent installations like LHC, CNGS and CTF3 are equipped with a modern state of the art system (RAMSES) whereas the rest of CERN including the LHC injector chain relies on a system (ARCON), which had been already developed for LEP. Obviously, the operational availability of this system decreased over the years due to aging, maintenance problems and the increasing incompatibility between the ARCON system and CERN’s continuously up‐graded computer network. The presentation will give an overview of the current status of both systems, focusing on ARCON and the efforts required to assure a safe operation of CERN’s non‐LHC facilities.
Speaker:
Markus Widorski
Slides
11:35
Supercycles in the SPS – towards full ppm operation and impact on the equipment15m
After having operated for countless years with machine settings that were strictly organized by supercycles, the SPS operations group is preparing the 2009 (not October!) revolution that will break up the supercycle constraints and organize settings by cycles, as it is done at the booster and the CPS. This presentation will motivate the reason for this revolution and explain the consequences on beam operation. It will also explain why to an outsider the SPS will still look the same as before.
Speaker:
Jorg Wenninger
Slides
11:50
Where do we stand 3 years after the recommendations from the BLRWG30m
Following the recommendations of BLRWG, an extensive campaign of studies have been done to reduce the losses in the different machines of the injector chain or better manage the impact of radiation. In particular, the discussion is focused on the work done to improve the situation of the PS and future studies.
Speaker:
Simone Gilardoni
Slides
12:20
→
14:00
LUNCH TIME
1h 40m
AT Auditorium
AT Auditorium
CERN
14:00
→
17:30
Session 4 - Technical infrastructureAT Auditorium
AT Auditorium
CERN
14:00
Major events in the technical infrastructure in 200830m
In 2008, the TI operators recorded 38 major events not related to LHC. These events primarily concern the injector complex. This talk will cover the different types of events occurring, study the recurring ones and show what actions have been taken after the events. It will also briefly describe how major events are dealt with in the TS Operations Committee and show what tools are available to the technical infrastructure operators.
Speaker:
Peter Sollander
Slides
14:30
Electrical network: Compensators15m
This presentation outlines the current status of the Static Var Compensators at CERN. It explains the transfer of the SVC's from EN‐EL to TE‐EPC beginning of 2009, and the mode of operation in 2009. An overview is given on the results of the 2008 consolidation programme, as well as a summary of annual maintenance activities in shut‐down 2008/2009. The presentation terminates with an outlook on future medium‐term priorities.
Speaker:
Karsten Kahle
Slides
14:45
Electrical network: 18 KV Network Review and status of the SPS consolidation15m
After a short introduction we will look at the status of the 18 kV cables networks, report case by case the source and nature of the problems encountered in 2008 and explain the corrective and preventive actions taken. The status of the SPS consolidation plan of the 18 kV network will be reviewed. The activities scheduled for the period 2009-2010 to continue with the consolidation will be presented and discussed.
Speaker:
Davide Bozzini
Slides
15:00
Review of irradiated cables in the SPS30m
The SPS accelerator complex includes roughly 127000 electric power and control cables. The selection criteria for cables are stated in the CERN-IS23 safety instructions that require retention of the cable functional capabilities up to an integrated radiation dose of 0.5 MGy for general-purpose cables and 10 MGy for special radiation resistant cables. In some SPS areas the cumulated dose over the past 33 years already exceeds those values. According to a replacement program defined in 1990, the control cables of a specific zone were partially or entirely replaced every year while the DC cables were never replaced. The progressive increase over time in the number of installed systems and cables makes the replacement campaigns more and more difficult and time consuming. As a consequence the criteria to be followed in the evaluation of the cable status become fundamental. This presentation summarizes the results of past cabling activities reporting on the overall conditions of the cables. A reflection about the cable replacement strategy is also proposed.
Consolidation of access system for the injector complex30m
In 2008 The ASE group started a project for the renovation of the PS Access system, this concerns the safety interlocks as well as the access control functionalities. In collaboration with BE/OP, the specification of the new system is progressing, covering aspects such as preliminary risk analysis, definition of the safety functions, access sectorisation, definition of the Important Machine Safety Elements.
In 2009 the work will focus on the validation of the specification by the various stakeholders and the design of a system architecture based on the LHC Access project experience, the technological evolution and the need for urgent renovation of some part of the system. The project will be organized in two main stages: the first one will deal with the design installation and validation of the access safety and access control infrastructure, the second one will cover the migration of each PS machine in the new infrastructure. This new system will cope with the need of the LINAC 4 project.
Speaker:
Pierre Ninin
Slides
16:30
Consolidation of buildings and tunnels related to the injector complex30m
The presentation gives a general overview on the consolidation needs on civil engineering infrastructure (surface and underground) related to LHC Injectors. The actions to be taken in the future are evaluated following priorities related to safety or to operational accelerator needs.
Speaker:
Cristiana Colloca
Slides
17:00
Cooling & ventilation30m
In order to increase reliability of CV systems in the non-LHC accelerator complexes, to reduce down time and to satisfy CV users, the group CV carried out works involving creation and modification of cooling, ventilation and control systems. The presentation describes the most outstanding singular works performed by CV in 2008 that are threefold; revamping of installation through significant maintenance and consolidation works, improvement of the systems and works for new complexes. The actions foreseen for 2009, extracted from the mid-term consolidation plan for the cooling and ventilation facilities, are described. Actions to improve spare parts inventory and to reduce mean time to repair are also presented.
As pointed out in previous ABOC/ATC days, the East Area beam lines are difficult to maintain, in particular due the large diversity of the magnets, many of them without spares, and the difficulty to access them whenever a repair is needed. A proposal is presented for a redesign of the area with fewer but more flexible test beams and better access to the equipment in case of failures. The magnets are of fewer types and for each type a sufficient number of operational spares will be available. Preliminary layout and possibly timelines and resource estimates will be presented.
The successful repair of the facility in 2008, allowed a smooth running with beam throughout the year, collecting in total 1.78E19 protons on target. Record duty cycle operation and daily integrated intensities were achieved towards the end of the 2008 run, after the stop of LHC and FT beams. The gained experience in operating the facility is vital for the understanding of the behavior of all installed systems. A system identified for improvement is the cooling circuit of horn and reflector. During the 2008 run, it was discovered that the lifetime of the installed filters, placed to capture the produced charged ions due to radiation and maintain the water conductivity at low values, is much shorter than originally expected. Work is going on during this shutdown to understand the origin of the problem and study possible solutions to minimize the impact on beam operations. The status of the work and prospects for the 2009 operation will be presented here along with a general review of the shutdown activities for the facility and readiness for the startup in May 2009.
Speaker:
Ilias Efthymiopoulos
Slides
10:00
n-TOF operation in 200930m
The neutron Time of Flight (n_TOF) facility at CERN is a source of high flux of neutrons obtained by the spallation process of 20 GeV/c protons onto a solid lead target and the remarkable beam intensity of the Proton Synchrotron (PS). From Nov 2008 the n_TOF facility resumed operation after a halt of 4 years due to radio-protection issues. It features a new lead spallation target with a more robust design, more efficient cooling, separate moderator circuit, target area ventilation and most important without any loss of the unique neutron performances of the previous target. The facility has been commissioned in Nov 2008, with performances similar of the previous target and predicted by Monte Carlo simulations and will resume operation for physics from May 2009, after the correct alignment of the last collimator, the proton beam transfer line, the necessary modifications in the cooling circuit, and ventilation of the primary area. There are already 4 experimental proposals approved by the INTC committee and the Research board granted the requested total of 2.5×1019 p. A letter of intent submitted to the INTC in April 2005 sketches the outlines of the Phase II physics measurements to be performed at the n_TOF facility, where there is a constant need of about 1.5-2×1019 p/yr for the next 4 years.
Speaker:
Vasilis VLACHOUDIS
Slides
10:30
Coffee break
20m
10:50
Physics requirements in the experimental areas in 2009 and beyond30m
Physics requirements in the experimental areas in 2009 and beyond – user requests and planning for for 2009 and beyond. The users schedule for 2009 will be presented. An increase of requests for the various testbeams (considering the upgrade for the LHC, the future ILC and the non-accelerator based experiments) has been observed. For the at present ongoing physics experiments I will give an outlook beyond 2009.
Speaker:
Horst Breuker
Slides
11:20
Findings and conclusions of the Working Group on Future Irradiation Facilities at CERN30m
The need for irradiation facilities to support developments for the LHC experimental particle detectors but also components installed in the accelerator tunnel is clearly identified, and expressed in several proposals and funding requests. To collect the requests from the user community bringing together accelerator, experiment and radiation safety teams and propose a coherent approach for the future facilities, a CERN-wide working group was created. The findings and conclusions from the working group as well as proposals for possible implementations in the existing or future CERN infrastructure are presented here.
Speaker:
Ilias Efthymiopoulos
Slides
11:50
Status and plans for CTFIII30m
The objective of the CLIC Test Facility CTF3 is to demonstrate the feasibility issues of the CLIC two-beam technology by 2010. The combiner ring and the connecting transfer line have been put into operation in 2007, and the remaining parts, namely decelerating section, probe beam linac and test beam line in 2008. In this talk we give the status of the commissioning, including the first results of the combination tests. We report on operation and infrastructure issues and resources. We present our plans for the future, exploring the possibility to run during the winter period 2009-2010, which will certainly add flexibility in order to reach all targets needed for the preparation of the CLIC Conceptual Design Report by the end of 2010. Finally, we discuss possibilities for the CTF3 beyond 2010.
Speaker:
Piotr Krzysztof Skowronski
Slides
12:20
Mitigation strategies in case of possible magnet failure in the DTL of Linac 220m
CERN's Linac 2 accelerator is the source of all primary proton beams, and has been in service since 1978. There are sub-systems of the Linac which are difficult to repair, but one main concern has been the inaccessibility of the ~130 quadrupole magnets: the girder supporting the drift tubes (containing the quadrupoles) cannot be lifted from the tank in the Linac 2 tunnel, with the present crane.
We will present the problem, the steps estimated to make a repair along with a time estimate. Certain investments are necessary in order to keep this estimate, and discussion should include to what extent time and money should be spent on mitigating potential problems at Linac2, with respect to the construction of Linac4.
Speakers:
Bettina Mikulec, Doris Forkel-Wirth, Frederick Bordry, Giovanni Rumolo, Giulia Bellodi, Klaus Hanke, Paul Collier, Peter Sollander, Roberto Saban, Stephan Maury, Stephane Deghaye, Thomas Zickler