M. S. Tillack

Some Thoughts on Phase II: Final Optics

HAPL Project Meeting, Georgia Tech5–6 February 2004

Goals for Laser IFE Phase II- (Page 1/2)

Overall Objective: Establish Science & Technology to buildEngineering Test Facility

1. Laser Facility1. Laser Facility

Lasers: Build a full-scale (power plant sized) laser beam line using the best laser choice to emerge from Phase I:

(KrF: 50-100 kJ)(DPPSL: 4-12 kJ)

The beam line will demonstrate all the fusion energy requirements, including efficiency, rep-rate, durability, and cost basis

 Final optics/target injection: Demonstrate the full scale beam line can be steered to hit a target that is repetitively injected into a chamber, with the required precision and optics LIDT durability.

Chamber Dynamics: Evaluate chamber clearing models: “Mini Chamber”

Chamber materials: Study candidate wall and/or optics materials  

Goals for Laser IFE Phase II – (Page 2/2)

2. Target Facility2. Target FacilityTarget fabrication: Demonstrate “batch mode” mass production of fusion class targets.

Target Injection: Demonstrate repetitive injection of above targets into a simulated fusion chamber environment. And the target survives.

3. Power Plant Design3. Power Plant Design  Produce a credible design for a power plant that meets the technical and

economic requirements for commercial power. 

4. Chamber and final optics:4. Chamber and final optics: Evaluate candidate materials/structures in a non-fusion environment. 

5. Target Physics:5. Target Physics: Modeling: Integrated high-resolution 3D target modeling.

Experiments: Validate design codes with target physics experiments at fusion scale energies single shot (e.g. NIF) and at lower energies on a rep-rate facility.

Assumed Outcomes of Phase I: Concept Exploration

1. A prime candidate concept has been defined– Materials choices– Design concept and design requirements

2. Backup options have been evaluated3. Specimen tests have been performed

– LIDT, x-rays, neutrons?, ions?– Optic size consistent with Phase-I facilities (100-500

J)

4. Pre-planning of Phase-II has been done– facilities, R&D needs

Main Themes of Phase II: Proof of Principle

1. Full scale optic fab/demonstration2. Optic lifetime demonstration (LIDT)3. Expanded radiation testing4. Integration into major facilities

1. Full Scale Optic Fab/Demonstration

• Fabricate and verify surface quality• Include all essential features (like cooling)

– Steering, adaptive wavefront control are not essential features of a final optic

amp 1

amp 2

one optical element ~1 kJ, 2000 cm2 (at 5 J/cm2 laser fluence)

2. LIDT Lifetime Demonstration

• Lifetime demonstration (LIDT) to 108 shots – 16 weeks at 10 Hz non-stop– 5 weeks at 100 Hz, 8-hr days

• Beam size ~1” 10 Hz, 400 mJ, 25 ns, 248 nm

3. Expanded Radiation Testing: lots of questions

• Neutron exposure– are achievable fluence levels

too low to be useful?– is there sufficient existing data?

• Ion implantation– low flux, high fluence is

probably OK– can be done with a “standard”

ion implanter

• X-rays– is low-energy testing adequate?

XAPPER operates withXe (113 eV), Ar (250-300 eV), N (430 eV)

4. Facility Integration

• Integration into major facilities– Phase-II target fab and injection facility– Phase-II laser facility (with chamber)

Targetfab labs

Cryogenic targetsupply systems

Differentialvacuum pumping

Sabotdeflector

Surrogatetargetchamber

In-chambertracking

Low powerhit on fly laser

Positiondetectors

Gun barrelLoadingchamber