X Ray Transport, Optics, and Diagnostics Overview

Donn H. McMahon

XTOD Configuration Overview [email protected]

October 24-26, 2005UCRL-PRES-216590

X Ray Transport, Optics, and Diagnostics Overview

FAC Photon Topical

Oct. 27, 2005

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.

Work supported in part by the DOE Contract DE-AC02-76SF00515. This work was performed in support of the LCLS project at SLAC.

Donn H. McMahon



Outline

XTOD Configuration

X-Ray Beam Conditioning & Diagnostics Goals

XTOD Interfaces

Upstream FEE Instruments

Mechanical & Vacuum

XTOD Work Plan

Technical Documents, Summary

Donn H. McMahon



The FEE Will House the Majority of XTOD Diagnostics and Beam Conditioning Systems

Fastclosevalve

Slit

Ion Chamber

Ion Chamber

Diagnostics Package

Gas Attenuator

SolidAttenuator

SiC Mirror 1

Be Mirrors 2 & 3

SiC Mirror 2

Collimator 1

DiagnosticsPackage

Collimator 2

Donn H. McMahon



The FEE Instruments Will Be Used to Characterize and Monitor the Performance of the LCLS Beam

SolidAttenuator

Gas Attenuator

Slit;Fixed Mask

Start of Experimental

Hutches

5 mm diameter

collimators

Muon Shield

FEL Offset mirror system

TotalEnergy

CalorimeterWFOV Direct

Imager

Spectrometer / Indirect Imager

Windowless Ion

Chamber

Windowless Ion

Chamber

e-

Diagnostic Package

Fast Valve Diagnostic Package

Donn H. McMahon



Experimental Halls and Tunnel are Comprised Primarily of Transport Systems and Imagers

Direct Imager

Direct Imager, CD4

Flipper Mirror

NEH

Hutch 2

FEHTUNNEL

Turbo Pump Offset Support

Beam Tube, 4.00” OD X .083” W X 120” L

Flex Support

Ion Pump Offset Support

Donn H. McMahon



Gas and Solids Attenuators Can Attenuate the FEL up to 4 Orders of Magnitude

Use Gas

Use Solids

Solid Attenuator

256 Attenuation Levels

Gas Attenuator

* For a transmission of 10-4

Donn H. McMahon



XTOD Redundant Commissioning InstrumentationInstrument Purpose Adjustment Calibration and

Physics risks

Direct Imager SP f(x,y), look for FEL, measure FEL u, f(x,y), x,y

ND filter, Attenuators

Scintillator linearity, Attenuator linearity and background

Indirect Imager Measure FEL u, f(x,y), spectral imaging of SP & FEL harmonics

Mirror Angle Mirror reflectivity, damage

Total Energy FEL u Attenuators Energy to Heat, damage

Ion Chamber FEL u, x,y,x',y' Pressure Signal strength

Spectrometers FEL, SP spectra Attenuators Resolution, damage

Donn H. McMahon



FEL Offset System Has Been Incorporated in the XTOD Plan

Baseline cost & schedule have been definedThe FEE layout has been modifiedRadiation Physics analysis has defined critical components (e.g, collimators, shielding)Development Schedule

Determine mirror and other system specifications

Produce concept and corresponding engineering specification

Complete conceptual engineering design

Donn H. McMahon



XTOD Interfaces Have Been DefinedXTOD to Linac (1.1-504)

Vacuum, fluid interfacesMechanical InterfacesControl Signals, electrical interfacesRadiation & other environmental issues

XTOD to XES (1.1-507)Vacuum & Mechanical interfaces for PPSControl Signals

XTOD to Conventional Facilities (1.5-108)HVAC ( thermal , humidity, gas supplies, exhaust systems)Mechanical, vibrationElectrical: Power, cable trays,communications

Donn H. McMahon



Fast and Slow Valve SpecificationsFast Valve

VAT Series 77 Flap Shutter with Pneumatic ActuatorCloses to less than 30 mTorr*L/s within 15 msOpens to full size of beam pipe2,000 cycles to first service

Slow ValveVAT Series 48 All Metal Gate ValveSeals within 3 seconds20,000 cycles to first service

ControlsVAT VF-2 ControllerVAT High Vacuum SensorEPICS Compatible

Meets or exceeds all requirements

Donn H. McMahon



Fixed Mask Key Requirements

Define clear aperture for diagnostics as a 5 x 10 cm image at NEH (757.404 m)

Protect downstream equipment from non-central radiation

Align aperture within 1 mm of beam position

Donn H. McMahon



Fixed Mask Concept

6 Strut System 0.03mm Resolution

Tantalum Mask – 5 cm thick

5 DOF Mount

Donn H. McMahon



X-ray Slit Key Requirements

Defines precision aperture of x-ray laserAble to choose any rectangular area inside clear aperture of fixed mask – 0.16 mm or larger10 micron linear resolutionBlocks aligns to beam axis within 29.5 arc-seconds

Compatible with high vacuum environmentOpens to clear aperture for diagnosticsCompatible with EPICS control system

Donn H. McMahon



X-ray Slit General Specifications

Two pairs of slitsOne horizontalOne vertical

Stages compatible with 1E-6 TorrSlits open beyond clear aperture6 strut system can yield 0.03 mm resolution

Donn H. McMahon



X-ray Slit Movement SpecificationsLinear motion

100 mm travel

1.25 m resolution

2 m accuracy

2 m repeatability

Motorized Rotary Stage

Manual Rotary Stage

Motorized Linear Stage

Limit Switch Adjuster (2)

Limit Switch (2)Horizontal Slit Block - B4C

Radial motion360 degree travel

3 arc-sec resolution

30 arc-sec accuracy

6 arc-sec repeatability

Donn H. McMahon



Solid Attenuator Concept

256 attenuation levelsEight beryllium slides

Each twice as thick as the last (0.3 to 38.4 mm)

Up to 99.998% attenuation of 8.26 keV x-raysMillions of attenuation levels when used with gas attenuatorPneumatically actuated

Donn H. McMahon



Sample of Predicted Transmission LevelsBeryllium

X-ray Energy (eV) 8267 7000 6000 5000 4000 3000 2000

Attenuation Length (microns) 6906.442 3965.672 2398.152 1327.45 647.367 259.157 72.958

Attenuation Length (mm) 6.91 3.97 2.40 1.33 0.65 0.26 0.07

Transmission thru Gas Attenuator at max pressure 0.8812 0.8066 0.7067 0.5438 0.3003 0.0575 0.0001

Thickness (mm) Transmission Transmission Transmission Transmission Transmission Transmission Transmission

0.0 1.00000 1.00000 1.00000 1.00000 1.00000 1.00000 1.00000

0.3 0.95749 0.92714 0.88241 0.79772 0.62913 0.31424 0.01638

0.6 0.91679 0.85959 0.77865 0.63636 0.39581 0.09875 0.00027

0.9 0.87782 0.79696 0.68709 0.50764 0.24901 0.03103 0.00000

1.2 0.84051 0.73890 0.60630 0.40495 0.15666 0.00975 0.00000

1.5 0.80478 0.68506 0.53500 0.32304 0.09856 0.00306 0.00000

1.8 0.77057 0.63515 0.47209 0.25769 0.06201 0.00096 0.00000

2.1 0.73781 0.58887 0.41658 0.20557 0.03901 0.00030 0.00000

2.4 0.70645 0.54597 0.36760 0.16399 0.02454 0.00010 0.00000

2.7 0.67642 0.50619 0.32437 0.13081 0.01544 0.00003 0.00000

3.0 0.64767 0.46931 0.28623 0.10435 0.00971 0.00001 0.00000

Donn H. McMahon



Design Point

0.00

0.05

0.10

0.15

0.20

0.25

0.30

0 2 4 6 8

Pressure (1E-6 Torr)

BeamLoss (%)

XTOD Vacuum System Requirements

Average Pressure < 10 -5 Torr

Long Pump life time> 10 yrs

Design Tube Vacuum Level 3x10-6 TorrMax Operating Level 6x10-6 Torr

Ion Pumps Operated below 10 -6 Torr

Specified life time for most ion pumps

@ 10 -6 Torr> 50,000 hrs (~6 yrs)

Specified life time for VacIon Starcell @ 10 -6 Torr> 80,000 hrs (~9 yrs)

Donn H. McMahon



Sketch of 212-m tunnelwith pump locations

57.8’ 116.3’ 57.8’

58.15’

57.8’ 116.3’ 57.8’ 57.8’ 116.3’ 57.3’

58.15’ 58.15’

231.9’24.85’

231.9’ 231.9’

718.5’

38 Flange Joints

VACUUM VALVE

ION PUMP

TURBO PUMP

4” OD tube is in 10ft sections with metal gaskets.At each pump, there are 7” bellows, 4” dia. cross,and gate valve – all joined with metal gaskets.

Donn H. McMahon



Turbo Pump and Support

Varian V70LP Turbo Pump

Bellows

Beam Tube, 4.00” OD X .083” W6” Conflat Flange

Cold Cathode Gauge, MKS 422

4-Way Cross

Support

Varian TriScroll 300 Pump

Valve, VAT Series 48DN 100 (4” ID, 6” Conflat)

Leak Check Valve

Flex Support

Donn H. McMahon



Ion Pump and Support

Varian StarCell 75 Ion Pump

Bellows

Beam Tube, 4.00” OD X .083” W6” Conflat Flange

Cold Cathode Gauge, MKS 422 Rupture Disk

4-Way Cross

Support Flex Support

Donn H. McMahon



Lumped parameter analysisS(L/sec)=Q (Torr-L/sec) / P(Torr)

Total volume = 1603 L

Total area = 6.6x105 cm2 outgassing at

1x10-10 Torr-L/sec/cm2 after 100 hrs

110 - 4” gaskets each leak at 6x10-7 Torr-L/sec

Then Q=1.3x10-4 Torr-L/sec, total gas load

at 100 hrs (50% is from 110

seals)

So for a design pressure of 3x10-6 Torr then

with no conductance loss, S = 44

L/sec

But for a 106-m tube, C = 1 L/sec

so we need multiple pumps

Donn H. McMahon



Pressure history is calculated at eachsubvolume N for 100 hours

Model solves the gas load matrix withN coupled differential equations 4 times

Roughing from 760 to 0.01 Torr for 5 hrsTurbo pumping to below 10-5 Torr for 30 hoursIon pumping in the -6 range to 100 hoursFailure of ion pumps for few minutes

Gas Load Balance: Vn dpn/dt = Qn in – Qn out for n =1,NWhere Qn in = leakage and time-dependent outgassing into n

Qn out = Cnm (Pn -Pm) where m is an adjacent volume Or Qn out = (S Cnp / (S + Cnp) Pn

where Cnp is the conductance between n and the pumpand S (Pn) is the pressure dependent pump speed.

Methodology verified in experimentPressure gauges on APT at LANL verified the predictions

by the Mathematica model that was programmed to fit that geometry

Donn H. McMahon



100 1000 10000 100000

.

Model provides 100 hr historyof pressure at any location

100 hrs311

Scroll

Turbo

Ion

Pressure,Torr

Time, sec

100

1

10-2

10-4

10-6

10-8

Donn H. McMahon



50 100 150 200Z, meters

0.8

1.0

1.2

0.6

0.4

Pressure,10-6 Torr

Pressure profile with 6-75 L/s ion pumps at 100 hrs

For SnomimalTotal = 450 L/s, SnetTotal = 327 L/s

Theory: P=Q/S = 4.1 x10-7 Torr. The best that can be achieved.

Code: Pavg = 8.4 x10-7 Torr. So our design is efficient!

Donn H. McMahon



50 100 150 200Nsv

Permanent turbo pumps can replace failed ion pumps to keep P < 6 x 10-6 Torr

Pmax = 7.2 x 10-6 Torr (above specs)

Pmin = 3.7 x 10-7 Torr

Pmax = 2.2 x 10-6 Torr (within specs)Pmin = 3.2 x 10-7 Torr

Two failedadjacent IPs

2 min

2

5

3

1

seconds0 400 80050 100 150 200Nsv

1

2

0

10-6 Torr 10-6 Torr

2

6

10-6 Torr

4

0Two failed adjacent IPswith middle turbo on

Donn H. McMahon



0

5

10

15

20

25

1 2 3 4 5 6 7

number of working ion pumps

Maxpressure

10-6

Torr3rd

,4th,5

th f

aile

d

2nd,3

rd

4th, 5

th

faile

d

2nd,4

th,5

th f

aile

d1, 2, or 3turbos on

3rd,4

th f

aile

d

Design pressureduring IP failure

Turbo pumps reduce pressure belowdesign even when 4 ion pumps fail

All

wor

king

2nd,4

th f

aile

d

4th f

aile

d

Donn H. McMahon



Six 75 L/s ion pumps meets the reqswith margin and reasonable costs

2 3 4 5 6 7 8 9 10

Number of Ion Pumps

Maximumpressure10-6 Torr

8

6

4

2 Designlimit

Max limit

Single failure,no backup

Normal

2 3 4 5 6 7 8 9 10

To optimize the system, number and pump size wasvaried to keep 450 L/s total nomimal pumping

Donn H. McMahon



The XTOD Work Plan Will Complete the Tunnel and Experimental Hall Mechanical & Vacuum Systems and

the 1st Half of FEE Systems in FY06FYO6 Efforts

Design mechanical and vacuum systems through tunnelDesign FEE up to Diagnostic Package (Fast Valve, Fixed Mask, Slit, Solid & Gas Attenuators, Ion Chambers)Complete conceptual designs for FEL Offset, TEM, Spectrometer, ImagersDesign XTOD Controls systems (details up to FEE Diagnostic Package and the Tunnel)Prototype Efforts for Gas Attenuator, Tunnel Vacuum System, and Total Energy Monitor (TEM)Complete Damage StudyContinue simulation efforts of physics models and to support engineering specificationsPrepare procurement package for all final design systems

FY07,FY08 EffortsFinal Design for FEE- Diagnostic Package and FEL Offset System (Nov 07)Complete XTOD ControlsProcure, Build, Test, and ship all systems to SLAC

(Beneficial Occupancy Dates: FEE-Oct. ’07, NEH-June ’07, Tunnel- Oct ’07, Sept ‘07)Refine simulation models and support commissioning activitiesXTOD Commissioning

Donn H. McMahon



Several Key XTOD Technical Documents/Specifications Have Been Completed

“LCLS Spontaneous Radiation with Reflection along the Beam Line in the Undulator Pipes “, Kirby Fong“The LCLS Gas Attenuator”, D.D. Ryutov“Photoluminescence as a way of non-destructive imaging at the LCLS facility”, D.D. Ryutov“Indirect Imager Requirements”, M. Pivovaroff“SiC Mirror Specifications”, M. Pivovaroff“Commissioning Diagnostics Specifications”, R. Bionta

Donn H. McMahon



Summary

FEE layout has stabilized including FEL Offset System

TTF Damage experiment has been conducted (SiC, B4C )

Significant progress on upstream FEE systems and Tunnel

Prototype efforts on the Total Energy Monitor are yielding promising results

Prototype efforts for Gas Attenuator to begin in November

Controls efforts are keeping pace developing entire XTOD system layouts, alignment of XTOD controls with LCLS standards, and installation of EPICS at LLNL