1 Injector Lasers Overview Sasha Gilevich, SLAC April 29, 2004 Drive Laser Specifications Challenges System Description Laser Procurement R&D Effort UV conversion Lasers Overview 04/29/2004Sasha Gilevich

2 Sector 20 Laser Laser Bay Transport Tube UV Launch and Condition. Accelerators Lasers Overview 04/29/2004Sasha Gilevich Laser Heater Drive Laser RF Gun 10 m

3 Laser Bay Lasers Overview 04/29/2004Sasha Gilevich

4 UV Beam Specifications at Photocathode ParameterNominal specTolerance Energetic:wavelength255nm nom.+ < 5 nm - 0 nm pulse energy > 0.20 mJ (for 1 nC production with 3x10 -5 QE) < 2 % rms variation Spatial:fluence profile Uniform (nom.) (adjustable) < 20 % (peak-to-peak) spot radius1.2 mm< 4 % (shot-to-shot) centroid position < 10 % radius (RMS over multiple shots) Lasers Overview 04/29/2004Sasha Gilevich

5 UV Beam Specifications at Photocathode (cont.) ParameterNominal specTolerance Temporal:rep rate120 Hz power profileUniform (adjustable plateau slope) < 5% (RMS noise on the plateau) profile FWHM10 psec adjustable to 20 psec < 2 % RMS (over multiple shots) profile rise/fall times 1.0 psec (10% - 90%) timing jitter (with respect to RF) < 0.5 psec (shot-to-shot) Lasers Overview 04/29/2004Sasha Gilevich Sasha Gilevich Lasers Overview 04/29/2004Sasha Gilevich

6 Challenges Short rise/fall time Requires temporal pulse shaping Reliability The system should operate 24x7 Pumping system Life time of the flash lamp – about h => Changing Lamps Every ~2wks Laser Diode Lifetime ~ 10000hr Changing Diodes Every ~ 60 wks (~1 yr) UV conversion unit Shaping hardware Automatic Operation Lasers Overview 04/29/2004Sasha Gilevich

7 Losses ComponentEfficiency UV Conversion Unit8 - 12% Dichroic Separation % UV Pulse Energy Control % Spatial Filter, Telescope, Collimator Flattener % Relay System to UV Launch Table (through vertical transport tube)60 – 80% UV Launch Optics to Grating80 – 90% UV Launch Grating45 – 55% Final Trimmer70 – 80% UV Waveplate, Vacuum Window90 -96% Net Transport and UV Conversion Efficiency – 0.7 – 2.1% Lasers Overview 04/29/2004Sasha Gilevich

8 Drive IR Laser Specifications ParameterNominal specTolerance Energetic:wavelength765 nm (10 nm bandwidth) + < 15 nm - 0 nm pulse energy> 25 mJ (1 nC production with 3X10 -5 QE) < 1 % rms variation (over multiple shots) Spatial:fluence profileUniform (nom.) (adjustable) < 10 % (peak-to-peak) Lasers Overview 04/29/2004Sasha Gilevich

9 Drive IR Laser Specifications (cont.) ParameterNominal SpecTolerance Temporal:rep rate120 Hz power profileuniform (adjustable) < 3 % (RMS noise on the plateau) profile FWHM10 psec (adjustable to 20 psec) < 2 % RMS (over multiple shots) profile rise/fall times2 psec Timing jitter (with respect to the external RF source) < 0.5 psec (shot-to-shot) Lasers Overview 04/29/2004Sasha Gilevich

10 Drive Laser TiS Oscillator (119MHz) Stretcher Pulse Shaper Amplifiers (preamplifier + final amplifier) Compressor UV Converter To the Laser Heater To EO Diagnostics Lasers Overview 04/29/2004 Sasha Gilevich To the Cathode UV specs IR specs Transport to the Tunnel UV Launch and Conditioning (at the Gun) Pumps TiS Oscillator (119MHz) Stretcher TiS Oscillator (119MHz) Stretcher TiS Oscillator (119MHz) Stretcher TiS Oscillator (119MHz) Pulse Shaper Stretcher TiS Oscillator (119MHz) Pulse Shaper Stretcher TiS Oscillator (119MHz) Pulse Shaper Stretcher TiS Oscillator (119MHz) Pulse Shaper Stretcher TiS Oscillator (119MHz) Pulse Shaper Stretcher TiS Oscillator (119MHz) Pulse Shaper Stretcher TiS Oscillator (119MHz) Pumps

11 Drive Laser Development by Outside Vendors Lasers Overview 04/29/2004 Sasha Gilevich  Demonstrated capability to build the IR system according to the specs  Can ship the system in 12 months  Can provide full integration  Will have service agreement  Showed similar estimated costs  Need some development to be done  Have expertise in UV conversion All three companies

12 Drive Laser Development by Outside Vendors Procurement Plan: Prepare Bid Package – June 2004 Receive Vendors Proposals – August 2004 Have Technical Review of Proposals – September 2004 Evaluate the proposals – September 2004 Issue the Award – October 2004 Lasers Overview 04/29/2004Sasha Gilevich

13 Drive Laser Design Issues Unresolved Issues:  Choice of the Temporal Pulse Shaping Technology  Amplification of the Temporally shaped pulses  Efficient UV Conversion of broadband temporally shaped pulses  25 mJ in the IR at 120 Hz is difficult R&D:  Temporal shaping R&D conducted with BNL  UV conversion R&D with ANL  Experiments at SLAC with spectral filtering  Modeling of the UV conversion using SNLO software  Temporal Shaping development by the outside vendor  UV Conversion development by outside vendor Lasers Overview 04/29/2004Sasha Gilevich

14 R&D Effort UV Conversion (ANL/SLAC) Baseline UV Conversion tests Spatial Profile Shaping UV Launching Sasha Gilevich Lasers Overview 04/29/2004Sasha Gilevich 04/29/2004Sasha Gilevich Lasers Overview

15 R&D Effort Pulse Shaping (BNL/INFN/SLAC) Baseline Pulse Shaping Tests UV Conversion Tests with Pulse Shaping Evaluate Effects of Shaping on the E-beam Pulse Shaping (SLAC)  Temporal Shaping of IR pulses with spectral filtering and compressor tuning Sasha Gilevich Lasers Overview 04/29/2004Sasha Gilevich 04/29/2004Sasha Gilevich Lasers Overview

16 UV Conversion UV Conversion Setup SHG Nonlinear crystal THG Nonlinear crystal λ=255nm Dichroic Separation Unit To EO Diagnostic To the Laser Heater Dichroic Separation Unit THG Nonlinear crystal SHG Nonlinear crystal λ=765nm Dichroic Separation Unit λ=765nm SHG Nonlinear crystal λ=382.5nm Dichroic Separation Unit To EO Diagnostic To the Laser Heater To the Photocathode To EO Diagnostic Lasers Overview 04/29/2004Sasha Gilevich Lasers Overview 04/29/2004Sasha Gilevich Lasers Overview 04/29/2004

17 UV Conversion Modeling Optimizing the crystals Type of crystal Crystal Length Optimizing the input beam Beam Diameter Beam Shape Input (IR and blue) beams energy ratio (for THG) Considering different setup methodology Sasha Gilevich Lasers Overview 04/29/2004

18 Nonlinear Crystals CrystalWalk off 765/382.5 mrad GVD 765/ ^5cm /sec cm-1 Deff pm/V Angle Tolerance mrad cm Tempe- rature Range Ko cm Accept. Bandwidth cm-1 cm BBO I o+o=e 0 / / CLBO I o+o=e 0 / / LBO xy o+o=e 0 / / SHG Sasha Gilevich Lasers Overview 04/29/2004

19 Nonlinear Crystals CrystalWalk off 765/382.5/ 255 mrad GVD 765/382.5/ ^5cm /sec cm-1 Deff pm/V Angle Tolerance mrad cm Tempe- rature Range Ko cm Accept. Bandwidth cm-1 cm BBO I o+o=e 0 / 0 / / / / 7.09 CLBO I o+o=e 0 / 0 / / / / KDP o+o=e 0 / 0 / / / / 14.5 THG Sasha Gilevich Lasers Overview 04/29/2004

20 UV Conversion Modeling Sasha Gilevich Lasers Overview 04/29/2004 Choice of the Crystal SHG Lasers Overview 04/29/2004 BBO narrowband output LBO narrowband output LBO accept bandwidth BBO accept bandwidth

21 UV Conversion Modeling Sasha Gilevich Lasers Overview 04/29/2004 Choice of the Crystal THG Lasers Overview 04/29/2004 KDP narrowband output BBO narrowband output

22 UV Conversion Modeling Spatial Shaping Sasha Gilevich Lasers Overview 04/29/2004 Shaped Gaussian Input 20mJ T=10ps Narrowband Gaussian Shaped

23 UV Conversion Modeling Spatial Shaping Sasha Gilevich Lasers Overview 04/29/2004

24 UV Conversion Modeling Temporal and Spatial Shaping SHG BBO I L=1mm Input E=20mJ Pulse Duration = 10 ps Sasha Gilevich Lasers Overview 04/29/2004 Output 400nm Beam Output 800nm Beam 800nm 400nm 04/29/2004 Lasers Overview

25 Status The Laser Specifications are defined Potential vendors were selected Requirements for the Laser Bay are specified R&D effort is outlined Baseline WBS has been completed Preliminary layout of the Gun Region is underway Sasha Gilevich04/29/2004 Lasers Overview

26 Drive Laser Overview Milestones Issue Request for proposals – June 2004 Review of Proposals – September 2004 Issue Award - October 2004 Completion of R&D – December 2004 (preliminary data – September 2004) Receive the IR Drive Laser – October 2005 Start Installation – October 2005 Sasha Gilevich Lasers Overview 04/29/2004

27 Temporal Pulse Shaping with the Dazzler Sasha Gilevich Lasers Overview 04/29/2004 Preliminary Results Using an Acousto-optic Dispersive Filter For Laser Pulse Shaping A Ghigo, F. Tazzioli, C.Vicario, S. De Silvestri, M. Nisoli, S. Stagira, I Boscolo, S. Cialdi, L. Serafini INFN

28 UV to the Cathode