Accelerator R&D

1. Accelerator R&D Projects and opportunities in the next period Norwegian CERN town meeting 13 April 2010 Erik Adli, Department of Physics, University of Oslo

2. Particle accelerators Particle accelerators : scientific instrument of increasing popularity (more than 20'000 accelerators in use world wide, including medical accelerators) Continuously more demanding requirements for higher power, better precision, more stable operation imply a need of improved understanding of charged particle beams as well as development of new technology A solid global accelerator research environment exists; major laboratories and universities have groups and courses in accelerator physics and technology (some examples in North-Europe: Uppsala, Lund, Hamburg, Darmstadt, Oxford, Manchester) • Relevant R&D fields: • charged particle beam physics (electrodynamics, classical mechanics, computational physics, statistical mechanics) • rf simulations and technology • beam instrumentation • material science • Ideal field for persons interested in both physics and technology

3. Particle accelerators • Competence in accelerator physics and technology are applicable across accelerator types • electrons, protons, ions • large, small • particle/nuclear physics, material sciences, medical, energy • Knowledge from one accelerator project applicable to a range of accelerator R&D; important competence for any industrialized country • Two of the largest projects involving European accelerator research the next decade : linear colliders and ESS

4. Linear collider R&D damping ring e- e+ source main linac beam delivery HEP agreement for next step: Complement LHC results with a TeV range, high-luminosity, linear e+e- collider High ECM(TeV scale) with reasonable accelerator length and cost requires very high accelerating field, and reasonable wall-plug to beam efficiency High luminosity (Lpeak ~ 1034-35 cm-2s-1) with limited repetition rate requires nanometer beams at the IP This requires ultra-low emittance generation (damping rings) and preservation (very tight tolerances),and very strong and accurate final focus (picture from A. Seryi, ILC@SLAC) (values for CLIC, 11/2008) 1 45 44000 Beam quality Magnet optics

5. Current projects, CLIC and ILC • CLIC – Compact LInear Collider • CERN based study for Multi-TeV e+e- collider • Normal conducting accelerators with field of 100 MV/m, using Two-Beam Acceleration • Feasibility study culminating in Critical Design Report (CDR) in 2010/2011 • ILC – International Linear Collider • Global study for 0.5 TeV e+e- collider • Superconducting accelerators with field of 31.5 MV/m • Feasibility proven – Ref. Design Report (RDR) completed 2007 Impetus for stronger collaboration between the communities (common working groups), and first joint CLIC/ILC workshop October 2010 at CERN. Ideally the global community should join efforts on one project when LHC results.

6. CLIC design Two-Beam Acceleration 100 A electron drive beam CLIC two-beam acceleration scheme

7. CLIC Test Facility 3 (CTF3) • CLIC: crucial to prove what is unique for CLIC (many parts similar to ILC) – the Drive Beam generation and Two-Beam acceleration • CLIC Test Facility 3: well-defined program to prove feasibility of CLIC by end of 2010, by a set of dedicated experiments : CTF3 – Layout DELAY LOOP • Manipulation of e- beams to reach very high intensities (~ 30 A) (Linac and rings) • Two-Beam acceleration: stable rf power production, acceleration, break down studies (Two-beam Test Stand) • Extraction of a large fraction (~60 %) of the electron beam energy (Test Beam Line) 4 A – 1.2 ms 150 Mev COMBINERRING DRIVE BEAM LINAC 30 A – 140 ns 150 Mev CLEX CLIC Experimental Area 10 m Norway (UiO), Sweden (Uppsala) and Finland (Helsinki IP) are members of the global CLIC/CTF3 collaboration, and heavily involved in the these experiments

8. Two-beam Test Stand PETS experiments • Examples of Studies of two-beam acceleration in the two-beam test stand acceleration: rf power production, spectrometer energy measurements, impact on beam (kicks), break down studies, power generation efficiency TBTS Experimental set-up The CTF3 Two-beam Test Stand experiment (Managed by University of Uppsala, Sweden) CLIC 12 GHz PETS prototype

9. NorduCLIC • A consortium has been set up for a Nordic Collaboration, NorduCLIC, to launch a Nordic branch for design, build and test of one of key components of CLIC: the accelerating structures (UiO, Uppsala, HIP+). The CLIC design specifiesmore than 200'000 micro-wave structures in order to reach 3 TeV ECM (large commercial potential) • Will enable to build Nordic competences within accelerator structures, high-power microwave techniques, rf simulations and break down phenomenology • By entering the field of accelerator structure design early, NorduCLIC will be in good position to play an important role in the research and development of vital CLIC components • First funding applications sent to the respective funding agencies in 2009; Sweden acquired money for one post.doc. and equipment (4 MSEK), Finland for post.doc., Ph.D. student and material money. Norway did receive get any funding this year, but we stay in the collaboration, with existing resources (EA)

10. Future steps for CLIC • The CLIC Conceptual Design Report (CDR) is due for completion towards end of 2010. University of Oslo contributes with one ~40 "responsible authors". • Next phase: technical design (TDR) including enlargement of test-facilities and larger scale production and test of rf structures • Norway together with NorduCLIC partners is in good position to take responsibility for future work related to the "heart of CLIC", energy extraction and two-beam acceleration, through the TBTS and TBL tests, design, construction and exploitation of larger test facilities) From "CLIC R&D Plan for the Technical Design Phase – V0.2" (R. Corsini) Contributions from outside CERN expected at same level Budget awaits council decisions in mid-2011

11. European spallation source • The European Spallation Source (ESS) will be located in Lund, Sweden: a 5 MW pulsed spallation source (1018 n/cm2/sec). The proton driver linac will require substantial amount of R&D the coming period. First beam planned for 2018-2019. • Key technology is the use of super-conducting rf, elliptical niobium cavities, operating at 1.8 K. • Example of other projects using super-conducting technology and high-power linacs: ADS, fusion, muon/neutrino physics, XFEL, ILC, LHeC, eRHIC [M. Lindroos et al., "The ESS Superconducting Linear Accelerator", SFR 2009]

12. ESS: Nordic engagements • Norway has jointed ESS, and has agreed to contribution of 2.5% of the construction cost (~ 37.5 MEUR) – opportunities to join in the linac part of ESS (will be designed and built as a collaboration). TDR starts 1/2011 for ~ 2 years. • Linac work has been divided into major workpackages : • Management (ESS) • Beam physics and instrumentation (ESS) • Infrastructure, including crygenics (Tekniker, ES) • Superconducting cavitites (IPNO, IN2P3, CEA, FR) • Front end and normal conducting linac (INFN, IT) • High energy beam transport (Århus U., DK) • Radio-frequency systems, inkl. low-level rf, klystrons, modulators (Uppsala, SE) Elliptical superconducting cavity, containing up to 1 MW of rf power at 704 MHz. Basic layout of ESS rf (Uppsala) : Safe and energy-efficient control of rf power.

13. ESS: Nordic engagements • We have had preliminary discussions with ESS management and Uppsala responsible for possibilities to participate in the beam physics and the rf systems work-packages • Good potential for student subjects in accelerator physics and technology within the mentioned work packages, examples : • Simulation of high-power proton beams • Instrumentation (monitoring of beam current, beam profile, losses) • Rf systems designs (high-power systems, low level control systems) • ESS could be a valuable resource for student training – a la CERN Technical Student programme (joint supervision university and laboratory) • An ESS accelerator activity would profit from already existing NorduCLIC collaboration, and in general strengthen the Nordic accelerator community

14. Norwegians in Accelerator R&D • Yngve Inntjore Levinsen (Ph.D. student, University of Oslo and CERN BE/ABP) • Studies of LHC machine induced background. In the past: machine induced background pose a problem in the early lifetime of a collider : • protons from the beam colliding with gas in the beam-pipe • Collision residues from one experiment travelling to another experiment • Residues from protons that hit the (tertiary) collimators Eksempel: Simulert “ladet hadron multiplisitet” for stråle-gass kollisjoner i LHCb, 450 GeV stråle-energi. Den lange halen ble også observert i målingene høsten 2009. Kilde: LHC proj.note 429 LHC loss studies by Y. Levinsen

15. Norwegians in Accelerator R&D Reidar L. Lillestol(Technical M.Sc. student, NTNU and CERN BE/ABP) Will do his master thesis on rf measurements in the CLIC/CTF3 Test Beam Line (with EA) Øystein Midttun (Fellow CERN BE/ABP) Simulating the H- source of Linac 4 Spectrometer simulations of e- dumping and H- corrections at the second stage of the source by Ø. Midttun A number of Norwegian technical students have involved in accelerator related studies the last few years (e.g. Anita Hansen, Erik Nesvold, Anders Eide). My experience is that most students choose to enter Norwegian industry after their 12 months at CERN.

16. Conclusions • Considering the important role of particle accelerators as scientific instrument and as tool for e.g. medical and energy applications, we consider it of importance for the physics community in Norway to gain competence in the field of particle accelerators • CLIC (normal conducting collider for particle physics) and ESS (super conducting high power proton driver) will require a large R&D effort the coming ~10 years (ESS TDR and construction, CLIC CDR, TDR) • An eventual Norwegian accelerator activity would get support from and synergy with Scandinavian partners (Uppsala, Finland), as well as CERN and ESS