1 / 22

Yasukazu Izawa Institute of Laser Engineering, Osaka University

Development of HALNA DPSSL for IFE. Yasukazu Izawa Institute of Laser Engineering, Osaka University. 5th US-Japan Workshop on Laser IFE March 21-22, 2005 General Atomics. Contributors. ILE OSAKA. Tadashi Kanabe*, Masanobu Yamanaka**, Ryo Yasuhara,

osborn
Télécharger la présentation

Yasukazu Izawa Institute of Laser Engineering, Osaka University

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. Development of HALNA DPSSL for IFE Yasukazu Izawa Institute of Laser Engineering, Osaka University 5th US-Japan Workshop on Laser IFE March 21-22, 2005 General Atomics

  2. Contributors ILE OSAKA Tadashi Kanabe*, Masanobu Yamanaka**, Ryo Yasuhara, Junji Kawanaka, Noriaki Miyanaga, Takayoshi Norimatsu, and Masahiro Nakatsuka Institute of Laser Engineering, Osaka University *Fukui University ** Graduate School, University of Advanced Photonics Osamu Matsumoto, Toshiyuki Kawashima, Takashi Sekine, Takashi Kurita, Tadashi Ikegawa, Masahiro Miyamoto, Takeshi Kanzaki and Hirofumi Kan Hamamatsu Photonics K.K. Hiroyuki Furukawa Institute for Laser Technology ILE OSAKA

  3. Roadmap for Laser Fusion Energy Development By IFE Forum (2003)

  4. Laser for implosion: 100kJ Target injector Turbine generator 4MWe Reactor chamber Laser for heating 100kJ FIREX LFER (10MJ, 1Hz) DEMO 1MJ Solid wall Liquid wall 200MJ, 3Hz Laser Fusion Experimental Reactor (LFER)

  5. Two approaches for IFE driver development ILE OSAKA ◇HALNA (High Average-power Laser for Nuclear-fusion Application) conceptual architecture consists of water-cooling, Nd:glass medium and zig-zag slab geometry and multi-pass amplifier. ◇Current goals of the HALNA are 100 J pulse energy, 10 Hz operation and beam quality less than 5 times of diffraction limit (TDL) with 10% overall efficiency. ◇New approach is to use cooled Yb: YAG ceramic slab. (20 x 20 x 5 cm for 1kJ, T = 150 ~ 225 K) (To be presented by J. Kawanaka)

  6. HALNA conceptual design includes diode-pumping, water-cooled glass and zig-zag slab optical geometry. ILE OSAKA

  7. Research and development plan for HALNA 100 ILE OSAKA 20 J x 10 Hz DPSSL for NEDO project Pump intensity : 2.5 kW/cm2 Zig-zag slab geometry : SSG 10 Beam fluence : 5 J/cm2 Pump efficiency : 50% Stored energy density : 0.5 J/cm3 Extraction efficiency : 50% Opt.-opt. Efficiency : 20% 1/5 fracture limit operation Larger aperture Edge-cladding for parasitic Fluence: 5 J/cm2 1/3 fracture limit Dual amplifier head Full aperture : 12 cm2 Fluence : 8 J/cm2 Part of research is supported by NEDO (New Energy and industrial technology Development Organization) under METI (the Ministry of Economy, Trade and Industry), Japan.

  8. 10J/10Hz system HALNA 10 has been developed. Spatial filter

  9. Total 2,400 bars have been integrated into two pump diode modules. Those have been activated in October, 2003 PHOTON IS OUR BUSINESS Pump module performance Left bank (Module 1) Right bank (Module 2)

  10. Peak power and efficiency Spectral profile 160 60 1.2 Module 1 (Left bank) 55 % Module 2 (Right bank) Peak wavelength : 804.13 nm HALNA driver requirements LD Current : 100 A 1 Repetition rate : 10 Hz E-O conversion efficiency [%] Pulse Width : 200 s m 120 45 Cooling water temp. : 25 deg. Peak power [kW] 0.8 Intensity [a.u.] 145.7 kW at 120A 52.8 % at 100A FWHM : 3.39nm 80 30 0.6 145.4 kW at 120A 52.1 % at 100A 0.4 40 15 Module 1 (Left bank) Module 2 (Right bank) 0.2 Repetition rate : 10 Hz Module 1 (Left bank) Pulse Width : 200 s m Module 2 (Right bank) Cooling water temp. : 25 deg. 0 0 0 790 795 800 805 810 815 820 0 20 40 60 80 100 120 140 Wavelength [nm] Current [A] Total 290 kW output peak power was successfully achieved from total 2,400 diode bars at 804 nm. ILE OSAKA Left bank (1,200 bars) Lasing !

  11. Nd doped phosphate glass laser material is suitable for high energy DPSSL applications. ILE OSAKA HAP-4(Nd:1.1wt.%), HOYA Co. Physical properties Amplifier housing □ □ □ 34 cm (length) x 1 cm (width) with slab aspect ratio 2:1 Sol-gel coated at incident faces Geometry for preventing parasitic without edge cladding

  12. Thermal analysis by LASCAD and THESLAC codes optimized slab dimension. ILE OSAKA Insulator Physical properties. 5° LD module Height of glass Slab pumping geometry Results of thermal effect analysis LASCAD gives temperature, stress and deformation of laser glass . THESLAC code calculates wavefront distortion and birefringence.

  13. 2. Thermal deformation Slab height ( mm ) Slab width ( mm ) Thermal modeling revealed optimum slab height for minimizing thermal lensing effects ILE OSAKA ■Optimum range of slab height Thermal analysis results by THESLAC code 1.Temperature distribution Temperature ( K ) Slab thickness ( mm ) Slab height ( mm ) 3.Wavefront distortion 4.Thermal birefringence λ( μm ) Loss ( % ) Slab thickness ( mm ) Slab height ( mm ) Slab thickness ( mm ) Slab height ( mm ) Slab height must be carefully decided, taking into account of pump efficiency and thermal lensing effects.

  14. Output energy was analyzed based on Frantz- Nodvik and Eggleston- Frantz equations. ILE OSAKA Pumping length : 26.8 cm Pumping energy : 48 J Beam width vs. output energy Input energy : 0.1 J Input energy vs. output energy Output energy greater than 10 J is predicted .

  15. Near-field Far-field 7.6mm 2TDL 17mm Filling factor : 49% The HALNA10 has successfully yielded 84-W average power at 10 Hz in December, 2004 ILE OSAKA 84 Waverage operation at 10 Hz 10.6 J operation at 1 Hz 26 ns (FWHM) Near-field Far-field 2TDL Filling factor : 63%

  16. The HALNA 10 has virtually accomplished their goals, demonstrating the feasibility of IFE driver ILE OSAKA

  17. HALNA 50/20 has been designed and is under construction. ILE OSAKA Yb: doped fiber oscillator Nd: YLF regenerative amplifier (8mmf, 0.5J/10ns) Nd: glass slab amplifier (5 x 1 x 30 cm, 4 pass) 2 slabs: 25J/10ns, G0 = 3 1 slab: 20J/10ns, G0 = 6.3 Wavefront control: deformable mirror/phase conjugate mirror

  18. HALNA 50/20 with thermally-edge-controlled slab (TECS) amplifier ILE OSAKA Edge heater Edge cladding 200-kW diode module (2000 bars) Laser slab Delivery optics 38 cm Laser beam 200-kW diode module (2000 bars) Diamond geometry due to zigzag path Laser material: Nd:phosphate glass Slab size: 5 x 1 x 30 cm Pump energy: 80 J Small signal gain: 3/pass Cooling water

  19. 25 Position in mm 0 -25 -50 0 -200 -150 -100 -50 50 100 150 200 Position in mm Overlapping pump irradiation from each diode stack is effective in obtaining 10% uniformity on the slab face Pump light ILE OSAKA • Pump area : 300 mm x 50 mm • Pump intensity : 1.3 ~ 2.5 kW/cm2 • Pump duration : 150 ~ 300 µs • Stored energy density : 0.19 ~ 0.32 J/cm3 • Small signal gain : 3.0 ~ 6.3 /pass Diode facet Lens cassette Laser slab Pump distribution on slab face (simulated by 3-D ray tracing) 50 Effective pump area Horizontal Vertical

  20. Summary ILE OSAKA ◇ HALNA driver for IFE has been developed. ◇ The HALNA 10 has achieved 8.4 J at 10 Hz with beam quality of 2 xDL in December, 2004. ◇ A larger slab amplifier with 5-cm2 aperture has been designed, and it is under construction. ◇ In 2005, the dual slab system will demonstrate the 20 J x 10 Hz operation with a wavefront correction for the NEDO project. ◇ In 2006, a half of HALNA 100 will be constructed with 10-cm2 aperture, the 50 J x 10 Hz operation will be the objective of the moment.

  21. ILE at Osaka collaborates on HALNA project with Hamamatsu Photonics and ILT ILE OSAKA

More Related