Richard M. Bionta XTOD Layout and Diagnostic October 12-13, 2004 UCRL-PRES-XXXXX XTOD Layout and Diagnostic Systems Facility Advisory Committee Meeting October 12-13, 2004 *This work was performed under the auspices of the U.S. Department of Energy by the University of California, Lawrence Livermore National Laboratory under contract No. W-7405-Eng-48 and by Stanford University, Stanford Linear Accelerator Center under contract No. DE-AC03-76SF00515.

Richard M. Bionta XTOD Layout and Diagnostic October 12-13, 2004 UCRL-PRES-XXXXX Outline XTOD Layout FEL parameters along Beam line Gas and solid attenuators Imaging detectors Commissioning strategy Conclusions

Diagnostics and Front-End Layout

Richard M. Bionta XTOD Layout and Diagnostic October 12-13, 2004 UCRL-PRES-XXXXX Fast close valve Slit A 13' Muon shield Gas Attenuator Solid Attenuator Slit B PPS 4' Muon shield Direct Imager Indirect Imager Comissioning: Spectrometer, Total Energy PPS Electron Beam Photon Beam Electron Dump Front End Enclosure NEH 1.5 Scope: Front End Enclosure/ Near Experimental Hall Flipper Mirror 83 m 112 m

Richard M. Bionta XTOD Layout and Diagnostic October 12-13, 2004 UCRL-PRES-XXXXX Front End Diagnostics Schematic Solid Attenuator Slits Gas Attenuator Slits Calorimeter or spectrometer Imaging Systems Muon Shield Front End EnclosureNear Hall Hutch 1 83 m from end of undulator 112 m from end of undulator

FEL parameters along Beam line

Richard M. Bionta XTOD Layout and Diagnostic October 12-13, 2004 UCRL-PRES-XXXXX FEL Parameters at KeV Z, mA,  /nm 2 W,  m Dose Be Dose Si Dose Mo Slit Solid Atten Slit Hutch Flipper mirror Far Hall

Richard M. Bionta XTOD Layout and Diagnostic October 12-13, 2004 UCRL-PRES-XXXXX Dose to melt for various materials Beryllium Diamond Aluminum Silicon Copper Molybdenum Tin Tungsten Lead Doses should be compared to dose needed to melt Z Melt dose ev/atom Dose in NEH Hutch 1 1 keV 8 keV

Richard M. Bionta XTOD Layout and Diagnostic October 12-13, 2004 UCRL-PRES-XXXXX FEL Parameters at KeV Z, mA,  /nm 2 W,  m Dose Be Dose Si Dose Mo Slit Solid Atten Slit Hutch Flipper mirror Far Hall

Richard M. Bionta XTOD Layout and Diagnostic October 12-13, 2004 UCRL-PRES-XXXXX FEL Parameters at KeV Z, mA,  /nm 2 W,  m Dose Be Dose Si Dose Mo Slit Solid Atten Slit Hutch Flipper mirror Far Hall

Richard M. Bionta XTOD Layout and Diagnostic October 12-13, 2004 UCRL-PRES-XXXXX Material suitability a strong function of photon energy Melts in NEH Fluence to Melt Low Z materials such as Be, C, B 4 C and Si will survive at least > 1 shot in the NEH NEH Peak Fluence at entrance

Gas and Solid Attenuators

Richard M. Bionta XTOD Layout and Diagnostic October 12-13, 2004 UCRL-PRES-XXXXX Gas and Solid Attenuators Autocad Gas Attenuator high pressure vesssel Solid Attenuator Slit B Gas Attenuator stage 1 Gas Attenuator stage 2

Richard M. Bionta XTOD Layout and Diagnostic October 12-13, 2004 UCRL-PRES-XXXXX Solid Be likely to survive at 88 m Be < 0.1 eV/atom for all photon energies

Richard M. Bionta XTOD Layout and Diagnostic October 12-13, 2004 UCRL-PRES-XXXXX Pressure or thickness for attenuation * 6 m of gas at pressure Use Gas Use Solids

Richard M. Bionta XTOD Layout and Diagnostic October 12-13, 2004 UCRL-PRES-XXXXX Gas Attenuator Differential Pumping Configurations

Richard M. Bionta XTOD Layout and Diagnostic October 12-13, 2004 UCRL-PRES-XXXXX Conductance – Intermediate Flow Modeled d mm Fg gas factor (air Fg = 1) Molecualr Flow Conductance Intermediate Flow Conductance Knudsen Theory Tube Air 300 K

Richard M. Bionta XTOD Layout and Diagnostic October 12-13, 2004 UCRL-PRES-XXXXX Calculations for 6-Port configuration Gas flow to chamber 37.7 T-L/sec 2976 sccm Pump Speed 6 x 50 L/s Inter-connection Coupling L = 3 cm Hole size = 3 mm dia. 6-port configuration can maintain 10 Torr with 3 mm apertures

Richard M. Bionta XTOD Layout and Diagnostic October 12-13, 2004 UCRL-PRES-XXXXX Bellows allow transverse positioning of opening in window Be disk on gate valve Bellows Gate valve X stage Y stage Be disk on gate valve transparent to high energy spontaneous, allows alignment of hole using cameras in NEH Hutch 1. Gate valve removes window when gas attenuator not in use. Y motion

Richard M. Bionta XTOD Layout and Diagnostic October 12-13, 2004 UCRL-PRES-XXXXX Gas Attenuator Prototype Design and Analyses Will Validate Concepts Conductance – Intermediate Flow Modeled +

Richard M. Bionta XTOD Layout and Diagnostic October 12-13, 2004 UCRL-PRES-XXXXX Gas attenuator issues Pressure / Flow still very high (3 l/min) Choice of gas N 2,Ar, Dry Air,CH-N… Recirculation / Dumping gas Normal operation Unexpected release Monitoring Cu L monitor under study

Imaging Systems

Richard M. Bionta XTOD Layout and Diagnostic October 12-13, 2004 UCRL-PRES-XXXXX NEH Hutch 1 Diagnostic systems Direct Imager Indirect Imager Comissioning Tank

Richard M. Bionta XTOD Layout and Diagnostic October 12-13, 2004 UCRL-PRES-XXXXX Imaging Detector Tank Direct Imager (Placed directly in beam) Indirect Imager (Sees only a low intensity reflection) Turbo pump Be Isolation valve

Richard M. Bionta XTOD Layout and Diagnostic October 12-13, 2004 UCRL-PRES-XXXXX Imaging detector head prototype CCD Camera Microscope Objective LSO or YAG:Ce crystal prism assembly X-ray beam

Richard M. Bionta XTOD Layout and Diagnostic October 12-13, 2004 UCRL-PRES-XXXXX Direct imager issues Vacuum Operation Low Photon Energy Performance 120 Hz Readout Afterglow in LSO High Energy Spontaneous Background Damage threshold

Richard M. Bionta XTOD Layout and Diagnostic October 12-13, 2004 UCRL-PRES-XXXXX Indirect Imager reflects small amount of FEL into camera, avoiding damage Be Mirror Reflectivity at 8 KeV Be Mirror Be Mirror angle provides "gain" adjustment over several orders of magnitude and discriminates against high energy spontaneous background

Richard M. Bionta XTOD Layout and Diagnostic October 12-13, 2004 UCRL-PRES-XXXXX Minimum mirror reflectivity needed to fill CCD well 1 keV4 keV8 keV Photons / nm Photoelectrons2.0 x x x 10 8 Full Well / PE2.5 x x x Objective mag2.5 x Solid Angle1.088E-3 Optical efficiency0.911 Scintillator Sensitivity  /MeV CCD QE0.67

Richard M. Bionta XTOD Layout and Diagnostic October 12-13, 2004 UCRL-PRES-XXXXX Indirect imager issues Calibration Mirror roughness Tight camera geometry Compton background Vacuum  mechanics Making mirror thin enough for maximum transmission Ceramic multilayers? Use as an Imaging Monochrometer

Richard M. Bionta XTOD Layout and Diagnostic October 12-13, 2004 UCRL-PRES-XXXXX Commissioning strategy Start with Low Power Spontaneous Saturate Direct Imagers, measure linearity with solid attenuators Raise power, Measure linearity of Calorimeter and Indirect imager. Cross calibrate Test Gas Attenuator Raise Power, Look for FEL in Direct Imager Verify linearity with attenuators switch to Indirect Imager if/when scintilator damages

Richard M. Bionta XTOD Layout and Diagnostic October 12-13, 2004 UCRL-PRES-XXXXX Summary Layout geometry is set. Placement of Gas and solid attenuators enhances survivability of solids relaxing gas attenuator requirements. Imaging detector concepts based on existing prototypes. Ready for detailed specification of scintillator, objective, … Commissioning strategy is to bootstrap detectors / attenuators to higher fluences, checking linearity along the way.