Post on 21-Dec-2015
Richard M. Bionta
XTOD Layout and Diagnostic Systems bionta1@llnl.gov
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 Systems bionta1@llnl.gov
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 Systems bionta1@llnl.gov
October 12-13, 2004 UCRL-PRES-XXXXX
Fastclosevalve
Slit A
13'Muonshield
Gas Attenuator
SolidAttenuator
Slit B
PPS
4'Muonshield
Direct ImagerIndirect Imager
Comissioning:Spectrometer,Total Energy
PPS
ElectronBeam
PhotonBeam
Electron Dump
Front End Enclosure
NEH1.5 Scope: Front End Enclosure/ Near
Experimental Hall
Flipper Mirror
83 m112 m
Richard M. Bionta
XTOD Layout and Diagnostic Systems bionta1@llnl.gov
October 12-13, 2004 UCRL-PRES-XXXXX
Front End Diagnostics Schematic
SolidAttenuator
Slits Gas Attenuator Slits
Calorimeter or spectrometerImaging
Systems
Muon ShieldMuon Shield
Front End Enclosure Near Hall Hutch 1
83 m from end of undulator
112 m from end of undulator
FEL parameters along Beam line
eAF w
yx
2
22
2
Richard M. Bionta
XTOD Layout and Diagnostic Systems bionta1@llnl.gov
October 12-13, 2004 UCRL-PRES-XXXXX
FEL Parameters at 8.261 KeV
Z, m A, /nm2
W, m
Dose Be
Dose Si
Dose Mo
Slit 1 73 62 131 0.001 0.139 1.151
Solid Atten
97 44 157 0.000 0.097 0.809
Slit 2 108 38 168 - 0.084 0.700
Hutch 1 115 35 115 - 0.077 0.641
Flipper mirror
150 24 213 - 0.052 0.435
Far Hall 386 4.8 472 - 0.011 0.089
Richard M. Bionta
XTOD Layout and Diagnostic Systems bionta1@llnl.gov
October 12-13, 2004 UCRL-PRES-XXXXX
Dose to melt for various materials
Beryllium 4 0.58 0.013 0.000Diamond 6 2.13 0.062 0.002Aluminum 13 0.20 0.072 0.058Silicon 14 0.91 0.100 0.078Copper 29 0.44 0.183 0.142Molybdenum 42 1.24 0.993 0.649Tin 50 0.14 1.873 1.292Tungsten 74 1.06 1.316 1.341Lead 82 0.14 2.016 2.042
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 Systems bionta1@llnl.gov
October 12-13, 2004 UCRL-PRES-XXXXX
FEL Parameters at 4.000 KeV
Z, m A, /nm2
W, m
Dose Be
Dose Si
Dose Mo
Slit 1 73 54 206 0.003 0.455 3.319
Solid Atten
97 35 256 0.002 0.296 2.156
Slit 2 108 29 279 0.001 0.249 1.817
Hutch 1 115 27 293 0.001 0.225 1.641
Flipper mirror
150 17 366 0.001 0.153 1.051
Far Hall 386 3.1 863 0.000 0.260 0.189
Richard M. Bionta
XTOD Layout and Diagnostic Systems bionta1@llnl.gov
October 12-13, 2004 UCRL-PRES-XXXXX
FEL Parameters at 0.826 KeV
Z, m A, /nm2
W, m
Dose Be
Dose Si
Dose Mo
Slit 1 73 23 734 0.030 0.231 2.295
Solid Atten
97 13 957 0.018 0.135 1.349
Slit 2 108 11 1060 0.015 0.111 1.101
Hutch 1 115 9.7 1125 0.013 0.010 0.977
Flipper mirror
150 5.9 1451 0.008 0.059 0.587
Far Hall 386 0.9 3652 0.001 0.009 0.093
Richard M. Bionta
XTOD Layout and Diagnostic Systems bionta1@llnl.gov
October 12-13, 2004 UCRL-PRES-XXXXX
Material suitability a strong function of photon energy
Melts in NEH
Flu
en
ce to
Me
lt
Low Z materials such as Be, C, B4C 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 Systems bionta1@llnl.gov
October 12-13, 2004 UCRL-PRES-XXXXX
Gas and Solid Attenuators
Autocad
Gas Attenuator high pressure vesssel
SolidAttenuator
Slit B
Gas Attenuator stage 1
Gas Attenuator stage 2
Richard M. Bionta
XTOD Layout and Diagnostic Systems bionta1@llnl.gov
October 12-13, 2004 UCRL-PRES-XXXXX
Solid Be likely to survive at 88 mXray Dose* Dose* Dose* Dose*
Ephoton Li Be B4C CeV eV/atom eV/atom eV/atom eV/atom
827 0.007 0.024 0.068 0.1131000 0.006 0.019 0.055 0.0922000 0.002 0.007 0.023 0.0403000 0.001 0.003 0.011 0.0194000 0.001 0.002 0.007 0.0125000 0.000 0.001 0.005 0.0086000 0.000 0.001 0.003 0.0067000 0.000 0.001 0.002 0.0048000 0.000 0.001 0.002 0.0038271 0.000 0.000 0.000 0.003
Be < 0.1 eV/atom for all photon energies
Richard M. Bionta
XTOD Layout and Diagnostic Systems bionta1@llnl.gov
October 12-13, 2004 UCRL-PRES-XXXXX
Pressure or thickness for 10-4 attenuation
* 6 m of gas at pressure
Use Gas
Use Solids
Richard M. Bionta
XTOD Layout and Diagnostic Systems bionta1@llnl.gov
October 12-13, 2004 UCRL-PRES-XXXXX
Gas Attenuator Differential Pumping Configurations
Richard M. Bionta
XTOD Layout and Diagnostic Systems bionta1@llnl.gov
October 12-13, 2004 UCRL-PRES-XXXXX
Conductance – Intermediate Flow Modeled
)413.231(
)958.181(114.1(
gavg
gavggavgmt FdP
FdPFdPCC
mC
tCd mmFg gas factor (air Fg = 1) Molecualr Flow Conductance Intermediate Flow Conductance
Knudsen TheoryTube Air 300 K
Richard M. Bionta
XTOD Layout and Diagnostic Systems bionta1@llnl.gov
October 12-13, 2004 UCRL-PRES-XXXXX
Calculations for 6-Port configuration
Gas flowto chamber
37.7 T-L/sec2976 sccm
0 5 10 15 201 10
6
1 105
1 104
1 103
0.01
0.1
1
10
100
ChamberStage 3Stage 4Stage 6
DP-Vacuum
Time (s)
Torr Pump Speed
6 x 50 L/s
Inter-connectionCouplingL = 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 Systems bionta1@llnl.gov
October 12-13, 2004 UCRL-PRES-XXXXX
Bellows allow transverse positioning of opening in window
Be disk on gate valve
BellowsGate 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 Systems bionta1@llnl.gov
October 12-13, 2004 UCRL-PRES-XXXXX
Gas Attenuator Prototype Design and Analyses Will Validate Concepts
Conductance – Intermediate Flow Modeled
)413.231(
)958.181(114.1(
gavg
gavggavgmt FdP
FdPFdPCC
+0 25 50 75 100
1 106
1 105
1 104
1 103
0.01
0.1
1
10
ChamberStage 2Stage 4
DP-Vacuum
Time (s)
Torr
Richard M. Bionta
XTOD Layout and Diagnostic Systems bionta1@llnl.gov
October 12-13, 2004 UCRL-PRES-XXXXX
Gas attenuator issues
Pressure / Flow still very high (3 l/min)
Choice of gasN2 ,Ar , Dry Air,CH-N…
Recirculation / Dumping gasNormal operation
Unexpected release
MonitoringCu L monitor under study
Imaging Systems
Richard M. Bionta
XTOD Layout and Diagnostic Systems bionta1@llnl.gov
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 Systems bionta1@llnl.gov
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
BeIsolation
valve
Richard M. Bionta
XTOD Layout and Diagnostic Systems bionta1@llnl.gov
October 12-13, 2004 UCRL-PRES-XXXXX
Imaging detector head prototype
CCDCamera
MicroscopeObjective
LSO or YAG:Ce crystal prism assembly
X-ray beam
Richard M. Bionta
XTOD Layout and Diagnostic Systems bionta1@llnl.gov
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 Systems bionta1@llnl.gov
October 12-13, 2004 UCRL-PRES-XXXXX
Be Mirror Reflectivity
1.E-08
1.E-07
1.E-06
1.E-05
1.E-04
1.E-03
1.E-02
1.E-01
1.E+00
0 0.5 1 1.5 2 2.5 3 3.5 4 4.5 5
Angle (degrees)
R
Indirect Imager reflects small amount of FEL into camera, avoiding damage
Be Mirror Reflectivity at 8 KeVBe Mirror Reflectivity at 8 KeV
1
0.1
0.01
0.001
0.0001
Be MirrorBe Mirror
Be Mirror angle provides "gain" adjustment Be Mirror angle provides "gain" adjustment over several orders of magnitude and over several orders of magnitude and discriminates against high energy discriminates against high energy spontaneous backgroundspontaneous background
Richard M. Bionta
XTOD Layout and Diagnostic Systems bionta1@llnl.gov
October 12-13, 2004 UCRL-PRES-XXXXX
Minimum mirror reflectivity needed to fill CCD well
1 keV 4 keV 8 keV
Photons / nm2 11.6 27.1 35.0
Photoelectrons 2.0 x 107 1.9 x 108 4.7 x 108
Full Well / PE 2.5 x 10-2 2.7 x 10-3 1.0 x 10-3
Objective mag 2.5 x
Solid Angle 1.088E-3
Optical efficiency 0.911
Scintillator Sensitivity 30000 /MeV
CCD QE 0.67
Richard M. Bionta
XTOD Layout and Diagnostic Systems bionta1@llnl.gov
October 12-13, 2004 UCRL-PRES-XXXXX
Indirect imager issues
CalibrationMirror roughnessTight camera geometryCompton backgroundVacuum mechanicsMaking mirror thin enough for maximum transmission
Ceramic multilayers?
Use as an Imaging Monochrometer
Richard M. Bionta
XTOD Layout and Diagnostic Systems bionta1@llnl.gov
October 12-13, 2004 UCRL-PRES-XXXXX
Commissioning strategy
Start with Low Power SpontaneousSaturate 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 FELin Direct Imager
Verify linearity with attenuators
switch to Indirect Imager if/when scintilator damages
Richard M. Bionta
XTOD Layout and Diagnostic Systems bionta1@llnl.gov
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.