1 / 12

19 th HAPL Meeting Madison, Wisconsin October 22, 2008 Naval Research Laboratory Plasma Physics Division Washington, DC

NRL J. Sethian M. Myers S. Obenschain J. Giuliani M. Wolford S. Haynes Commonwealth Tech F. Hegeler M. Friedman T. Albert RSI P. Burns SAIC R. Jaynes PLEX M. McGeoch APP S. Glidden H. Sanders Georgia Tech S. Abdel-Khalik D. Sadowski K. Schoonover.

caraf
Download Presentation

19 th HAPL Meeting Madison, Wisconsin October 22, 2008 Naval Research Laboratory Plasma Physics Division Washington, DC

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. NRL J. Sethian M. Myers S. Obenschain J. Giuliani M. Wolford S. Haynes Commonwealth Tech F. Hegeler M. Friedman T. Albert RSI P. Burns SAIC R. Jaynes PLEX M. McGeoch APP S. Glidden H. Sanders Georgia Tech S. Abdel-Khalik D. Sadowski K. Schoonover Electra (KrF) Laser Development 19th HAPL Meeting Madison, Wisconsin October 22, 2008 Naval Research Laboratory Plasma Physics Division Washington, DC Presented by M. Wolford Work supported by DOE/NNSA/DP

  2. Electra Laser System (Single Typical Shot) Main AMP Pre-AMP LPX

  3. Electra Laser System (Single Typical Shot) Main AMP Pre-AMP LPX

  4. Electra Main Amplifier ExperimentsTo Evaluate 5 Hz Foil Cooling Techniques on Focal Spots (Target) • Nike Laser System (Single Shot) • ISI smooth focal profiles • Rep-Rate Considerations • Possible Additional Phase Aberrations • Recirculator baseline gas flow • Leftover energy (pressure gradients) from last shot • Foil Temperature (Boundary Layer) • Gas Temperature after one roundtrip of recirculator

  5. VIEW FROM GAS INTO THE DIODE foil Tubes Main Gas Flow Jets "Jet" foil cooling technique developed by Georgia Tech Keeps foil cool Scalable to large apertures Low power consumption (minimal efficiency penalty)Should not mess up the focal profile e-beam side foil TOP VIEW Rib tube Jet Gas Side

  6. Jet flow E-beam Jet Cooling keeps foil at 350 C, which is comfortably below thermal fatigue limit 440 C Stripped Cathode Monolithic cathode

  7. Bulk flow V-plate Jets T>400 C T~265 C T~240 C 0ms e-beam shot 13.28 ms 26.56 ms Time (ms) 39.84 ms 53.12 ms Interferometry Shows Single Shot Recovery With Jet Cooling Technique Interferometer with f/127 diverger

  8. Focal Spot Comparison at Rep-Rate Georgia Tech Jet Cooling 500 shots @ 5 Hz Previous Result 30 shots @ 2.5 Hz KrF No ‘V’ Plate (5 Hz foil failures) HeNe Probe Beam

  9. No Decline in Energy in the Focal Spot at 5 Hz for 50 shots 66 CFM GT, Monolithic Cathode, 1.5 atm Ar, 30 Hz Recirculator Average 11 x 11 pixel with No E-Beam No GT 100% 95% >95% Energy in Focal Spot at 5 Hz Operation SIMILAR RESULT WITH STRIP CATHODE & GT at 92 CFM!! (GOOD SCALING)

  10. Solid State Pulsed Power Development Switches based on low cost commercial product Very durable--nine individual switch modules have been tested to over 200 M shots continuous. • Demonstrated IFE Class Pulsed Power Architecture • 12 stage PFL/Marx, plus magnetic switch, • 250 kV, 7 kA, 270 ns • Rep rate up to 14 Hz • Demonstrated > 106 shots, 5 Hz continuous, > 80% efficiency • Will be delivered to NRL for longevity demo and to evaluate cathodes (Switches provided by APP, module built by PLEX Corp)

  11. KrF Laser Status Uniformity: minimizes hydrodynamic instabilities Single shot: < 0.2% non-uniformity  Rep Rate Amplifier: < 5.8 XDL (provisional) with Georgia Tech Jet Cooling Wavelength: 248 nm (shortest of any ICF laser) Maximizes absorption & rocket efficiency Minimizes risk from Laser Plasma Instabilities (LPI) Efficiency: Predict > 7% wall plug based on Electra Research Cost: Demonstrated cost effective Solid State Pulsed power module Durability: 35,000 shots, up to 270 J @ 2.5 Hz (NEW) 25,000 shots, 80 J @ 2.5 Hz continuous 16,000 shots, 300 J @ 2.5 Hz (one pause) 7,000 shots, 300 J @ 5 Hz in 3 bursts Still need to demonstrate > 1 M shots 300 J @ 2.5 Hz ~9,000 shots

  12. Summary • Jet Cooling (Georgia Tech) of Hibachi maintains high quality laser beam at 5 Hz operation with temperatures below thermal fatigue limit - Focal Profile Measurements - Interferometry - Pyrometer • Angularly Multiplexed Electra Laser System - Beam Line Laser Intensity, Energy (522 J) • Solid State Pulsed Power Development switch modules tested to over 200 M shots continuous • 35,000 shots @ 2.5 Hz up to 270 J per shot.

More Related