Proposal for UK participation in the completion of the EUROnu and IDS-NF Conceptual Design projects

Transcription

1 Proposal for UK participation in the completion of the EUROnu and IDS-NF Conceptual Design projects June 2011 P. Kyberd, D.R. Smith Brunel University, Uxbridge, Middlesex UB8 3PH, United Kingdom N. Bliss, N. Collomb, C. White STFC Daresbury Laboratory, Warrington, UK R. Bayes, F.J.P. Soler School of Physics and Astronomy, Kelvin Building, The University of Glasgow, Glasgow, G12 8QQ, UK M. Aslaninejad, P. Dornan, L. Jenner, A. Kurup, K. Long, J. Pasternak, J. Pozimski Imperial College London, Prince Consort Road, London SW7 2BW, UK H. Witte John Adams Institute, Denys Wilkinson Building, Keble Road, Oxford OX1 3RH, UK S. Brooks, D. Kelliher, S. Machida, C. Prior, C. Rogers STFC-ASTeC, Rutherford Appleton Laboratory, Chilton, Didcot, Oxfordshire, OX11 0QX, UK A. Kalinin, A. Moss, S. Pattalwar STFC-ASTeC, Daresbury Laboratory, Warrington, UK R. Edgecock, J. Thomason STFC Rutherford Appleton Laboratory, Chilton, Didcot, Oxfordshire, OX11 0QX, UK

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3 Executive summary This proposal seeks the resources required to complete the UK contributions to the EC FP7 Design Study EUROnu and the International Design Study for the Neutrino Factory (the IDS-NF). Support for these activities to date has been provided by the STFC through the UKNF project grants and by the EC through the FP7 funding awarded to EUROnu. The principal objective of the proposal is to complete the Reference Design Report (RDR) for the Neutrino Factory by The RDR is conceived as the document that can be used as a basis for the proposals that will be required to take the Neutrino Factory project to the next level. The RDR will therefore document the baseline design for the facility, demonstrate that it is feasible to construct the various subsystems, evaluate the technical risk and present an R&D programme by which these risks can be mitigated and provide an estimate of the cost of the Neutrino Factory. The timely completion of the RDR is essential if the international community is to reach an informed consensus on the facilities required to elucidate the properties of the neutrino. The UK played the seminal role in the creation of both EUROnu and the IDS-NF. UK personnel hold key positions of responsibility in both studies and UK scientists and engineers are making substantial contributions to each of the projects. Continued UK participation in EUROnu and the IDS-NF is therefore critical to the success of the projects. The technology that is being developed for the Neutrino Factory will have an important impact not only in High Energy Physics (HEP), but also in applied science, medicine and energy production. Advances in accelerator technology, such as high gradient RF systems, high field superconducting (SC) magnets, research on Fixed Field Alternating Gradient (FFAG) machines, strong kicker and SC septum magnets for injection/extraction etc., will have a broad range of applications including next generation spallation-neutron sources, new hadron therapy solutions and machines for Accelerator Driven Subcritical Reactor (ADSR) systems. The work proposed here is limited to that required to bring to a satisfactory conclusion the work to which the UK has committed on EUROnu and the IDS-NF. Through the UKNF programme, the conceptual design activity has proven to be very successful in delivering its milestones. The emphasis of the effort over the period of this award will shift towards professional engineering support. This effort is essential in this final stage of the studies, in particular for the more assessment of the feasibility of hardware components and the estimation of the cost. The UK group will be strongly supported by the international collaborators, thus ensuring the success of EUROnu and the IDS-NF. The detailed description of the proposed research work within the Conceptual Design Study group, including deliverables together with organisation and schedule is presented in this proposal. The timetable for completion of the IDS-NF was set out in the Interim Design Report (IDR) and the EUROnu mid-term report.

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5 Contents Executive summary Introduction The Neutrino Factory facility Overview Status of the EUROnu/IDS-NF Projects Positions of responsibility held by UK personnel Proposal for continued UK participation in the EUROnu/IDS-NF Conceptual Design Work Package 1: Proton Driver Work Package 2: Pion Capture and Muon Front End Work Package 3: Muon Acceleration Work Package 4: Decay Ring and Neutrino Detectors Work Package 5: Management and Technology Project Organization and Schedule Project Organization Cost & Financial Management Plan Schedule Milestones Risk analysis...13 References...14

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7 1. Introduction The recent discovery of the neutrino oscillation phenomenon, in which the neutrino changes flavour, while travelling between a source and detector implies that neutrinos have a tiny but non-zero mass; lepton flavour is not conserved; and that the Standard Model of particle physics is incomplete. These observations have far reaching consequences: neutrino interactions may be responsible for the matterantimatter asymmetry of the Universe; the neutrino may have played a central role both in creating the homogeneous Universe in which we live and in the formation of the galaxies; and most fundamental of all, the neutrino may have played a crucial role in the birth of the Universe itself. Precise and detailed measurements of the properties of neutrinos and in particular the verification of the existence of CP violation in the lepton sector are essential to understand the mysterious properties of the neutrino and in conjunction with LHC data will allow us to develop a theory beyond the Standard Model. The facility proposed to address these important questions is the Neutrino Factory, which is an accelerator source of neutrinos based on decay of muons stored in rings, with long straight sections pointing towards far detectors located several thousand kilometres from the source. The main advantages of the Neutrino Factory compared with conventional neutrino sources are intensity, perfectly known flavour content and energy spectrum of the neutrino flux, well suited to the needs of neutrino experiments. This comes from the fact that the muon decay governing the neutrino beam generation in the Neutrino Factory, is one of the best known processes in particle physics. In addition, designing a Neutrino Factory and meeting some of the technological challenges, solves many of the problems required for the front end of a Muon Collider. The UK particle and accelerator communities are playing leading roles in the R&D studies for the Neutrino Factory. The UKNF collaboration, with strong support from STFC, has established an internationally recognised R&D programme towards the conceptual design for the Neutrino Factory. The International Scoping Study (ISS) [1,2] successfully created the baseline for the facility and its successor is the International Design Study for a Neutrino Factory (IDS-NF) [3] led by K. Long (Imperial), for which European contributions are coordinated by the EC FP7 EUROnu Design Study [4]. The IDS-NF is developing the design with more focus on engineering aspects and improving the performance of the facility, aiming for a full conceptual design to be published in the Reference Design Report (RDR) in As the major milestone towards the RDR the Interim Design Report (IDR) [5] has been recently published by the IDS-NF collaboration. This proposal seeks the necessary funding to complete the conceptual design study and the RDR. 2. The Neutrino Factory facility 2.1. Overview The Neutrino Factory is an accelerator source of neutrinos, based on the decay of muons injected into decay rings equipped with long straight sections pointing towards distant neutrino detectors. It contains a multi-mw proton driver capable of producing compressed bunches, in the few GeV range, which are directed into the pion production target at a 50 Hz repetition rate. The target, for which the baseline solution is a mercury jet, is located inside a 20 T pion capture solenoid, followed by the pion decay section, where the magnetic field is reduced causing the divergence of the muon beam to gradually decrease. The decay channel is followed by the muon front end, which prepares the beam for acceleration. Firstly the single muon bunch is transferred into a train of microbunches at the 201 MHz RF frequency and the energy spread is reduced using phase rotation. Secondly the transverse emittance is 1

8 reduced using ionization cooling by passing the beam successively through absorbers made of lithium hydride and reaccelerating in RF cavities, keeping the mean energy constant. Downstream of the muon front end, the beam enters a linear accelerator, which needs to have a very large acceptance as the beam emittance is still large even after cooling. In addition it needs to accelerate very rapidly as muons are unstable particles. The linac is focused by superconducting (SC) solenoids and uses 201 MHz SC RF cavities. In order to reduce the cost of acceleration, the beam then passes a number of times through the same accelerating SC RF structures in a Re-circulating Linear Accelerator (RLA). The beam enters at energy of 0.9 GeV and exits with a boosted energy of 3.6 GeV and is then transferred to a second RLA. The RLAs have a characteristic dog-bone shape, consisting of a single linac with a series of arcs on both ends, which allow the beam to be redirected back to the same linac for a number of passes. Both beam polarities travel together in the linac and in opposite directions in the arcs. In order to improve the efficiency of acceleration further, the beam is injected at 12.6 GeV into a Non-Scaling FFAG ring, which serves as the final acceleration stage to an energy of 25 GeV. All this in much less than the muon lifetime of 2.2 μs. Figure 1: Layout of the Neutrino Factory baseline. The FFAG consists of identical cells with triplet symmetry. It has very strong focusing optics with a quasi-isochronous condition, which allows the use of a fixed high frequency RF system. The focusing is performed by combined function SC magnets in which dipole and quadrupole fields are superimposed. After extraction from the FFAG, the beam is transferred into two decay rings, which are equipped with long straight sections oriented towards far neutrino detectors, located several thousands of kilometres away. This implies that the decay ring needs to be inclined with respect to the horizontal plane in order to 2

9 take into account the curvature of the earth. A schematic diagram of the layout of the Neutrino Factory is shown in Figure 1. More details concerning the Neutrino Factory facility can be found in the IDR [5] Status of the EUROnu/IDS-NF Projects The EUROnu project is considering three, generic types of second-generation neutrino facility: a next generation super beam, a beta beam and the Neutrino Factory. The Neutrino Factory work carried out within EUROnu constitutes the European contribution to the IDS-NF. Both projects have achieved excellent progress in all work packages [4, 5] and the current status of the Neutrino Factory related work is discussed here. Several intensive studies were undertaken, leading to improvements in the baseline definitions, optimisation of the design, identification of potential critical areas; and suggestions to mitigate known problems. Only activities with significant impact on the machine definition are discussed below. A common proton driver for a spallation neutron source and the Neutrino Factory has been proposed in synergy with possible ISIS upgrades at RAL. The energy deposition in the superconducting coils around the pion production target was addressed and led to a major redesign, which successfully improved the shielding. The work on solid targets produced results on the lifetime of tungsten targets and the measurement of Young s modulus and yield strength of both tungsten and tantalum at high temperature. To prevent an unacceptable number of protons and other secondary particles being transported from the target into the muon front-end, the optics for a chicane, filtering high-energy particles has been designed, which together with the proton absorber eliminates these secondary particles. The breakdown potential of the copper cavities used in the muon front end is reduced in the presence of a magnetic field. This reduction has been ascribed to phosphor impurities in the surface of the copper which give rise to a virtual magnetic state and it is the separation of this state from the vacuum level depends on the applied magnetic field. To test this hypothesis a large sample of high-purity oxygen free copper buttons have been produced and will be tested in the Fermilab Muon Test Area (MTA). In order to decrease the magnetic field at the position of the RF cavities in the cooling-channel lattice, a bucked coil lattice has been proposed, which consists of coils of opposite polarity and different radius, placed at the same position along the beam axis. The effect of beam loading has been estimated, leading to no significant increase of the beam energy spread all over the acceleration chain and is no longer considered as a challenge. An extensive study of the hardware components (superconducting solenoids and RF cavities) in the muon linac has been followed by detailed tracking using realistic field maps. The injection/extraction systems for the Non-Scaling FFAG ring have been investigated, leading to the redefinition of the baseline with the new design based on longer straight sections. The performance of energy resolution measurement for the muon beam circulating in the decay ring, based on the observation of electron spin has been successfully modelled. New simulations of near and far detectors have been carried out and the performance of the Neutrino Factory detector systems has been determined. Simulations now include quasi-elastic, resonant production and deep inelastic neutrino interactions, the detectors have been fully simulated in GEANT4, reconstruction and pattern recognition of neutrino events have been carried out and a full analysis, taking into account all sources of background, has been optimised. The result is an improved performance of the detector systems at a Neutrino Factory, yielding CP discovery reach down to values of sin 2 13 of ~ and demonstrating that a Neutrino Factory outperforms all other facilities for any value of 13 [5]. 3

10 2.3. Positions of responsibility held by UK personnel UK personnel have key roles within the EUROnu/IDS-NF Projects, especially in the Neutrino Factory part of the study. Experimental programmes to develop crucial technologies such as ionisation cooling (MICE) and the Non-Scaling FFAG (EMMA) are being conducted in the UK. Although not directly part of the conceptual study, both projects have strong implications on the machine design. The joint UK-US programme at the MTA in Fermilab will lead to a better understanding of RF breakdown in magnetic fields, which is an important issue in the muon front end design. In addition, essential knowledge of high power targets and RCS technology centred around the ISIS spallation neutron source at RAL is beneficial for the design of multi-mw class targets and proton drivers, which are at the heart of the Neutrino Factory or any other future high intensity muon source. The overall International Design Study for a Neutrino Factory is led by K. Long (Imperial College). R. Edgecock (RAL, Huddersfield) is the EUROnu Coordinator, J. Pozimski (Imperial College/STFC- RAL) leads the EUROnu Neutrino Factory work package and C. Densham (RAL) co-leads the EUROnu Super-beam work package. The Conceptual Design work undertaken by UKNF has been conducted by an energetic and fruitful design group led by J. Pozimski (Imperial College/STFC-RAL) and C. Rogers (STFC-ASTeC-RAL). The group has conducted numerous studies of various machine components, leading to improvements and optimisation of the baseline design, identification of potential critical areas and solutions to mitigate existing problems. The Conceptual Design Group is working in the areas of beam dynamics, electromagnetic modelling and engineering of the key hardware components. In particular, the costing effort was started in the design group, which is an essential ingredient of the RDR. The detector design and performance optimisation, led by F.J.P. Soler (Glasgow) in the context of the EUROnu/IDS Projects, has yielded improved performance of a Neutrino Factory for a realistically achievable design. Continuation of the Conceptual Design until the submission and review period of the RDR is essential for the completion of the EUROnu/IDS-NF Projects. In particular, further engineering work for various hardware components needs to be continued, together with the costing effort and the final evaluation of the performance in the form of end-to-end simulations. It is proposed to divide the studies into the following Work Packages related to the machine subsystems: Proton Driver; Pion Capture and Muon Front End; Muon Acceleration; and Decay Ring and Detectors. The programme of work proposed for every Work Package is discussed in more detail in the next section. 3. Proposal for continued UK participation in the EUROnu/IDS-NF Conceptual Design 3.1. Work Package 1: Proton Driver The proton beam needs to be delivered to the pion production target in the form of a few (typically three) ultra-short multi-gev bunches, 4 MW total power and an overall repetition rate of 50 Hz. Except for the bunch time duration these parameters are almost identical to those for a next generation, high-power, short-pulse spallation neutron source, which makes the concept of a common proton driver shared by the neutron and muon/neutrino communities an attractive proposal. The Conceptual Design Group will focus on the further development of this proton driver in the context of ISIS upgrade plans at RAL. Although lattice designs for all major accelerator components (including a dedicated 800 MeV linac, 3.2 GeV RCS and final RCS ring for the Neutrino Factory) exist, further research on the feasibility of the final bunch compression needs to be performed. The possible scenarios include compression in the final RCS or alternatively in a dedicated compressor ring. Both schemes need to be compared on feasibility and cost. In particular the RF requirements for the bunch compression need to be carefully examined. Proton acceleration could also be based in part, on FFAG technology and this option will be examined. 4

11 The transfer line to the target represents a non-trivial task, which is still to be addressed. The compressed bunches need to be delivered without loss, with no time dilution and matched to demanding conditions at the target position. Finally the performance of the RAL proton driver needs to be compared with other proposed solutions Work Package 2: Pion Capture and Muon Front End Although studies of the pion capture and muon front end are quite advanced, a detailed lattice design exists and beam dynamics calculations have been performed using elaborate tracking codes, continuation of the ongoing work is required. The studies of energy deposition and activation around the target in the pion capture section need to be developed in collaboration with the target group. The design of the chicane and its optimisation is necessary to mitigate the effect of energy deposition by secondary particles produced at the target from entering the front end section. Alternative cooling lattice solutions developed to mitigate the problem of RF breakdown in the presence of magnetic fields must be further investigated. The baseline cooling lattice, together with alternative ones, need to be confronted with the results of the RF tests in magnetic fields which are to be performed at the MTA. Optimisation of the performance of the proposed cooling lattices must minimise muon beam losses. This analysis should take into account field errors and the effects of misalignment. Final conclusions of those studies will be used to fix the final version of the baseline. The preliminary engineering of the cooling channel must be developed and used for cost evaluation, and to determine the beam diagnostics required. Detailed tracking studies, based on realistic pion distributions from the most recent version of the target design, will be used to evaluate the performance of the muon front end and as an input for the end-to-end simulations in the downstream parts of the facility Work Package 3: Muon Acceleration Acceleration of muons is a challenging task: the accelerator must have a large acceptance to capture the muon beam which has a large emittance even after cooling; and the shortness of the muon lifetime means that very high accelerating gradients must be produced. Despite substantial progress in this area several topics still need to be addressed. The transmission through the muon linac must be improved by careful assessment of the matching conditions out of the muon front end and between the different modules of the linac itself. Preliminary magnet designs for the RLAs need to be performed once the final design of the lattice is complete. The magnet designs need to be included in the machine costing. Detailed tracking studies in the RLAs are required, including field errors and misalignments and taking into account a realistic beam splitter design. An error analysis is essential for the Non-Scaling FFAG ring to define the field tolerances of the magnets. The chromaticity correction schemes will be carefully assessed in tracking studies, and their effect on the baseline determined. The engineering of the SC FFAG magnet needs further work, taking into account the study of tolerances and the requirements of chromaticity correction. These results will then be used as an input for the cost estimate. The injection/extraction hardware requires more work, especially for the kicker and septum magnets. Transfer lines will be developed to transport the beam to the Non-Scaling FFAG and to the Decay Ring. Essential beam diagnostics need to be identified for all muon accelerator types. End-to-end simulations using realistic muon distributions from the muon front end will be launched throughout the entire Neutrino Factory acceleration chain in order to calculate its performance. 5

12 3.4. Work Package 4: Decay Ring and Neutrino Detectors The decay ring deserves a special position in the Neutrino Factory chain as it is the source of the neutrino beam, and is fundamental to the success of the facility. In order to ensure that the decay ring delivers the required performance an interdisciplinary work package is proposed, in which the accelerator design is closely linked to the decay ring and the detection systems. The design of the injection system needs to be addressed and the parameters of the necessary hardware must be identified. A muon beam abort system needs to be carefully considered and, if required, its details should be determined. The current design of the ring does not incorporate chromaticity correction, which should be studied. The potential effect of such a correction will be investigated in tracking studies. Installation of an RF system could assure the preservation of the beam time structure, with subsequent effect on neutrino flux timing and detector signal, but at the expense of increasing the overall cost. The installation of RF in the decay ring should be considered taking into account accelerator, detector and cost issues. A preliminary magnet design should be performed and included in the cost estimate. The feasibility of the decay ring installation in an inclined tunnel deep underground needs to be investigated, including the delivery of the main machine services. The beam diagnostics required for the decay ring commissioning needs to be defined and the role of the additional ring instrumentation for detailed measurements of the beam divergence and energy spread must be understood. Figure 2: Schematic of a Magnetised Iron Neutrino Detector. The position and design of the near detectors at the end of the decay straight needs to be finalised and their performance determined. Neutrino flux, neutrino cross-sections and charm production crosssection uncertainties will be determined at a near detector to evaluate the systematic errors in the physics performance of the facility. The shielding requirements of the near detector and the design of the shield will also be determined. The extrapolation algorithms from near to far detector need to be explicitly included in the final performance errors to evaluate the neutrino oscillation probabilities. The far detector simulations of the Magnetised Iron Neutrino Detector (MIND), see figure 2, need to be finalised. Optimisation of the new detector design, with an octagonal geometry and toroidal magnetic field, is being carried out by explicitly simulating and evaluating its performance. Cosmic ray backgrounds to the neutrino oscillation analysis will also be simulated to determine the minimum underground depth required for the far detector. Evaluation of an alternative design based on a Totally Active Scintillator 6

13 Detector (TASD) will be carried out in parallel. Finally, full cost for both near and far detectors will be calculated, based on the final detector designs Work Package 5: Management and Technology The roles of the management work package are threefold: Firstly, to manage the Project by organising regular meetings, communicating with the international partners within the EUROnu/IDS-NF Projects, coordinating the timescale of deliverables, performing the risk analysis and the decision making process to ensure the submission of the RDR in the required form, and acting as the UK editorial board for the RDR; Secondly, to look into the future by coordinating the proposals both in the UK and internationally; and Finally, to lead the engineering effort, strengthening the design work at the technology frontier and coordinating the cost evaluation for the entire Neutrino Factory facility. The core management role will be assumed by the Principal Investigator together with the Executive Panel, which will be formed from the senior members of the Management WP with representation from both the Universities and STFC. The preparation of future proposals will be coordinated by R. Edgecock (RAL), who is currently the EUROnu project leader. The engineering effort will be led by N. Bliss (TD) and will be mainly focused on mechanical, electrical, RF and diagnostics aspects of the machine from the selected WPs. The cost evaluation exercise will be led by N. Bliss together with A. Kurup (Imperial), who will develop the necessary tools for the cost analysis. Input from the international neutrino detector community to the International Design Study will be coordinated by F.J.P. Soler (Glasgow). The necessary administrative and computing support will be provided by C. Barlow and R. Beuselinck, respectively. 4. Project Organization and Schedule 4.1. Project Organization The table showing the organization structure of the Project is shown below: Work package Content Leader(s) 1 Proton Driver J. Pasternak 2 Pion Capture and Muon Front End C. Rogers 3 Muon Acceleration J. Pozimski 4 Decay Ring and Detectors D. Kelliher and P. Soler 5 Management and Technology (Executive Board, Engineering Support, RDR Editorial Board) PI J. Pasternak (Engineering Support N. Bliss) The staff, who are expected to contribute to this proposal, are listed below: Brunel Kyberd, P.; academic, rolling grant Paul Kyberd leads the group at Brunel which is working on scintillator detector development for the Neutrino Factory and represents Brunel on the UK Neutrino Factory steering committee. He has many years of experience in detector modelling and will provide the simulation expertise to support Dr. Smith. 7

14 He is an expert on Grid computing and will use this knowledge to enable large scale simulations to be rapidly performed. He will provide the academic leadership of the Brunel effort. Smith, D.; academic, rolling grant David Smith is an experienced detector physicist, with many years experience in detector and read out technologies for space programmes. He has recently joined the Brunel efforts on the Neutrino Factory developments where his knowledge and industrial links are an invaluable adjunct to the project team. He rapidly established his credentials and has worked with the Warwick group on read out of liquid argon detectors for the Neutrino Factory. He is part of the Liquid Argon proposal to the PRD being lead by Neil Spooner at Sheffield. Glasgow Bayes, R.; post-doc, project grant Ryan Bayes is a postdoctoral research associate at the University of Glasgow. He did his PhD at the University of Victoria (Canada), working on the TWIST experiment at TRIUMF (Vancouver, Canada). TWIST is an experiment that measured the Michel parameters of muon decay with unprecedented accuracy (10-4 ), thereby constraining models of new physics that might affect this decay. Bayes worked on this experiment from the design, construction, data taking and final publication. He is currently working on the EUROnu project, where he is in charge of carrying out the far detector (MIND and TASD) simulations and analysis. Soler, P.; academic, rolling grant Paul Soler is a Reader at the University of Glasgow, leads the detector effort for the IDS-NF, the Detector Work Package of EUROnu and the Glasgow effort on MICE. He has built hardware and performed physics analysis for a number of particle physics experiments (NOMAD, HARP, LHCb), including being neutrino beam coordinator of NOMAD. Soler has performed neutrino target simulations and comparisons to HARP data, performed Neutrino Factory detector simulations and analysis and worked on the development and physics analysis of MICE data. Imperial College London Aslaninejad, M.; post-doc, project grant Morteza Aslaninejad is a research associate at Imperial College London. He is an accelerator and plasma physicist who did his PhD at GSI in Germany on the collective behaviour of the charged particles in accelerators. Later he joined LNF at Frascati in Italy to work on the ILC. He has been involved in the design of an injection system for a Proton/Carbon FFAG machine and also a LINAC for the Neutrino Factory project in the last few years. His area of expertise is charged particle simulations using different accelerator codes. Barlow, C.; administrator, project grant Carol Barlow is an experienced administrator and a dedicated member of the Imperial High Energy Physics Group s support staff. She will support the administration of the project and rolling grant at Imperial. Beuselinck, R.; programmer, rolling grant Raymond Beuselinck is the Research Fellow in the HEP group at Imperial College. He is also an IT specialist who will help support the extensive simulation work for the Conceptual Studies by taking responsibility for maintenance of the computer systems and the software packages. Dornan, P.; academic, rolling grant Peter Dornan has extensive experience in particle-physics experiments. He has made important contributions to the UKNF programme and the MICE experiment. He was chairman of the International 8

15 Scoping Study of a future Neutrino Factory and super-beam Programme Committee. He continues to work within the IDS-NF collaboration. His expertise and insight are of great value to the project. Jenner, L.; post-doc, project grant Leo Jenner is a joint IC/FNAL fellow. After his PhD work in neutrino oscillations, he moved into accelerator physics, concentrating on projects related to muon physics and a future Neutrino Factory. His main focus is helping to develop a new proton driver and beam manipulation strategies that would lay the path for future physics, such as low energy muon experiments, a Neutrino Factory or a Muon Collider. He is also attempting to incorporate an FFAG into such a proton driver. Kurup, A.; post-doc, project grant Ajit Kurup was contributing to the RF design of the RFQ for FETS before working as IC/FNAL fellow on the subject of high power RF cavities for the Neutrino Factory. He is currently leading the costing exercise for the Neutrino Factory facility in the RDR working at Imperial College. Long, K.; academic, rolling grant Ken Long s research time is devoted to the development of the Neutrino Factory as the means by which to study the properties of the neutrino with great precision. The focus of the work at present is the demonstration of ionization cooling through the international Muon Ionization Cooling Experiment (MICE) at the Rutherford Appleton Laboratory and the development of the design for the facility through the IDS- NF. Pasternak, J.; academic, rolling grant Jaroslaw Pasternak is a joint lecturer at Imperial College and STFC. He is an accelerator physicist, having previously worked at CERN for the LHC project and at CNRS in Grenoble on the design of FFAG accelerators for medical applications. He is now strongly involved in the development of a Non-Scaling FFAG for the Neutrino Factory. He is also involved in the ISIS upgrade studies and is leading the PRISM Task Force initiative. His areas of expertise are charged particle optics, lattice design and beam dynamics. Pozimski, P.; academic, rolling grant Jürgen Pozimski is Reader at Imperial College. He is an expert on space charge related problems (space charge compensation, space charge lenses) having worked for several international accelerator projects like ESS, IFMIF and HIDIF over the last two decades. He leads Imperial s accelerator activities on the field of hadron cancer therapy and is responsible for Imperial s contribution to FETS. His activities include particle dynamics, development of accelerator structures (RFQs, IH/CH structures, spokes) and beam diagnostics. He is currently leading the Conceptual Studies within the UKNF Project. John Adams Institute Witte, H.; post-doc, rolling grant Holger Witte has some 10 years' experience in magnet design and construction, which includes high field pulsed solenoids and superconducting accelerator magnets. He holds three patents on novel winding geometries for multipole magnets for particle accelerators, which have been shown to be particularly suitable for FFAGs. Holger Witte is the record holder for very high magnetic fields (66T) at the Clarendon Laboratory at Oxford University. He also has experience with designing kicker and septum magnets. STFC-ASTeC Brooks, S.; physicist, project grant Stephen Brooks has worked for seven years as an accelerator physicist in the ASTeC Intense Beams Group since graduating with a first class degree in mathematics from Oxford University. He attained a DPhil in particle physics from Oxford in 2010 for work on the UKNF pion capture and decay channel, 9

16 which included pion yield and energy deposition studies of the solid Neutrino Factory target using the MARS code. He has also evaluated energy deposition in the ISIS targets and studied shape optimisation of the Neutrino Factory target. Stephen has extensive expertise in computer codes and modelling, having written a muon tracking code including pion decays for his thesis. Kelliher, D.; physicist, project grant David Kelliher is an accelerator physicist with expertise in beam dynamics and the development of tracking codes. He works on the EMMA Non-Scaling FFAG which is currently being commissioned at Daresbury laboratory. He participates in neutrino factory research - mainly in the muon FFAG and decay ring design. He also has an interest in other novel FFAG accelerators such as the PAMELA hadron therapy machine, and in ISIS upgrade studies. Machida, S.; physicist, project grant Shinji Machida is a senior accelerator physicist at STFC, having previously worked in the US for the superconducting super collider and at KEK in Japan for J-PARC and on FFAG accelerators. He is now strongly involved in the development of FFAG accelerators for many applications. He is also involved in the EMMA FFAG commissioning and is leading the commissioning team. His areas of expertise are beam physics especially multi-particle dynamics of hadron beams and accelerator technology needed for hadron accelerators. Prior, C.; physicist, project grant Chris Prior, the head of ASTeC s Intense Beams has a wide range of mathematically based skills with applications to the physics of charged particle beams. These include the development of numerical techniques and the construction of computer codes to model existing accelerators and for use in the design of future machines. The present research projects include high intensity proton accelerators; studies of possible options for upgrading the ISIS spallation neutron source; study of proton and muon accelerators for a Neutrino Factory or Muon Collider; study of different types of accelerator for applications in areas such as transmutation, ADSR, medical therapy. Rogers, C.; physicist, project grant Chris Rogers is an accelerator physicist working on MICE and on the muon front-end of the Neutrino Factory. He is currently co-leading the Conceptual Studies within the UKNF Project. He is a member of ASTeC Intense Beams Group. Kalinin, A.; physicist, project grant Alexander Kalinin is an expert in electronics system development and signal manipulation, and processing for advanced beam diagnostics system solutions. With >35 years experience in this field, both in industry and national laboratories in Russia and in STFC ASTeC, Alexander has recently developed an extremely complex electron beam position monitoring system for the EMMA FFAG facility. Alexander will develop the technology choices for the beam diagnostics systems and develop cost models to optimize solutions. Moss, A.; engineer, project grant Andy Moss is an RF engineer with more than 20 years experience of RF hardware design, build and optimisation for wide ranging accelerator projects both UK and internationally, more recently the ALICE and EMMA FFAG RF systems. Andy is also playing a lead role in the delivery of the MICE RF power and distribution systems to the cooling channel cavities. Andy will develop the technology choices for the RF systems and develop cost models to optimise solutions. Pattalwar, S.; engineer, project grant Shrikant Pattalwar is an expert in cryogenics with >20 years experience in industry and >5 years experience working in STFC ASTeC delivering cryogenics solutions to the ALICE project and delivering 10

17 large cryogenic plant proposals for light source projects. Shrikant recently chaired the organizing committee for the Centennial Symposium on Superconducting Accelerators held at the Cockcroft Institute on April 8th 2011, featuring historical developments and future perspectives of cryogenic technology for particle accelerators. Shrikant will develop the technology choices for the cryogenic systems and develop cost models to optimize solutions. STFC-TD Bliss, N.; engineer, project grant Neil Bliss is a senior mechanical engineer, group leader and project manager in STFC Technology with over 30 years experience in the design and construction of multi-disciplined teams delivering accelerators and instrumentation for a range of UK and international projects including SRS, ESRF, DLS, ALICE, NLS and EMMA. Neil was recently the project manager for EMMA responsible for delivery of the project. Neil will be responsible for developing engineering solutions for the FFAG accelerator, managing the technology scope and contributing to the costing exercise for the Neutrino Factory Design Study based on his extensive experience of costing large scale facilities. Collomb, N.; engineer, project grant Norbert Collomb is an experience mechanical and project engineer in STFC Technology with experience in developing design studies for large fundamental physics projects. Norbert has relevant accelerator design experience on linear colliders and CLIC. He is also playing a design role on the MICE tracker radiation shield and system integration. Norbert will contribute to the specification of the Neutrino Factory engineering systems, in particular the muon decay ring. White, C.; engineer, project grant Chris White is an experience electrical engineer in STFC Technology specialising in advanced power supplies for accelerators. Chris has wide ranging knowledge of high voltage pulsed fast power supplies used on septum and kicker magnets for the injection and extraction systems of particle accelerators and extremely stable DC power supplies for steering and corrector magnets. Chris has over 9 years experience delivering electrical engineering design and construction solutions for the SRS, DLS, ALICE, MICE and EMMA. Chris will develop the technology choices for the challenging powers supplies on the accelerator complex and develop cost models to optimise solutions. STFC PPD Edgecock, R., physicist, project grant Rob Edgecock is PI of the EUROnu FP7 Design Study and has been a leading member of the UK Neutrino Factory project since it started in He has led the target activities in UKNF since 2005 and was the project leader of the EMMA work package in the Basic Technology funded CONFORM project. Since October 2010 he has had a joint appointment as a Research Professor with the University of Huddersfield and is taking a leading role in the Jacobs ADTR design study for a thorium reactor as part of that appointment. He is also the STFC scientific and technical contact person for the EuCARD FP7 IA and was PI of the MuScat experiment, a predecessor of MICE. He is the PI of the High Power Target proposal being submitted in parallel to this one and will also act as a link between the activities of that project and this. STFC ISIS Thomason, J.; physicist, project grant John Thomason is the ISIS Synchrotron Group Leader and is also the Project Manager for MW Upgrades to the ISIS accelerator. He is a physicist and oversees accelerator physics, diagnostics and synchrotron RF activities at ISIS. 11

18 4.2. Cost & Financial Management Plan The project costs are summarised in Je-S, which is also presented in the Annex. It will be the responsibility of the Work Package leaders to monitor the actual expenditure against expectation. These will be coordinated by the PI and the Executive Board, which will ensure that action is taken to fix any significant deviations from the expected spend profile. Approval will be required for all travel. Travel with a total cost of less than 1000 will need to be approved by the corresponding task manager. Travel costs above this limit must be referred to the PI by the task leaders and be approved by the Executive Board Schedule The project schedule closely follows the IDS-NF one published in the IDR, as shown in figure 3. This is also reflected in the milestones/deliverables shown in the section 4.4, which are arranged and distributed in the logical order, being in many cases designed as subparts of the RDR especially at the end of the grant period. As the main deliverable is the RDR document, the final part of the grant period is dedicated to the final editorial work followed by the final review. Figure 3: IDS-NF schedule towards the RDR [5] Milestones The Project will produce the following milestones/deliverables, which are based on the expected status of the Conceptual Design study at the beginning of the grant period. They are listed for every WP separately. WP1 Proton Driver: 1. Review of the proton bunch compression scenarios for the Neutrino Factory (June 2012). 2. Critical comparison of the proton driver solutions based on the RCS and the FFAG principle (November 2012). 3. Review of the RF options for the proton driver (February 2013). 12

19 4. Design of the transfer line to the target (May 2013). WP2 Pion Capture and Muon Front End: 1. Critical review of the status of the RF breakdown issues and the alternative solutions for the cooling lattice (June 2012). 2. Review of the problem of the energy deposition by the secondary particles in the pion capture region (in collaboration with the target group) - (November 2012). 3. Review of the problem of the energy deposition by the secondary particles in the muon front end and the chicane design (December 2012). 4. Report on the engineering studies for the cooling cell (March 2013). 5. Report on the final design of the cooling cell and the particle tracking for the end-to-end simulation (April 2013). WP3 Muon Acceleration: 1. Critical review of the status of the acceleration systems for the Neutrino Factory (June 2012). 2. Preliminary design of the magnets for the RLA (November 2012). 3. Review of tracking studies in the RLA (February 2013) 4. Review of the chromaticity correction scenarios for the NS-FFAG (November 2012) 5. Report on engineering studies for the FFAG cell (March 2013). 6. Status of engineering for the injection/extraction systems for the NS-FFAG (March 2013). 7. Report on the end-to-end simulations for the entire acceleration chain (with the input from WP2) (May 2013). WP4 Decay Ring and Detectors: 1. Status of beam dynamics and injection/extraction in the Decay Ring (June 2012). 2. Preliminary design of the magnets for the Decay Ring (December 2012). 3. Tracking studies in the Decay Ring (with input from WP3) - (June 2013). 4. Review of detector studies and preliminary cost (November 2012). 5. Final report of the detector studies and final cost evaluation (May 2013). WP5 Management and Technology: 1. Review of the feasibility of the SC RF technology for muon acceleration (December 2012) 2. Critical review of the feasibility of hardware installation and operation for the decay ring (March 2013). 3. Review of the cost estimate evaluation (June 2013) Risk analysis The design of an accelerator facility on such a scale as the Neutrino Factory is unavoidably associated with several risk factors, which need to be carefully analysed. The proton driver, which is at the heart of the facility, although primarily based on existing technology, needs to deliver a power never achieved before. The management of the risk for the proton driver is based on the fact that two families of design exist, based on different technological solutions: the RCS and the SC linac. It is expected that at least one of these should be capable of delivering the proton beam with the required specification. The highest risk for the facility is associated with the target area. The challenges of the target are being addressed in a separate proposal, where its risk is discussed. A closely related risk is the energy deposition by secondary particles produced by the target in the pion capture system. Mitigation of that 13

20 risk will be produced in collaboration with the target group. The principal strategy is based on increased shielding levels and changes in the geometry of the capture magnets. In the worst case scenario the capture system may be replaced by a horn system not based on SC technology, which allows a partial reduction of the risk. The problem of energy deposition by secondary particles in the muon front end is being solved by a dedicated chicane design. This study will be carried out and the chicane design improved. RF breakdown in the magnetic fields, which is a risk factor most affecting the ionization cooling stage, has been addressed already in numerous studies and several mitigating scenarios have been produced [5,6]. These studies will be pursued further, which potentially could result in the discovery of a full solution, with help from new experiments (the MTA tests at Fermilab) and simulations. According to the current baseline very high accelerating gradient needs to be achieved in the SC RF cavities in muon accelerators. The feasibility of the gradient figure (25 MV/m for 201 MHz Ni sputtered cavities) can be assessed by extrapolations of the existing figures and will be addressed within this study by the RF engineer and by contacting external experts. In the worst case scenario, the baseline design can be altered to accommodate more cavities and by changing the final energy at each stage. This would ensure the feasibility of the machine, while increasing the overall cost. One of the accelerating stages is the Non-Scaling FFAG, with the scientific challenges being addressed in the ongoing commissioning of EMMA at Daresbury Lab. The operation of the Non-Scaling FFAG machine for muon acceleration requires challenging injection/extraction systems. Although the final feasibility of such a system needs to be addressed via hardware tests, the preliminary design of the kicker system is based on existing technology, which can be realised. These studies will be continued, including studies of the SC septum. Alternatively, the SC septum magnets may be replaced by normal conducting ones but with very demanding power supply requirements, which would also increase the cost of this system. If these designs are not feasible, then the design of the Non-Scaling FFAG may be further altered to facilitate injection and extraction. In the worst case scenario, if the Non-Scaling FFAG has to be ruled out as a useful solution, it may be replaced by another RLA. This could have a significant impact on the cost of the facility. The assembly and operation of the muon decay ring is very challenging, as its long straight sections need to be oriented towards far neutrino detectors, dictating the need of the installation of the hardware in inclined (up to 30 degree) tunnels deep underground (down to 500 m), including SC magnets. The associated risks have yet to be identified and the appropriate safety procedures developed. The main risk associated with the near detector is the shielding from an extreme photon environment (from radiative decay of muons) and from aborts of the muon beam on the near detector. A photon shield and beam dump need to be carefully designed to address this issue. Also, building the near detector on a large slope will be challenging so full engineering specifications will need to be carried out. Another detector risk associated to the near and far detectors is the evaluation of the performance based on simulations. Mitigation of this risk is by measuring the detector performance at the EU FP7 AIDA test beam at CERN. The UK contribution to the AIDA test beam programme, where detector performances will be measured, will help reduce this risk. A further risk for the far detector is the construction of a 100 kt detector underground. A feasibility study to place the detector on the surface by simulating and rejecting the background expected from cosmic rays could reduce this technical risk and cost escalation. References [1] M Apollonio et al., ISS Accelerator Working Group, JINST 4, P07001 (2009). [2] T. Abe et al., ISS Detector Working Group, JINST 4, T05001, (2009). [3] The International Design Study for the Neutrino Factory, 14