JTO’s Perspective and Investment in High Energy Laser Systems 8 Nov 2004

1. JTO’s Perspective and Investment in High Energy Laser Systems8 Nov 2004 LCDR Rich Nguyen NAVY Rep, HEL JTO

2. JTO Organization JTO Portfolio JHPSSL FEL FY05 S&A Call for Papers MRI Outline

3. JTO Programmatic Organization DUSD(S&T) Technology Council S&T Executives (Army,Navy, AF, MDA, DARPA, DTRA) Contractor Technical Support Director, Joint Technology Office Executive Assistant Budget/Finance MDA DARPA DTRA USMC Reps Army Representative Navy Representative Air Force Representative Tech Area, Contracts Monitor Tech Area, Contracts Monitor Tech Area, Contracts Monitor Technology Area Working Groups

4. Mission: To lead DOD’s development of HEL weapon technology Vision: Lasers will be a viable weapons in modern warfare Objectives: Make HELs Lightweight, Affordable, and Supportable JTO Mission, Vision, and Objectives

5. JTO Thrust Areas Laser Device - Solid State - Chemical - Free Electron - Advanced Beam Control Lethality Diode Pump Atmospheric Propagation - Thermal Blooming - Turbulence Laser-Target Interaction Pointing Heat Heat Beam Combining Thermal Management Target Beam Conditioning & Adaptive Optics Heat Wavefront Sensor Windows & Mirrors Power Conditioning Engagement Modeling Diode Pump Illuminator Fire Control Example: Solid State Laser

6. JTO maintains a portfolio of approx 80 Projects/Programs Addresses all thrust areas of HEL system Typical program size is $1M/yr Have larger programs in Electric Laser Initiative JHPSSL FEL JTO Portfolio

7. JTO – 25KW JHPSSL $15M (FY03), $15M (FY04), $3.7M (FY05) AFRL – 25KW JHPSSL $10.2M (FY03/04) Army – 25KW JHPSSL $26M (FY03/04) JTO – 10KW Free Electron Laser $4M (FY03), $4M (FY04) Navy – 10 KW Free Electron Laser $14.1M (FY03/04) JTO Investments(Larger Programs)

8. Near Term Goal: Demonstration and Fabrication of a 25 kW Laser System with near diffraction limited beam quality and useful metrics Ultimate Goal: Demonstration of 100 kW Militarily Significant Laser System Joint High Power Solid State Laser Program (JHPSSL) Mission:to significantly accelerate development of solid state laser technology for future High Power Tactical Laser programs

9. JHPSSL Technical Requirements SOA: P=500W, BQ=1.1xDL, Eff<5%, <2W/kg Parameter Desired Value Development Goals

10. 25 KW lab demonstrations is scheduled in Jan-Mar 2005 at all three facilities (LLNL, Raytheon, NGST) Raytheon & NGST contracts are fully funded LLNL will need 1QFY05 funds from Army Gov’t team (MIT/LL, JTO, ARL, SMDC, & AFRL) perform BQ and power measurements at each facility, Mar 2005 100KW RFP plan in 3QFY05 (open competition); Tech Council decision for contract(s) award Sep 2005 BAA solicitation/ technical criteria set by joint team FY05 JTO funds available for kick-off effort JHPSSLProgram Plan

11. FEL -- Surface Navy Threats Protection

12. FELTactical System Goal Top Level • Power = 1 to 3 MW, controllable down to 100 kW • λ = 1 - 3 µm • BQ < 2 times diffraction limit • Duty Cycle = 30 seconds run time, repeatable after 5 minutes • Injector & Accelerator • ~ 0.5 Amp average current & ~ 0.5 nC/bunch per MW • 2 °K Superconducting RF (500 - 750 MHz) linac • 100 MeV Beam with Energy Recovery • Wiggler & Resonator • Short Rayleigh length • 1% - 2% Extraction efficiency wiggler • Near concentric resonator

13. MW-Class FELKey Technical Issues • Photoinjectors with ~ 1 A average current, ~ 1 nC/bunch injector • Development needed to achieve all requirements simultaneously • Issues with photocathodes, drive lasers, and emittance control • Anchored Models & Simulations • Coherent synchrotron radiation (CSR) and other beam break-up effects degrade the electron beam quality when focusing & bending • Where are the limits? - More data & better models are required to manage effects • Efficient wiggler & compact, survivable optical resonator • High intracavity power & small beam stress conventional resonators & optics • Need short Raleigh length wigglers, resonator concepts & improved optics/coatings • Propagation efficiency of an intense FEL beam • Effects of maritime and other tactical atmospheric paths not yet adequately understood • Effect of the FEL pulse format on beam propagation (degrade or enhance?) • Optimum FEL concept for scale-up • Trades required to balance the challenges faced by the evolving subsystem requirements and competing approaches

14. FELPhoto Injectors • Three classes of potentially scalable Photo Injectors are being developed • All generate free electrons by striking a photocathode emitter with a pulsed laser beam • All need robust, long life drive lasers and high QE photocathodes in visible • DC guns (Jlab & AES) • Accelerate the electron bunch using a DC electrostatic field (~500 kV) • Inject 500 kV electrons into SRF cavity to accelerate to 5 – 10 MeV • Have demonstrated continuous (hi rep-rate), low charge/bunch operation • Challenge: large charge/bunch without space charge effects degrading emittance • Most mature, probably leading candidate for 100 kW FEL • RF guns (LANL & AES) • Accelerate/control the electron bunch using RF fields & focusing magnets • Uses normal conducting RF accelerators if are required • Have demonstrated low rep-rate, high charge/bunch operation • Challenge: thermal management of room temperature RF accelerator at high accelerator gradient • Less mature than DC gun, probably lowest risk for MW FEL • SRF guns (BNL & AES) • Accelerate the electron bunch using RF fields in SRF linac cavities • Cryogenic photocathode • Challenge: thermal management of cryogenic and superconducting portions of the injector with high power drive laser beam and high average current • Least mature but best fit to SRF FEL if technical challenges can be addressed

15. FY05 S&A CallFEL • FEL: 01) High Average Current Electron Gun and Injector Technology • FEL: 02) Amplifier Technology Development • FEL: 03) Technologies To Reduce FEL Construction Costs • FEL: 04) Compact RF Sources

16. FY05 S&A CallFEL: 01 • FEL: 01) High Average Current Electron Gun and Injector Technology “ Proposals in this area should address technologies that support low-emittance consistent with 1 micron wavelength FELs and average currents approaching 1 ampere. Robust electron gun technology, e.g. employing photocathodes, is required that permits long term operation in realistic vacuum environments with a quantum efficiency leading to workable power requirements for the cathodes drive laser. Superconducting and normal conducting technologies are of interest.”

17. High Average Power Diode Pumped Solid State Lasers PM: John Zavada, Army Research Office Principal Investigator: Dr. Robert Byer, Stanford University Affordable High Energy Laser Systems PM: Arje Nachman, Air Force Office of Scientific Research Principal Investigator: Dr. Jerry Moloney, University of Arizona High Power, Closed-Cycle Chemical Lasers PM: Michael Berman, Air Force Office of Scientific Research Principal Investigator: Dr. William McDermott, Denver University High Power, Closed-Cycle Chemical Lasers PM: Michael Berman, Air Force Office of Scientific Research Principal Investigator: Dr. Wayne Solomon, University of Illinois Urbana-Champaign Atmospheric Propagation & Compensation of HEL PM: Kent Miller, Air Force Office of Scientific Research Principal Investigator: Dr. Steve Gibson, University of California-Los Angeles Multi-Disciplinary Research Initiative Projects

18. High Power, Lightweight Optics PM: Charles Lee, Air Force Office of Scientific Research Principal Investigator: Dr. Hubert Martin, University of Arizona FEL -- High Quantum Efficiency Robust Dispenser Photocathodes PM: Quentin Saulter, Office of Naval Research Principal Investigator: : Dr. Patrick O'Shea, University of Maryland Issues: Photocathodes are a weak link in FELs Goal: High quantum efficiency, robust dispenser photocathode using green light or IR drive laser Approach: Theory and Experiment with a focus on dispenser photocathodes FEL -- Diagnostics & Control Methods PM: Quentin Saulter, Office of Naval Research Principal Investigator: Dr. Todd Smith, Stanford University Issues: Need Better Phase Space Mapping techniques for High-Quality Beams Goal: Develop techniques for measuring high average current beams that are suitable for interface with control system Approach: New schemes using: Optical Diffraction radiation, Optical pepper pots, Optical synchrotron interferometry Multi-Disciplinary Research Initiative Projects (Cont’d)

19. Questions?