# Presentation: 305722

## FIRE Design: FY03 PFC Tasks

**Mike Ulrickson (FIRE Divertor Design Team)**
**presented by**** **
**Richard Nygren (new member, NSO PAC)**
***Sandia National Laboratories***

- Sandia is a multiprogram laboratory operated by Sandia Corporation, a Lockheed Martin Company,for the United States Department of Energy under contract DE-AC04-94AL85000.

***NSO PAC Meeting******	******San Diego, February 27-28, 2003***

## Best guess for readiness for PVR is     late August or early September 2003. 
Continuing resolution in FY03 has constrained the initial schedule.
In the following slides: 
	green text indicates completed tasks, 
	blue text indicates tasks in progress,  
	black text indicates planned tasks that 	can be done with the FY03 budget.

**Continuing resolution in FY03 has constrained the initial schedule.**
**In the following slides:**** **
**	****green text**** ****indicates ****completed**** tasks,**** **
**	****blue text**** ****indicates tasks ****in progress****,****  **
**	****black text ****indicates ****planned tasks**** that ****	****can be done with the FY03 budget.**

**Introduction**

## Plasma Equilibrium

**Define baseline plasma shape for 2.14 m.**
**Use TSC to compute vertical and radial disruption cases.**
**Define the range of ********, l****i****, ********, and P****aux**** that should be accommodated and provide magnetic data.**

**green ****(completed)**** **

**black text ****(can be done with FY03 $$)**

## Edge modeling

**Use UEDGE to reestablish edge plasma conditions with the proper fusion power and heating**
**Determine heat flux profiles**
**Determine boundaries for partial detachment**

**blue**** ****(in progress)****  **
**black text ****(can be done with FY03 $$)**

***Note: for high density plasma in ARIES-RS/CLIFF for APEX, Rognlien found steady state solution for strongly radiating regions near X-point.***

## Disruption Forces

**Rebuild OPERA model of vessel and PFCs including copper**** *****(input from design at Boeing)***
**Use TSC data as input to Opera to find eddy currents and forces**
**Use Opera to determine the effect of the copper shell on magnetic diagnostics**
**Run a vertical disruption case to compare to vertical disruption on 2.0 m machine and use results to scale radial disruption forces to 2.14 m **

## Design 

**Revise baseline divertor design (input to Opera)**
**Revise the divertor hardware to accommodate the new plasmas and check shape variations**
**Compute stresses in the revised design for both thermal and disruption loads (input from Opera)**
**Revise design as needed to accommodate stresses**

**green ****(completed)**** **
**black text ****(can be done with FY03 $$)**

## Heat flux testing 

**Investigate new concept for W rod attachment to improve reliability **
***	******(PFC base program but input from FIRE design)***
**New design completed**
**Negotiating with vendor for production**

**green ****(completed)**** **
**black text ****(can be done with FY03 $$)**

## W-rod Armor 

**Mockups have survived high heat flux tests to 24MW/m****2****   and thermal cycling for 500 cycles*.  **
**We recommend two design improvements. **
**	****- Creep resistant Cu alloy as the rod bed.  **
**	****- Positive mechanical lock of rod to bed (grooved rod tip).    ****	**** Vendor bids have been received.**

- *PW-8 rods reached 3300oC at 24MW/m2.  Some erosion of rods occurred but no cracking or melting.  PW-8 was then subjected to thermal fatigue cycles After 370 cycles (10s-ON:10s-OFF) at 20MW/m2, one rod began to melt.  The affected area grew to 9 rods; we terminated testing at 500 cycles.

## ELMs on FIRE

** ****Assumptions for ELM energy deposited on FIRE divertor plates. **
**Either (a) 2% or (b) 5% of stored energy is lost.**
**Footprint for deposition is either (a) same as normal operation or (b) up to three times larger**
**Duration of ELM is 0.1<t****ELM****<1ms**

***ELMS are not a problem if no surface melting occurs******.***
***We must reduce the magnitude of ELMS.***

**Most of the 2% cases and a few 5% cases are acceptable.**
**Limit for 0.1ms ELM is ~0.3 MJ/m****2**** ****(partially detached, 12 MW/m****2****)**
**Limit for 1.0ms ELM is ~1.0 MJ/m****2**** ****(partially detached, 12 MW/m****2****)**

## ELMs Melting LIMIT

**Melting will not occur when the deposited energy density is less than**** ****the value at the intersection of **
**(a) T-rise curve**
***and***
**(b) T****LIMIT,normalHF.**

**Energy Density >1.25MJ/m****2**** to avoid melting.**

- T-rise (1ms ELM) 5% (loss Estored)
- 6MW/m2  q”normal

## PFC Task Progress

## Reporting 

**Provide data needed for Physics Validation Review**
**Revise divertor section of engineering report to include new design**

## Summary

**A redesign of the PFC components can be completed in time for the PVR, but the effort must start immediately.**
**Funding is not adequate for iterating the divertor design.**
***We can only scale the design to the new size and analyze the forces***
***Local areas of excessive stress are likely to exist on the supports or vacuum vessel***