# Presentation: 468352

## Progress on Z-Pinch IFE and HIF Target Work on Z 

**Craig Olson**
**Sandia National Laboratories  **
**Albuquerque, NM 87185**

**     ****Part 1:  Z-Pinch IFE concept**
**     ****Part 2:  Z-Pinch IFE program plan for FY04 $4M   **
**     ****Part 3:  HIF/Z-Pinch collaborations:  P4 experiments on Z**

**15th Int. Symp. on Heavy Ion Inertial Fusion**
**Princeton University**
**Princeton, NJ**
**June 7-11, 2004**

- Pulsed Power External Review, May 4-6, 2004

##         Z-Pinch IFE concept

**       **

## What has already been accomplished   

**What has already been accomplished   **
**      ****that is relevant to Z-Pinch IFE**

_***x-rays:***_***         *****1.8 MJ of x-rays on Z (****demonstrated****) available now**
_***low cost***_***:      *****$30/J for ZR  (****demonstrated**** cost)**
**                     ****$17/J goal for X-1 high yield study (1999)**
_***high efficiency***_***:      ***** wall plug to x-rays:  ~15% on Z (****demonstrated****)**
**                                 ****can be optimized to: ~25% or more**
_***capsule compression experiments on Z:***_*** ***
***      *****double-pinch hohlraum****1****:  Cr ******** 14-20 (****demonstrated****),**
**                                                   ****symmetry ~3% (****demonstrated****) **
**      ****dynamic hohlraum****2****:   ******** 24 kJ x-rays absorbed, Cr ******** 10,**
**                                           ****up to 8x10****10**** DD neutrons (****demonstrated****) **
**      ****hemisphere compression for fast ignition****3****:   Cr ******** 3 (****demonstrated****)**
**                     *****(******1******Cuneo, et al.; ******2******Bailey, Chandler, Vesey, et al.; ******3******Slutz, et al.)***
_***repetitive pulsed power***_***:  ***
***                           *****RHEPP magnetic switching technology:  **
**                                 ****2.5 kJ @ 120 Hz (300 kW ave. pwr. ****demonstrated****)**
**                           ****LTD (linear transformer driver) technology:**
**                                  ****being developed (compact, direct, simple****)                                                   **

## The  long-term goal of Z-Pinch IFE is to produce an economically attractive power plant using high-yield z-pinch-driven targets 

**(********3 GJ) at low rep-rate per chamber (********0.1 Hz)**

**Z-Pinch IFE DEMO (ZP-3, the first study) used 12 chambers, each with 3 GJ at 0.1 Hz, to produce 1000 MWe **

**The *****near-term *****goal of Z-Pinch IFE is to address the science issues of **
**repetitive pulsed power drivers, recyclable transmission lines, high-**
**yield targets, and thick-liquid wall chamber power plants **

_**Z-Pinch IFE Team (1000 and 6000, plus Universities &Industry)**_
**   ****C. L. Olson,****a ****G. E. Rochau,****a**** S. A. Slutz,****a**** C. W. Morrow,****a**** G. A. Rochau,****a**** R. E. Olson,****a**** A. R. Parker,****a**** M. E. Cuneo,****a**** D. L. Hanson,****a**** G. R. Bennett,****a ****T. W. L. Sanford,****a**** G. A. Chandler,****a**** J. E. Bailey,****a ****W. A. Stygar,****a**** J. L. Porter,****a****  R. A. Vesey,****a**** T. A. Mehlhorn,****a**** K. W. Struve,****a  ****M. G. Mazarakis,****a  ****L. X. Schneider,****a****  K. R. Prestwich,****a  ****G. Benevides,****a****  T. J. Renk,****a**** T. J. Tanaka,****a**** M. A. Ulrickson,****a**** D. H. McDaniel,****a**** M. K. Matzen,****a**** J. P. Quintenz,****a**** W. B. Gauster,****a ****P. F. Peterson,****b**** J. S. De Groot,****c**** R. R. Peterson,****d,e ****D. Kammer,****e****  I. Golovkin,****e**** G. L. Kulcinski,****e**** E. Mogahed,****e**** I. Sviatoslavsky,****e**** M. Sawan,****e**** C. Gibson,****f**** ***** *****H. Tran,****g***** ***** P. Panchuk****h****, R. Lumia****i****                        **
**                                                             ****a****Sandia National Laboratories, Albuquerque, NM **
**b****University of California, Berkeley, CA ****c****University of California, Davis, CA **
**d****Los Alamos National Laboratory, Los Alamos, NM**
**e****University of Wisconsin, Madison, WI **
**f****General Atomics, San Diego, CA **
**g****University of New Mexico, Albuquerque, NM   **
**h****EG&G, Albuquerque, NM**
**i****InControl, Inc., Albuquerque, NM**
_**US/Russia collaboration on Z-Pinch IFE **_
**-**

- Pulsed Power External Review, May 4-6, 2004

## Z-Pinch IFE Road Map

**Z-Pinch ETF**
****** ******** ****$1B**

**Z-Pinch IRE**
****** ****$150M (TPC)**
**+op/year**

**Z-Pinch IFE PoP**
****** ****$10M /year**

**Z-Pinch High Yield**
****
**Z-Pinch Ignition**
**HY**

**Laser **
**indirect-drive**
**Ignition**

**2038**
**2024**
**2018**
**2012**
**2008**
**2004**
**1999**

**FI**
**ZR**
**Z**

**    ****NIF**

**    ****Year                        **_**Single-shot**_**, NNSA/DP                                            **_**Repetitive**_** for IFE, OFES/VOIFE**

**Z-Pinch IFE **
**target**
**design**
****** ****$2M /year**

**Z-Pinch IFE**
**target fab.,**
**power plant **
**technologies**
****** ****$2M /year**

**Z-Pinch IFE**
**target**
**design**
****** ****$5M /year**

**Z-Pinch IFE**
**target fab.,**
**power plant**
**technologies**
****** ****$5M /year**

**Z-Pinch IFE CE**
****** ****$400k /year**
**(SNL LDRD +)**

_**Z-Pinch IFE Road Map**_

## Z-Pinch IFE Matrix of Possibilities

***         ******(choose one from each category)***

_**Driver pulsed power:                                                                                 _________**_
**   ****Marx generator/               magnetic switching          linear transformer driver**
**   ****water line technology       (RHEPP technology)       (LTD technology)**
_**Power feed:                                                                                                            ____**_
**     ****                              ****triax                                           coax**
_**RTL:                                                                                                                      ____**_
**            ****Flibe/electrical coating           Flibe          immiscible material                                                                                                **
**                                                                                ****(e. g., low activation ferritic steel)**
_**Target:                                                                                                                         __**_
**    ****        ****double-pinch                dynamic hohlraum****                         ****fast ignition**
_**Chamber:                                                                                                                      _**_
**            ****dry-wall                wetted-wall              thick-liquid wall     solid/voids**
**                                                                                                                  **_**                                      **_

_**Z-Pinch Driver:                                                                                 ______________  **_
**   ****Marx generator/               magnetic switching          linear transformer driver**
**   ****water line technology       (RHEPP technology)       (LTD technology)**
_**RTL (Recyclable Transmission Line):                                                              _____                                                                                                       **_
**                  ****Flibe/electrical coating                              immiscible material                                                                                                **
**                                                                                ****(e. g., low activation ferritic steel)**
_**Target:                                                                                                                         _**_
**    ****        ****double-pinch                dynamic hohlraum****                         ****fast ignition**
_**Chamber:                                                                                                              ____                                                                                                                      **_
**            ****dry-wall           wetted-wall          thick-liquid wall            solid/voids**
**                                                                                                        ****(e. g., Flibe foam)**
**                                                                **

***Mainly science:  *****z-pinch target physics**
***Mainly engineering/technology:  *****z-pinch driver, RTL, chamber***** ***

## Z-pinches offer the promise of a cost-effective energy-rich source of x-rays for IFE

**Z-pinches offer the promise of a cost-effective energy-rich source of x-rays for IFE**

**Supermite**

**Proto II**

**Saturn**

**Z**

**X-1 (total energy)**

**ZX**

- 

- ZR

**ZR will be within a factor of 2-3 in current (4-9 in energy) of a High Yield driver.**

## (1 MA)

**(1 MA)**

**(10 MA)**

**(******** 60 MA)**

**(******** 90 MA)**

**(18 MA)**

**(28 MA)**

**(all are ******** 60 MA)**

**(10 MA)**

## Linear Transformer Driver (LTD) technology is compact and easily rep-rateable

**      **

**LTD uses parallel-charged capacitors in a cylindrical geometry, with close multiple triggered switches, to directly drive inductive gaps for an inductive voltage adder driver (Hermes III is a 20 MV inductive voltage adder accelerator at SNL)**
**LTD requires ****no oil tanks or water tanks**
**LTD study (as shown) would produce 10 MA in ****about 1/4 the size**** of Saturn**
**LTD pioneered in Tomsk, Russia **

**Modular**
**High Efficiency  (~ 90% for driver)**
**Low Cost**
**Switches: ball-gaps in air, pressurized gas, solid-state**
**Easily rep-rateable for 0.1 Hz**

## The Recyclable Transmission Line (RTL) Concept

**The Recyclable Transmission Line (RTL) Concept**

## Z-pinch power plant chamber uses an RTL (Recyclable Transmission Line) to provide the standoff between the driver and the target

**INSULATOR STACK**
**(connects to driver)**

**FLIBE**
**JETS**

**10-20 Torr**
**Inert Gas**

**RTL**

**Z-PINCH**
**TARGET**

**Yield and Rep-Rate:  few GJ every 3-10 seconds per chamber (0.1 Hz  - 0.3 Hz)**
**Thick liquid wall chamber:  only one opening (at top) for driver;  nominal pressure (10-20 Torr)**
**RTL entrance hole is only 1% of the chamber surface area  (for R = 5 m, r = 1 m)**
**Flibe absorbs neutron energy, breeds tritium, shields structural wall from neutrons **
**Eliminates problems of final optic, pointing and tracking N beams, high speed target injection**
**Requires development of RTL**

- RTL movement (“automobile assembly line technology”)*
- RTL electrical turn-on*
- RTL low-mass limit and electrical conductivity*
- RTL structural properties/ chamber pressure*
- RTL mass handling*
- RTL shrapnel formation
- RTL vacuum connections/ electrical connections*
- RTL activation/ waste stream analysis*
- RTL shock disruption to fluid walls
- RTL manufacturing/ cost*
- RTL optimum configuration (coax, triax, convolute,
-              shape, inductance, material, mass)
- RTL power flow limits (physics of magnetic insulation)
- Effects of post-shot EMP, plasma, droplets, debris up the RTL
- Shielding of sensitive accelerator/power flow feed parts
- ...
**    **
**        ****     **

*** initial investigations during LDRD phase**
**considerable list of science issues remains**

## RTL research completed under LDRDs

**RTL electrical turn-on****      **_**Saturn experiments**_**     (2000)**
**                                             ****tin, Al, stainless-steel all show negligible losses**
**RTL low-mass and****             **_**Saturn experiments**_**     (2001)**
**electrical conductivity****        20******** mylar; 50********, 100********, 250******** steel**
**                                              ****RTL mass could be as low as 2 kg**
**                                              ****RTL mass ******** 50 kg has low resistive losses**
**RTL structural****                   Calculations (U. Wisconsin)    (2002)**
**                                             ****full-scale RTL (********50 kg) of 25 mill steel ok for **
**                                                 ****background pressure ******** 10-20 Torr**
**RTL manufacturing****          (allowed RTL budget is a few $ for 3 GJ)**
**                                             ****Flibe casting  (********$0.70/RTL)**
**                                             ****ferritic steel stamping  (******** $1.20-3.95/RTL)**

## RTL FINITE ELEMENT MODEL constructed in ANSYS to perform structural analysis

**R = 50 cm**
**r = 5 cm**
**L = 200 cm**
**25 mil steel**
**disc 10 cm lip**

**Fusion Technology Institute**
**University of Wisconsin, Madison**

**RTL Structural**

## PRELIMINARY BUCKLING ANALYSIS of steel RTL

_**78 Torr**_
**    ****RTL buckles at **
**     ****1.52 psi = 78 Torr**
**     ****as shown**
_**20 Torr**_
**     ****no effect**
**     ****(safe operating point)**

**Fusion Technology Institute**
**University of Wisconsin, Madison**

**RTL Structural**

## Slide 17

## Z-pinch-driven-hohlraums have similar topology to laser-driven-hohlraums, but larger scale-size

**Z-pinch-driven-hohlraums have similar topology to laser-driven-hohlraums, but larger scale-size**

**Double ended hohlraum**

**35 mm**

**Dynamic hohlraum**

**6 mm**

## Code calculations and analytic scaling predict z-pinch driver requirements for IFE DEMO

**Double-Pinch Hohlraum**

**Dynamic Hohlraum**

**current /x-rays**
**E****abs ****/ yield**

**2 x 62-68 MA**
**2 x (16-19) MJ**
**1.3 – 2.6 MJ**
**400 – 4000 MJ **

**54 – 95 MA**
**12-37 MJ**
**2.4 – 7.2 MJ **
**530 – 4400 MJ**

***J. Hammer,  M. Tabak, R. Vesey, S. Slutz, J. De Groot***

**current /x-rays**
**    ****E****abs ****/ yield**

**Based on these results, an IFE target for DEMO will require: **
**    **_**double-pinch hohlraum**_**          **_**dynamic hohlraum**_
** ****36 MJ of x-rays (2x66MA)    30 MJ of x-rays (86 MA)                                                           **
**            ****3000 MJ yield                        3000 MJ yield**
**                ****(G = 83)                                 (G = 100)**

**Notes:**
As many of you know, we are currently pursuing 2 approaches to high-yield ICF that utilize z-pinches as the x-ray source.

Left: Z-pinch driven hohlraum uses 2 wire array z-pinches as x-ray sources. The capsule is located at the center of a secondary hohlraum where it is isolated from the direct pinch radiation.  

Right: Dynamic hohlraum.  Key difference is that the capsule is located at the center of the wire array.  X-rays formed at impact of wire array on convertor(us. foam) are contained within the imploding wire and convertor material.
Offers potential for higher efficiency.  Joel Lash will describe the high-yield design for this concept on Friday morning.

DH relies on internal pinch radiation while ZPDH relies on external pinch radiation transported to the capsule by wall re-emission.

## Thick liquid walls essentially alleviate the “first wall” problem,             and can lead to a faster development path 

**Thick liquid walls essentially alleviate the “first wall” problem,             and can lead to a faster development path **

## Z-Pinch Power Plant - Proposed Cartridge Cycle

##   Z-Pinch IFE Program Plan 

**  ****Z-Pinch IFE Program Plan **
**for $4M for FY04 **

## Key Scientific Question for Z-Pinch IFE

**Given that the key target physics issues are being addressed in the NNSA DP ICF program, the key scientific question for z-pinch IFE is:**
***“******Can a repetitive pulsed power driver be connected directly to a fusion target with a recyclable transmission line to make an attractive inertial fusion energy power plant?”***

## Primary Issues for Z-Pinch IFE

***For this Initiative, research is proposed to address the following primary issues for z-pinch IFE:***
**1.  How feasible is the RTL concept?**
**2.  What repetitive pulsed power drive technology could be used for z-pinch IFE?**
**3.  Can the shock from the high-yield target (~3 GJ) be effectively mitigated to protect the chamber structural wall?**
**4.  Can the full RTL cycle (fire RTL/z-pinch, remove RTL remnant, insert new RTL/z-pinch) be demonstrated on a small (PoP) scale?**
**5.  What is the optimum high-yield target for 3 GJ, and what are the power flow requirements for this target?**
**6.  What is the optimum power plant scenario for z-pinch IFE?**
**7.  What is the path forward for z-pinch IFE?**

## Task 1.  Recyclable Transmission Line (RTL)

**Deliverables:**
**  ****Develop integrated solutions to the RTL issues  (RTL shape, materials, inductance, physics of power flow, chamber/interface issues, etc.) to validate the credibility and practicality of the RTL concept.**
**  ****Design, build, and begin structural testing of RTLs to be used in 1 MA PoP experiments in subsequent FYs.**
**  ****Design, cost, and schedule an RTL demonstration on Z/ZR.**
**  ****Initiate a baseline RTL conceptual design for a 60 MA driver for a High Yield/ Engineering Test Facility (ETF).**

## Task 2. Repetitive Driver Development

**Deliverables:**
**  ****Assess the three approaches to repetitive pulsed power **
**for z-pinch IFE to validate LTD technology is the best **
**approach.**
**  ****Form a standing working group to assess and develop**
** ****long-lifetime repetitive switches (ball-gaps in air, pressurized gas, magnetic switching, solid-state, etc.) for z-pinch IFE. **
**  ****Develop an explicit conceptual power flow plan for a z-pinch IFE driver, using LTD technology coupled to an RTL to a z-pinch target.   Include details of the RTL/MITL interface.   **
**  ****Initiate development of a 1 MA, 1 MV, 100 ns, 0.1 Hz driver using LTD technology as a PoP scale driver.   Utilize and complement existing SNL work at Tomsk (Russia) on LTD technology.**
**  ****Collaborate with the HIF-VNL on the possible use of LTD technology for HIF drivers. **

## Summary of Collaborating Institutions

- _Collaborating National Laboratories_:
-      LLNL, LBNL, LANL, NRL, INEEL*
- _Collaborating Universities_:
-      UCB, U.Wisc., UCD, UCLA, Georgia-Tech, U.
-      Missouri*, Texas Tech*, UNM, UNR*, Cornell*,
-      UCSD
- _Collaborating Industry_:
-      PSI, GA, Luxel, MRC, FPA
- _Collaborating Institutions in Russia:_
-      Kurchatov (Moscow),
-      Institute for High Current Electronics (Tomsk)
-      Institute for Theoretical and Experimental Physics (Moscow)
-     *Potential Collaborator

## HIF and Z-Pinch Collaboration Areas

**          ****indirect-drive targets****1**** - e.g. P4 symmetry**
**          ****thick liquid walls****2**
**          ****LTD driver technology**
**          ****target fabrication **
**          ****waste stream analysis**
**              ****1****see D. Callahan, talk M.I-06**
**              ****2****see W. Meier, talk F.I-05**

## Roger Vesey, Guy Bennett, Debra Callahan*, Mike Cuneo, Max Tabak*, John Porter, R. Adams, P. Rambo, L. Ruggles, W. Simpson, and I. Smith
* LLNL 

**Roger Vesey, **_**Guy Bennett**_**, **_**Debra Callahan**_*******, Mike Cuneo, Max Tabak*********, John Porter, ****R. Adams, P. Rambo, L. Ruggles, W. Simpson, and I. Smith**
*** ****LLNL**** **

**Symmetry Control Developments:****Radiation Shimming in Double-Ended Hohlraums **

**Double z-pinch target on Z**

**HIF hybrid target**

## We diagnose radiation asymmetry on Z with x-ray point-projection backlighting of an imploding capsule

**We diagnose radiation asymmetry on Z with x-ray point-projection backlighting of an imploding capsule**

**Z-Beamlet Laser beam**

**Target foil**
**(e.g. Fe)**

**X-ray film**

**Secondary hohlraum**

**2 x 16 MA**
**40 TW/side**
**1 MJ**

**negative P4 flux**

**positive P4 flux**

**RAV6-2004 2**

## HIF target calculations with and without the shim layer show the improvement in symmetry*

**Contours of imploded shell density near ignition time**

**393 MJ**

**< 1 MJ**

**Applied radiation source with -12% P****4**** in flux during foot pulse**

**DT gas 0.6 mg/cc**

**DT 0.25 g/cc**

**CH 1.044 g/cc**

**Au shim (thickness exaggerated)**
**@ 19.3 g/cc**

**1.66 mm**

**2.01 mm**

**2.3 mm**

**Fusion yield**

**Radiation shim layer placed directly on the capsule surface may work for high-convergence, high yield capsules (simple target fab)**
**0.9 to 1.3x nominal shim thickness also produced nearly 1D yield**

- *D. Callahan APS-DPP 2003

**RAV 6-2004 9**

## The first rad-shimmed capsule shots on Z in April, 2004 were successful in demonstrating the potential

**Chose Z hohlraum which previously gave good data on –P****2**** and –P****4**
**Capsule is 4.7-mm diameter, 30-********m thick CH shell with 2% Ge dopant for increased backlighter contrast at 6.7 keV**
**Gold shim layer designed (Callahan) to zero out both P****2**** and P****4**
**Shim layer as deposited was somewhat thicker at equator and somewhat thinner near P****4**** extrema than designed**

**P****2**** = - 6.0 %**
**P****4**** = - 6.9 %**

**Unshimmed capsule:**

**Shim blowoff**

**Capsule**

**P****2**** = + 15 % **
**P****4**** = - 3.0 %**

**design sim.**

**1276**

**1048**

**RAV 6-2004 10**

## Refinements for September, 2004 series on Z include: Improved shim quality for P4

**Refinements for September, 2004 series on Z include: Improved shim quality for P****4**

**Sept series uses hohlraum designed for zero P****2****, resulting in thinner overall shim to remove the remaining P****4 ****asymmetry**
**GA will redesign the coating mask to remove the thickness discrepancies**
**Target development is only pushed by actually having shots on the schedule**

**Shim characterized by Abbas Nikroo (General Atomics)**

**Gold shim thickness vs. polar angle**

**Coating masks on flat vs. spherical surface resulted in different profiles**
**Target required coating masks for both P****2**** and P****4**** to be developed**

**1.0**

**0.9**

**0.8**

**0.7**

**0.6**

**0.5**

**0.4**

**0.3**

**0**

**50**

**100**

**150**

**Thickness (********m)**

**RAV 6-2004 12**

## Radiation shims appear promising for removing early time asymmetries in ICF and IFE capsules

**Calculations show that shims can take out significant early time asymmetries**
**This may open up new possibilities such as smaller case-to-capsule ratio and different hohlraum geometries**
**Rad-shimmed capsules can now be coated, characterized, and mounted accurately to perform symmetry control experiments on Z**
**Demonstration of rad-shim performance will occur on Z and will impact target designs for:**
**Heavy-ion fusion**
**Z-pinch double-ended hohlraums**
**Z-pinch dynamic hohlraums**
**NIF hohlraums**

**RAV 6-2004 13**