slide1 n.
Download
Skip this Video
Loading SlideShow in 5 Seconds..
Div. Of Plasma Application & Tech. PowerPoint Presentation
Download Presentation
Div. Of Plasma Application & Tech.

Loading in 2 Seconds...

play fullscreen
1 / 20

Div. Of Plasma Application & Tech. - PowerPoint PPT Presentation


  • 96 Views
  • Uploaded on

H 2 Retention and Physical/Chemical Evaporation Problems from the Interactions between ECR Plasma and FLiNaK Molten Salt. Taihyeop Lho , Yong-Sup Choi, and HyonJae Park. National Fusion Research Institutes, 113 Gwahangno , Yusung-Gu , Daejeon 305-333, Korea.

loader
I am the owner, or an agent authorized to act on behalf of the owner, of the copyrighted work described.
capcha
Download Presentation

PowerPoint Slideshow about 'Div. Of Plasma Application & Tech.' - infinity


An Image/Link below is provided (as is) to download presentation

Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author.While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server.


- - - - - - - - - - - - - - - - - - - - - - - - - - E N D - - - - - - - - - - - - - - - - - - - - - - - - - -
Presentation Transcript
slide1

H2 Retention and Physical/Chemical Evaporation Problems from the Interactions between ECR Plasma and FLiNaK Molten Salt

TaihyeopLho, Yong-Sup Choi, and HyonJae Park

National Fusion Research Institutes, 113 Gwahangno, Yusung-Gu, Daejeon 305-333, Korea

PMIF 2011, Julich in Germany / 19 ~21 Sep. 2011

Div. Of Plasma Application & Tech.

1

slide2

CONTENTS of PRESENTATION

  • Introduction - Objectives
  • Experimental Setup
  • o Plasma Parameters
  • o Magnetic field structure
  • Interaction between the plasma and molten salt (FLiNaK)
  • oAr plasma
  • o H2 Plasma
  • Hydrogen retention
  • Morphology
  • Future Plan - Research Load Map
slide3

INTRODUCTION - OBJECTIVES

  • Molten salts have been suggested as the one of the liquid wall
  • material in a fusion device.
  • The advantages of the liquid wall materials are heat removal, refreshing
  • wall conditions and more.
  • Molten salts have low thermal conductivitywhich indicates low heat transfer to the structure of the device.
  • In addition, molten salts have low electrical conductivity (~102Ω-1 m-1) which is relatively weak MHD effects on the surface flow comparing to the liquid lithium.
  • The molten salt also have low chemical reactivity and low evaporation.
  • However, we don’t know about the possibility of molten salts as a
  • plasma facing material.
  • This research aims on the feasibility test of the possibility.
slide4

EXPERIMENTAL SET-UP

  • Overall Review on Molten Salt Exp. System

Magnetron

ECR Source

Process Chamber

Magnet Power

MagnetronPower

Pumping System

slide5

EXPERIMENTAL SET-UP

Function Gen.

520 mm

Resonance Layer

Langmuir Probe : ¼ inch one side planar probe

150mm

To DAS

640 mm

To DAS

Thermocouple

Focal Length : 750mm

Apeture Ratio : f/9.8

Grating : 1800 Gr/mm

Resolution : ~ 0.02 nm

PM Tube

To Pumping System

RGA : Stanford Laboratory

slide6

174 mm

MAGNETIC FIELD STRUCTURE

80 mm

221mm

91mm

25mm

55mm

20mm

55mm

Probe

position

20

MoltenSalt

slide7

PLASMA PARAMETERS

■ Hydrogen Plasma density, Temperature and potential

  • Cylindrical Langmuir probe
  • : Diameter 0.5 mm, Length 12 mm
  • Unmagnetized plasma assumption
  • : Laframboise Analysis
  • Hygrogen Plasma
slide8

Interaction between Ar ECR plasma and solid FLiNaK

Experiment condition

Base pressure: 6ⅹ10-6Torr

Working pressure: 1mTorr, Ar 16 sccm

ECR head input current: 17A

Microwave input power: 500 watt

Initial FLiNaK temp.: 28 ℃

II. Measured by monochromator

Measuring range: 300~850 nm

Resolution: 0.275 nm

2000 point

slide9

Interaction between Ar ECR plasma and Liquid FLiNaK

Experiment condition

Base pressure: 6ⅹ10-6Torr

Working pressure: 1mTorr, Ar 16 sccm

ECR head input current: 17A

Microwave input power: 1000 watt

Initial FLiNaK temp.: 539 ℃

II. Measured by monochromator

Measuring range: 300~850 nm

Resolution: 0.275 nm

2000 point

slide10

NUMERICAL SIMULATION

Resonance Layer

Molten salt bath

  • Ar plasma interaction with the molten salt
  • Heat load by ions and electrons to the molten salt is about 30kW/m2 MAX
  • Radial density profile included
  • ΔT ~ 50℃ after plasma load (initial temperature =500 ℃)
slide11

Interaction between H2 ECR plasma and solid FLiNaK

Experiment condition

Base pressure: 4.3ⅹ10-6Torr

Working pressure: 1mTorr, H2 46 sccm

ECR head input current: 17A

Microwave input power: 500 watt

Initial FLiNaK temp.: 15 ℃

II. Measured by monochromator

Measuring range: 300~850 nm

Resolution: 0.275 nm

2000point

slide12

Interaction between H2 ECR plasma and liquid FLiNaK

Experiment condition

Base pressure: 3.9ⅹ10-6Torr

Working pressure: 1mTorr, H2 57 sccm

ECR head input current: 17A

Microwave input power: 500 watt

Initial FLiNaK temp.: 539 ℃

II. Measured by monochromator

Measuring range: 200~850 nm

Resolution: 0.2 nm

3250 point

slide13

EDS ANALYSIS - MORPHOLOGY

  • EDS analysis before the interaction
slide14

RGA CALIBRATION

  • RGA can detect the elements from the molten salt even though without the plasma interaction.
  • Need RGA calibration for hydrogen retention to find the total amount of hydrogen retention.

H2 Pressure (Torr)

Time (sec)

slide15

RGA DATA – HF MEASUREMENT

Plasma irradiation time

Plasma irradiation time

10min

5min

Plasma irradiation time

20min

  • The potasium is the main element from the molten salt evaporation .
  • Hydrogen fluoride formation increase with plasma interaction time.
  • It is possibly come from the chemical formation of HF.
slide16

H2 RETENTION - RESULTS

H2 retention depends on the interaction time with H2 Plasma

  • Measured the partial pressure of out-gassed H2from the molten salt surface
  • as a reference without plasma interaction.
  • The difference between the measured lines and reference have been
  • integrated with the time to convert into the total amount of the
  • hydrogen molecules retention.
slide17

H2 RETENTION - RESULTS

  • Hydrogen retention mainly result from the ion flux into the molten salts.
  • If the charge exchange which is the high energy neutral particle formation process in the pre-sheath is considered, the retention ratio will be decreased by factor 2.
  • Considering only the ion bombardment on the Molten Salt
  • Considering on High Energy Neutral Particles by the Charge Exchange in the Pre-sheath
slide18

SUMMARY and FUTURE PLANS

  • Sodium and Potasium are main impurities from the molten salt.
  • Fluorine forms the Hydrogen fluoride molecules, which is very corrosive, by chemical reaction at the surface of molten salt or in the bulk plasma.
  • The composition of the molten salt changed with the interaction time and the position of molten salt.
  • The amount of hydrogen retention in the molten salt is about 30-40% when the charge exchange in the pre-sheath not included.
  • We need to understand some issues in the near future
  • The analysis methods to evaluate the composition of the molten salt.
  • Physical properties, especially viscosity of molten salt, after plasma interaction.
  • The impurities from the molten salt, quantitatively.
  • Influence of HF to the structure.
slide19

CONCEPTUAL DESIGN OF THE FLOWING SYSTEM

  • Roughly request minimum
  • Molten Salt over 4kg
  • Conceptual design parameters
  • for the flowing system

ECR

Helicon

2

1170 mm

1

3

  • Helicon and ECR are the
  • candidates of the plasma sources

3

4

1030 mm

slide20

FUTURE PLANS – ROAD MAP

  • Molten Salt exp. in a Torus device from 2020 ?

2020 -

  • CPC will move to the new site in 2012.
  • The flowing system of the molten salt will be built.
  • New molten salt, such as FLiBe, FLiNaBe, will be studied from 2018

2018

2015

2010

2012

  • The linear device will be operated in 2015.