Transcript PPT

Concepts for Fabrication of Inertial Fusion Energy
Targets
P. Gobby, A. Nobile, J. Hoffer, A. Schwendt
and W. Steckle
Goal of this work is to evaluate the feasibility of
fabricating targets for an IFE plant at an acceptable cost
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Develop concepts for target fabrication plant:
 Iterate with target designers, agree on acceptable
target materials and tradeoffs
 Evaluate processes for fabrication of targets in large
quantities at low cost
 Evaluate the tritium inventory of a target filling facility
Begin demonstrating synthesis of key target materials.
Evaluate response of the direct drive cryogenic target to the
target chamber during rapid injection
Evaluate capital and operating cost of a target fabrication
facility.
Define issues for future R&D needed to achieve cost goals.
Target fabrication feasibility and cost is being
evaluated for HIF and Direct Drive approaches
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Baseline target for HIF is close-coupled target
 Callahan-Miller, et al.
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Baseline target for Direct Drive is NRL target design
The HIF target has many parts, but only a few different
types of materials
Part
A
B
C
D
E
F
H
I
J
K
L
M
N
O
Close Coupled
Material
Density
DT
0.0003
DT
0.25
Be0.995 Br0.005 1.845
Fe
0.016
(CD2)0.97 Au0.03 0.011
Al
0.070
(CD2)0.97 Au0.03
0.032
AuGd
0.11
AuGd
0.26
AuGd
0.1
AuGd
13.5
Al
0.055
AuGd sandwich 0.1/1.0/0.5
CD2
0.001
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DT (solid and gas)
CH (capsule)
Fe foam
Al foam
Metal-doped CH foam
Metal hohlraum
D2
There are two major approaches in the target
fabrication and filling process for HIF (indirect
drive) targets
hohlraums
Metal foams
Pre-assemble
Final assembly & Inject
CH foams + metals
Fabricate capsules
Fill capsules + layer
OR
hohlraums
Metal foams
Assemble
CH foams + metals
Fabricate capsules
Fill capsules + layer
Inject
Direct drive IFE target fabrication is simple
Fabricate capsules
Fill capsules + layer
Inject
HIF IFE target filling sequence
Assemble
Hohlraum
DT
Diffusion
Fill
Cool
to Cryo
Temps
Evacuate
DT
TSH
DT Ice
Layer
Hohlraum
Cryogenic
Assembly
“Cold Assembly”
Manufacture
Materials
DT Ice
Layer
CAH
Inject
“Warm Assembly”
DT Ice
Layer
Assemble
Hohlraum
DT
Diffusion
Fill
Cool
to Cryo
Temps
Evacuate
DT
TSH
We are using a JIT approach to evaluate minimum
tritium inventory required for the fill process
“Cold Assembly”
Manufacture
Materials
Inject
DT
Diffusion
Fill
Cool
to Cryo
Temps
Evacuate
DT
DT Ice
Layer
Assemble
Hohlraum
DT inventory during filling
DT
Diffusion
Fill
DT pressures during filling
MW  V  Vcapsule 
gfill_outs ide 
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R  Tfill
0
Nfill
Pext ( n) dn
Nfill
Pressure
fill
pressure
MW Vinner 
gfill_inside

R  Tfill 0
P ( n) dn
gfill_TOTAL gfill_outside  gfill_inside
Pressure
{
Nfill = (shot rate) x (fill time)
Po
Time
fill time
Pext, V
Vcapsule
P, Vinner
HIF tritium inventories have been evaluated for fill in
hohlraum and fill before assembly
Theoretical Minimum tritium inventory
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(Actual inventories will be higher)
HIF-fill in
hohlraum
HIF-fill before
assembly
Direct Drive
Buckle Pressure
533 atm
533 atm
.062 atm
Fill Time
4 hours
4 hours
5 days
Tritium Inventory
(beta-layering only)
29.4 kg
1.5 kg
8.9 kg
Tritium Inventory
(beta-layering + IR)
28.9 kg
1.0 kg
8.4 kg
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Cool time - 2 hr
Evac time - 1 hr
 layer time - 8 hr
IR layer time - 2 hr
Fill overpressures
are 75% of buckle
pressure
The above analysis has been performed to evaluate “minimum” tritium inventory
- this allows comparison of inventories for different IFE approaches without
assuming any engineering approach
“Actual” tritium inventories based on real engineering scenarios will be evaluated
in the future
Target fabrication process modeling to produce targets
at capacities necessary for an IFE plant is underway
Capsule Manufacture
Stream Heaters
Input Streams
100 Liter PAMS Mandrel
Polymerization
Reactor
Fluidized Bed
Drier
Ethanol Extraction
PAMS Mandrel/
Water Separator
Shell Water Wash
Water Decant Stream
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Uses existing PAMS/GDP technology that is currently used
to produce ICF capsules.
Existing bench scale processes are being scaled up using
chemical plant design software (Aspen Plus)
Fluidizd Bed
PI or GDP
Coat Capsule
We are attempting to demonstrate fabrication of metaldoped foams
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Foams with composition of (CH)0.97M0.03 are
the current focus. Foam densities of 11 and
32 mg/cc are needed.
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Metals must have the desired x-ray emission
characteristics, acceptable ES&H properties,
as well as chemistry and separation
characteristics that are compatible with the
reactor Flibe and balance of plant.
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We have demonstrated synthesis of
polystyrene foam with a densities of 10 mg/cc
and 32 mg/cc.
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The lower density foam is very fragile.
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We are preparing to conduct experiments to
demonstrate doping of foams with various
metals (Au, W, Ta, Hf, Sc, Re, and Bi) using a
simple wet impregnation technique.
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We have developed a list of candidate
organometallic compounds to be used for
doping studies.
10 mg/cc
Critical issues
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Cold assembly of targets will have to be developed to keep
tritium inventories low.
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Innovative approaches to DT filling will have a large leverage in
reducing tritium inventories.
– Liquid DT injection
– Be foam structural enhancement of capsules
– Improved permeability and strength of capsule materials
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Scale-up of materials fabrication processes is an important
issue.