# Presentation: 318478

##  Status of Fast Ignition-High Energy Density Physics

**                                                           ****October 19, 2003**
**                                                          ****Fusion Power Associates**

** ****Status of Fast Ignition-High Energy Density Physics**
**Joe Kilkenny**
**Director Inertial Fusion Technology**
**General Atomics**
**San Diego, California**

## Slide 2

##  Ignition and gain curves for multiple target concepts show the advantages of Fast Ignition 

** ****Ignition and gain curves for multiple target concepts show the advantages of Fast Ignition **

**— ****Fast ignition potentially gives more gain and lower threshold energy  then “Hot Spot” ICF but the science and technology are far  less developed**

**FI at NIF **

**Intensity ~10****14**** - 10****15**** w/cm****2**

**Intensity ~10****20**** w/cm****2**

**Indirect **
**Drive**

**Advanced Indirect **
**Drive on NIF**

## Fast Ignition has attractive features in addition to high gain at lower total drive energy

**Challenging science and technology**
**Compression MIGHT be possible with all Drivers**
******0.53 ********m , 1.05********m (?)**
**Brightness requirements for compression drivers are reduced**
**Radiation temperatures of ****~100ev**** required for compression!**
**Direct and Indirect target schemes for compression**
**Innovative target concepts**
**one-sided indirect drive**
**indirect drive illumination ( PDD) for direct drive**
**asymmetric compression drive configurations**
**Target fabrication tolerances are relaxed**

## NIF produces ~4 MJ at 1.05 m 

**NIF produces ~4 MJ at 1.05 ********m **

## Fast Ignition is compatible with all drivers

**Fast Ignition is compatible with all drivers**

- Innovative target designs are possible
-              **BUT**
**Ignitor laser energy must be determined!**

## NNSA is interested too! The photons, electrons and ions from PW lasers can be used to heat and diagnose HEDP plasmas

**NNSA is interested too! The photons, electrons and ions from PW lasers can be used to heat and diagnose HEDP plasmas**

**Multi-kJ PW’s are now planned for OMEGA(EP), Z-R, and NIF**

## Slide 8

## The Z-Beamlet laser is being upgraded to provide a high energy PW laser for use on Sandia’s Z facility

**Z-Beamlet multikilojoule laser facility**

**Z-Beamlet and Z-PW laser facility**

**Z z-pinch facility**

**Z multimegajoule z-pinch facility**

**•  ****The Z-Beamlet laser will provide a 2-4 kJ, 1-10 psec  laser  ~  2007**

**•  ****A  50-200 J, 0.5 - 10 psec prototype laser system will begin operation in 2004.  **

** ****High energy radiography and fast ignitor experiments on  Z facility**

## Slide 10

## Slide 11

## Slide 12

## Resistive inhibition needs testing under ignition relevant conditions

**Resistive inhibition needs testing under ignition relevant conditions**

**Experiments are needed in low resistivity plasmas **

**Critical Surface**
**Dense Gold**
**Coronal Plasma/Gold**
**Compressed Core**

- e

## US OFES effort addresses all aspects of FI

**OFES support is highly leveraged**
- Complementary programs
- Internal funds
- Overseas collaborations
**FI Target design efforts at NNSA funded labs**
- SNL - Z - PW
- LLE - Omega EP
- LLNL - NIF -HEPW

- US Fusion Energy program
- OFES

- UC Davis

- Princeton

- GA

- Vulcan

- GekkoXII

- LULI

- LLNL

- LLE

- SNL

- UN,Reno

-  Ignition target design

-  Fast Ignition Concept Exploration

- OMEGA

## Slide 15

## Hydro Modeling agrees very well

**Hydro Modeling agrees very well**

**Stagnation time, shape**
**Compressed density**
**Emission from target**
**Model does not include mixing of Au vapor with collapsing shell **- will measure from excess self-emission

- Models may be sufficiently accurately to for target design extrapolations

**• ****Compact mass, ~60 mg/cm****2****  **
** ****minimal cone vapor**

## Electron beam is moderately well directed

**Al thickness micron**** **

**180 ********m**

**Cu**
**20********m**

**Al**
**20 ********m**

**Minimum spot size 70 ********m, cone angle 40°**
**Insensitive to pulse energy (to 100 J)**

## Integral FI experiments at Gekko XII-PW have catalyzed FI interest worldwide

- GEKKO laser: 12 green laser beams
**E= ****10 kJ**, t = 1-2 nsec.
- Uniform irradiation(phase plates) for **high **
**density compression.**
**I ~10****14 **** watts/cm****2**

- PW laser: 1 beam **(~400  J)**
- At 1 micron.
- PW peak power is utilized for **fast heating**.
**I~10****19 ****watts/cm****2**

**Integral FI experiments at Gekko XII-PW have catalyzed FI interest worldwide**

## Integral experiments at ILE show efficient heating

**Nine drive beams, 2.5 kJ**
**1/2 PW ignition beam**
**Deuterated plastic target**

- 300 J short pulse doubled the core plasma temp to 0.8 keV implying 40% coupling of EPW

**Rqd timing ~50ps**

**T~0.8 keV**

- ILE Osaka

## A credible pathway to take FI to concept demonstration exists

**Proof of Principle (Concept Extension**) **Significant core heating at relevant conditions**
- FIREX1 (Japan)
**Concept Demonstration ****(Ignition/gain****)**
- US Facilities (, Z, NIF) with PW

## Summary

**Short pulse (******** < ~10 psec), high brightness lasers (B > 10****15 ****Watts/cm****2****-st) have enabled the new field of “high energy density physics (HEDP)”**
**There is an increasing national and international interest in HEDP**
**Fast Ignition exploits the physics and technology of HEDP**
**	****&  features:**
**Science frontier-relativistic plasmas, etc**
**Compatible with all drivers**
**Flexibility in reactor concepts**
**International collaborations ?**
**High gain potential at  sub-megajoule energies**