stewart shen [email protected] october 27, 2005 1 lcls-xtod gas attenuator lcls fac meeting october 27,...
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Stewart Shen
October 27, 2005 1
LCLS-XTOD Gas Attenuator
LCLS FAC Meeting
October 27, 2005
Stewart Shen, Keith Kishiyama and Marty Roeben
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.
Stewart Shen
October 27, 2005 2
Contents
Requirements
Passive Pumping Design
Performance Analysis
Prototype Plan
Project Schedule
Conclusions
Stewart Shen
October 27, 2005 3
Physics Requirements
Be able to reduce the FEL beam intensity by up to
4 orders of magnitude at any energy within the design range (0.8 to 2 keV)
Provide stable, reproducible (to within 1%) attenuation for repeated FEL shots.
Implied Requirements
Provide matched boundary vacuum conditions
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October 27, 2005 4
Use gas to attenuate below 2 keV
Autocad
Gas Attenuator SolidAttenuator
Use Gas
Use Solids
* For a transmission of 10-4
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October 27, 2005 5
Gas Pressure (600 cm)
0
5
10
15
20
25
0 0.5 1 1.5 2 2.5
Photon Energy (KeV)
Pre
ssur
e (T
orr)
Ar
N2
Argon and Nitrogen for 104 Attenuation*
* Based on NIST X-Ray Form Factor, Attenuation, Scattering Tables
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October 27, 2005 6
Nitrogen Pressure Requirements
Required N2 Pressure for Different Attenuation600 cm
0
5
10
15
20
0.0001 0.001 0.01 0.1 1
Attenuation Factor
N2
Pre
ssur
e (T
orr)
1.95 KeV
1 KeV
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October 27, 2005 7
100-cm Design*
Gas Attenuator Design (L=100 cm & A=10000)
0
50
100
150
200
250
300
0.0 0.5 1.0 1.5 2.0 2.5 3.0
Photon Energy (KeV)
Ope
rati
ng N
2 P
ress
ure
(Tor
r)
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October 27, 2005 8
Passive System Design
Physical VariablesChamber Length (3-7.5 m)Overall Length (< 10 m)Aperture (3 mm – 5 mm)# of ports (4- 6)
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October 27, 2005 9
Chamber Length
Overall Length
Pumping (Turbo & Roughing L/s)
Chamber Pressure
Injected Gas (sccm)
Boundary Vacuum Pressure
Design Consideration – Critical Parameters
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October 27, 2005 10
Gas Attenuator Differential Pumping Configurations -Full Scale
Parameter Unit Value Value Configuration Passive 6-port A Passive 6-port B Total Length m 10 8 Gas Chamber Length m 7.50 6.0 Diameter m 0.15 0.15 Port 2 &3 Length m 0.33 0.33 Diameter m 0.15 0.15 Port 4 &5 Length m 0.23 0.23 Diameter m 0.125 0.125 Port 6 &7 Length m 0.23 0.23 Diameter m 0.125 0.125 Total Equivalent Combined Pumping Speed (turbo+scroll)
L/s 720 720
Gas N2 N2 Chamber Pressure for 104 Attenuation
Torr 15.2 19
Max Gas Flow sccm 5053 6276 1st Port Pressure (V2) Torr 0.15 0.19 Last Port Pressure (V7) Torr 1.5x10-6 2.0x10-6
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October 27, 2005 11
10-m 6 port 3-mm Aperture720 L/s Qi = 0 sccm Pump Down
0 150 300 450 600 750 9001 10
81 10
71 10
61 10
51 10
41 10
30.01
0.1
1
10
100
1 103
ChamberPort-2Port-5Port-7
DP-Vacuum
Time (s)
Torr
• Final outgassing rates of 10-9 T-L/s-cm2 is assumed• Scroll Pump Speed vs Pressure is modeled• Turbo Pump Speed vs Pressure is modeled
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October 27, 2005 12
4.298 4.177 tanh 0.469 ln P1
310.673 296.442tanh 0.617 ln P2
Turbo Pumping Speed Modeling
Scroll (Roughing) Pumping Speed Modeling
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October 27, 2005 13
6 port 3-mm Aperture720 L/s Qi = 5053 sccm Normal Operation with N2 Injection
t 0 .01 20
0 4 8 12 16 200
25
50
75
100Nitrogen Gas Flow
Time
T-L
/s Qi t( )
t
0 4 8 12 16 200
25
50
75
100Nitrogen Gas Flow
Time
T-L
/s Qi t( )
t
n 1 10 20000
0 1.25 2.5 3.75 51 10
8
1 107
1 106
1 105
1 104
1 103
0.01
0.1
1
10
100
ChamberPort-2Port-5Port-7
DP-Vacuum
Time (s)
Torr
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October 27, 2005 14
6 port 3-mm Aperture720 L/s Qi = 5053 sccm Normal Operation with N2 Injection
t 0 .01 20
0 4 8 12 16 200
25
50
75
100Nitrogen Gas Flow
Time
T-L
/s Qi t( )
t
0 37.5 75 112.5 1501 10
8
1 107
1 106
1 105
1 104
1 103
0.01
0.1
1
10
100
ChamberPort-2Port-5Port-7
DP-Vacuum
Time (s)
Torr
15.24 Torr
1.5x10-6 Torr
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October 27, 2005 15
PrototypeGas Attenuator Differential Pumping - Passive 3-Port
ConfigurationObjectives
Phase 1
Demonstrate stable control of gas chamber pressure
Validate the vacuum design for intermediate flow
Verify mechanical & thermal stability
Phase 2 (Optional)
Demonstrate stable control of gas chamber pressure
Calibrate the Ion Chamber
Validate the intensity attenuation
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October 27, 2005 16
System ConfigurationPhase-1
Gas Chamber
Port 1,2,3
Scroll
Turbo
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October 27, 2005 17
X-Ray Source Requirements
Within the range of 0.8 – 2 keV
Characteristic Beam
Collimated
Accessible (on site)
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October 27, 2005 18
Soft X-Ray Source @ Bldg. 179Technical Contact: Jim Emig (NTED)Max 10 kV with Be window (~1 mA)
Available after October 05
Power Supply & Vacuum Control
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October 27, 2005 22
Condition Specification Design Parameters Unit Total Length m 3.27 3.27 Pumping Turbo-1 Turbo-2 Turbo-3 Scroll Total Equivalent
L/s 150 60 60 20
290
300 70 70 20
490 Gas N2 N2 Max Gas Chamber Pressure
Torr 20 25
Max Gas Flow sccm 4000 5000 1st Port Pressure (V2) Torr <0.4 <0.2 Last Port Pressure (V4) Torr <3.0x10-6 <1.0x10-6
Prototype System Major Parameters
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October 27, 2005 23
Vacuum Modeling- Pump Down
0 100 200 300 400 500 6001 10
81 10
71 10
61 10
51 10
41 10
30.01
0.1
1
10
100
1 103
ChamberPort-2Port-3Port-4
DP-Vacuum
Time (s)
Torr
• Final outgassing rates of 10-9 T-L/s-cm2 is assumed• Scroll Pump Speed vs Pressure is modeled• Turbo Pump Speed vs Pressure is modeled
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October 27, 2005 24
D t P( )
Qi t( ) Q1 C12 P2
P1
V1
0.25 310.673 296.442tanh 0.617ln P2 2.468 P
2 2 4.298 4.177tanh 0.469ln P
2 0.782 P2
Q2 C231.114 D23 10 P
2P
3
2
1 18.958D23 10
2P
2P
3
1 23.413D23 10
2P
2P
3
P3
P2
C12 P1
P2
V2
Q3 C34 P4
P3
0.1 310.673 296.442tanh 0.617ln P3 2.468 P
3 C23
1.114 D23 10 P2
P3
2
1 18.958D23 10
2P
2P
3
1 23.413D23 10
2P
2P
3
P2
P3
V3
Q4 0.1 310.673 296.442tanh 0.617ln P4 2.468 P
4 C34 P
3P
4
V4
t 0 .01 20
0 4 8 12 16 200
20
40
60Nitrogen Gas Flow
Time
T-L
/s Qi t( )
t0 20 40 60 80 100 120
0
5
10
15
20
25P1- Gas Chamber
Time (s)To
rr
Vacuum Modeling- Gas Injection
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October 27, 2005 25
0 20 40 60 80 100 1201 10
8
1 107
1 106
1 105
1 104
1 103
0.01
0.1
1
10
100
ChamberPort-2Port-3Port-4
DP-Vacuum
Time (s)
Torr
0 20 40 60 80 100 1201 10
8
1 107
1 106
1 105
1 104
1 103
0.01
0.1
1
10
100
ChamberPort-2Port-3Port-4
DP-Vacuum
Time (s)
Torr
0 1 2 3 4 51 10
8
1 107
1 106
1 105
1 104
1 103
0.01
0.1
1
10
100
ChamberPort-2Port-3Port-4
DP-Vacuum
Time (s)
Torr
Vacuum Modeling- Normal Operation with injected N2 gas
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October 27, 2005 26
Prototype Testing Program
Procured Components
Delivery IWS/QA Plan
1 Assembly & Alignment
Facility Readiness
3 N2 Gas Injection Tests
2 Integration in Vacuum
Circuits
4 Log-Term Extended Tests
Repair or Modification Repair
or Modification
tion
Test Plan Alignment & Tolerance
Vacuum control Evacuation Base pressure Gas loads
Leak Check Repair or Modification
Vacuum Control Mass-Flow
Control Base pressure
Gas loads/ Pump speed
Repair or Modification
Mechanical Stability Vacuum Control
Base pressure Gas loads/
Pump speed
Repair or Modification
6 Gas Attenuation Tests (Phase 2)
Data Analysis
Data Analysis
Data Analysis
5 Integration with
Soft X-Ray Source & Ionnization Chamber
(Phase 2)
• Facility Ready (132S RM 1571)• IWS Approved (IWS #12599) • Test Plan prepared• Engineering drawings being prepared• QA Plan prepared
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October 27, 2005 27
MKS Type 649 Electronic Pressure Controller
• Fully integrated baratron, mass flow meter, normally closed proportioning control valve and closed loop proportional/integral control electronics
• Flows to 5000 sccm
• Pressure control + 0.2% of full scale
• Time response – 1 sec (excluding system time constants)
Mass Flow Control
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October 27, 2005 30
LCLS Gas Attenuator Prototype Procurement Cost EstimateVendor Description Part number Unit cost Quantity CostVarian Turbo-V 301 Navigator pump CFF 8" 9698921 $7,775.00 1 $7,775.00Varian Turbo-V 301 Controller, rack mount, 120 vac 9699537 $2,525.00 1 $2,525.00Varian Vent Valve, for standard rack controller 9699843 $665.00 1 $665.00Varian Air cooling kit 9699299 $369.00 1 $369.00Varian Inlet screen DN160 9699304 $129.00 1 $129.00
Varian TriScroll 600 single phase motor, US cord PTS06001UNIV $8,580.00 2 $17,160.00Varian Vacuum pump isolation valve VPI401205060 $675.00 2 $1,350.00
Varian Turbo V70LP Pump CFF 4.5 " 9699366 $4,155.00 2 $8,310.00Varian Turbo V70LP Controller, 120vac 9699505 $1,759.00 2 $3,518.00Varian Vent Valve, for standard rack controller 9699843 $665.00 2 $1,330.00Varian Air cooling kit (V70LP) 9699310 $245.00 2 $490.00Varian Inlet screen DN63 9699300 $65.00 2 $130.00
MKS Type 649 Electronic pressure controller 649A-51T-53C-3-V-T $2,900.00 1 $2,900.00MKS Type 246C Single channel power supply/readout 246C $925.00 1 $925.00MKS Cable connects 649 to 246, 10 feet CB649-1-M1 $55.00 1 $55.00MKS Type 626A Baratron 100 Torr, 8 VCR female 626A12TBE $915.00 5 $4,575.00MKS PDR2000 Digital Power Supply and Readout PDR2000AO $550.00 3 $1,650.00MKS 20 foot cable for Type 626 Baratrons CB2000S-1-M2 $135.00 3 $405.00
Granville-Phillips 370 Stabil-ion Gauge controller 370501-C10-T1 $3,090.00 2 $6,180.00w/ Dual Convectron modulew/ IEEE-488 computer interface module
Granville-Phillips Stabil-Ion Gauge, extended range 370120 $645.00 3 $1,935.00Granville-Phillips Stabil-Ion gauge cable, 25 ft. 360116-25 $205.00 2 $410.00
Leybold Inficon Transpector 2 RGA, C100M TSP2-0211100000 $7,905.00 1 $7,905.00
$70,691.00
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October 27, 2005 31
Conclusions
Gas Attenuator preliminary design is near its completionPrototype design completed and hardware procurement startedProject is on schedule