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Top level overview of target fabrication tasks. Presented by Dan Goodin at the. High Average Power Laser Program Workshop Princeton Plasma Physics Laboratory October 27 and 28, 2004. Summary - target fabrication. What are we trying to do in Phase I? What is the target design? - PowerPoint PPT Presentation
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Top level overview of target fabrication tasks
High Average Power Laser Program Workshop
Princeton Plasma Physics Laboratory
October 27 and 28, 2004
Presented by
Dan Goodin
at the
1. What are we trying to do in Phase I?
2. What is the target design?
3. What are the basic target specifications?
4. How is the target fabricated?
5. What are the remaining issues?
6. What’s being done to address the issues?
Summary - target fabrication
1. Develop mass production methods to fabricate cryogenic DT targets that meet the requirements of the target design codes and chamber design. Includes characterization.
2. Combine these methods with established mass production costing models to show targets cost will be less than $0.25.
What are we trying to do in Phase I?
Address issues about the feasibility of the laser fusion target supply
Phase I goals for target fabrication:
A 1000 MW(e) power plant will operate at about 6 Hz - about 500,000 targets per day.
Some Expected Direct Drive Specifications
Capsule Material CH (DVB) foam
Capsule Diameter ~4-5 mm
Capsule Wall Thickness ~260 m
Foam shell density 100-120 mg/cc
Out of Round <1% of radius
Non-Concentricity <1% of wall thickness
Shell Surface Finish ~20 nm RMS
Ice Surface Finish <1 m RMS
Temperature at shot ~15 - 18K
Positioning in chamber ± 5 mm
Alignment with beams <20 m
What is the target design and what are the requirements?
(A) “Baseline” Direct Drive High
Gain Target Design
Divinyl benzene foam shellPolyvinyl phenol overcoatAu/Pd “reflector” on top
1. Baseline target (18K): <0.68 W/cm2 (970C and no gas)
2. Foam-insulated: <3.7 W/cm2 (970C and 12.5 mtorr @ 4000K)
3. Foam-insulated (16K): <9.3 W/cm2 (970C and 40 mtorr @ 4000K)
DT gas
DT solid
DT + foam
Insulating foam
Permeation barrier
~1 m fill holes
(B) “Backup” target with
additional “dry” foam to provide
insulation
Au and/or Pd on top
Foam-insulated target is thermally robust
Pressure cell
Micro-encapsulation and/or sputter coating (Be)
Synergism with ICF programs and decades of R&D
Fabricate Capsules
Fabricate Capsules
DT Fuel Fill
DT Fuel Fill
DT Fuel Layer
DT Fuel Layer
Fabricate hohlraum or sabot
Fabricate hohlraum or sabot
Load capsule
Load capsule
Fluidized bed (CH) Advanced manufacturing
methods
IFE target fab processes have many common elements - which are derived from ICF experiments
Injector demo experiment
Inject/Track or insert
Inject/Track or insert
Existing and major new ICF facilities
Z-ROMEGA EP
NIF
How is the target fabricated and what are the issues?
Pressure cellwith trays
Microencapsulation
600 Å Pd onPAMS shell
Cryogenic fluidizedbed layering
Advantage = started with ICF experience base
injector
Step Methods Demonstrated? Remaining IssuesCapsules, Microencapsulation, Yes, including DVB Non-concentricity, overcoat
polydensation quality, mass-production, meeting specs
Metal Overcoat Sputter Coating Yes, on small scale Standard industrial process..
Filling with DT Permeation Yes, including DVB shells Optimize for min. DT inventory
Layering -layering Yes, but on single targets Mass-production demo
Cryo HandlingCryostats Yes, but on single targets Part of layering/injection demoInjection EM, gas gun Room Temp. demo now, Accuracy, tracking demo,
cryo survival
So the specific issues in this session are………
Capsule non-concentricity - spec is NC <1% of wall thickness Overcoat - delamination of the overcoat, surface finish of 20 nm Gas tightness of overcoat & “buckle pressure” for filling Production process yield improvement Mass-production methods for 500,000/day - online characterization DT behavior under heat flux (really injection issue) - understand the limits of DT when exposed to heat flux (impact on chamber
design)
QuickTime™ and aTIFF (LZW) decompressor
are needed to see this picture.
Batch of ~400 3.5 mm OD DVB
Coating
Droplet generator
4 mm dia., 200 m foam layer, CH overcoat, Schroen, Streit
DT layer after ~1 W/cm2 for 24 ms
Failures during overpressure
The presentations deal directly with these issues………
Five talks/posters:
1) Divinyl benzene (DVB) shells - Diana Schroen, Jon Streit
2) Mass production of IFE targets - Brian Vermillion
3) Solid DT studies - Jim Hoffer, Drew Geller, John Sheliak
4) Poster: DVB foam shells with a dual initiator - Reny Paguio
5) Poster: Foam characterization with ultrasound - Leonard Bond, Morris Good, Diana Schroen
GDP Coated RF Foam (related ICF studies)
~ 5 µm PVP
DVB Foam
W2
Amp
DAQ
PCLaser
Data
Laser
PhotodiodeSensors
“Online” feedback & characterization