John Trent [email protected] April 20, 2006 UCRL-PRES-218897 FAC: XTOD Beam Transport X-ray Slit and Tunnel Design Pat Duffy, Kirby Fong, Keith Kishiyama,

John Trent

[email protected]

April 20, 2006 UCRL-PRES-218897

FAC: XTOD Beam Transport

X-ray Slit and Tunnel Design

Pat Duffy, Kirby Fong, Keith Kishiyama, Steve Lewis, Stewart Shen, Pete Tirapelle,

John Trent, Louann Tung

April 20, 2006

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.

John Trent

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XVTS Overall Layout

FEE NEH FEHTunnel

John Trent

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Front End Enclosure (FEE) Configuration

Fast Valve

X-ray Slit

Ion Chamber

Attenuator

Fixed Mask

Diagnostics

Offset Mirrors

John Trent

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X-ray Slit Key Requirements

Defines precision aperture of x-ray laserAble to choose any rectangular area inside clear aperture of fixed mask (45 x 15 mm)

Attenuate spontaneous radiation energy 1000 times

Compatible with high vacuum environment

Opens to clear aperture for diagnostics

Resistant to damage by FEL

John Trent

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X-ray Slits Concept

Fixed Mask ApertureSlit Block

John Trent

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Slit Block Concept

Single block larger than entire aperture of Fixed Mask

70 mm thick block50 mm Heavy Met

Tungsten Alloy

Great attenuation

20 mm Boron CarbideGreat damage resistance

Boron Carbide

Heavy Met

Radiation

Cutting Face

John Trent

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X-ray Slit Concept

Vertical Slit

Horizontal Slit

Stand

Linear Stage

Size (in):

28.62 long (Z)

54.45 wide

81.22 high

John Trent

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Slit Block Support and Cooling

Slit block can be water cooled or air cooledSix DOF adjustment for each slit block: 3 struts, 3 push-pull screw pairsBellows isolate block assemblies from vacuum vesselDesign features borrowed from SSRL

Slit Block

Bellows Strut

Water Cooling

John Trent

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X-ray Slits Features

Slits close to zero aperture, open beyond clear aperture of fixed mask

Slits allow extremely little radiation past that will stop in scintillator

Blocks align to beam direction manually

Negative rake on slit blocks (~3 mrad)Set using alignment features external to vacuum

Blocks are offset in Z – they can’t touch

Compatible with UHV

John Trent

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Slit Pair Remote Motions

Each slit block pair has adjustable degree of freedom

Aperture width – linear stage adjustment

Aperture center – linear stage adjustment

Linear motion specs based on IDC DS4 stage:

50 or 100 mm travel, 1.3 m repeatability

200 lb axial load capacity – 100 lb axial load

John Trent

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Slit Block Assembly Thermal Model – Water Cooling

Heat in: internally generated 1 W input from spontaneous radiationConduct heat through block, interface, and end of Glidcop support rodHeat out: remove by forced convection with waterSteady state model

Qin

Qcond

Qconv

Qout

John Trent

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Thermal Model Results – Water Cooling

Slit block is 1.2 C hotter than cooling water

Rod in contact with water is 0.1 C hotter than cooling water

Total expansion is 0.6 micron due to heating from radiation

Slit block expands 0.5 micron

Support rod expands 0.1 micron

John Trent

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Thermal Model Results – Air Cooling

Slit block is 6 C hotter than ambient

Rod in contact with air is 5 C hotter than ambient air

Total expansion is 4 micron due to heating from radiation

Slit block expands 1.4 micron

Support rod end expands 2.5 micron

John Trent

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Stability

Stability is based on temperature variationRoom temperature effects stand

Incident power effects slit block assembly

PRD gives diurnal room temperature variation of +/- 1 C

1.4 m tall steel stand moves 16.4 microns

Incident power adds 0.3 m for water cooling or 2 m for forced air cooling (plus/minus)

John Trent

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Predicted Stability and Repeatability

Predicted Long-termStability: 17 m (Water), 18.5 m (Air)

Repeatability: 18 m (Water), 19.5 m (Air)

Predicted Short-termStability: 2 m (Water), 3.6 m (Air)

Repeatability: 3.3 m (Water), 4.9 m (Air)

Recommend forced air cooling for simplicity

John Trent

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Vacuum

Ion pump under fixed mask – pumps Fast Valve, Fixed Mask, and X-ray Slit

Single pump is more efficient design

Good conductance 2.7m long section

4 in tube or larger

Gate ValveX-ray SlitFixed

MaskFast

Valve

Ion Pump

John Trent

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Slit Block First Article

The is some risk is in the manufacture of the slit blocks themselves

Bonding of Boron Carbide to Heavy MetTime to produce and yield

Step 1: Use bonding coupons to prove bonding process – coupons are on orderStep 2: Make slit block pair this FY to lessen risk and shorten production timeFirst article to be used in final assembly

John Trent

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Attenuation Simulation – It will work!

After Fixed Mask After Slit at Direct Imager

With slit closed, nothing stops in scintillator plate – full distributionIn fully closed slit simulation – 100,000,000 high energy (1.2 MeV+) photons to slit, 17,260 after slit, zero stopped in scintillator of DI

John Trent

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X-ray Slit Schedule Summary

System Concept Review 1 – 3/1/06

System Concept Review 2 – April ‘06

Preliminary Design Review – July ‘06

Final Design Review – September ‘06

X-ray Slit Available at SLAC – June ‘07

John Trent

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X-ray Tunnel

John Trent

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Key Tunnel Design Requirements

Provides environment to transport x-ray laser

Average vacuum < 1 E-5 Torr

Does not obstruct FEL

Ion pumps to last 10 years

Meets SLAC Seismic Design Standard

Aligns to laser beam-lineVertical and lateral adjustments, at a minimum

John Trent

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Typical Section of Tunnel Beamline

Bellows

Pump Stand with Gate Valve

Beam Tube, 4” OD, 10.5 foot sections

Tube Support Stand

Pump Stand w/ Ion Pump

Bellows

John Trent

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Pump Stand

Stand is designed to support ion or turbo pump, a gate valve, and load from beam-line tubingTop of stand will include features for 5 DOF adjustment (no beamline)Defined lift points – Four threaded holes for swivel lifting eyesAligned using clamp-on fixture

Ion Pump

Pump Cross

Stand

John Trent

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Tube Support Stand

Constrains vertical and lateral motion

5 DOF adjustment (no beamline)

Clamps to tube - beamline adjustment is not required

Aligned using clamp-on fixture

Adjustments

Beamline Clamp

John Trent

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Stress from 2” wide Tube Clamp is Acceptable

Maximum stress: 11200 psi

3600 lb. load from 2 in. clamp using ¼” bolts

Vacuum contributes 350 psi stress (included)

John Trent

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Structural Engineering Inputs

Pump spacingYields stand spacing of approx. 60 ft.

Sections isolated by bellowsComponent weights

Ion pumps, tubing, gate valves, etc.

Accelerations due to seismic loadingFrom SLAC Seismic Design Specification1.6g’s horizontal,1.35 g’s vertical - 2% damping, 17 HzHorizontal acceleration applied in worst case direction – beamline for pump stand, lateral for tube support

John Trent

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Output of Seismic FEA – Pump Stand

Maximum deflections:

0.000” Beamline

0.010” Lateral

0.000” Vertical

Formed bellows allow 0.25” lateral offset

Maximum stress:

18% of allowable stress in

3/4” threaded supports

Per AISC LRFD

First mode 31 Hz

Load applied in lateral and vertical directions

John Trent

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Output of Seismic FEA – Tube Support

Maximum deflections:

0.000” Beamline

0.045” Lateral

0.012” Vertical

Load applied in lateral and vertical directions

Maximum stresses:

13% of allowable stress in Tube Supports

Per AISC LRFD

First mode 16 Hz

John Trent

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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!

Peaks wellwithin designat 3 x 10-6

Life shouldexceed9 yrs here

9 yr life at this pump pressure

John Trent

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Pressure profile and time response with 4th pump failed

Pmax = 3.4 x 10-6 Torr

Pmin = 3.4 x 10-7 Torr

P(4th pump) goes from 3.4 x 10-7 to

3.4 x 10-6 Torr within 2 minutes

Pressure,10-6 Torr

1

2

3

0.5

1

2

0.2

Pressure,10-6 Torr

seconds0 10 100 200 300

2 min

Even with one failed pump,peak pressure is below 6x10-6

and pump pressures are safelyin the -7 range

50 100 150 200Z

John Trent

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100 1000 10000 100000

.

Vacuum 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

John Trent

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Scroll

Turbo

Ion

100 1000 10000secondshrs1.51

Normal pumpdowns will be much faster than 100 hrs

Most optimistic rate of constant10-10 Torr-lit/sec/cm2 is assumed

Pressure,Torr

100

10-2

10-4

10-6

1

600 DS would roughin 30 min vs. 60 min for the 300DS = Volume/Speed

John Trent

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Ethernet

IOC

Gauge Controller

Ion Pump Controller

Vacuum set points and alarms

TunnelGate Valves

Ion Pump

Pirani , CCG

Gate Valve I/O

Eth

erne

t Int

erfa

ce

17

56 E

NE

T

17

94 A

EN

TFlex I/O

EtherNet/IP

Scroll PumpScroll pump control

Vacuum Interlocks

Ser

ial i

nter

face

OPIPC/Linux

Co

ntr

ol L

og

ix

RS-232

RS-232

Magnetic Starter

LCLS XTOD Vacuum System Controls Block Diagram

PC/WindowsRSLogix software

OPIPC/Linux

John Trent

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X-ray Tunnel Schedule Summary

Preliminary Design Review – Complete

Seismic Safety Document – In Review

Final Design Review – May ‘06

Equipment Available at SLAC – July ‘07

Documents

John Trent [email protected] April 20, 2006 UCRL-PRES-218897 FAC: XTOD Beam Transport X-ray Slit and Tunnel Design Pat Duffy, Kirby Fong, Keith Kishiyama,