Overview of the Components of an IFE Chamber and a Summary of our R

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Overview of the Components of an IFE Chamberand
a Summary of our RD to Develop Them

• Presented by A. René Raffray
• UCSD
• With contributions from John Sethian and the HAPL
  Team
• HAPL Meeting
• PPPL
• Princeton, NJ
• October 27-28, 2004

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The HAPL Program Aims at Developing a New Energy
Source IFE Based on Lasers, Direct Drive Targets
and Solid Wall Chambers

• Modular, separable parts lowers cost of
  development AND improvements
• Conceptually simple spherical targets, passive
  chambers
• Builds on significant progress in US Inertial
  Confinement Fusion Program

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Chamber Physics Needs to be Understood
Ion and Photon Threat Spectra and Chamber
Conditions Prior to Each Shot Must Be Well
Characterized (UW) Attenuation of ion and
photon spectra seen by wall by using a
protective chamber gas
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Injecting Tracking the Target(GA/UCSD/LLE)
Target injection tracking - Gas gun or
electromagnetic injection - 5 mm target
injection accuracy, 2 mm target/laser
accuracy - mirror steering synchronized
with target tracking
GA target injection facility
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Long Term Survival Optical Fidelity Required of
Final Optics
We are developing damage-resistant final optics
based on grazing-incidence metal mirrors and
testing them (effort coordinated by UCSD LLNL)
Mirror requirements - 5 J/cm2 - 2 yrs, 3x108
shots - 1 spatial non-uniformity - 20 mm
aiming - 1 beam balance
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We are Developing a Credible Armor/First Wall
Configuration to Accommodate the Threat Spectra
and Provide the Required Lifetime
Separation of function armor for threat
accommodation FW for structural
function - Front runner configuration thin W
armor ( 1 mm) on FS
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We are Assessing the Potential Causes of Armor
Failure and Considering Advanced Engineered
Material for Potentially Superior Performance
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The Blanket and Beyond Strategy for Blanket
Development and Integrated System Studies Study
(UCSD/UW/LLNL)

• Our blanket strategy aims at making the most
  of MFE design and RD info in developing an
  attractive IFE blanket concept
• 1. Scoping study of blanket concepts coupled
  to selected power cycle(s) to the point
  where we can intelligently evaluate them
  and select most attractive one(s).
• 2. Detailed design analysis of selected
  concept(s) closely integrated with our
  system studies and with design of
  interfacing components

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We Have Focused on Developing and Analyzing
Components to a Credible Level. However, Some Key
Questions Remaining That Have a Strong Impact on
the Interfaces of These Components, e.g. (in no
particular order)
1. How do we avoid a protective gas in the
chamber? If we cannot, what density of
chamber gas do we need? - Where do we pump
the chamber gas and micro-explosion
products - If we need to puff gas in the
chamber or in the laser lines, where do we do it?
2. How do we integrate target injection,
tracking and mirror steering? - Where is the
target injection line? What is its
dimension? - What requirements does the
injection method (e.g. gas gun or
electromagnetic) impose on the machine
layout and on the chamber environment? - What
requirements are imposed by target tracking and
mirror steering? - Where exactly are the
final optics with respect to the vessel? How many
lines are there and what are their
dimensions? - Optics too close to chamber
might require ion magnetic deflection protection,
possibly impacting the choice of blanket
coolant (MHD effects). - Optics too far might
affect target illumination.
3. Where is the vacuum vessel and the
biological boundary?

• 4. What do we need to know to develop and
  evaluate a credible maintenance scheme?
• - Detailed layout of the in-vessel components
  (including coolant and purge lines)?
• - Ancillary equipment needed around the chamber
  (including the above)? How do they interfere
  with the maintenance scheme?

5. Do we have an in-situ way of repairing the
armor? If so, what is it and does it impose any
requirement on the machine layout?
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The Responses to Many of These Questions and
Others Would Benefit from an Integrated View of
the HAPL Power Plant
Evolution of a consistent integrated
concept for an HAPL power plant based on
the most updated information available for the
various components. - Concept will evolve as
RD and analysis progress. - Provide
visualization of an attractive HAPL concept
instead of relying on past studies. - Help
build credible case to go to Phase II.
Initial Effort on Evolving In-Vessel Machine
Layout as Part of Blanket Study
- We should start an effort on this fairly
soon.