Richard M. Bionta XTOD Beam and Detector October 12-13, 2004 UCRL-PRES-XXXXX XTOD Beam and Detector Simulations 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 Beam and Detector October 12-13, 2004 UCRL-PRES-XXXXX Outline Spontaneous Radiation Model Spontaneous and FEL signals in Direct Imager Diagnostic Spontaneous Reflection in Undulator Vacuum Chamber Conclusions

Spontaneous Radiation Model

Richard M. Bionta XTOD Beam and Detector October 12-13, 2004 UCRL-PRES-XXXXX Spontaneous Data Chain UCLA Near-Field Calculator ~2 Gbyte HDF5 HDF5 to Paradox Converter (x,y,E,P) Paradox format, 4 X 1 GByte ReBinner – Coarser Energy Bins (159) (x,y,E,P) Paradox format, 350 MByte Blob DB Converter – faster to read (E,P[x,y]) Paradox, 50 MBytes Viewer x y E

Richard M. Bionta XTOD Beam and Detector October 12-13, 2004 UCRL-PRES-XXXXX Spontaneous Fluence at NEH Hutch 1 Te = 4.5 GeV Z = 243 m  x = 1.0 mm  y = 0.3 mm 1.85 mJ Te = 14.5 GeV Z = 243 m  x = 0.3 mm  y = 0.1 mm 18.2 mJ 2” 4”

Richard M. Bionta XTOD Beam and Detector October 12-13, 2004 UCRL-PRES-XXXXX Energy Slices 0 < E < 10 keV7.6 < E < 9.0 keV10 < E < 20 keV 20 < E < 27 keV 20 mm Far-Field calculation 400 m from Center-of-Undulator, Roman Tatchyn, SSRL Near-Field calculation 88 m from End-of-Undulator, Sven Richie, UCLA

Richard M. Bionta XTOD Beam and Detector October 12-13, 2004 UCRL-PRES-XXXXX 2-3 mJ FEL 20 mJ Spontaneous 3 mJ High energy core E  > 400 keV LCLS beam footprint At entrance to NEH, FEL tuned to 8261 eV Fundamental Expected LCLS beam profile contains FEL and Spontaneous halo

Spontaneous and FEL signals in the Direct Imager Diagnostic

Richard M. Bionta XTOD Beam and Detector October 12-13, 2004 UCRL-PRES-XXXXX Camera Image Calculator Chain Spontaneous DB (E,P[x,y]) FEL x  Spontaneous +  x FEL Absorbed in 25  m LSO Photoelectrons in Camera (2.5 x Zeiss + SITEC CCD) Transmitted by Material x y E

Richard M. Bionta XTOD Beam and Detector October 12-13, 2004 UCRL-PRES-XXXXX 14.5 GeV Spontaneous, NEH H1 Stops in 25  m LSO All photons

Richard M. Bionta XTOD Beam and Detector October 12-13, 2004 UCRL-PRES-XXXXX 14.5 GeV Spontaneous Direct Imager Signal PhotonsEnergy Stops in 25  m LSO All photons CCD photoelectron levels < 150K e - Full well (16 bit) 327K e - so this is ½ scale on CCD readout Photoelectrons/Pixel (X-Ray resolution  x  m)

Richard M. Bionta XTOD Beam and Detector October 12-13, 2004 UCRL-PRES-XXXXX 14.5 GeV Spontaneous + FEL Stops in 25  m LSO All photons Photoelectrons/Pixel PhotonsEnergy Need attenuation of 2.4 x for CCD full well (X-Ray resolution  x  m)

Richard M. Bionta XTOD Beam and Detector October 12-13, 2004 UCRL-PRES-XXXXX Use of 16.9 mm B 4 C Attenuator Photons/keV Raw photon spectra of FEL + Spontaneous Spectra of FEL + Spontaneous after B4C Spectra of photons stopping in LSO

Richard M. Bionta XTOD Beam and Detector October 12-13, 2004 UCRL-PRES-XXXXX Direct Imager Image 100% FEL + Spontaneous through 16.8 mm B 4 C into 25 mm LSO 14.5 GeV Good FEL signal at ½ CCD Full Scale but increased background in image (X-Ray resolution  x  m)

Richard M. Bionta XTOD Beam and Detector October 12-13, 2004 UCRL-PRES-XXXXX How faint can FEL be? 1% FEL + Spontaneous directly into 25 mm LSO 14.5 GeV 0.01% FEL + Spontaneous into 25 mm LSO (X-Ray resolution  x  m)

Richard M. Bionta XTOD Beam and Detector October 12-13, 2004 UCRL-PRES-XXXXX 4.5 GeV Spontaneous, NEH H1 Stops in 25  m LSO mJ All photons1.852 mJ 8 x Photons / keV Direct Imager Photoelectrons (X-Ray resolution  x  m)

Richard M. Bionta XTOD Beam and Detector October 12-13, 2004 UCRL-PRES-XXXXX 4.5 GeV Spontaneous +  x FEL Direct Imager Photoelectrons Direct Imager Image 1 % FEL 0.01 % FEL (X-Ray resolution  x  m)

Richard M. Bionta XTOD Beam and Detector October 12-13, 2004 UCRL-PRES-XXXXX Commissioning with Direct Imager Direct Imager will see spontaneous on a single shot at GeV Direct Imager will need attenuation for on scale operation at full FEL power, which increases background. These calculations show a factor of ~5-10 margin. Without attenuator, Direct Imager will see FEL at 0.01% power at 4.5 GeV and significantly < 0.01% at 14.5 GeV

Spontaneous Reflection in Undulator Vacuum Chamber

Richard M. Bionta XTOD Beam and Detector October 12-13, 2004 UCRL-PRES-XXXXX Spontaneous Monte Carlo Chain Spontaneous Blob DB (E,P[x,y]) Paradox, 50 Mbytes Inject FEL (E,P[x,y]) Paradox, 50 Mbytes Cumulative DB (x,y,F[E]) Paradox, 50 Mbytes Photon MC Generator – creates random photons according to cumulative distribution (x,y,z,vx,vy,vz,E) of individual photons

Richard M. Bionta XTOD Beam and Detector October 12-13, 2004 UCRL-PRES-XXXXX Spontaneous Monte Carlo Simulation Photon starting x, y matches electron distribution, a Gaussian with  = 30  m Photon starting z is uniform along undulator (from 0 < z < 130 m) Photon starting angles generated to give calculated spontaneous spatial distribution

Richard M. Bionta XTOD Beam and Detector October 12-13, 2004 UCRL-PRES-XXXXX Each photon final x, y has its own cumulative energy distribution x y E Monte Carlo Energy Distribution Calculated far-field energy spectrum

Richard M. Bionta XTOD Beam and Detector October 12-13, 2004 UCRL-PRES-XXXXX Simulated spatial distributions agree with far-field calculation Monte Carlo 465 m from beginning of undulator Far-Field Calculation 400 m from center of undulator All Photons

Richard M. Bionta XTOD Beam and Detector October 12-13, 2004 UCRL-PRES-XXXXX Simulated spatial distributions agree with far-field calculation – higher orders

Richard M. Bionta XTOD Beam and Detector October 12-13, 2004 UCRL-PRES-XXXXX Spontaneous Emission Angle Below Critical Angle 130 m 243 m  max = 0.5 – 1.8 mRad  min = 0.2 – 0.8 mRad mm

Richard M. Bionta XTOD Beam and Detector October 12-13, 2004 UCRL-PRES-XXXXX Vacuum Pipe Simulation 14.5 GeV With pipeWithout pipe

Richard M. Bionta XTOD Beam and Detector October 12-13, 2004 UCRL-PRES-XXXXX Line outs through center With pipeWithout pipe

Richard M. Bionta XTOD Beam and Detector October 12-13, 2004 UCRL-PRES-XXXXX Reflection at higher orders Monte Carlo, with pipe 0 < E < 10 keV10 < E < 20 keV20 < E < 30 keV UCLA Calculation, without pipe Monte Carlo, without pipe

Richard M. Bionta XTOD Beam and Detector October 12-13, 2004 UCRL-PRES-XXXXX Photon Energies > 400 KeV With pipe Without pipe

Richard M. Bionta XTOD Beam and Detector October 12-13, 2004 UCRL-PRES-XXXXX Reflection in pipe at 4.5 GeV

Richard M. Bionta XTOD Beam and Detector October 12-13, 2004 UCRL-PRES-XXXXX Tilted pipe at 14.5 GeV Pipe parallel to beam Pipe tilted 19  R, raised 0.9 mm, and shifted to the right 0.9 mm

Richard M. Bionta XTOD Beam and Detector October 12-13, 2004 UCRL-PRES-XXXXX Vacuum chamber reflections We will see a lot of reflection of the spontaneous off of the tube. The reflection will increase the spontaneous background in the center by x 3 to 4. Twists and tilts in the vaccum chamber will make it hard(er) to interpret the observed spontaneous radiation pattern

Future work and conclusions

Richard M. Bionta XTOD Beam and Detector October 12-13, 2004 UCRL-PRES-XXXXX Near term activities planned Modeling and Simulation - during CR Spontaneous / FEL simulations Calculate Beam sizes at Gas Attenuator, Cameras, etc. … with apertures Re-sampling for true response at 14.5 GeV Simulations of Camera response to mix of Spontaneous and FEL with optimum attenuators and scintillator Decide on the apertures! Pipes, Muon shield, … Component R&D - after CR Spectrometer, Total Energy, Damage Mechanical & Vacuum - after CR Decide on the apertures! Pipes, Muon shield, … Gas Attenuator Calculations and Prototype Beam Line Layout / Standardization / Detailed Specifications

Richard M. Bionta XTOD Beam and Detector October 12-13, 2004 UCRL-PRES-XXXXX Summary Layout geometry is set Beam modeling codes in place Reflection off of undulator vacuum chamber seriously distorts the spontaneous radiation pattern Direct imager model in progress to specify scintillator and attenuator thickness, and CCD gain parameters. Need similar model for Indirect Imager, and Calorimeter. Modeling of other diagnostics will proceed in FY05