Top level overview of target injection and tracking tasks

1. Top level overview of target injection and tracking tasks Presented by Dan Goodin at the High Average Power Laser Program WorkshopPrinceton Plasma Physics LaboratoryOctober 27 and 28, 2004

2. Summary - target injection, tracking, and beam steering • What is target injection and tracking? • What are the basic requirements? • What are the issues to be addressed? • What’s being done?

3. Expansion Tanks Sabot Deflector Turbo Pumps Target Position Detectors Target Catcher Gun Barrel Revolver Chamber Phase I injection/tracking/steering tasks Phase I goals for target injection and tracking: • Build an injector that accelerates targets to a velocity to traverse the chamber (~6.5 m) in 16 milliseconds or less. • Demonstrate target tracking with sufficient accuracy for a power plant (+/- 20 microns).

4. Injection, tracking, & steering requirements are “challenging” 7 3 R 7 m T ~1500 C • Inject about 500,000 targets per day (~6 Hz) for 1000 MW(e) • High velocity - ~400 m/s, separable sabot for handling/accelerating • Acceleration limited to about 1000 g’s (for “real” cryo target, TBC) • Need membrane support to avoid point-loading of target • Reliable, repetitive placement to 5 mm • Direct drive tracking and beam steering to 20 m • Integration of tracking & beam steering (reference system)

5. What are the issues and what’s being done? We have demonstrated with the gas-gun: • Rep-rated operation (6 Hz, “burst” mode) • Two-piece sabot separation and deflection • Membrane support of target in sabot • Injection velocity of ≥400 m/s • Time “jitter” at chamber center of ~ 0.5 ms • In-flight tracking • Target placement accuracy at one sigma of 10 mm 1) Showing a method to repetitively inject targets at high velocity • Gas gun demo • “Advanced” injection methods (EM injector) 2) Showing in-flight tracking to 20 m • Ex-chamber tracking demo • Develop in-chamber tracking methods Sabot separation at 400 m/s Evaluating/testing electromagnetic, non-contacting coil gun design for the future Approximately 25 meter length reflects SOMBRERO plant fueling layout

6. Axisymmetric Tmax = 4.36 103 K Tave = 1.42 103 K Vmax = 261.7 m/s What are the issues and what’s being done (continued)? 3) Showing how to integrate the tracking and beam steering systems • Conceptual designs and analyses 4) Showing target survival during the injection process • Modeling of DT heatup during injection • Modeling of DT response to heatup • Experiments with rapid DT heatup • Measurements of DT strength Reference sphere to define target chamber center Design of cell for measuring strength of DT (2mm X 2mm view) Chamber conditions affect heatup and tracking DT cell for rapid heatup testing Simulation of 18K target entering 4000K chamber gas

7. The presentations deal directly with these issues……… Talks in this session: 1) Target survival during injection - René Raffray 2) Target injection issue, background gas and plasma - David Harding 3) In-chamber tracking and integration with beam steering - Graham Flint 4) Status of target injection experiments - Dan Frey 5) Status of target tracking experiments - Ron Petzoldt In-flight tracking at 400 m/s Injection experiment setup to simulate full-length of Sombrero fueling