Transcript ppt

GLAST LAT Project
25 May 2005
LAT Environmental Test Planning and Design
Delta-Preliminary Design Review
25 May 2005
LAT T-Vac Test
Final version: 10 June 2005
Jack Goodman
LAT TVAC Test Delta-PDR
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GLAST LAT Project
25 May 2005
Thermal-Vacuum Test Sequence
Prep Lat
for TVAC
Chamber
Pump Down
Load LAT
into Chamber
Pre-Bake
Hot
Performance
Cold Op
Thermal Control
LAT TVAC Test Delta-PDR
Connect
Instrumentation
Hot Op
T-Balance
Cold Survival
T-Balance
Thermal
Cycling (4)
Hot Op
Thermal Control
Open Door
Checkout
Hot Op
Peak Power
Cold
Performance
Cold Op
T-Balance
Bake Out
Return to
Ambient P&T
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GLAST LAT Project
25 May 2005
Temperature Requirements for Simulated Sink Hardware
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Operating/Performance
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Hot at 40°C
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Cold at 0°C
Thermal Balance
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Hot balance at 30°C
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Cold balance at 0°C
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Cold survival at -2°C
Test Cycle
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Hot soak at 40°C
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Cold soak at 0°C
Test: EGSE Failure/Safe Hold (not relevant to orbit)
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Four TVAC Cycles, 8 Transients
+25°C
Bake out
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+45°C
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GLAST LAT Project
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LAT Surfaces Requiring Thermal Conditioning
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ACD thermal conditioning
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Radiator and X-LAT Plate MLI Blankets (Spacecraft Bus simulator) thermal conditioning
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ACD temperature controlled by thermal sink plates electrically heated with radiation
cooling to TVAC Chamber cold shroud
Spacecraft bus temperature controlled by thermal sink plates electrically heated and
cryogenically cooled
Radiator thermal conditioning – 3 options
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Thermal Control Unit sink plate system
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NRL thermal conditioning system
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Radiator temperature controlled by thermal sink plates heated and cooled with Thermal Control
Units
Radiator temperature controlled by thermal sink plates electrically heated and cryogenically
cooled
Cal Rod cage system
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Radiator temperature controlled by balance of IR heating from Cal Rods and radiation cooling
to TVAC chamber cold shroud
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ACD Thermal Conditioning
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ACD thermal conditioning
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ACD Temperature
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Thermal sink plate requirements
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–
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Dimensions
1.8 m x 1.3 m (approx)
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Temperature
-89 °C to +60 °C
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Temperature Uniformity
+/- 5 °C
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Emissivity
~0.5 (Anodized Al or paint)
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Power Absorption
<20W from ACD (TBD)
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Cycle
none
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Quantity
5
Heating of thermal sink plates is provided by resistive heaters
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Film/strip heaters—built into the plates
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Power supplies—outside chamber with feedback control off of TC’s on plates
Cooling of thermal sink plates is passive radiation cooling to the TVAC chamber cold shroud
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TVAC Chamber Cold Shroud Temperature = -150 °C
Thermal control
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varies: -60°C to +60°C
5 independent heater circuits controlled by chamber CDACS system with feedback on TC temps
Power requirements (includes 20% margin)
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ACD
ACD
ACD
ACD
ACD
+X sink plate: 985 W
+Y sink plate: 625 W
-X sink plate: 625 W
-Y sink plate: 625 W
+Z sink plate: 911 W
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GLAST LAT Project
25 May 2005
Spacecraft Bus Thermal Conditioning
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Spacecraft Bus thermal conditioning
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SC Bus temperature
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Thermal sink plate requirements
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Dimensions
1.6 m x 1.8 m (approx)
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Temperature
-40 °C to +25 °C
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Temperature Uniformity
+/- 5 °C
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Emissivity
>0.85 (Anodized Al or paint)
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Power Absorption
<25W (TBD)
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Cycle
none
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Quantity
3
Heating of thermal sink plates is provided by resistive heaters
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Film/Strip heaters—built into plates
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Power supplies—outside chamber with feedback control off of TC’s on plates
Cooling of thermal sink plates is primarily LN2/GN2 with some radiation loss
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Active cooling supplied by LN2 solenoid valves
Thermal control
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varies: -40°C to +25°C
3 independent heater circuits controlled by chamber CDACS system with feedback on TC temps
Power requirements (includes 20% margin)
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SC Y-side sink plates: 2 @ TBD W
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SC top-deck sink plate: TBD W
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GLAST LAT Project
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Radiator Thermal Conditioning – Option 1
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Option 1 - Thermal Control Unit (TCU) sink plate system
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Radiator Temperature
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Thermal Sink Plate Requirements
-13°C to +2°C (Hot Case orbit average)
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Dimensions
1.65 m x 1.85 m (approx)
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Temperature
-126 °C to +4 °C (Hot transient); -95 °C to -64 °C (Cold transient)
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Temperature Uniformity
+/-2.5 °C (balance); +/-5 °C transient
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Emissivity
>0.85 (Anodized Al or paint)
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Power Absorption
0 W to 800 W max per Plate (includes margin)
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Cycle
92 minutes sinusoidal
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Quantity
2
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Heating and cooling of thermal sink plates is provided by 1 TCU per Radiator
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Thermal control
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1 control zone per Radiator, controlled by TCU
Power requirements
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TBD, rough estimate by 6/15/05
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GLAST LAT Project
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Radiator Thermal Conditioning – Option 2
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Option 2 – NRL Thermal Conditioning System
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Radiator Temperature
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Thermal Sink Plate Requirements
-13°C, +2°C (Hot Case orbit average)
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Dimensions
1.65 m x 1.85 m (approx)
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Temperature
-126 °C to +4 °C (Hot transient); -95 °C to -64 °C (Cold transient)
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Desired Temperature Uniformity
+/- 2.5 °C (balance); +/- 5 °C transient
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Actual Temperature Uniformity
TBD; rough estimate available by 6/1/05
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Emissivity
>0.85 (Anodized Al or paint)
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Power Absorption
0 W to 800 W max per Plate (includes margin)
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Cycle
92 minutes sinusoidal
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Quantity
2
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Heater Power
5 amps per circuit (max)
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Heating of thermal sink plates is provided by resistive heaters built into panels
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Cooling is provided by active cooling supplied by LN2 solenoid valves
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Thermal control
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1 heater/cooling circuit per Rad controlled by chamber CDACS system with feedback on TC temps
Power Requirements
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# of circuits and power per circuit TBD, rough estimate available by 6/15/05
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GLAST LAT Project
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Radiator Thermal Conditioning – Option 3
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Option 3 - CAL Rod Cage System
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Radiator Temperature
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Thermal Sink Cage Requirements
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–
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Dimensions
1.6 m x 1.8 m (approx)
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Temperature Uniformity
+/- 2.5 °C (balance); +/- 5 °C transient
•
Emissivity
>0.38 (sandblasted stainless steel)
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Power Absorption
N/A
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Cycle
92 minutes sinusoidal
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Quantity
2
Heating and cooling
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Radiator temperature control is by balance of radiation loss to TVAC chamber cold shroud (-150
°C) and IR Heating from CAL Rod cage
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IR power from Cal-Rod resistive heating elements
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TVAC Chamber Cold Shroud Temperature = -150 °C
Thermal Control
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-13°C, +2°C (Hot Case orbit average)
3 independent Cal-Rod circuits per Radiator controlled by chamber CDACS system with feedback
from radiometers mounted in front of Radiators
Power Requirements (includes 50% margin)
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2400 W/cage
– Radiator top: ~400 W
– Radiator middle: ~ 1600 W
– VCHP reservoirs: ~400 W
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Trade Study - Radiator Thermal Conditioning
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A trade study of the three Radiator thermal control options was done to establish the optimal
solution
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The results of this show that the Cal-Rod cage system is the preferred implementation
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Baseline: Cal-Rod cage
THERMAL CONTROL UNIT
SYSTEM
Tem p Control System Availability Thermal Control Unit (QTY = 2)
NRL THERMAL CONDITIONING
SYSTEM
CDACS System (QTY = 1)
CALROD SYSTEM
CDACS System (QTY = 1)
Proportional Solenoid Valves (QTY = 2) Calrod Heating Elements (QTY = 22)
Heaters (QTY = TBD, rough estimate by
6/15/05)
Therm al Sink Plates
Radiator Sink Plates/Calrod Box
(QTY = 2)
(QTY = 2)
(QTY = 2)
Temp Uniformity Across Plate
5 °C Steady-State, 10 °C Transient 5 °C Steady-State, 10 °C Transient
5 °C Steady-State, 10 °C Transient
Pow er Absorption (total)
0 W to 800 W (max) - per Plate
0 W to 800 W (max) - per Plate
N/A
Pow er Dissipation to Shroud
Minimal
Minimal
TBD
Max Current
N/A
5 A per Circuit (max)
5 A per Circuit (max)
Pow er Supplies
N/A
(QTY = TBD, rough estimate by 6/1/05)
(QTY = 8)
Pow er Feedthroughs
N/A
(QTY = TBD, rough estimate by 6/1/05)
(QTY = 1)
Pow er Requirements
Req'd TC's/Heat Flux Meters
LAT Support
Test Support
Thermcouple Feedthroughs
Cost
LAT TVAC Test Delta-PDR
See Table 3 of LAT Intrumentation
Plan
See Table 3 of LAT Intrumentation
Plan
TBD
TCU Purchase = $84,250 each
TCU Rental = $100,000 - $120,000
for tw o
Sink Plates = $7,450 each
See Table 3 of LAT Intrumentation Plan
See Table 3 of LAT Intrumentation Plan
TBD
Sink Plates = estimated at $12K each;
true pricing available by 6/15/05
See Table 3 of LAT Intrumentation
Plan
See Table 3 of LAT Intrumentation
Plan
TBD
CAL Rods: $1100 per cage for rods
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GLAST LAT Project
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Option 3 Cal-Rod/Baffle Sensitivity Study
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Basis of study and boundary conditions:
Rad
Temp (C)
0
20
40
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Chamber shroud temperature = -150C
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Panel internal heat gen = 300W
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Panel temp uniformity goal: 5 C
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Size system to maintain Rad temp at 0 C, 20 C, and 40 C
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Stainless steel Cal Rods, 0.25” OD
Power (W)
Per Rod
Total
55
600
100
1100
153
1685
Temperature (C)
Min
Max Spread
-1.4
0.6
2
18.5
21.8
3.3
37.5
42.0
4.5
Results of Thermal Analysis
Results: Cal-rods need 5.6” max spacing 7” set-back from Rad surface
Polished Al Frame
Cal-Rod spacing = 5.6”
Cal-Rod Box
Height = 12”
Cal-Rod Box
Offset = 1.0”
LAT TVAC Test Delta-PDR
Panel Dimensions = ~1.5 x 1.5 m (for the study)
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GLAST LAT Project
25 May 2005
Option 3 Cal-Rod Panel Temperature Distribution
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Option 3 Cal-Rod Cage Heater Circuit Requirements
Transient and steady-state thermal analyses of LAT system shows that the hot-case transient
test case is the defining case for the heater system
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At one extreme of the transient, all 600 W of LAT power is radiated off of one Radiator
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The Cal-Rod cage on the opposite side of the LAT draws the most power at that time
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Max power needed: 1600 W/Radiator
Heater cage requirements and boundary conditions
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Power: 1600 W * 1.5 margin = 2400 W/Rad
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Temp uniformity: 5 degC over surface of Radiator
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Max process power: 300 W (with Cal-Rods operating at full-power)
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Minimum of 3 control zones
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Cold shroud minimum temp: -150 C
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Low-profile/low-mass design to
increase cool-down and warm-up
rates
Calrod Temperature
(°C)
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750
700
650
600
550
500
450
400
350
300
250
200
150
100
50
0
-50
-100
-150
-200
500 W
250 W
100 W
0
1
2
Calrod Dissipation
LAT TVAC Test Delta-PDR
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4
5
6
7
8
9 10 11 12 13 14 15 16 17 18 19 20
Time
(min.)
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GLAST LAT Project
25 May 2005
Option 3 Cal-Rod Cage Heater Circuit Implementation
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Power requirements (includes 50% margin)
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2400 W/cage
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Radiator top: ~400 W
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Radiator middle: ~ 1600 W
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VCHP reservoirs: ~400 W
Cal-Rods
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Heated length of 60 inches
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O.D of 0.25 inches
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Emissivity >0.38 (sandblasted stainless steel)
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Resistance of at least 89 ohms
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Max operating temperature: 750°C
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Min non-operating temperature: -150°C
Cal-Rod Heater
Use standard NRL power supplies
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1000 W max and 5 A max or 240 V max
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Cal-Rod cage will likely be powered by 4 supplies: one for top, one for reservoirs, and two
ganged together for middle zone
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25 May 2005
Summary of Heater Requirements
Sink Location
Radiator11
Radiator21
ACD +X Sink
ACD +Y Sink
ACD -X Sink
ACD -Y Sink
ACD +Z Sink
SC +Y-Side Sink 3
SC -Y-Side Sink 3
SC Top-Deck Sink 3
Test Stand
Equiv Sink Temp
deg C
Min
Max
-77
-77
-76
-89
-79
-89
-82
-40
-40
-40
TBD
-14
-14
60
25
25
25
25
25
25
25
TBD
Htr Pwr2
W/m2
Min
Max
N/A
N/A
36
26
34
26
31
N/A
N/A
N/A
N/A
N/A
342
217
217
217
217
N/A
N/A
N/A
Area Tot Pwr4 Req'd
m2
W
Control
Zones
3.0
3.0
2.4
2.4
2.4
2.4
3.5
3.0
3.0
3.0
2400
2400
985
625
625
625
911
TBD
TBD
TBD
TBD
3
3
1
1
1
1
1
1
1
1
4
1
Note: Cal Rod Cage power for Rad's calc'd based on 4C Rad temp
Note: ACD heater power based on 0.5 plate emissivity and 123K ultimate sink
3
Note: SC sink heater power calc'd based on cryogen temperature and flow rate
4
Note: Tot pwr includes 20% margin on sink plates, 50% margin on Cal-Rod cages
Note: 1000W DC power supply limited to 240 volt or 5 amp
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