1. W.S. Graves, ASAC Review, Sept 18-19, 2003 Accelerator Overview Goals for proposal Description of technical components: injector, linac, compressors, etc. Summary of technical challenges Elements of R&D program William S. Graves MIT-Bates Laboratory Presentation to MIT X-ray laser Accelerator Science Advisory Committee September 18-19, 2003

2. W.S. Graves, ASAC Review, Sept 18-19, 2003 1.Describe an integrated laser laboratory integrating sources that span the visible to x-ray wavelengths. 2.Produce accelerator and laser design for a user facility. 3.Increase the user community’s perception that required accelerator and laser technologies are mature. Goals for proposal Three key attributes: 1.Many beamlines are planned, each running at 1 kHz or more. 2.Laser wavelengths spanning visible to x-ray are available in a single facility. 3.Seeding for longitudinal coherence at all wavelengths is included in the initial design.

3. W.S. Graves, ASAC Review, Sept 18-19, 2003 A brief history of the MIT effort Spring 2002 D. Moncton approaches R. Milner about the possibility of an x-ray FEL at Bates lab. Summer 2002 Workshop held at Bates on the source technologies. Spring 2003 Proposal for 4 GeV user facility submitted to NSF. Collaboration meeting held for contributors to proposal. Summer 2003 User program committee meets. Fall 2003 First accelerator concept review. Today!

4. W.S. Graves, ASAC Review, Sept 18-19, 2003 1.High repetition rate photoinjector, cathode, drive laser. 2.SRF sections, preferably CW, including 3 rd harmonic cavity. 3.Bunch compressors. 4.Electron beam switchyard to undulator halls. 5.Seed lasers, HHG generation. 6.FEL output properties, undulator layout. Technical Components Little presentation on x-ray components and diagnostics, or electron beam diagnostics.

5. W.S. Graves, ASAC Review, Sept 18-19, 2003 Facility layout 0.3 nm0.1 nm UV HallX-ray Hall Nanometer Hall SC Linac 4 GeV2 GeV1 GeV 1 nm 0.3 nm 100 nm 30 nm 10 nm 3 nm 1 nm Master oscillator Pump laser Seed laser Pump laser Fiber link synchronization Injector laser Undulators Future upgrade to 0.1 nm at 8 GeV SC Linac

6. W.S. Graves, ASAC Review, Sept 18-19, 2003 Key accelerator elements and issues Photoinjector SRF linac Bunch compressor Ebeam switch Undulators Photocathode laser Photocathode laser:Timing and power stability Photoinjector:Produce low emittance ebeam at 5% duty factor Linac:Rf amplitude and phase Compressor:Produce high peak current ebeam, low CSR. Switch:Rate, stability Undulators:Tunability, variable length Seed lasers:HHG generation, stable operation, timing Seed laser

7. W.S. Graves, ASAC Review, Sept 18-19, 2003 Photoinjector 3 cell pulsed room temperature cavity operating at 10 kHz -presentation by Manouchehr Farkhondeh

8. W.S. Graves, ASAC Review, Sept 18-19, 2003 Direct diode-pumped, fiber amplifier -presentation by Franz Kaertner Yb:fiber amplifier IPG-Photonics 20ps, 10  J, 1-10 kHz @ 1064 nm 4 th -Harmonic 20ps, 1  J, 1-10 kHz @266 nm Yb:YAG, 1ps rep. Rate 100 MHz Pulse Selector Temporal: Flat-top shaped Photoinjector drive laser Acousto-Optic Programmable Pulse Shaper (Dazzler, Fastlight)

9. W.S. Graves, ASAC Review, Sept 18-19, 2003 RF and cryoplant -presentation by Townsend Zwart

10. W.S. Graves, ASAC Review, Sept 18-19, 2003 Beam dynamics, bunch compression -presentation by Fuhua Wang

11. W.S. Graves, ASAC Review, Sept 18-19, 2003 Electron beam switchyard -presentation by Jan van der Laan

12. W.S. Graves, ASAC Review, Sept 18-19, 2003 Laser seeding Noble Gas Jet (He, Ne, Ar, Kr) 100  J - 1 mJ @ 800 nm XUV @ 3 – 30 nm  = 10 -8 - 10 -5 Recombination Propagation -W b  XUV Energy  x bb 0 Laser electric field Ionization Cut-off Harmonic: -presentation by Franz Kaertner

13. W.S. Graves, ASAC Review, Sept 18-19, 2003 FEL output properties Seeding for short pulses Seeding for narrow bandwidth SASE

14. W.S. Graves, ASAC Review, Sept 18-19, 2003 1.Achieve ~10 fs timing synchronization between FEL output, seed lasers, and pump-probe lasers. 2.Necessary RF phase and amplitude stability for timing above. 3.Stability in energy per pulse, timing, and pointing appropriate for a user facility. 4.Reduced power consumption for CW operation. 5.Reliable laser seed generation including tunability and stability. 6.Development of fast RF or ferrite switches necessary to deliver beam to multiple undulators. 7.Development of a high repetition rate, high brightness photoinjector. 8.Development of tunable undulators. Matching of undulator resonance. Rapid orbit correction at different wavelengths. 9.Electron beam diagnostics. 10.Coherent photon beam diagnostics. Technical challenges

15. W.S. Graves, ASAC Review, Sept 18-19, 2003 NSF referee reports Proposal covers very large range of activities…difficult for individuals to review. Several referees recommend stronger R&D program. Doubts expressed about maturity of technologies. Reviews and our response to specific issues will be discussed Fri a.m. Provide your input and feedback on the reviews and our response. Give advice on R&D issues and effort level. Is substantial R&D necessary before proceeding to design stage? Identify best path forward. MIT remains committed to building an x-ray laser lab

16. W.S. Graves, ASAC Review, Sept 18-19, 2003 R&D program at Bates Demonstrate some of the key technologies at lower energy including 1.Seeding with ultrashort HHG pulses 2.Development of tunable seed laser 3.Cascaded HGHG FEL output 4.Timing synchronization of FEL, seed, and pump lasers below 100 fs Identify key R&D issues.

17. W.S. Graves, ASAC Review, Sept 18-19, 2003 Original schedule

18. W.S. Graves, ASAC Review, Sept 18-19, 2003 Concluding remarks Concept is still at an early stage. Simulations of separate systems (injector, linac, switchyard, FEL) are underway, but not yet connected as a start-to-end effort. This review should assess the directions we are taking rather more than the initial results.