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.