Transcript ILC Cryogenic Systems (edited to remove cost estimate numbers) Tom Peterson for the cryogenics global group 15 Dec 2006 SLAC Cryogenics Global Group.

ILC Cryogenic Systems
(edited to remove cost estimate numbers)
Tom Peterson
for the cryogenics global group
15 Dec 2006
SLAC
Cryogenics Global Group
1
Active participants in the
cryogenics global group since July
• Tom Peterson (Fermilab) (~1/2 time)
• Jay Theilacker, Arkadiy Klebaner (Fermilab)
(a few hours per week)
15 Dec 2006
SLAC
Cryogenics Global Group
2
Others who have provided input
• Laurent Tavian, Vittorio Parma (CERN) (very active
initially, but recently swamped with LHC work)
• Michael Geynisman (Fermilab)
• Claus Rode, Rau Ganni, Dana Arenius (Jefferson
Lab)
• Bernd Petersen, Rolf Lange, Kay Jensch (DESY)
• John Weisend (SLAC)
• Kenji Hosoyama (KEK), co-leader of global group,
has not had time to become involved yet
• Others …
– Industrial contacts, TESLA TDR
15 Dec 2006
SLAC
Cryogenics Global Group
3
ILC cryogenic system definition
• The cryogenic system is taken to include cryogen
distribution as well as production
– Cryogenic plants and compressors
• Including evaporative cooling towers
– Distribution and interface boxes
• Including non-magnetic, non-RF cold tunnel components
– Transfer lines
– Cryo instrumentation and cryo plant controls
• Tunnel cryo controls are in the ILC controls estimate
• Production test systems will also include significant
cryogenics
– We are providing input to those cost estimates
15 Dec 2006
SLAC
Cryogenics Global Group
4
15 Dec 2006
SLAC
Cryogenics Global Group
5
Electron side
Pre-accelerator
Baseline
Configuration
Layout
Positron side
Beam
delivery
Electron linac
Positron linac
Keep-alive
Booster
RTML
RTML
Crab-cavity
Final doublet
Cryo-unit
Undulator
DR cavities
DR wigglers
Damping
ring
Damping
ring
Electron side
Electron linac
Reference
Design
Layout
Positron side
Booster
Pre-accelerator
Positron linac
RTML
RTML
Undulator
Keep-alive
Crab-cavity
Final doublet
DR wigglers
Beam
delivery
Cryo-unit
DR cavities
Damping
ring
Legend:
2 K cryoplants
4.5 K cryoplants
Distribution boxes
Transfer lines
15 Dec 2006
SLAC
Cryogenics Global Group
6
ILC RF cryomodule count
8-cavity
1 quad
282
278
18
18
11
12
2
9-cavity
no quad
564
556
30
30
8-cavity
2-quad
6-cavity
6-quad*
Cryomodules
Total 1300 MHZ
Main Linac e846
Main Linac e+
834
RTML e48
RTML e+
48
e- source
6
4
21
e+ booster
6
4
22
e+ Keep Alive
2
e- damping ring
e+ damping ring
TOTAL
621
1180
12
8
1821
* I would make these 3 cavities and 3 quads per module and double the number of modules
650 MHZ
16
16
32
• Above are installed numbers, not counting
uninstalled spares
15 Dec 2006
SLAC
Cryogenics Global Group
7
ILC superconducting magnets
• About 640 1.3 GHz modules have SC
magnets
• Other SC magnets are outside of RF modules
– 290 meters of SC helical undulators, in 2 - 4
meter length units, in the electron side of the
main linac as part of the positron source
– In damping rings -- 8 strings of wigglers (4
strings per ring), 10 wigglers per string x 2.5 m
per wiggler
– Special SC magnets in sources, RTML, and
beam delivery system
15 Dec 2006
SLAC
Cryogenics Global Group
8
Major cryogenic distribution components
• 6 large (2 K system) tunnel service or “distribution” boxes
– Connect refrigerators to tunnel components and allow for
sharing load between paired refrigerators
• 20 large (2 K) tunnel cryogenic unit “feed” boxes
– Terminate and/or cross-connect the 10 cryogenic units
• ~132 large (2 K) string “connecting” or string “end” boxes of
several types
– Contain valves, heaters, liquid collection vessels,
instrumentation, vacuum breaks
• ~3 km of large transfer lines (including 2 Kelvin lines)
• ~100 “U-tubes” (removable transfer lines)
• Damping rings are two 4.5 K systems
– Various distribution boxes and ~7 km of small transfer lines
• BDS and sources include transfer lines to isolated components
• Various special end boxes for isolated SC devices
15 Dec 2006
SLAC
Cryogenics Global Group
9
XFEL linac cryogenic components
This slide from XFEL_Cryoplant_120506.ppt
by Bernd Petersen
‚regular‘ string connection box
End-BOX
The ILC string
end box concept
is like this -- a
short, separate
cryostat
Cool-down/warm-up
JT
Feed-Box
Bunch Compressor
Bypass Transferline
(only 1-phase helium)
15 Dec 2006
SLAC
Cryogenics Global Group
The ILC cryogenic
unit service boxes
may be offset from
the beamline,
reducing drift space
length, with a
concept like this.
10
XFEL Bunch-Compressor-Transferlines
This slide from XFEL_Cryoplant_120506.ppt by Bernd Petersen
The cryogenic unit service boxes may be offset from the
beamline as shown, but they would be larger. Drift space is
reduced to about 2 meters on each end plus warm drift space.
15 Dec 2006
SLAC
Cryogenics Global Group
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TTF cold-warm transition ~ 2 m
Cryogenic lines
End module
Structure for
vacuum load
Warm beam pipe
15 Dec 2006
SLAC
Cryogenics Global Group
12
ILC cryogenic plant size summary
A rea
N umber of plants
M ain L inac + RT M L
Sourc es
D amping Rings
BD S
TO TA L
1 0 .0 0
2 .0 0
2 .0 0
1 .0 0
I ns talled
plant s ize
(eac h)
(M W)
4 .3 5
0 .5 9
1 .2 6
0 .4 1
I ns talled
total power
(M W)
4 3 .5 2
1 .1 8
2 .5 2
0 .4 1
O perating
power
(eac h)
(M W)
3 .3 9
0 .4 6
0 .8 8
0 .3 3
47.63
O perating
total power
(M W)
3 3 .9 1
0 .9 2
1 .7 6
0 .3 3
36.92
• TESLA 500 TDR for comparison
–
–
–
–
15 Dec 2006
5 plants at ~5.15 MW installed
2 plants at ~3.5 MW installed
Total 32.8 MW installed
Plus some additional for damping rings
SLAC
Cryogenics Global Group
13
Cryoplants compared to TESLA
• Why more cryo power in ILC than TESLA?
– Dynamic load up with gradient squared (linac
length reduced by gradient)
– Lower assumptions about plant efficiency, in
accordance with recent industrial estimate, see
table below
Cry oplant coef f icient of perf ormance (W/W)
40 K - 80 K
5K-8K
2K
TESLA TDR:
17
168
588
XFEL:
20
220
870
Industrial est:
16.5
200
700
ILC assumption:
16.4
197.9
703.0
15 Dec 2006
SLAC
Cryogenics Global Group
14
Items associated with plants
• Compressor systems (electric motors, starters,
controls, screw compressors, helium purification,
piping, oil cooling and helium after-cooling)
• Upper cold box (vacuum-jacketed heat exchangers,
expanders, 80 K purification)
• Lower cold box (vacuum-jacketed heat exchangers,
expanders, cold compressors)
• Gas storage (large tank “farms”, piping, valves)
• Liquid storage (a lot, amount to be determined)
15 Dec 2006
SLAC
Cryogenics Global Group
15
Main Linac
• The main linac cryoplants and associated equipment
make up about 60% of total ILC cryogenic system
costs
• Main linac distribution is another 20% of total ILC
cryogenic system costs
– About half of that is 132 string connecting boxes
• Total is about 80% of ILC cryogenic system costs
attributable to the main linac
• The following slides describe some of the main linac
cryosystem concepts
– Will focus on main linac, then follow with about 1 slide
each for the other areas
15 Dec 2006
SLAC
Cryogenics Global Group
16
Main Linac Layout
modules
RF unit (lengths in meters)
without
quad
12.652
RF unit
RF unit RF unit RF unit end box
37.956
37.956 37.956 37.956 2.500
twelve modules plus string end box
string (vacuum length)
possible segmentation unit
Cryogenic Unit
(16 strings)
without
with
quad
quad
12.652
12.652
three modules
string
string
string
string
154.324 154.324 154.324 154.324
48 modules
(segmentation box is the same as string end
box (2.5 m) and all contain vacuum breaks)
service
service
box end segment segment segment segment box end
2.500 617.296 617.296 617.296 614.796 2.500
(1 cryogenic unit = 192 modules = 4 segments*48 CM
with string end boxes plus service boxes.)
2471.7 meters
15 Dec 2006
SLAC
Cryogenics Global Group
17
Main Linac Layout - 2
BC1
SC
3
warm
solenoids modules space
Electron linac
RTML BC2
4 strings
16 RF units
warm
space
~300 m
619.8
~200 m
10 strings
40 RF units
1545.7
warm
drift
space
7.652
16 strings
64 RF units
2471.7
~1300 m
1549.6
~2840 m total cryogenic unit length with RTML
Cryogenic plant locations
5536.2
CU-7b
171 modules and a few SC solenoids
including RTML and 500 m of transfer lines
Cryogenic loads
undulator region
warm
drift
space
7.652
14 strings
56 RF units
2163.0
warm
space
600
supercon
magnets
290.0
warm
space
367
13 strings
2 short string
58 RF units
2241.4
approx 5540
shaft spacing
CU-7a
192 modules
warm
drift
space
7.652
16 strings
64 RF units
2612.3
3056.9
5536.2
space
for
3.50%
more
2471.7
368.6
2475.5
400.0
5087.8
5540
shaft spacing
CU-5b
168 modules
plus undulator
magnets
15 Dec 2006
2479.3
Shaft 7
and cryogenic plants
(start of main linac)
warm
drift
space
7.652
SLAC
Shaft 5
and cryogenic plants
approx 5100
shaft spacing
CU-5a
174 modules
including 12 energy
recovery modules
Cryogenics Global Group
Shaft 3
and cryogenic plants
(end of main linac)
CU-3b
192 modules
18
Main linac modules
• Maintain liquid level in
helium vessels over a
154 m string length
• Pipes sized for pressure
drops in 2.5 km
cryogenic unit
• Very limited cryogenic
instrumentation
15 Dec 2006
SLAC
Cryogenics Global Group
19
Module predicted heat loads
Cryomodule
• Heat loads
scaled from
TESLA
estimates
• Heat load
estimates still
need
quantitative
evaluation of
uncertainty
Temperatur e Level
Supports
Input coupler
HOM coupler (cables)
HOM absorber
Beam tube bellows
Current leads
HOM t o st ructure
Coax cable (4)
Instrumentation t aps
Static, dy namic sum
2K Sum [W]
Static, dy namic sum
5K Sum [W]
SLAC
ILC 9-8-9
Static
Dy namic
2K
RF load
Static, dy namic sum
40K Sum [W]
15 Dec 2006
TESLA
Static
Dy namic
2K
4.95
0.60
0.76
0.01
0.14
0.14
0.27
0.02
0.24
0.04
7.45
0.60
0.55
0.01
0.14
0.28
1.68
0.05
0.07
1.67
9.0
11. 4
5K
5K
11. 32
4.62
10. 56
15. 1
40K
40K
87. 89
162.1
9.75
4.58
15. 9
74. 23
Cryogenics Global Group
7.30
0.05
0.07
1.70
0.16
0.19
0.02
0.36
0.28
1.28
59. 19
98. 50
157.7
20
Cryogenic unit parameters
Predicted module static heat load
Predicted module dynamic heat load
Number of modules per cryo unit (8-cavity modules)
Non-module heat load per cryo unit
Total predicted heat per cryogenic unit
Heat uncertainty f actor on static heat (Fus)
Heat uncertainty f actor on dynamic heat (Fud)
Heat load per cryogenic unit including uncertainty
Mass f low per cryogenic unit including uncertainty
Weighted ideal pow er
Ef f iciency (f raction Carnot)
Ef f iciency in Watts/Watt
Operating pow er including uncertainty
(W/module)
(W/module)
(kW)
(kW)
(kW)
(g/s)
(kW)
(W/W)
(kW)
40 K to 80 K 5 K to 8 K
2K
59.19
10.56
1.70
98.50
4.58
9.75
192.00
192.00 192.00
1.00
0.20
0.20
31.28
3.11
2.40
1.10
1.10
1.10
1.10
1.10
1.10
34.40
3.42
2.64
164.87
106.63 127.66
158.43
162.35 407.84
0.28
0.24
0.22
16.45
197.94 702.98
565.83
676.46 1853.84
Overcapacity f actor (Fo)
Overall net cryogenic capacity multiplier
Heat load per cryogenic unit including Fus, Fud, and Fo (kW)
Installed pow er
(kW)
Installed 4.5 K equiv
(kW)
Installed 4.5 K equiv per unit length
(W/m)
Percent of total pow er at each level
Total operating pow er f or one cryo unit including uncertainty f actor (MW)
Total installed pow er f or one cryo unit (MW)
Total installed 4.5 K equivalent pow er f or one cryo unit (kW)
Fraction of largest practical cryoplant per cryogenic unit
15 Dec 2006
SLAC
Cryogenics Global Group
1.40
1.54
48.17
792.16
3.62
1.46
0.18
1.40
1.40
1.54
1.54
4.78
3.69
947.04 2595.37
4.33
11.86
1.75
4.80
0.22
0.60
3.72
4.33
19.80
0.79
21
CERN LHC capacity multipliers
• We have adopted a modified version of the
LHC cryogenic capacity formulation for ILC
• Cryo capacity = Fo x (Qd x Fud + Qs x Fus)
– Fo is overcapacity for control and off-design or
off-optimum operation
– Qs is predicted static heat load
– Fus is uncertainty factor static heat load
estimate
– Fud is uncertainty factor dynamic heat load
estimate
– Qd is predicted dynamic heat load
15 Dec 2006
SLAC
Cryogenics Global Group
22
Heat Load evolution in LHC
Basic Configuration: Pink Book 1996
Design Report: Design Report Document 2004
Temperature
level
Heat load increase
w/r to Pink Book
Main contribution to the increase
50-75 K
1,3
Separate distribution line
4-20 K
1,3
Electron-cloud deposition
1,9 K
1,5
Beam gas scattering, secondaries,
beam losses
Current lead
cooling
1,7
Separate electrical feeding of MB, MQF
& MQD
At the early design phase of a project, margins are needed
to cover unknown data or project configuration change.
15 Dec 2006
SLAC
Cryogenics Global Group
23
Cryogenic unit length limitations
• 25 KW total equivalent 4.5 K capacity
– Heat exchanger sizes
– Over-the-road sizes
– Experience
• Cryomodule piping pressure drops with 2+ km
distances
• Cold compressor capacities
• With 192 modules, we reach our plant size limits,
cold compressor limits, and pressure drop limits
• 192 modules results in 2.47 km long cryogenic
unit
• 5 units (not all same length) per 250 GeV linac
– Divides linac nicely for undulators at 150 GeV
15 Dec 2006
SLAC
Cryogenics Global Group
24
Source cryogenics
• Electron source
– 21 modules, about half special with extra
magnets, assembled as two strings
– SC spin rotator section, 50 m long
• Positron source
– 22 modules, about half special with extra
magnets, assembled as two strings
– Undulator cryo in Main Linac
– Overall taken as same load as electron side
• Costed as separate cryoplants, but may at
least share compressors with pts 2 and 3.
15 Dec 2006
SLAC
Cryogenics Global Group
25
RTML
• Included in Main Linac layout as a cryogenic
unit cooled from pts 6 and 7
• Cost of refrigeration scaled like 2 K heat
loads
Note on dividing costs between RTML and Main Linac
Heat loads for transfer lines like module static, so 15% of module
3 modules in BC1 plus 3*15 modules in BC2
500 m of transfer lines = 75 m of modules = 6 modules
Count SC solenoids as one module for equivalent heat
RTML total modules =
Fraction of ML total =
15 Dec 2006
SLAC
55 modules equivalent heat load
0.065
Cryogenics Global Group
26
RTML BC2 follows main linac pattern
RTML
(updated to show standard RF units, one quad in three modules)
modules
RF units (module lengths in meters)
without
quad
12.652
with
quad
12.652
without
quad
12.652
standard
RF unit
without
quad
12.652
with
quad
12.652
without
quad
12.652
standard
RF unit
1 quad
1 quad
1 quad
1 quad
RF unit
RF unit
RF unit
RF unit
end box
37.956
37.956
37.956
37.956
2.500
Standard strings with 4 RF units plus end box
(short string with 3 RF units plus end box)
strings
BC2 modules in RTML
service box
2.500
x4
short
string
string
string
string
154.324
154.324
154.324
116.368
15 RF units plus string end boxes plus 1 service box
(String end boxes all contain vacuum breaks)
RTML BC2
581.8
15 Dec 2006
SLAC
Cryogenics Global Group
27
Damping ring cryogenics
e- RF module
e+ RF module
(one c avity per module)
Static 4 .5 K heat per module or magnet (W)
D ynamic 4 .5 K heat per module or magnet (W)
4 .5 K liquid per pair wiggler c urrent leads (g/s )
N umber of modules or magnets per s tring
T otal 4 .5 K heat per s tring (W)
T otal 4 .5 K liquid per s tring (g/s )
N umber of s trings per ring
N umber of modules or magnets per ring
3 0 .0
4 0 .0
3 0 .0
4 0 .0
9
6 3 0 .0
9
6 3 0 .0
2
1 8 .0
2
1 8 .0
N umber of s trings per c ryoplant
T otal 4 .5 K heat per c ryoplant (W)
T otal 4 .5 K liquid per c ryoplant (g/s )
1
6 3 0 .0
Static 7 0 K heat (W)
D ynamic 7 0 K heat (W)
N umber per s tring
T otal 7 0 K heat per s tring (W)
N umber of s trings per c ryoplant
T otal 7 0 K heat per c ryoplant (W)
5 0 .0
1 0 .0
9
5 4 0 .0
1
5 4 0 .0
e- wiggler
e+ wiggler
(2 .5 meters ) (2 .5 meters )
5 .0
0 .0
0 .0 1
20
1 0 0 .0
0 .2
4
8 0 .0
5 .0
0 .0
0 .0 1
20
1 0 0 .0
0 .2
4
8 0 .0
1
6 3 0 .0
2
2 0 0 .0
0 .4
2
2 0 0 .0
0 .4
5 0 .0
1 0 .0
9
5 4 0 .0
1
5 4 0 .0
5 0 .0
0 .0
20
1 0 0 0 .0
2
2 0 0 0 .0
5 0 .0
0 .0
20
1 0 0 0 .0
2
2 0 0 0 .0
N otes :2 c ryoplants total for damping rings
• Result is two cryoplants each of total capacity
equivalent to 4.5 kW at 4.5 K.
15 Dec 2006
SLAC
Cryogenics Global Group
28
e+
shaft/large cavern A
short straight A (249 m)
wiggler
RF cavities
Arc 1 (818 m)
Arc 2 (818 m)
short straight B (249 m)
wiggler
Arc 3 (818 m)
long straight 1 (400 m)
injection
long straight 2 (400 m)
small cavern 1
small cavern 2
Arc 4 (818 m)
Arc 6 (818 m)
short straight D (249 m)
wiggler
Arc 5 (818 m)
15 Dec 2006
SLAC
extraction
RF cavities
wiggler
short straight C (249 m)
shaft/large cavern C
A. Wolski, 9 Nov 2006
Cryogenics Global Group
29
Beam delivery system cryogenics
• Crab cavities (3.9 GHz) at 1.8 K plus magnets
– Not including detector cooling nor moveable magnets
• 80 W at 1.8 K ==> 4 gr/sec liquefaction plus roomtemperature pumping
• In total for one 14 mr IR
– 4 gr/sec at 4.5 K
– 400 W at 4.5 K
– 2000 W at 80 K
• Overall capacity equivalent to about 1.9 kW at 4.5 K
for one plant cooling both sides of one IR
– Similar in size and features to an RF test facility
refrigerator
15 Dec 2006
SLAC
Cryogenics Global Group
30
ILC cryogenic system inventory
Volumes
One module
String
Cryogenic unit
ILC main linacs
12 modules
16 strings
2x5 cryo units
Helium
(liquid liters
equivalent)
372.9
4,474.5
67,862.5
678,998.2
Tevatron
equivalents
LHC Inventory cost
equivalents
(K$)
0.1
1.1
11.3
13.42
203.59
2036.99
0.1
0.9
Since we have not counted all the cryogenic subsystems
and storage yet, ILC probably ends up with a bit more
inventory than LHC
15 Dec 2006
SLAC
Cryogenics Global Group
31
Cryogenic system design status
• Fairly complete accounting of cold devices with heat
load estimates and locations
– Some cold devices still not well defined
– Some heat loads are very rough estimates
• Cryogenic plant capacities have been estimated
– Overall margin about 1.54
– Main linac plants dominate, each at 20 kW @ 4.5 K equiv.
• Component conceptual designs (distribution boxes,
end boxes, transfer lines) are still sketchy
– Need these to define space requirements and make cost
estimates
– Used area system lattice designs to develop transfer
line lengths and conceptual cryosystem layouts
15 Dec 2006
SLAC
Cryogenics Global Group
32
Decisions still pending
• Features for managing emergency venting of helium
need development effort
– Large vents and/or fast-closing vacuum valves are
required for preventing overpressure on cavity
– Large gas line in tunnel?
– Spacing of vacuum breaks
• Helium inventory management schemes need more
thought
• Consider ways to group compressors, cooling towers,
and helium storage so as to minimize surface impact
– New ILC layout with central sources and damping rings
may provide significant opportunities for grouping at
least of compressors, which are major power and water
users and have the most visible surface impact.
15 Dec 2006
SLAC
Cryogenics Global Group
33
Basis for the cost estimate
C ost Basi s
1 Recent Linde ILCT A plant est imat e, CERN experience and dat a provided in, ÒEconomies of Large
Helium Cryogenic Syst ems: Experience from Recent P roject s at CERN,Ó S. Claudet , et . al., and a
recent indust rial cost estimat e for a large cryoplant
2 2 K cold box and cold compressor costs included in cryoplant est imat e
3 CERN: 20 bar warm gas storage at $330 per kg, store half
4 CERN/Fermilab: Liquid helium st orage at $150 per kg, based on 10,000 gallon dewars, store half.
Also need small cryoplant for vapor recovery, not costed yet .
5 Fermilab, AD Cryo: est imate from 2003 USLC study
6 Fermilab helium cost s: $1500/500 lit ers so $3/lit er
7 Linde est imat es 15% of plant cost for inst allat ion
8 Fermilab est imat e: $400 K each for a st ring box wit h vacuum break, valves, inst rument at ion included
9 Fermilab est imat e: $500 K each for a 4.5 K dist ribution, feed, or end box fully inst rument ed
10 Fermilab est imat e: $1 M each for a 2 K dist ribut ion, feed, or end box for main linac st yle cryomodules, fully in
11 CERN and Fermilab: $8000/met er for large (600 mm OD vac jacket ) t ransfer line (inst alled cost )
12 Scaled from recent Fermilab CHL cooling t ower replacement
13 Fermilab: $1000/met er for 4 K T -line.
14 CERN/Fermilab: Stainless st eel pipe inst alled cost s based on recent pipe procurement wit h inst alled
cost = 2.5 x mat erial cost (reference document (T om P et erson): P ipeP rices.xls)
15 $1M for cont rols for a large cryogenic syst em based on recent Linde ILCT A budget ary quot e
16 Fermilab liquid nit rogen syst em procurement for Magnet T est Facilit y
17 Fermilab: indust rial quot es for similarly sized room-temperat ure pumps
15 Dec 2006
SLAC
Cryogenics Global Group
34
Cost estimate: Cryoplant
• CERN provided a large cryoplant cost estimate last
summer
– Scaling LEP/LHC plants based on equivalent 4.5 K
capacity to the power^0.6, which is commonly used and
documented in LHC-PR-317 and other review papers
• In another estimate, I also used LHC-PR-317 -convert plant capacity to 4.5 K equivalent and scale
by capacity^0.60.
– Added cold compressor costs separately in a different
way using some information from other papers
– Got a 10% higher result
15 Dec 2006
SLAC
Cryogenics Global Group
35
CERN report -- LHC-PR-391
• LHC-PR-391 rovides a more detailed
cryoplant cost scaling formulation than the
power^0.6 which is commonly used and
reported in LHC-PR-317.
• Incorporates cost estimates of features
unique to large 2-Kelvin cryoplants
• Also provides a slightly higher result
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More recent plant cost estimates
• Problem: two recent Linde cryogenic plant estimates imply that
one needs another 1.5 factor beyond cost-of-living for scaling up
costs from the 1990’s LEP/LHC experience to current costs
– One industrial estimate was for our relatively small ILCTA test
area cryoplant at Fermilab
– The other was an estimate for a very large plant for Cornell’s
ERL concept
• Why would scaling from mid-1990’s by inflation and currency
conversion differ from current industrial estimates by 1/1.5?
– Many costs have increased faster than average inflation.
• Labor costs have increased since 1998 by 1.24 (Dept of Labor, Bureau
of Labor Statistics)
• Carbon steel up by 1.5 to 1.8 (http://metals.about.com/)
• Stainless steel up by 1.44 through 2005 (CRU steel price index,
http://www.cruspi.com/).
– The recent industrial estimates were both severely scaled to
get to ILC plant size -- could have introduced errors
– Multiple plant procurement, like LHC or ILC plants, may save
via some significant non-recurring costs such as engineering.
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Linde comments
•
I asked Linde Cryogenics about our scaling of costs from their ILCTANML test plant estimate, the small plant for Fermilab. They confirm that
our simple scaling may underestimate the large plant costs.
– The refrigeration requirements for the SRF test facility are relatively
small and simple compared to the refrigeration requirements and
complexity of the ILC project
– The recycle compressors & the vacuum screw compressors as used
for the SRF test facility are basic Kaeser compressors. Industrial
compression systems for recycle and vacuum compression for ILC are
much higher in price!
– Large refrigeration systems, as required for ILC, need to be distributed
in two or more (shielded) cold boxes. This requires additional
equipment and transfer lines.
– For large systems, usually more instrumentation and sophisticated
control mechanisms are required by the costumer.
– All these points are cost drivers which need to be carefully reviewed
and taken into account for extrapolation for larger refrigeration
systems.
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Plant cost conclusion
• I averaged these estimates as follows:
– 75% (CERN initial estimate last summer)
– 95% (my best scaling from CERN experience and
various documents)
– 130% (scaled from Cornell industrial study of a large
plant)
– Conclusion: 100% +/- 25%
• Gives an uncertainty +/- 25%, on the total for 10 plants
• +/- 10% on the system total cost due to plant uncertainty
• An industrial cryogenic plant cost study specifically
for ILC main linac plants would be useful. We should
do one as part of TDR effort for both technical input
and cost input.
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Cryogenic boxes cost basis
• Long history of Fermilab and CERN cryogenic box
procurements from industry
• TESLA Test Facility feedbox was designed and built
at Fermilab
– And we kept detailed cost records
• We have much cost history, but non-standard custom
designs which are only conceptual right now adds to
the cost uncertainty
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Laboratory labor estimate basis
• Based on SSCL cryogenic department
personnel counts in March 1991 and April
1992
– With some judgments about fraction of staff
working on system design as opposed to
string test and local R&D efforts
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Cost Roll-Up Status
• Main linac and RTML cost estimates complete
– But some rather rough estimates could be refined
– Particularly, distribution and tunnel box concepts need
more conceptual design work for better cost estimates
• Main Linac and RTML cryogenic systems are
combined with costs attributed by ratio of number of
modules in each
• Damping ring plants have been sized and estimated
• Source and beam delivery cryogenic system
concepts are still sketchy but amount to only about
12% of total system costs
• Judge overall +/- 25% for cryosystem estimate for
reasons similar to plant estimate uncertainty plus lack
of design detail for tunnel cryogenic boxes
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Possibilities for Cost Reductions
• Cryomodule / cryogenic system cost trade-off studies
– Additional 1 W at 2 K per module ==> additional capital
cost to the cryogenic system of $4300 to $8500 per
module (depending on whether we scale plant costs or
scale the whole cryogenic system). (5 K heat and 80 K
heat are much cheaper to remove than 2 K.)
– Additional 1 W at 2 K per module ==> additional installed
power of 3.2 MW for ILC or $1100 per year per module
operating costs.
– Low cryo costs relative to module costs suggest that an
optimum ILC system cost might involve relaxing some
module features for ease of fabrication, even at the
expense of a few extra watts of static heat load per
module.
• For example, significant simplification of thermal shields, MLI
systems, and thermal strapping systems
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Towards the TDR
• Continue to refine heat load estimates and required plant sizes
• Refine system layout schemes to optimize plant locations and
transfer line distances
– Particularly for the sources, damping rings, and beam delivery
system
– Develop cryogenic process, flow, and instrumentation
diagrams and conceptual equipment layouts
• Develop conceptual designs for the various end boxes,
distribution boxes, and transfer lines
• Refine liquid control schemes so as to understand use of
heaters and consequent heat loads (allowed for in Fo = 1.4)
• Consider impact of cool-down, warm-up and off-design
operations
• Evaluate requirements for loss-of-vacuum venting
• Contract with industry for a main linac cryogenic plant
conceptual design and cost study (which will also feed back to
system design)
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