1 / 52

Future Irradiation Facilities at CERN

Future Irradiation Facilities at CERN. Status report of the working group on future irradiation facilities at CERN http ://www.cern.ch/irradiation-facilities Helmut Vincke on behalf of the Working Group SPSC meeting, September 4 th 2008. Outline. Motivation

grazia
Télécharger la présentation

Future Irradiation Facilities at CERN

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Future Irradiation Facilities at CERN Status report of the working group on future irradiation facilities at CERN http://www.cern.ch/irradiation-facilities Helmut Vincke on behalf of the Working Group SPSC meeting, September 4th 2008

  2. Outline • Motivation • Working group, composition and mandate • Present/past CERN irradiation facilities • Radiation fields produced with 24 and 450 GeV/c protons • Evaluation of the requirements for irradiation facilities • Preliminary conclusions • Outlook

  3. Motivation • Irradiation facilities are the crucial tools to study • Damage to electronics (e.g.: CNGS, LHC …) • Material damage (e.g.: LHC collimators) • Detector performance under radiation • Reliability of simulation codes (benchmark test) • Dosimetry calibrations • … • CERN’s high-energy high-intensity beams are fundamental to carry out these studies. Hence, future irradiation facilities at CERN may influence the plans for PS and/or SPS beam line layouts and scheduling

  4. Working group Following the 6th LHC radiation workshop Nov 2007: http://indico.cern.ch/conferenceDisplay.py?confId=20366 … and in view of several funding requests for irradiation facilities (White Paper, EU projects) CERN-wide working group: AB department: * Ralph Wolfgang Assmann - AB/ABP * Markus Brugger AB/ATB * Ilias Efthymiopoulos - AB/ATB * Roberto Losito - AB/ATB * Yves Thurel - AB/PO PH department: * Mar Capeans - PH/DT * Lucie Linssen - PH/DI (chair) * Michael Moll - PH/DT * Christoph Rembser - PH/ADE Safety Commission: * Fabio Corsanego - SC/GS * Hans-Georg Menzel - SC/RP * Marco Silari - SC/RP * Ralf Trant - SC/GS * Helmut Vincke - SC/RP TSdepartment: * Emmanuel Tsesmelis - TS/LEA * Thijs Wijnands - TS/LEA ATdepartment: * JeremieBaucheAT/MCS

  5. Mandate Essential elements of the mandate: • Collect requirements for future irradiation facilities at CERN (taking into account availability of facilities outside CERN). • Put these requirements in the context of presently available facilities/infrastructures at CERN. • Produce a report on the findings

  6. See: http://indico.cern.ch/conferenceDisplay.py?confId=20366 Present/past CERN irradiation facilities

  7. Present/past irradiation facilities (I) PS East hall facility (in use) • Protons and mixed field irradiation • Up to 1014 protons/(cm2hr) on a 2*2 cm2 surface • Up to 1012 neutrons/(cm2hr) on a 30*30 cm2 surface (1 MeV equiv.) • Since 1992, up to 1500 irradiated samples per year • Mainly used by detector communities (trackers, electronics) • Drawback: parasitic operation (DIRAC), access via primary beam area, personnel exposure, limited space, limited rate Always fully booked

  8. Hadron beam Present/past irradiation facilities (II) CERF facility (in use) Detectors • SPS, H6 beam line, 120 GeV/c • Long copper target, various shielding geometries, well-defined mixed radiation fields • Since 1992, 1-2 weeks per year • Test/calibration of passive and active detectors (dosimetry), FLUKA benchmarking, beam loss monitor studies, … • Drawback: limited dose rates, high muon background from TCC2 Concrete shielding Always fully booked Copper target 1 m

  9. Present/past irradiation facilities (III) GIF facility (in use) Always fully booked 137Cs source irradiation over large surfaces, 740 GBq (in 1997) , running the entire year Combined with SPS West area beam (until 2004) Clients: detector community, mainly muon detectors Detector irradiation, and detector performance under harsh background conditions (photon source= background; particle beam= signal) Shortfalls: need more intensity, need high-energy muon beam

  10. Present/past irradiation facilities (IV) TCC2 target area (not used anymore) • Mixed field irradiation, high doses within reasonable time • Clients: LHC accelerator groups, testing components and electronics • Up to 25 experiments/year • Sufficient space to test complete systems • Shortfalls: • Parasitic, no reproducible radiation conditions • High residual dose rate in the area (access, safety) Test area

  11. Present/past irradiation facilities (V) TT40 area (not used anymore) • Used for LHC collimator studies and material tests in 2004 and 2006 • Short and intense pulses at 450 GeV/c • Up to 3.31013ppp (approx. 2 MJoule) • Drawbacks: • Space too limited • Interference with CNGS operation and LHC fill • Area not ideal in terms RP aspects (production of radioactivity close to beam line elements)

  12. Present/past irradiation facilities (VI) New facility (2008) at the CNGS area (in use) • Exposure to mixed high-energy radiation fields, well-known field thanks to extensive FLUKA simulations • With full (1.2 km long) installation of services, allowing for complete systems tests (crates), SEU testing • Dose rates : • CNGS : 1 to 150 Gy per week • ARC-DS : 1 to 200 Gy per year • Drawbacks: Parasitic to CNGS, access conditions, long access tunnel, safety

  13. First thoughts concerning a future mixed field irradiation facility For high-energy experiments in mixed radiation fields either the PS (24 GeV/c) or the SPS (450 GeV/c) beam could be used. In order to understand the advantages and the disadvantages of the two, the secondary radiation fields emerging from a beam-on-target situation has to be simulated carefully.

  14. Simulation of radiation fields produced with 24 GeV/c and 450 GeV/c protons

  15. Simulation (I) Simulation of irradiation fields using hypothetical “CERF++ facility “geometry and 24 GeV/c and 450 GeV/c proton beams Copper target 7 cm diam, 50 cm length

  16. Simulation (II) Dose rate mapping at beam height 24 GeV/c 450 GeV/c 1011 protons/spill 1010 protons/spill Reference locations Reference locations Outside downstream Inside downstream Outside lateral Inside lateral Contours: 15 µSv/h 15 µSv/h µSv/h Eduard.Felbaumer@cern.ch

  17. Simulation (III) “Outside downstream” • With a factor 10 incoming particle rate difference, particle spectra at 24 and 450 GeV/c in the lateral and back-scattered positions look very similar • Main difference: forward muon spectrum

  18. Simulation (IV) Safety issues related to outgoing muon fluences First estimates (collimated beam assumed). To be compliant with proton facility requirements we need 1.1E12 protons per spill (16.8s)  2.4E14 protons per hour • To stay at a level of 2.5 uSv/h (non designated area, non-permanent access) we need: • ~ 100 m of additional iron for 450 GeV/c • ~ 5 m of additional iron for 24 GeV/c Required Concrete shielding length= 2.6*Iron shielding length

  19. Fluence comparison:LHC vs. Irradiation facility

  20. Fluence comparison:LHC vs. Irradiation facility (I) LHC accelerator Radiation field seen at the irradiation facility at position “inside lateral” (E. Feldbaumer et al. ) Fluences in the LHC tunnel (C. Fynbo, G. Stevenson, CERN, 2001) Very similar shape of the two spectra

  21. Fluence comparison: LHC vs. Irradiation facility (II) LHC accessible area 450 GeV/c 24 GeV/c Radiation field seen at the irradiation facility at position “outside lateral” (E. Feldbaumer et al. ) • Particle fluence spectra for the LHCb counting barracks (C.Theis, et al.) Very similar shape of the spectra

  22. Fluence comparison: LHC vs. Irradiation facility (III) LHC experiment, inner tracker Radiation close to the innermost CMS detector layers surrounding the interaction point. (N. Mokhov) Charged hadrons seen at the irradiation facility at position “inside downstream” (E. Feldbaumer et al. ) Very similar shape of the two spectra

  23. Requirements Questionnaire Requirements questionnaire

  24. Requirements Questionnaire • Web-based enquiry launched to a very wide community http://irradiation-facilities.web.cern.ch/irradiation-facilities/ • Enquiry addresses 5 main irradiation categories: • Pure gamma • GIF++ (gamma irradiation combined with particle test beam) • Proton • Mixed field (neutron-dominated) • High-energy high-Z ion • Questions asked on: particle energy, fluence, total dose, spill-type, irradiation surface, object dimensions, required annual access, year of operation, required peripheral infrastructure…

  25. Feedback • In total 134 forms filled:

  26. Feedback Proton feedback

  27. Proton Facility -- Who answered ? • In total 51 forms filled: • Type of equipment • 44% Detector and detector components • 26% Material tests • 12% Accelerator components • 9% Radiation monitors and dosimeters • Feedback for proton facility dominated by Inner Tracker communities of the experiments

  28. Proton Facility: Beam parameter requirements • Beam parameters required • Machine Community prefers 450 GeV/c and Experiment Community prefers 24 GeV/c. • The majority of the users prefer the slow (fixed target type) extraction • Collimator studies definitely require 450 GeV/c, fast extraction (CNGS type) HiRaDMaT slides • Required maximum integrated proton fluence: • 2 x1016 p/cm2 (94% require this or less);to be achieved in ~1 week  1.1E12 protons per 16.8s

  29. Proton Facility: other requirements • Beam size required • 88% < 10cm x 10cm • 8% < 25cm x 25cm • 4% < 1 m x 1 m • Size of sample: • 67% <10cm , <10kg • 16% <1m, <25kg • 16% >1m, >25kg • Annual beam time requirements: • Collective annual requirements are compatible with one single facility.

  30. Feedback Mixed field feedback

  31. Mixed field irradiation -- Who answered ? • In total 36 forms filled CERN: mainly LHC related topics CERF: beside LHC topics also dosimetry topics for accelerators, aircraft and space applications

  32. Primary beam parameters required • Preferred momentum of primary beam: • Both, 24 and 450 GeV/c is satisfying the users • Fast or slow beam extraction: • The majority of the users prefer the slow extraction

  33. Radiation field conditions required (I) • Comments: • Muonfield is only provided by 450 GeV/c facility • LHC like environment was desired very often as source field • Annual beam time requirements: • Collective annual requirements are compatible with one single facility. • Field type required (Spercentage >100% due to multiple choice) : • Neutron field perpendicular to target: 83% • Field at different angles behind shielding: 42% • High dose radiation fields: 33% • Muon field: 14% note: these clients are asking for other particles as well  no “explicit/exclusive” request for muons • Others: 14%

  34. Radiation field conditions required (II) • Size of irradiation field: • Smaller than 25 x 25 cm2 72% • Smaller than 1 x 1 m2 25% Strong correlation between available dose/fluence rate and desired irradiation surface: Close to target: high fluence/dose rate but small area with constant beam conditions • Maximum integrated neutron fluence/ fluence rate: • 2*1016 n/cm2 • 1011 n/(cm2 s) • Maximum dose and dose rate: • 107Gy • 10 Gy/s

  35. First dose/n-fluence estimates, 24 GeV/c mixed field Beam intensity of 1E11 protons@24 GeV/c per 16.8 s and an continuous operation of 1 week (3.6E15 protons) A significant number of the dose/fluence requirements cannot be achieved in a reasonable time Beam intensity of 1.1E12 protons@24 GeV/c per 16.8 s and an continuous operation of 1 week (4E16 protons) * * An intensity of 1.1E12 protons/16.8 s requires a reinforcement of the conceptual CERF++ shielding design by 1 m of concrete in order to remain compliant with given RP constraints

  36. Summary of inconsistency between user requirements and CERF++ irradiation parameters The final comparison is based on a beam intensity of 1.1E12 protons@ 24GeV/c per 16.8 s and a continuous irradiation of 1 week.

  37. Feedback Heavy ion feedback

  38. Heavy ion feedback “Conclusion”: If the availability of ions can be added at low cost to the plans for one of the future CERN irradiation facilities, they should definitely be included. • 12 replies received • 4 from CERN, 8 from outside institutes • The use of ions for irradiation studies is justified, as their radiation effects on materials are quite different from those induced by e.g. protons.

  39. Feedback Photon feedback

  40. Photon feedback • The questionnaire offers two options: • Pure photons: Strong gamma source for irradiation • GIF++: Strong gamma source for irradiation over very large areas plus a simultaneous particle beam • ANSWERS TO THE QUESTIONNAIRE • Number of answers for Gamma irradiation: 35 • Pure photons: 28 • GIF++: 7,representing many users (LHC experiments)

  41. User communities and applications • User Communities: • LHC experiments; mostly muon detectors • AB and AT department • SC (Radioprotection, Safety & Environment) Applications: • Pure photons • Radiation hardness tests of materials, small prototype detectors and electronic components. • Radiation monitors and dosimeters performance tests • GIF++ Focuses on the characterization and understanding the long-term behavior of large particle detectors. Test of detector reliability (measure particle signal) under harsh background (photon) radiation conditions.

  42. Towards Implementation of a GIF++ facility • User requirements are summarizedin a dedicated document: “The GIF++ Gamma Irradiation Facility at CERN” http://cern.ch/WP7/WP7_DOCUMENTS.htm • The document has been discussed and agreed with the users on 19/8/08 • Some specifications of the new facility: • Photon source: 137Cs, 10 times stronger than former GIF source • Particle beam: Muon beam at ~100 GeV/c , about 104 particles per spill, beam size: 10 x10 cm2. • Area size: ~ 10m x 7.5m x 3 m. • The facility should be operational from 2010 for min. 5 years

  43. Feedback and status Fast extraction, thermal shock tests

  44. Towards implementation HiRadMat Facility In order to guarantee a safe operation of the LHC, critical beam line equipment has to be able to withstand a high-intensity, high-energy pulsed beam impact (e.g.: LHC collimators). Hence, a dedicated test facility is needed. •  HiRadMat: • Uses the existing SPSLHC injection beam to create high power, short duration beam impacts at 450GeV or 177GeV/n! • Status of the implementation work • HiRadMat is included in the phase 2 collimation project (White Paper, 2008) • Dedicated working group was founded to implement the facility in the TT60 area. • AB and SC/RP are involved. • Collaboration with various outside institutes are already established

  45. Preliminary conclusions and outlook

  46. WG conclusions In view of the various demands, requirements and constraints, the working group sees the following optimized scheme for future facilities (in arbitrary order): • Facility for “pulsed proton” irradiations at the SPS (beg. 2010) • HiRatMat (work is already ongoing) • A GIF++ facility at the SPS (2010) • Specification document ready • A combination of proton and mixed-field facility (which can be placed behind each other in the same beam line).

  47. WG conclusions 3 (cont.)About the combined proton and mixed-field facility: 2 possible options : • PS East hall (24 GeV/c) • + cost-effective solution • +- number of protons marginally sufficient (to be checked further) • - requires the finishing and dismounting of DIRAC experiment!!! • - PS reliability? PS lifetime? • SPS North Area (400 or 450 GeV/c) • + Required number of protons can be reached in well-shielded location • -More expensive, need to fulfill shielding requirements • If the availability of ions can be added at low cost to the plans for one of the future CERN irradiation facilities, they should definitely be included.

  48. Next steps of the WG • Work on implementation plans • Propose designs with their cost estimates • Full radiation protection studies and safety plans for proposed facilities • Write full report • Work on financing models and seek approval • The working group foresees to make another presentation in about 4-6 months from now, with a description of implementation options for the required irradiation facilities

  49. END

  50. Primary proton intensity estimates

More Related