10th ITPA TG Meeting on Diagnostics10-14 April 06, Moscow

Radiation Effects WG

Eric Hodgson (presented by Benoit Brichard)Input from JA: T.Nishitani, T.Shikama. RF: A. Krasilnikov, K.Vukolov. US: L.Snead

• Last meeting of Radiation Experts at 15th IEA Workshop held during ICFRM-12 (Dec 05) in Santa Barbara. 18 people attended the 4 1/2 h meeting.

• Updates on activities from EU, JA, RF, and US.

• 6-7 April EFDA Ceramics Irradiation meeting

• Now have ITER, but still waiting new structure for common tasks.

EU update 1

EU laboratories involved in TW4/6-IRRCER programmes

AEUL Riga Ferroelectric bolometers

CEA Cadarache NBI insulation

CIEMAT Madrid H/D/T effects, windows, bolometers, T/RIEMF , RIC/RIED

IPP.CR Prague Hall probes

FZK Karlsruhe H/D/T effects, ECRH windows

MEdC Bucharest Windows, fibres, optoelectronic components

ÖAW Vienna Ferroelectric bolometers

SCK/CEN Mol Bolometers, fibres, T/RIEMF, RIED

EU update 2

• MI cables (CIEMAT, SCK/CEN)

RIEMF - serious problem - difficult to separate Rad. and T effects

TIEMF (centre conductor) detailed study (CIEMAT, SCK/CEN)

EMF (V) T. No annealing of the effect observed up to 550 C

Not due to geometry

Combined effect of inhomogenieties, transmutation/dpa and temperature gradient

Need more data and experimental test To fully understand further the combined RIEMF/TIEMF effect

Damage to MI cable Cu core

Impurity analysis underway

“Normal” copper wire

copper core in MI cable !

Severe damage in Cu core extracted from MI cable

Cause of TIEMF ?

No TIEMF effect observed in “normal” copper wire

-20

-15

-10

-5

0

5

10

15

20

29-11-05 06-12-05 13-12-05 20-12-05Date

core

-to-

core

vol

tage

(µV

) .

data

model

AISI304L

Core to Core induced voltage

Va

10 kΩ

10 kΩ

Va

b

Vb

Is it radiation damage related (Dpa) ?

Cu

-10

0

10

20

30

40

50

29-11-05 06-12-05 13-12-05 20-12-05Date

core

-to-

core

vol

tage

(µV

) .

data

model

In-core irradiation in BR2

Transmutation ?

Change of seebeeck coefficient

EU update 3

• Bolometers

(AEUL, CIEMAT, IPP, ÖAW, SCK/CEN)

JET resistance type: Pt on Alumina and AlN

n irradiated - SCK/CEN --->0.01 dpa, 400 CPIE: Pt and substrates OKProblem: electrical contacts

Ferroelectric type:

PbZrO3 beingprepared

Pt on Al2O3 and AlN

• Double Pt meanders• Absorber, reverse side• First check T and

ionization effects

Move to neutron irradiation (BR2)

Good linearity of sensor

No change in resistance at 350°C up to 10-3 dpa

350

390

430

470

510

550

9/03/05 10/03/05 11/03/05 12/03/05

Res

ista

nce

, Oh

m

0

100

200

300

400

500

600

Tem

per

atu

re, C

r1 r2 T1 T2

Pt/AlN

Pt/Al2O3

T°C

Problem with electrical contact that not withdstand high temperature

RIED in Al2O3

I - centre sample 12

50150250350

-13.00

-12.00

-11.00

-10.00

1.00E-03 2.00E-03 3.00E-03 4.00E-03 Temp. 1/T (°K)

log. I (A)

I-Centre before irr.

I-Centre after irr.

°C

• 4.3 10-3 dpa => small differences (a few pA) are observed.

= > start of microstructural analysis

• Irradiation facility fully operational

– Active vaccuum, 10-2 mbar – Active Heating up to 400°C

Pt on Si3N4

• IPP bolometer - “SiN” for mica

• First check T and ionization effects --->No adverse effects

Also Pt on Si3N4 (IPP)

EU update 4

• Hall probes (IPP.CR, Ukraine)

InSb Hall devices (MSL, Lviv, Ukraine) showed acceptableperformance up to 10-3 dpa (70% of original sensitivity)But upper temperature for operation is low (< 100C)

7 new sensors based on solid solutions of InSb and InAs and similarmaterials with potential high T survival ( > 200°C )

1st in-reactor tests completed -->But none survived beyond 10-3 dpa at 160-190 C.

Problems: electrical connections, solder joints, thin wire insulation ....

EU update 5

• Optical properties (CIEMAT, MEdC, SCK/CEN)

Enhanced surface degradation (optical and electrical)from low energy H and He implantation. General problem ?

Mirrors: Coatings for extended UV reflectivity

No suitable UV fibres, and UV absorption extends to visibleH loading has limitations

Windows: High energy proton irradiations => for low dose ≈ n

Window materials Surface degradation

10-6

10-4

10-2

100

102

104

1014 1015 1016 1017 1018

Ele

ctri

cal c

urre

nt (

µA

)

Dose (ions/cm2)

450 ºC

250 ºC

50 ºC

0

0.5

1

1.5

2

500 1000 1500 2000 2500 3000

Op

tica

l ab

sorp

tion

Wavelength (nm)

450 ºC

250ºC

50 ºC

Ele

ctri

cal c

urre

nt (

µA

)

Opt

ical

Abs

orpt

ion

(cm

-1)

XPS analysis shows extreme O lossResults => Si and SiO rich surface zoneGeneral problem for insulator surfaces ? 0

2

4

6

8

10

12

14

16

0.5 1 1.5 2

Energy (keV)

Si

O

Unimplanted

450ºC

250ºC

50 ºC

A.U

Low energy He ion bombardment of KS-4V Produces enhanced absorption and surface electrical conductivity

Coated mirrors

Work on mirror coatings for general protection and LOCA

SiO2 (SiO) and alumina MgF (HfO2) for extended UV

0

20

40

60

80

100

500 1000 1500 2000 2500

UV enhanced (Newport)

Newport as recNewport irrad 40MGy 170ºC N

2%

R

Wavelength (nm)

0

20

40

60

80

100

500 1000 1500 2000 2500

Visible enhanced (Coherent)

Coherent as rec

Coherent irrad 40MGy 170ºC N2

% R

Wavelength (nm)

No change when irradiated in N2 atmosphere but …

No protection against LOCA

• Radiation + humidity

• Degradation attacks the Al coating even when protected

• Enhanced diffusion and reactions (Al(OH)3)

• Swelling SiO -> SiO2

Usually, SiO2 better resistance against corrosion

EU update 6

• T diffusion / effects (CIEMAT, FZK)

Windows the primary barrier to confine tritium

Modelling on effects of H isotopes (T) in diamond indicates strongtrapping.

In-situ radiation enhanced diffusion in different materials is now beingmeasured.

Work starting on effects of H isotopes on physical properties

Radiation enhanced diffusion

• Disc samples electron irradiated on vacuum side

• H/D on other side• High sensitivity leak

detector for diffusion• Pressure sensors for

absorption

Disc for analysiselectrons

H/D chamber

EU update 7

• EFDA Ceramics Irradiation Meeting 6-7 April 06

2 day meeting with presentations of all on-going EU TW5/6 tasks

Information / presentations shortly available

New data base task / specifications discussed

JA update

JAEA, NIFS, Tohoku IMF (Data from T.Shikama and T Nishitani )

RIC - stable insulators for blanket applications. Data for gamma, and fission and fusion neutrons

Fast ion conductor behaviour during reactor irradiation

450 nm radioluminescence in silicas - band suppression with OH content (full agreement with earlier data)

Radiation and temperature measurements using luminescence

DT neutronGamma ray

Fissionreactor

▲ Y2O3

◆ CaZrO3

● Er2O3

0 100 200 300 400 500 60010- 14

10- 13

10- 12

10- 11

10- 10

10- 9

10- 8

10- 7

10- 6

10- 5

10- 4

Condu

ctivi

ty (

S/m

)

Temperature (oC)

Under irradiation

CaZrO3 (8.8 Gy/s, Bias: +250V)

RIC Withoutirradiation

0 100 200 300 400 500 60010- 14

10- 13

10- 12

10- 11

10- 10

10- 9

10- 8

10- 7

10- 6

10- 5

10- 4

Condu

ctivi

ty (

S/m

)

Temperature(oC)

Y2O3 (5.1 Gy/s, Bias: +250V)

Under irradiation

Withoutirradiation

RIC

Teruya Tanaka (NIFSTeruya Tanaka (NIFS) ) on RIC of MHD on RIC of MHD insulators for blanket insulators for blanket applicationapplication

Bun TsuchiyaBun Tsuchiya JMTR irradiation: H-inplanted in ceramic material JMTR irradiation: H-inplanted in ceramic material

Conclusion: RIC enhancement in H-inplanted materialConclusion: RIC enhancement in H-inplanted material

0

200

400

600

800

1000

1.5 MeV H+ 5 x 1017 H/m2

0 ppm OH (T-2630) 200 ppm OH (T-2630) 800 ppm OH (T-2630)

Nor

mal

ized

lum

ines

cenc

e in

tens

ity

(arb

itra

ry u

nits

)

Under successive ion irradiation 2.7 eV: B2αbands in low-OH silica1.9 eV: NBOHC in high-OH silica

At very low fluences

3.1 eV: Intrinsic B2βbands in low-OH silica

Shinji NagataShinji Nagata on radioluminescence of silica on radioluminescence of silica

Luminescence decrease with OH content

1.5 2.0 2.5 3.0 3.5 4.00

200

400

600

800

10001.5 MeV H

+ 1 x 10

19 H/m

2

0 ppm OH 200 ppm OH 800 ppm OH

Photon energy (eV)

RF update

FORC, Kurchatov, TRINITI (Data from Anatoli Krasilnikov)

• Fibres – RL and RIA

Irradiations at IR-8 (Kurchatov)

At 3x1013 n/cm2/s, 400 Gy/s to 1018 n/cm2, 16 MGy

Fibres from FORC, Heraeus, Mitsubishi, and Fijukura

H loaded fibres give best results (lowest RL)

RL reactor power (=> nuclear radiation monitor)

NO. FIBERS TYPE The manufacturer COATING MAIN IMPURITIES

1 KU-1 FORC ALUMINIUM OH~800 PPM, CL~140 PPM 2 SSU HERAEUS QUARZGLAS GMBH &

CO POLYMER OH~800 PPM

3 STU HERAEUS QUARZGLAS GMBH & CO

POLYMER OH~20 PPM

4 SILICA, FABRICATED, PROBABLY, BY THE

VAD- TECHNOLOGY

MITSUBISH POLYMER OH~800 PPM, CL~140 PPM

5 SILICA, FABRICATED, PROBABLY, BY THE

VAD- TECHNOLOGY

FUJIKURA POLYMER OH<20 PPM, CL- PROBABLY, HIGH

CONCENTRATION

6

KU-1 FORC ALUMINIUM OH~800 PPM, CL~140 PPM, H2-LOADED

7 KS-4V-H2 FORC ALUMINIUM OH 0.2 PPM, CL 20 PPM, H2-LOADED

8 Silica, fabricated by the VAD - technology

The silica core rod was fabricated in the Tokyo Technology Institute. The perform and the fiber were fabricated in FORC

ALUMINIUM OH~3 PPM, CL~20 PPM, H2-LOADED

H2Loaded

Radiation induced luminescence spectra. Figures denote fibre numbers according to Table 1. Fast neutron fluence - 4.71017 n/см2, gamma-dose –7.2 МGy(Si), fast neutron fluxe -2.81013 n/см2 s, gamma-dose rate –400 Gy/s.

0.0E+00

1.0E-10

2.0E-10

3.0E-10

380 480 580 680

nm

RL

capa

city

, W/(n

m*m

)

1

2

3

4

6,7,8

Luminescence spectra corrected for re-absorption

IR-8 reactor irradiation

A.V. Bodarenko & al., instru. and exp. tech., 2006, Vol. 49, No2, pp 190-198

1

100

10000

0 100 200Irradiation time, h

Rea

cto

r p

ow

er,

kW1.E-14

1.E-13

1.E-12

1.E-11

1.E-10

RL

cap

acit

y, W

/(n

m*m

)

Time evolutionLuminescence spectrum

H2-loaded fibres

US update

ORNL (Data from L. Snead, D. Swain, D. Rasmussen, K. Leonard)

“Long ago” US was active during ITER CDA, on RIC in MI cables, RIED, windows

Now beginning activity once again:

ICRH insulators, thermal conductivity degradation, multilayer mirrors

Ion Cyclotron Insulators Radiation Effects

• Five ceramics (alumina in polycrystal and single crystal form)

– Al2O3 (Wesgo Al995, Deranox 999*); Al2O3 (Kyocera single crystal),

– BeO (Thermalox),

– AlN (Tokuyama SH-15),

– Si3N4 (Kyocera SN-235P),

– single crystal MgAl2O4 (Princeton Scientific Corp.)

• HFIR fission reactor irradiation at 80-100oC: 0.001, 0.01, 0.1 dpa (1018-1020 n/cm2, E>0.1 MeV)

• Pre- and post-irradiation testing of dielectric properties (dielectric constant, loss tangent at ~100 MHz) and thermal conductivity

*Only one Deranox 999 specimen irradiated, at 0.1 dpa (material supplied by Eric Hodgson)

Theory is being developed to better understand defects

• Thermal conductivity in ceramic materials can be described as a summation of various scattering centers for phonons as :

K (T) 1

1

Ku(T)

1

Kgb (T)

1

Kd 0

1

Krd

• The appropriateness of addition of thermal resistances is suggested by the addition of inverse relaxation times to obtain the combined relaxation time.• Above 1/3 of the Debye temperature defect scattering is temperature independent.

Umklapp(phononScattering)

boundaries

intrinsicdefects

radiationdefects

1

Krd

1

K irr

1

Kunirr

Thermal defect resistance

Thermal Conductivity of Ceramics for Diagnostic Application

0.000

0.002

0.004

0.006

0.008

0.010

0.012

0.014

0.016

0 200 400 600 800 1000 1200

Sapphire

Coors AD-998

Wesgo AL-998

Sapphire

Coors AD-998

Wesgo AL-998

Def

ect

Res

ista

nce

1/K rd (

m-W

/K)

Annealing Temperature (C)

0.001 dpa

0.01 dpa

More complex defects formed during higherdose irradiation are more thermally stable.

60°C Neutron Irradiated Alumina

Performance of Diaelectric Mirrors Under Irradiation

• Work just starting.

• Purpose : Development of multilayer dielectric and performance of these materials under neutron and gamma irradiation.

• Approach: Fabrication of mirror structures without use of silica containing layers.

- substrate materials, sapphire and silicon carbide

- layer materials:

Alumina

Magnesium aluminate spinel

Hafnium Oxide

Magnesium Oxide

• Intermediate dose irradiation to be carried out in June 06. (0.01 to ~ 1 dpa)