University Based Linear Collider Accelerator R&D

1. University Based Linear Collider Accelerator R&D George Gollin Department of Physics University of Illinois at Urbana-Champaign USA g-gollin@uiuc.edu George Gollin, University Based Linear Collider Accelerator R&D, Victoria, ALCPG 2004

2. Can university groups do accelerator physics? • Accelerators are BIG, EXPENSIVE devices. • Many university HEP groups have concentrated on detector projects, perhaps because they believe these are: • more suitable in scale for a university group than would be an accelerator physics project • more practical, given their prior experience in detector development. • Is this really true? Should university groups stay away from accelerator physics projects? George Gollin, University Based Linear Collider Accelerator R&D, Victoria, ALCPG 2004

3. Of course university groups can do accelerator physics! There are interesting, important projects whose scope is ideal for a university group. The (inter)national labs welcome our participation and will help us get started, as well as loaning us instrumentation. Many projects involve applications of classical mechanics and classical electrodynamics. These are perfect for bright, but inexperienced undergraduate students. The projects are REALLY INTERESTING. (Also, it’s fun to learn something new.) George Gollin, University Based Linear Collider Accelerator R&D, Victoria, ALCPG 2004

4. At UC Santa Cruz (July, 2002): • DOE, NSF declared $400k, $500k as accelerator funding goals. • USLCSG organized schedule for proposal submission and review • A University Program of Accelerator and Detector Research for the Linear Collider ( “Big Document”) sent to DOE, NSF October 24, 2002. • 33 accelerator, 38 detector proposals, 47 universities, 6 labs, 297 authors, 545 pages. • accelerator support requests: $625k LCRD, $379k UCLC Brief UCLC + LCRD history background image: copies of Big Doc on the way to Washington

5. Congressional budget was months late: Feb. 14, 2003 • “The cap” on DOE LC accelerator R&D • DOE funding began arriving July, 2003. • DOE managed to find ~all the funds they had hoped for: $400k/$500k accelerator/detector. (yippee!) • Long delay was a problem (some groups didn’t get summer students). Discouraging (and ultimately inaccurate) projections came from some grant officers before funds were actually found. • NSF hit a pothole. UCLC only received a “planning grant.” The startup (FY03) was bumpy George Gollin, University Based Linear Collider Accelerator R&D, Victoria, ALCPG 2004

6. Most groups started their projects, in spite of budget glitches. Renewal/resubmission: autumn, 2003. A University Program of Accelerator and Detector Research for the Linear Collider, volume II sent to DOE, NSF November 24, 2003. • 29 accelerator, 39 detector proposals, 48 universities, 5 labs, 303 authors, 622 pages. • FY04 accelerator support requests: $772k LCRD, $380k UCLC Starting up; renewal proposals background image: Big Doc author list

7. December, 2003 reviews of UCLC, LCRD projects: • Norbert Holtkamp (ORNL) chaired the accelerator review • Howard Gordon (BNL) chaired the detector review. Detector review procedures were adjusted so that reports from the Gordon Committee could be used by DOE to make funding decisions. DOE chose not to do this with the Holtkamp Committee. There was a second round of reviews required before funding was provided. Proposal reviews this year George Gollin, University Based Linear Collider Accelerator R&D, Victoria, ALCPG 2004

8. HEPAP says LC is important. DOE/NSF need to find ways to support LC work. • Engagement of (university) community is essential. • Support from DOE/NSF is necessary to show it’s really worth our time to put aside some of our other activities to do LC work UCLC + LCRD Funding George Gollin, University Based Linear Collider Accelerator R&D, Victoria, ALCPG 2004

9. Scope of U.S. university work in this initiative Funding is only now beginning to arrive at universities for proposals written in November, 2003. What can we do to streamline this process? George Gollin, University Based Linear Collider Accelerator R&D, Victoria, ALCPG 2004

10. Here come the professors! Faculty of the world unite! Self-organizing efforts seem entirely possible. participants graphics from 15 of 68 projects George Gollin, University Based Linear Collider Accelerator R&D, Victoria, ALCPG 2004

11. LC at U.K. universities Coherent effort to address beam delivery system issues. Very good idea: technology-neutral, important, and done cooperatively nationwide.

12. EuroTeV could play a similar role for European universities. EuroTeV

13. Information about particular projects Physicists in Africa, Asia, Europe, North, and South America participate in accelerator and detector projects. Many of the projects are LC-related. That’s too much to cover in a short talk! Let’s look briefly at some of the LCRD/UCLC accelerator projects. George Gollin, University Based Linear Collider Accelerator R&D, Victoria, ALCPG 2004

14. Beam simulations and other calculations: 6 • Kickers, magnet technologies, mechanical support systems: 4 • Instrumentation and electronics: 9 • Ground Motion: 1 • Control Systems: 1 • RF Technology: 5 • Non-e+e- collisions: 1 • Electron and positron source technology: 2 University R&D topics Let’s take a look… background image: acoustic wave in copper simulation

15. A Simplified Method to Compute Single-Pass Coherent Synchrotron Radiation with Shielding (New Mexico, SLAC) “We formulate a Vlasov approach to CSR from arbitrary planar orbits with shielding. A new method of computing the CSR field is much simpler than the usual retarded potential scheme” George Gollin, University Based Linear Collider Accelerator R&D, Victoria, ALCPG 2004

16. Development of beam modeling software using BMAD (Cornell) Working on BMAD extensions for use with linacs, among other things. George Gollin, University Based Linear Collider Accelerator R&D, Victoria, ALCPG 2004

17. umm… Transverse Phase Space Measurements for a Magnetic Bunch Compressor by Using Phase Space tomography (UCLA, BNL, JLab) George Gollin, University Based Linear Collider Accelerator R&D, Victoria, ALCPG 2004

18. Progress, both in modeling and in fabrication of prototypes for studies. Ring-tuned, permanent magnet-based Halbach quadrupole (UCLA) George Gollin, University Based Linear Collider Accelerator R&D, Victoria, ALCPG 2004

19. Investigate a “Fourier series kicker”: a series of rf cavities creates a kicking function with periodic zeroes and an occasional spike. Perhaps this will allow construction of a much smaller TESLA damping ring? Investigation of novel schemes for TESLA damping ring kickers (University of Illinois)

20. c 0.5 c 0 0.4 GHz 1 GHz 10 ns 340 ns wave guide group velocity vs. frequency Chirped waveform pulse compression kicker for TESLA damping ring (Cornell, Illinois) Dispersive wave guide compresses chirped RF signal. Commercial broadcast RF amplifier ~100kW, but compression generates large peak power for kicking pulse in low-Q cavity.

21. Compact damping ring using multiple transfer lines(Cornell)

22. Current Goal: investigate modifying the existing FFTB magnet mover design to achieve 50nm/step resolution Status: CSU has built a modified FFTB mover to test, including precision rotary encoders, stepper motors with microstep capability, and high precision capacitive metrology. High precision magnet movers (Colorado State) Assembled Mover at CSU

23. Compact Wakefield Facility (Chicago, Argonne, FNAL) A dedicated facility for high-resolution wakefield measurements of NLC structures. Work needed: • A 20 MeV, high-brightness, Drive Beam excites wakefield • A 5 MeV Witness Beam probes the wakefield • Downstream Optics measures the witness beam deflection George Gollin, University Based Linear Collider Accelerator R&D, Victoria, ALCPG 2004

24. RF Beam Position Monitors for Measuring Beam Position and Tilt (UC Berkeley) Analysis of test beam data from KEK ATF using SLAC-built device. George Gollin, University Based Linear Collider Accelerator R&D, Victoria, ALCPG 2004

25. Beam Test Proposal of an Optical Diffraction Radiation Beam Size Monitor at the SLAC FFTB (UCLA) Simulation work so far. ODR Yield in 0.1/g angle range s: rms transverse beam size George Gollin, University Based Linear Collider Accelerator R&D, Victoria, ALCPG 2004

26. Bunch length interferometry(NIU, Georgia)

27. An explicitly radiation-hard fast gas Cerenkov calorimeter for bunch-by-bunch luminosity measurement(Iowa State, Texas Tech, Oregon, Purdue, SLAC, NIPT) Production of Cherenkov photons by 10 GeV electron transversing 2mm gas conduits in Pb. Studying electroplating and electropolishing... Working on W absorber. George Gollin, University Based Linear Collider Accelerator R&D, Victoria, ALCPG 2004

28. Basic idea: image synchrotron radiation from damping rings • Snapshots of transverse bunch shape • Measure sx, sy, distortions, rotations, etc. • Bunch-by-bunch: single bunch resolution • Motivation: “The LC needs two things: RF cavities to make the energy, and beam diagnostics to make the luminosity.” • Exploring possible parameters, configuration for device. Fast Synchrotron Radiation Imaging System for Beam Size Monitoring (Cornell, SUNY Albany)

29. Beam Halo Monitor & Instrumented Collimators (Mississippi) George Gollin, University Based Linear Collider Accelerator R&D, Victoria, ALCPG 2004

30. Ground Motion studies versus depth (Northwestern)

31. Beam loss monitors for LC (Northwestern) Secondary emission detectors, tested at CLIC test facility at CERN. Fast, rad hard, large dynamic range. George Gollin, University Based Linear Collider Accelerator R&D, Victoria, ALCPG 2004

32. Control of Beam Loss in High-Repetition Rate High-Power PPM Klystrons (MIT)

33. 34 GHz rf studies (Yale)

34. Superconducting RF investigations(Cornell University) Vertical electropolishing Improved cavity shape Eacc = 30 MV/m Eacc = 33 MV/m Lots of other progress too…

35. Acoustic properties of copper and studies of LC rf Cavities (Univ. Mississippi)

36. Investigation of Acoustic Localization of rf Cavity Breakdown(Univ. Illinois) Can we learn more about NLC rf cavity breakdown through acoustic signatures of breakdown events?

37. Design and Fabrication of a Radiation-Hard 500-MHz Digitizer Using Deep Submicron Technology (Ohio State) Some of the circuit functional blocks have been designed, but none fabricated for test yet.

38. Undulator Based Production of Polarized Positrons for Linear Colliders (Tennessee, Princeton) • 50 GeV e- beam and 1 m-long, helical undulatorto make 10-MeV polarized photons. • Photons are converted into e+, e- with ~ 50% polarization. • Measure e+, e- polarization • Scheduled to run in Oct. 2004. Concept: Balakin and Mikhailichenko (1978) George Gollin, University Based Linear Collider Accelerator R&D, Victoria, ALCPG 2004

39. Development of Polarized Photocathodes for the Linear Collider (Wisconsin, SLAC) “Bandgap engineering of strained GaAs.” George Gollin, University Based Linear Collider Accelerator R&D, Victoria, ALCPG 2004

40. A0 photoinjector lab at Fermilab produces a relativistic (16 MeV now, 50 MeV in a few months), bunched low-emittance electron beam. (It’s rather like a TESLA injector.) This should be an excellent facility for all sorts of device tests as well as beam physics studies! Fermilab/ Northern Illinois University photoinjector lab George Gollin, University Based Linear Collider Accelerator R&D, Victoria, ALCPG 2004

41. We are having a lot of fun (and you can too!) The Illinois projects have proved to be well suited for undergraduate participation. The students are very good! Three of them have worked with me for a couple of years in a row. They are exceptionally productive. We are finding it very natural to work in an area that is new to all of us. Consider giving it a try! George Gollin, University Based Linear Collider Accelerator R&D, Victoria, ALCPG 2004

42. How can we make the proposal/review process more efficient? We would be able to better plan our summer hirings if we could know in February about support. How should we modify our loose-knit organizational structure in response to the technology recommendation? It will soon be time to start focusing our efforts. Better communication among project proponents, ALCPG, and working group leaders would be helpful. We need to discuss this. Things to tune George Gollin, University Based Linear Collider Accelerator R&D, Victoria, ALCPG 2004

43. Summary/conclusions Linear Collider accelerator R&D is a fertile area for university groups. It is too much fun to leave to the accelerator physicists. Spontaneous organization, without waiting for structure to be imposed from external sources (administrations of large labs, for example), can be an effective way to start a new, large, coherent, national R&D effort based at universities. BUT it needs to be watched over. Things drift, focus is lost,… otherwise. Realization of the Linear Collider will proceed most smoothly if detector physicists participate actively in the machine design. The accelerator and detector are closely coupled. George Gollin, University Based Linear Collider Accelerator R&D, Victoria, ALCPG 2004