mice status report – december 2008

MICE STATUS REPORT – DECEMBER 2008 The MICE collaboration Y. Karadzhov, D. Kolev, I. Russinov, R. Tsenov Department of Atomic Physics, St. Kliment Ohridski University of Sofia, 5 James Bourchier Boulevard, BG-1164 Sofia, Bulgaria L. Wang, F. Xu Institute for Cryogenic and Superconductivity Technology, Harbin Institute of Technology, Harbin, 150080, PR China R. Bertoni, M. Bonesini, S. Terzo INFN Milano, Dipartimento di Fisica G. Occhialini Piazza Scienza 3, 20126 Milano, Italy V. Palladino INFN Napoli e Università Federico II, Napoli, Italy G. Cecchet, A. de Bari INFN Pavia, Italy M. Bogomilov, D. Orestano, F. Pastore, L. Tortora INFN Roma III and Physics Department of ROMA TRE University, Via della Vasca Navale 84, I00146 Roma, Italy G. Giannini University of Trieste and INFN Trieste, Italy S. Ishimoto, K. Yoshimura High Energy Accelerator Research Organization (KEK), Institute of Particle and Nuclear Studies, Tsukuba, Ibaraki, Japan Y. Mori Kyoto University Research Reactor Institute, Kumatori-cho Sennan-gun, Osaka 590-0494, Japan Y. Kuno, M. Yoshida Osaka University, Graduate School of Science, Department of Physics, Toyonaka, Osaka, Japan F. Filthaut NIKHEF, Amsterdam, The Netherlands M. Vretenar, S. Ramberger CERN, Geneva, Switzerland A. Blondel, J.-S. Graulich, E. Perrin, V. Verguilov DPNC, Section de Physique, Université de Genève, Switzerland R. Seviour, M. Stables The Cockcroft Institute, Daresbury, Warrington WA4 4AD, UK M. Ellis, P. Kyberd, H. Nebrensky Brunel University, Uxbridge, Middlesex UB8 3PH, United Kingdom D. Forrest, F. J. P. Soler Department of Physics and Astronomy, The University of Glasgow, Glasgow, G12 8QQ, UK

P. Cooke, R. Gamet Department of Physics, University of Liverpool, Oxford St, Liverpool L69 7ZE, UK A. Alecou, M. Apollonio, G. Barber, C. Barlow, A. Dobbs, P. Dornan, R. Hare, A. Jamdagni, V. Kasey, M. Khaleeq, K. Long, H. Sakamoto, J. Pasternak Imperial College of Science, Technology and Medicine, Prince Consort Road, London SW7 2BW, UK J. Cobb, W. Lau, M. Rayner, H. Witte, S. Yang Department of Physics, University of Oxford, Keble Road, Oxford OX1 3RH, UK J. Alexander, G. Charnley, S. Griffiths, B. Martlew, A. Moss, I. Mullacrane, A. Oats, S. York STFC Daresbury Laboratory, Daresbury, Warrington, Cheshire, WA4 4AD, UK RJ. Alexander, D. E. Baynham, T. W. Bradshaw, M. Courthold, P. Flower, T. Hayler, M. Hills, A. Nichols, C. Prior, J. H. Rochford, C. Rogers, W. Spensley STFC Rutherford Appleton Laboratory, Chilton, Didcot, Oxfordshire, OX11 0QX, UK C. N. Booth, P. Hodgson, M. Mohammad, R. Nicholson, P. Smith Department of Physics and Astronomy, University of Sheffield, Sheffield S3 7RH, UK D. Adey, J. Back, S. Boyd, P. Harrison Department of Physics, University of Warwick, Coventry, CV4 7AL UK J. Norem Argonne National Laboratory, 9700 S. Cass Avenue, Argonne, IL 60439, USA R. B. Palmer Brookhaven National Laboratory, Upton, NY 11973-5000, USA R. A. Rimmer Jefferson Lab, 12000 Jefferson Avenue, Newport News, VA 23606, USA A. D. Bross, S. Geer, D. Neuffer, A. Moretti, M. Popovic, R. Raja, R. Stefanski, Z. Qian Fermilab, P.O. Box 500, Batavia, IL 60510-0500, USA A. DeMello, M. A. Green, D. Li, S. Virostek, M. S. Zisman Lawrence Berkeley National Laboratory, Berkeley, CA 94720, USA T. J. Roberts Muons Inc., Batavia, IL 60510, USA B. Freemire, P. Hanlet, T. Hart, D. Huang, D. M. Kaplan, Y. Torun Illinois Institute of Technology, 3101 S. Dearborn St., Chicago, IL 60616, USA U. Bravar University of New Hampshire, Durham, NH 03824, USA Y. Onel University of Iowa, Iowa City, IA52242, USA D. Cline UCLA Physics Department, Los Angeles, CA 90024, USA S. B. Bracker, L. M. Cremaldi, R. Godang, G. Gregoire, D. J. Summers University of Mississippi, Oxford, MS 38677, USA L. Coney, G. G. Hanson

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University of California, Riverside, Riverside, CA 92521-0413 USA

......................................................................................................................... 1 MICE STATUS REPORT – December 2008 ................................................................... 1 1 Overview................................................................................................................... 4 2 Status of the project .................................................................................................. 7 2.1 collaboration life ................................................................................................. 7 2.1.1 Common Fund ............................................................................................. 8 2.1.2 Publications and conferences ...................................................................... 9 3 MICE PHASE I........................................................................................................ 12 3.1 Infrastructure .................................................................................................... 12 3.2 MICE Beam line ............................................................................................... 13 3.2.1 Beam intensity ........................................................................................... 15 3.2.2 Beam line design and tuning ...................................................................... 15 3.2.3 The MICE target......................................................................................... 16 3.2.4 Decay solenoid .......................................................................................... 18 3.2.5 Diffuser ...................................................................................................... 19 3.3 Detectors .......................................................................................................... 20 3.3.1 Tracker....................................................................................................... 20 3.3.2 Beam Cerenkovs ....................................................................................... 23 3.3.3 Time-of-Flight Counters ............................................................................. 24 3.3.4 KL Calorimeter ........................................................................................... 25 3.3.5 The Electron-Muon-Ranger........................................................................ 28 3.4 Software and analysis ...................................................................................... 30 3.4.1 DAQ and Controls ...................................................................................... 30 3.4.2 MICE Software........................................................................................... 32 3.4.3 MICE Analysis group................................................................................. 34 3.5 Spectrometer solenoids .................................................................................... 35 3.6 Lithium hydride absorber for STEP III ............................................................... 37 4 MICE PHASE II....................................................................................................... 39 4.1 MICE Absorber and Focus Coil module............................................................ 39 4.1.1 Focus coils ................................................................................................. 39 4.1.2 Liquid hydrogen absorbers......................................................................... 40 4.1.3 Liquid Hydrogen system............................................................................. 41 4.2 MICE RF cavity and Coupling Coil module (RFCC) .......................................... 43 4.2.1 RF cavity test at Fermilab .......................................................................... 43 4.2.2 RF cavities design and construction ........................................................... 45 4.2.3 MICE Coupling coils................................................................................... 46 4.2.4 RF power sources ...................................................................................... 48 4.2.5 MICE Radiation shield................................................................................ 49 4.3 Comments on Infrastructure for Phase II .......................................................... 50 4.4 Outlook: use of MICE infrastructure after MICE ................................................ 51 5 References ............................................................................................................. 54

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1 OVERVIEW Ionization cooling of intense muon beams is a key technology for high-performance Neutrino Factories or Muon Colliders. In MICE1 the emittance of tuneable muon beams from 140–240 MeV/c is precisely measured before and after a section of cooling channel providing about 10% reduction of transverse emittance. MICE will test one full cell of a solenoidal cooling channel lattice under various conditions to demonstrate our understanding of the muon cooling process. It permits an evaluation of the component engineering and fabrication requirements and, after detailed comparisons with simulations, provides a validated design tool for future optimization of a Neutrino Factory or Muon Collider. The MICE collaboration was born in 2001 at the NUFACT01 meeting where a steering group was mandated to prepare a proposal. A LOI was submitted to jointly PSI and RAL in Nov01. PSI declined, but offered a used 5m long 12 cm bore 5 T superconducting decay solenoid for the beam line. RAL encouraged the submission of a full proposal, which was done in Jan03. The experiment was scientifically approved by the RAL CEO in October 2003. In the US, after MUTAC recommendations, funding was granted in 2004, and, in UK, following the gateway process, funding was granted for MICE Phase I in April 2005. Driven by methodology, practicality and realities of funding, the experiment will proceed in stages, as shown in Figure 1. A muon beam of central momentum between 140 and 240 MeV/c is generated from the ISIS protons by the MICE target and beam line. PID detectors ensure muon purity better than 99.9%. The input beam emittance is tuneable between 2-12! mm.rad. The 6D emittance is measured in a 5-station scintillating-fibre tracker immersed in the 4T uniform magnetic field of a superconducting solenoid. The tracker measures x,x´,y,y´ and momentum, the TOF, the sixth phase-space coordinate, t. Measurement of individual particles is mandatory to provide the emittance with a precision of 10-3. The cooling section consists of a succession of absorbers and normal-conducting RF cavities, with a series of coils providing an axi-symmetric magnetic field that focuses and contains the muons. The exiting beam emittance is measured in a second spectrometer system (tracker and TOF) identical to the first one. Electrons from muon decay bias the emittance measurement and are removed by calorimeter and muon ranger system. The first step of MICE is presently underway. The beam line elements have been laid down and operated, and the MICE hall and control room infrastructure is now nearly complete; the last piece should be the personnel protection system operational in May09. The beam Cherenkov and the beam counters have been delivered at RAL and placed on the beam, as well as the first two TOF hodoscopes and the KL calorimeter. A first MICE target has been successfully operated in parasitic mode on ISIS and first particles were transmitted in Mar08. The observed rate has been used to relate the number of protons intersected by the target to the observed losses in ISIS to conclude that a factor of between 500 and 1000 was missing. A campaign of measurements is underway to increase intensity to what was assumed for evaluating the MICE performance. Beams of protons, pions and positrons have been successfully produced. The first tracker has been operated in a cosmic bench since July 2008 and is fully ready for installation in the first spectrometer solenoid. At this point no muon beam has yet been produced: the decay solenoid from PSI has not been cooled down successfully and will require intervention in the shut down of dec08-jan09. The target long-term reliability is also a source of concern and a more robust solution is being designed and expected to be operational in May09. The aim is observe first muons in May09 and to finish Step I by Jun09. This step will allow run-in of detectors and data acquisition, as well as characterization of 4

the beam composition and its ability to generate a muon beam of the required intensity emittance and momentum.

Figure 1: The MICE phases and steps and aspirational schedule. The first spectrometer solenoid (SSI) is expected to arrive at RAL Apr08. It will take about two months to cool it down and equip it with the first tracker, the diffuser and the TOFI counter. STEP II will be performed from Jul09 onwards, providing a first precise measurement of input emittance. The second solenoid should arrive three months later (Aug09), and after about two month of preparation the STEPIII should be run before the end of 2009. Step III is a crucial MICE step. By comparing directly two emittance measurements with high precision, it will allow a precise determination of the measurement biases and test the correction procedures. A spool piece has been built to place solid absorbers between the two solenoids. This will allow determination of interactions of muons with a variety of materials such as plastic, aluminium and lithium hydride. Steps I–III constitute the ’first phase’ of MICE. Phase I of MICE is fully funded. The funding for the elements of the first Focus Coil (in UK) windows (in US) and absorbers (in Japan) is assured, so that these elements will be delivered at RAL by Nov09. Step IV will require significant Liquid hydrogen infrastructure, for which a potential shortage of manpower in the RAL engineering group has been identified and is being addressed. Assuming sufficient infrastructure support can be provided, STEP IV will be assembled from Nov09 onwards with running taking place in spring 2010. A first measurement of muon cooling will be performed using the first liquid hydrogen absorber-focus-coil module. This will also allow a test of the focussing optics, both in flip 5

(the pair of focus coils oppositely powered) and non-flip modes, for values of the optics " function from 5–42 cm. The RF cavities for Step V have been designed and, following a recent construction readiness review, the construction has been launched under responsibility of Berkeley. The coupling coils that surround them are under construction at Harbin in China. The 8 MW RF power station is being assembled at Daresbury Lab, from components recuperated at LBNL and CERN. CERN has refurbished a 4MW RF amplifier, which is being shipped to DL. The main components will arrive at RAL in the first months of 2010, so that the technology limited schedule would allow operation of MICE Step V from summer 2010 onwards; at this moment, while UK funding for step V is approved, the funding for the RF infrastructure at RAL is not available in time; if not corrected, this would delay the experiment by more than a year. With Step V begin tests of “sustainable cooling”, momentum lost in absorbers being restored in RF cavities. Finally with Step VI, a full cooling cell will be tested, allowing tests of configurations with and without field reversal in the central absorber, as well as a sufficient length to allow significant studies of longitudinal beam dynamics. This is the goal of MICE. The overseas contributions for this step consist of the second RFCC module, while the UK contribution is the completion of the RF power source, the third Focus pair and the associated infrastructure. A major source of concern for the collaboration is that the Step VI UK project has not been approved yet, while the funding for Step V has been approved with a funding profile that substantially delays the experiment. The lack of UK funding for Step VI is forcing decisions in collaborating institutions: the provision in two separate batches of material for the RFCC modules, for instance, leads to additional expenses and delays. The MICE infrastructure, with the muon beam, emittance measurement instrumentation, RF power sources and cryogenic liquid infrastructure, offers possibilities for tests of other cooling cells, including longitudinal cooling, which is necessary for a muon collider. Discussions in this direction have begun within the collaboration, and a working group has been set to evaluate various possibilities.

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2 STATUS OF THE PROJECT 2.1 COLLABORATION LIFE The MICE collaboration, as can be seen by the author list, comprises 117 members from 35 institutions from eight countries. The distribution of responsibilities in the experiment is displayed on a country-by-country basis on Figure 2. In 2008 two new groups joined the collaboration: the Group of University of Warwick (Prof. Paul Harrison and collaborators) and the group of INFN Pavia (Giorgio Cecchet). The Pavia group had already participated in the development of the TOF detectors and will continue, while the group of Warwick has declared interest in contributing to the software and online software, in which there is a shortage of hands in MICE.

Figure 2 National contributions to MICE. UK contributes also the host lab and infrastructure project. The collaboration is operated according to a collaboration charter2. The collaboration officers are at present the following. Spokesperson and chair of the executive board: Alain Blondel (Geneva); deputy Mike Zisman (Berkeley) Collaboration board chair: Ken Long (Imperial), secretary Chris Booth (Sheffield) Project manager and chair of technical board: Andy Nichols (RAL) Chair of Speakers Bureau: Vittorio Palladino (Napoli) Chair of Editorial Board: Dan Kaplan (IIT Chicago) Principal Contractor: Willie Spensley (MERIT Inc) 7

The MICE Operation Manager (MOM) position is held in rotation among senior physicists and experienced post-docs who accept to stay at RAL for durations of typically one month and to be on call. The system has been in place since Nov07 and has functioned very effectively. The collaboration holds 3 collaboration meetings a year: in 2008: at RAL in February, Daresbury Lab in June, and RAL in October, in 2009 at Harbin (China) in January, at RAL in June and Berkeley in October. At each collaboration meeting is held a collaboration board meeting. In addition the collaboration holds monthly video-conferences. Technical board and executive board meetings are also held monthly in conjunction with the video-conferences. These monthly meetings are held by phone. The technical board has organized reviews of each construction project in MICE, involving outside members. Reviews take place at the conceptual design level and at the readiness-for-construction level. At the recent MICE collaboration meeting were held four reviews: Review of RFCC module design (in view of construction), review of RF power system, review of liquid H2 system, and review of infrastructure. The MICE Installation Commissioning and Operations group (MICO) involves one person per MICE subsystem; it is convened weekly by phone by the project manager to review and coordinate short term actions across the collaboration. It is locally complemented by a weekly ‘hall’ meeting, at which installation issues are discussed with the Principal Contractor. The safety aspects are under the responsibility of the MICE Project Manager. Safety issues are dealt with regularly by ISIS-MICE safety meetings chaired by the director of ISIS (David Findlay). Internal MICE safety related issues are discussed at special sessions of the technical board held monthly. The MICE funding status is given in a separate document.

2.1.1 Common Fund Over the past year the MICE collaboration has established a Common Fund to help defray the costs incurred in running the experiment. The collaboration has drawn up a Common Fund Agreement’*, which has been endorsed by the CMPB, in which provision has been made for the collection of £3k for each member of the MICE collaboration holding a PhD. The agreement also provides for the payment of the Common Fund ‘in kind’ through the provision of equipment or personnel. Further, the Agreement defines the types of expenditure that may legitimately be charged to the Common Fund, including: 1. Utilities and infrastructure services to operate MICE (e.g. power, water, gases and cryogens); 2. Technical/engineering support for repair, maintenance of MICE infrastructure and experiment; 3. MICE Muon Beam operation and maintenance; 4. Office facilities (e.g. desks, pc/internet access, phones, photocopiers etc); 5. Access to RAL services (e.g. purchasing & financial, HSE); 6. Miscellaneous cabling (cable trays, break out panels, etc., ethernet connections, and wireless transmitters) for electronics, DAQ and communication; 7. Data-storage media and facilities for data taking; 8. User support for MICE collaborators and visitors, including local transport, and housing; and 9. (On-site) office supplies, including computing supplies. *

http://www.hep.shef.ac.uk/research/mice/collabbd/2008-06-06-MICE-Common-Fund-Final.pdf.

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The operation of ISIS and the delivery of beam to the MICE Hall are identified as a contribution from the host laboratory. The Common Fund will be levied annually, the Common Fund census date taken to be the 1st of April. The levy for the year April 2008 to March 2009 is now complete†. A total of 59 collaborators eligible to pay the Common Fund have been identified; the breakdown by country is shown in Table 1. The collection of the 2008 Common Fund levy is in hand, full details of the financial status are provided separately. To date, total £46.5k (of £192k) has been received. The UK contribution (£63k, bring the total to £109.5k) will be credited when the UK funding situation is resolved early in the New Year. The US NSF institutions require additional resources to allow the Common Fund levy (£36k) to be paid. A number of institutions (ICST, Harbin, Milan, Napoli, Pavia, Roma III, Trieste, and Osaka) will make an in-kind contribution. Commitments on the Common Fund to date include user-support and secretarial staff costs as well as the purchase of a van for the use of collaborators requiring to transport equipment and personnel while at RAL.

Table 1: Summary of the 2008 MICE Common Fund levy by country. Summary of 2008 Common Fund levy Country Number of Common Fund Contributors Bulgaria 3 China 2 Italy 6 Japan 5 Netherlands 1 Switzerland 3 UK 21 USA 23 Total 64

2.1.2 Publications and conferences The MICE Speaker’s Bureau has four main functions: (1) stay alert to opportunities to report on the progress of MICE, (2) keep track of abstracts and publications submitted by the collaboration, (3) submit MICE abstracts to relevant conferences and workshops if no other collaborators do so (and finds speakers for them if necessary), and (4) arrange for accepted MICE talks to be reviewed by the collaboration in advance (typically at one of the monthly MICE videoconferences). The Editorial Board is responsible for promulgating high editorial standards in the submitted papers. During 2007–8, MICE collaborators submitted 42 papers for publication as listed in the following table. In addition, talks or posters have been presented at APS08 and Neutrino 2008, and 16 abstracts have been submitted to PAC09, TIPP09, and NeuTel09. Author M. Apollonio †

Title Measuring Single Particle Amplitudes with MICE

http://www.hep.shef.ac.uk/research/mice/collabbd/2008-07-14-MICE%20Common-Fund-contributors.pdf.

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Ref. PAC07 Proceedings, p.

Year 2007

Author M. A. Green et al. T. L. Hart S. P. Virostek et al. M. S. Zisman D. M. Kaplan, K. Long

Title Progress on the design of the coupling coils for MICE and MUCOOL MICE: the International Muon Ionization Cooling Experiment: Phase Space Cooling Measurement Progress on the design and fabrication of the MICE spectrometer solenoids Status of the International Muon Ionization Cooling Experiment MICE MICE: The International Muon Ionization Cooling Experiment.

L. Howlett, C. Rogers

Simulation of MICE using G4MICE

D. M. Kaplan

Muon cooling and future muon facilities

M. Bonesini

The R & D effort towards a neutrino factory

M. Bonesini et al.

A systematic study to characterize fine-mesh PMTs in high magnetic fields

S. Q. Yang et al.

The physical connection and magnetic coupling of the MICE cooling channel magnets and the magnet forces for various configurations

M. A. Green et al.

The design parameters for the MICE tracker solenoid

A. P. Bondel, J.-S. Graulich

The cold mass support system and the helium cooling system for the MICE focusing solenoid MICE -- The International Muon Ionization Cooling Experiment

M. Bonesini

The Design of the time-of-flight system for MICE

M. A. Green, H. Witte

Using High Temperature Superconducting Leads in a Magnetic Field

M. A. Green, H. Witte

The Use of Small Coolers in a Magnetic Field

M. A. Green et al.

Progress on the MICE Tracker Solenoid

S. Q. Yang et al.

L. Wang et al. L. Wang et al. M. A. Green et al.

The Engineering Design of the 1.5 m Diameter Solenoid for the MICE RFCC Modules The Helium Cooling System and Cold Mass Support System for the MICE Coupling Solenoid The Effect of Magnetic Field on the Position of HTS Leads and the Cooler in the Services Tower of the MICE Focusing Magnet

M. Bonesini et al.

The Design of the time-of-flight system for MICE

M. Apollonio et al.

Emittance measurement in MICE

T. Matsushita et al.

The MICE scintillating-fibre tracker

R. Sandstrom et al. F. J. P. Soler et al.

Status of MICE, the international Muon Ionization Cooling Experiment Measurement of particle production from the MICE target

M. S. Zisman

MICE construction status

D. Li et al.

MUCOOL/MICE RF cavity R&D programs

M. A. Green H. Wu et al.

The Effect of Extending the Length of the Coupling Coils in a Muon Ionization Cooling Channel A Single-band Cold Mass Support System for MICE Superconducting Coupling Magnet

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Ref. 2895 PAC07 Proceedings, p. 500 PAC07 Proceedings, p. 3543 PAC07 Proceedings, p. 497 PAC07 Proceedings, p. 2996 LP07 Proceedings, arXiv:0707.1915 ICHEP06 Proceedings, World Scientific, p. 1211 ICHEP06 Proceedings, World Scientific, p. 1207 NOW 2006, Nucl. Phys. B Proc. Supp. 168, 189 Frontier Detectors for Frontier Physics, NIM A 572, 465 IEEE Trans. Appl. Supercond. 17:1225 IEEE Trans. Appl. Supercond. 17:1247 IEEE Trans. Appl. Supercond. 17:1251 COOL07, Conf. Proc. C07091010:tum2i05 EPS-HEP200, J. Phys.: Conf. Ser. 110, 092004 CEC2007, AIP Conf. Proc. 985:1251 CEC2007, AIP Conf. Proc. 985:1299 IEEE Trans. Appl. Supercond. 18:933 IEEE Trans. Appl. Supercond. 18:937 IEEE Trans. Appl. Supercond. 18:941 IEEE Trans. Appl. Supercond. 18:1447 EPS-HEP2007, J. Phys. Conf. Ser. 110:092004 EPS-HEP2007, J. Phys. Conf. Ser. 110:122002 EPS-HEP2007, J. Phys. Conf. Ser. 110:122016 NuFact07, AIP Conf. Proc. 981:107 NuFact07, AIP Conf. Proc. 981:259 NuFact07, AIP Conf. Proc. 981:293 NuFact07, AIP Conf. Proc. 981:299 NuFact07, AIP Conf. Proc. 981:339 ICCR-22, Shanghai, China

Year 2007 2007 2007 2007 2007 2007 2007 2007 2007 2007 2007 2007 2007 2008 2008 2008 2008 2008 2008 2008 2008 2008 2008 2008 2008 2008 2008 2008 2008

Author

C. T. Rogers M. Apollonio et al. K. Tilley C. N. Booth et al.

Title A 201-MHz Normal Conducting RF Cavity for the International MICE Experiment MICE RF System MICE: The International Muon Ionization Cooling Experiment: Diagnostic Systems Statistical Weighting of the MICE Beam The MICE Diffuser System Commissioning Status of the MICE Muon Beamline Design and Operational Experience of the MICE Target

A. D. Bross, D. M. Kaplan

Status of MICE

T. L. Hart, D. M. Kaplan

Emittance Measurement in MICE

M. Bonesini

The MICE PID Instrumentation

D. Forrest, F.J.P. Soler

Alignment errors on emittance measurements for MICE Experimental Tests of Cooling: Expectations and Additional Needs

D. Li et al. A. J. Moss et al. A. D. Bross, T. L. hart

M. S. Zisman

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Ref.

Year

EPAC08-MOPP098

2008

EPAC08-MOPP099

2008

EPAC08-TUPC012

2008

EPAC08-TUPC088 EPAC08-WEPP108 EPAC08-WEPP122 EPAC08-WEPP110 ICHEP08, arXiv:0809.4795 ICHEP08, arXiv:0809.4796 NuFact08 (submitted), arXiv:0810.0420 NuFact08 (submitted)

2008 2008 2008 2008

NuFact08 (submitted)

2008

2008 2008 2008 2008

3 MICE PHASE I

3.1 INFRASTRUCTURE Stepping in the MICE hall, progress is striking. Both of the magnetic shield walls, which protect both the ISIS LINAC and the MICE control room from stray magnetic fields are effectively installed and complete, they are currently being painted.

Figure 3 Entering the MICE hall in October 2008. The false floor, on which the cooling channel will be assembled, is in the advanced stage of fabrication at the manufacturer. Its delivery was originally scheduled for mid December 2008, but this is now in some doubt due to workload difficulties with the supplier. Work is being done to understand this and it is hoped the original date can be met, or one near to it. However, this item is not on the critical path for MICE. The rolling platforms for steps two & three have been seriously delayed due to distortion during manufacture & welding. This was not recoverable and the only solution was to remake the items using a mostly bolted design. Delivery of the re-worked rolling platforms is expected in early December. Again, this is not a critical path item yet.

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The PPS (Personal Protection System) for the DSA (Decay Solenoid Area) is complete and working and has been accepted by ISIS as such. However, it needs to be accredited to the relevant safety standard before it can be integrated – this work is in progress.

Figure 4 Personnel Protection System: Left at the entrance of the DSA; right at the passage from the MICE control room to the MICE hall. The PPS specification for the main Hall has been agreed among the project and with ISIS and some hardware has been installed. The main Hall PPS is scheduled to be operational in May 2009. The compressed air system for the complete experiment has been specified and the order is placed; installation will be completed by April 2009. (Figure 4). The electrical infrastructure workpackages have been extracted and defined separately; these are being handled by Daresbury staff and Building Projects Group at RAL. Typically this work includes detector power and readout wiring, PPS wiring and hardware, control engineering and domestic installations such as fire alarms, lighting and smoke detection. Most of these topics are on target to meet their parts of the schedule. The mound excavation for Liquid Hydrogen vents and vacuum ducts is now complete; what seemed like a minor exercise turned into a big job. However it is no longer a bottleneck to the Liquid Hydrogen system. The local Authority Planning Officer has visited RAL and assured us that retrospective planning permission for work done on the MICE Hall should be reasonable – an application is being prepared

3.2 MICE BEAM LINE The MICE beam line is sketched in Figure 5. Its principle is as follows. A secondary particle beam is generated by dipping a small target into the ISIS proton beam at 800 MeV. The pions are captured by a quadrupole triplet and momentum-selected by a dipole, all situated inside the ISIS vault. Pions decay within a 5-m-long, 12-cm-bore, 5T decay solenoid. The pion-decay muons are momentum-selected in a second dipole. This second momentum is about half of the first (backward pion decay) ensuring excellent muon purity. Finally the desired muon beam emittance is generated: the quadrupoles are tuned for appropriate beam size and the angular divergence in generated at the entrance into MICE by a variable-thickness beam diffuser.

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All magnets have been installed, and all have been powered except for the decay solenoid. All conventional magnets are perfectly functional (polarity checks, cooling systems and interlocks) and can be remotely controlled one by one via EPICS from the MLCR. This has become a common practice during MICE shifts and allows easy tests on the bending (focussing) power of the dipoles (quadrupole triplets). Some measurements of the effective lengths of the quadrupoles in the first triplet would be advisable during the ISIS shutdown.

Figure 5 The MICE beam line at ISIS: from the production point, the Target, FermiLab Monitor, GVA1 and GVA2, TOF0, Ckova and b, TOF1 and the calorimeter KL. Until now, the decay solenoid is not powered and the second dipole is set to the same momentum as the first one, so that only beams of protons, pions and electrons have been generated. The first TOF station (TOF0), a double-layer scintillator hodoscope, and the beam Cherenkovs have been installed and operated successfully. The second TOF (TOF1) arrived at RAL on December 4 and will be mounted downstream of Q9. With 50ps resolution, complemented by the beam Cherenkovs, it will provide !/µ separation up to 300 MeV/c. Temporary scintillators GVA1 and GVA2 have been installed for beam commissioning, and operated with the Cherenkov in the MICE DAQ. Once the two TOF stations will be installed they will be used to measure 2D beam profiles at these two locations and to measure the alignement of the beam center with sufficient precision. (In effect TOF0 is already used to align the beam center in the horizontal plane). There are no vertical steering magnets in the MICE beam line and one of the first task once the muon beam is achieved will be to evaluate the need for a corrector scheme. Interestingly, since the two TOF stations provide a measurement of time with a precision