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ARIES Conference Call, 20 March 2003

Documented by L. Waganer

(ANL) -
(Boeing) Waganer
(DOE) -
(FPA) -
(GA) Petzoldt
(GT) Abdel-Khalik
(LANL) -
(LLNL) Abbott
(MIT) -
(MRC) Rose, Welch
(ORNL) -
(NRL) -
(PPPL) -
(RPI) -
(SNL) Olson
(UCB) Debonnel
(UCSD) Najmabadi, Raffray, Tillack
(UW) El-Guebaly


Les Waganer summarized the plans for the Town Meeting on Liquid Wall Effects and that the ARIES meeting to be held in Livermore, CA, May 5-8. The agenda for the Town Meeting can be found on the ARIES web site. Wayne Meier asked that any attendees respond to Judy Knecht [] so the arrangements can be made.

Les Waganer noted the minutes of the January ARIES meeting and the February 11 conference call have been finalized and placed on the ARIES web site. The team is reviewing the minutes of the 25 February electronic conference call. The next call ARIES-CS will be on 1 April 2003.

The ARIES FTP site at UCSD is available for use. Mark Tillack sent out the address and password to the team.

Farrokh mentioned that high-level efforts are underway to help restore some of the budget that had been reduced from the prior year's budget.

Status of ARIES-IFE Technical Areas

René Raffray said that most of the ARIES-IFE manuscripts for the FS&T special issue are completed, but a few remain to be completed after receiving feedback from the authors.

It was suggested the team address the prior meeting's action item list, in order, to organize the conference call discussions.

1. Assess vortices collection at chamber side and wall protection in that location (C. Debonnel/S. Yu/P. Peterson) - Ryan Abbott said that one of the areas of investigation is the surface roughness inside the vortex tubes. He noted that photographs of the vortex have been taken to analyze the macroscopic processes. Christophe Debonnel presented vortex results on behalf of the UCB group at the July ARIES meeting. Per Peterson will summarize these results, as well as the current work, at the May 2003 ARIES Town Meeting.

2. Detailed 3-D assessment of HYLIFE maintenance scheme (W. Meier/R. Abbott) - Ryan Abbott said they are modeling the HYLIFE chamber to determine how to remotely install and remove the internal components. In addition to the CAD model, an animation has been constructed to illustrate the maintenance process.

3. Assess tolerance of criss-crossing jets to nozzle flow blockage (S. Abdel-Khalik/W. Meier) -Although not related to flow blockage, Ryan mentioned there is investigation of other methods to protect the chamber without the cross jets. This effort is in conjunction with the Robust Point Design. A question was asked as how to condition and remove the boundary layer to maintain the surface roughness at a very low level and avoid the generation of large amounts of aerosols that are detrimental to beam propagation.

4) Assess reproducibility of nozzle motion over desired lifetime and pocket formation tolerance to out of phase nozzle motion (W. Meier/L. Waganer) - No action has been accomplished on this action item.

5) How cleanly is the pocket formed? (W. Meier/S. Abdel-Khalik) - Said Abdel-Khalik stated there is no way to estimate the number density of the atmosphere inside the pocket and if Per Peterson is investigating this effect experimentally. Per Christophe Debonnel, UC-Berkeley has been concentrating on the disruption and re-establishment of the on the oscillating jets. Detailed investigation of the generation and subsequent sweeping of pocket droplets and slugs is underway.

6) Comparison of self-pinch and assisted-pinch (S. Yu) - Simon Yu mentioned they are addressing the assisted pinch in a similar manner to the neutral ballistic transport for the Robust Point Design. PPPL will look at the approach to assemble and maintain the magnets, similar to that for the RPD.

7) Adjust breeding to avoid breeding behind solid walls (L. El-Guebaly) - Laila El-Guebaly noted there are techniques to adjust the breeding level, but she preferred to wait to adjust the breeding level until after the next ARIES meeting when the final decision will be made regarding the incorporation of crossing jets. This allows the design to firm up and minimize analysis iterations.

8) Assess criss-crossing jet motion under impulse load (C. Debonnel/S. Yu) - Christophe Debonnel mentioned that little analysis has been done on the dynamic loads on the cross jets. Per Peterson will present simple models and preliminary experimental results at the Town Meeting.

9) Improve aerosol analysis (P. Sharpe) - René Raffray noted that he has been working with Phil Sharpe, who is updating the analysis in a chamber size closer to that suggested by the team with a HYLIFE type wall. Phil is increasing the chamber radius to compensate for the added area of the multiple jets and slab flows and will present his results at the next ARIES meeting.

10) Correct target and driver constraints (as integrated values) on aerosol distribution (R. Raffray) - René reminded the team that the aerosol number density is much larger than presently allowed for the beam transport, e.g., >> 1 mtorr for NBT and > 100 mtorr for self pinch. He will present more detail on these constraints at the May Town Meeting.

11) Perform detailed estimate of spall for candidate liquid armor and characterize ablated material as aerosol source term. (M. Zaghloul, R. Raffray) - René Raffray noted that UCSD is working on a characterization of the ablated material in a manner similar to that for the explosive boiling process. The results will be presented at the May town meeting.

12) Develop rationale for number of workers and for lower cost with shared target facility (R. Petzoldt) - Ron Petzoldt presented these data at the last ARIES IFE conference call.

13) Investigate how to mitigate impact of last target assembly process failure (R. Petzoldt) - Ron Petzoldt presented these data at the last ARIES IFE conference call.

14) Develop assembly/disassembly/maintenance sequence for RDP (T. Brown) - No PPPL personnel were on the call, but Simon Yu noted that PPPL is planning to accomplish a maintenance sequence for the magnet assembly.

15) Calculate average WDR over entire magnet assembly (shield, structure, coil, insulator, etc…)(J. Latkowski/W. Meier) - Ryan Abbott said that Jeff Latkowski is doing this analysis.

16) Analyze impulse imparted to and the prompt evaporation from the crossing jets for the thick liquid robust point design (Don Haynes) - Laila el-Guebaly was not aware of what Don Haynes has done on this subject.

Other Subject Areas:

Target Fabrication and Injection - Ron Petzoldt mentioned that an experiment is underway to test injection and tracking of targets. Ron will present available data and results at the next meeting. He also noted that several researchers have been providing input and recommendations for hohlraum materials selection.

Beam Engineering - Simon Yu stated that up to this point, the Robust Point Design (RPD) has concentrated mostly on the driver and the beam transport. They are now concentrating on upstream subsystems. These subsystems will be defined and analyzed in more detail to optimize the overall system design.

Chamber Engineering - Laila El-Guebaly mentioned that eliminating the crossing jets impacts the breeding level and shortens the lifetime of the port plug structure. The latter effect defeats the purpose of the thick liquid wall concept that provides lifetime protection for the structure.