j=σT 4 Jožef Stefan Institute SEWG meeting Cadarache, June 2009 D retention in inhomogeneous layers and castellation gaps by micro-NRA WP09-PWI-01-02/MHEST Primož Pelicon, Primož Vavpetič, Zdravko Rupnik, Iztok Čadež Microanalytical Centre, Department for Low and Medium Energy Physics (F2), Jožef Stefan Institute, Jamova 39, Ljubljana, Slovenia Association EURATOM-MHEST http://www.rcp.ijs.si/~mic
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J=σT 4 Jo ž ef Stefan Institute SEWG meeting Cadarache, June 2009 D retention in inhomogeneous layers and castellation gaps by micro-NRA WP09-PWI-01-02/MHEST.
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j=σT4 Jožef Stefan Institute SEWG meeting Cadarache, June 2009
D retention in inhomogeneous layers and castellation gaps by micro-NRA
Microanalytical Centre, Department for Low and Medium Energy Physics (F2),Jožef Stefan Institute, Jamova 39, Ljubljana, Slovenia
Association EURATOM-MHEST
http://www.rcp.ijs.si/~mic
j=σT4 Jožef Stefan Institute SEWG meeting Cadarache, June 2009
Contents:
1. Introduction: 2 MV tandetron
2. Elastic Recoil Detection Spectroscopy (ERDA)
3. High Energy Focused Ion Beam: micro-ERDA and micro-NRA
4. Conclusion
j=σT4 Jožef Stefan Institute SEWG meeting Cadarache, June 2009
j=σT4 Jožef Stefan Institute SEWG meeting Cadarache, June 2009
RBS/ERDA :Beam: 4230 keV 7Li2+, Sample tilted 75°RBS detector at 160°, ERDA detector at 30°ERDA detector equipped with 11 µm Al foilDose controlled by mesh charge integrator Pelicon et al., NIM B 227, 591 (2005)
2. Elastic Recoil Detection Analysis (ERDA) for hydrogen depth profiling in PFCs
j=σT4 Jožef Stefan Institute SEWG meeting Cadarache, June 2009
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Measurement Three-layer simulation Single layer simulation
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Li-ERDA, three-layer model Li-ERDA, one-layer model BAM reference value Round-robin average value
Results of the round robin measurements "Hydrogen in Silicon", organized by “Bundesastalt Für Materialforschung und –prüfung” (BAM), Berlin. The result of the IJS, obtained with the Elastic Recoil Detection Analysis (ERDA) with Li ions, is marked by red circle, average value by thick blue line. Result of the laboratory 1 is the result of BAM. (Source: U. Reinholz, H.P. Weise, BAM Berlin, Round robin test "Hydrogen in Silicon", Results sent to the participants of the round-robin, Pelicon et al., NIM B 227, 591 (2005))
j=σT4 Jožef Stefan Institute SEWG meeting Cadarache, June 2009
In 2008, ERDA has been configured inside new measurement chamber at JSI for studies of hydrogen in surfaces, thin films, dinamic processes of interaction of hydrogen and surfaces.
Fig.1: Erda spectrum of a:C:D film for calibration of D detection methods, measured by 4.2 MeV 7Li beam (In collaboration with Th. Schwartz-Seliger, IPP Garching, sept. 2008)
j=σT4 Jožef Stefan Institute SEWG meeting Cadarache, June 2009
3. High Energy Focused Ion Beam: micro-ERDA and micro-NRA
Focused beam formation:Magnet quadrupole triplet lensis focusing the beam at the analyzing object.Example: beam envelope for the focusing of 7Li2+ beam to 3x3 µm2
Blue: horizontal planeRed: vertical plane
j=σT4 Jožef Stefan Institute SEWG meeting Cadarache, June 2009
Data acquisition:All detectors (incl. Chopper RBS) Connected to the sameMultiplexing ADCDetector event:(E,i,Ux,Uy)
On-line datasorting
Off-linedata sorting(list modemeasurements)
PIXE De t. RBS De t.
Protonskižarek
Pre isko va nid e l vzo rc a
Prem iki žarka
SE De t.
STIM Thin samples
AnnularRBS Det.
Deflecting coils (x,y)
Sample positioned in the focal plane
Ion beam
RBSdetector
Chopper(dose normalization)
Quadrupole lens
ERDA With 75º tilted sample
Foil
Data acquisition:All detectors (incl. Chopper RBS) Connected to the sameMultiplexing ADCDetector event:(E,i,Ux,Uy)
On-line datasorting
Off-linedata sorting(list modemeasurements)
Data acquisition:All detectors (incl. Chopper RBS) Connected to the sameMultiplexing ADCDetector event:(E,i,Ux,Uy)
On-line datasorting
Off-linedata sorting(list modemeasurements)
PIXE De t. RBS De t.
Protonskižarek
Pre isko va nid e l vzo rc a
Prem iki žarka
SE De t.
STIM Thin samples
AnnularRBS Det.
Deflecting coils (x,y)
Sample positioned in the focal plane
Ion beam
RBSdetector
Chopper(dose normalization)
Quadrupole lens
ERDA With 75º tilted sample
Foil
j=σT4 Jožef Stefan Institute SEWG meeting Cadarache, June 2009
Areal distribution of molybdenum (islands)measuredby Li-beam excited X-ray emmision (LIXE)
and simultaneously measuredhydrogen lateral distribution by Li-beam ERDA over an area of 1240 x 450 µm2. Sensitivity of the method is 0.1 at. %.
1240 µm
450
µm
Mo Lα
Hydrogen
Distribution of hydrogen is anti-correlated with the distribution of molybdenum. Hydrogen retention is higher in the surface of uncoated graphite.
Micro-ERDA: lateral mapping of hydrogen at plasma-exposed surface of castellated limiter[1]
[1] Litnovsky et al, J. Nucl. Mater. 337-339, 917 (2005).
j=σT4 Jožef Stefan Institute SEWG meeting Cadarache, June 2009
Cleavage direction
Plasma-exposed surface
Example: Deuterium depth distribution in Carbon Fibre Composite NB31 after deuterium exposure experiment in Textor [2]
Scanned region
As the surface roughness strongly affects the ERDA due to sample tilting to an angle of 75°, micro-NRA with the 3He beam for deuterium detection is alteranatively developed, being less sensitive to surface topography (no sample tilting required). Micro-NRA: 3He focused ion beam with 5 x 5 µm2 with 500 pA. Beam size limited by the brightness of the ion source for neg. 3He beam production. Ion source reliability problem solved in 2008.
Micro:NRA with 3He beam and D(3He,p)4He formation
j=σT4 Jožef Stefan Institute SEWG meeting Cadarache, June 2009
D counts
90 μm
500 μm
Cleaved CFC NB31: D penetrates below surface (50 micrometers) in distinct points due to CFC micro-structure (fibre, pores)
Kreter et al, Deuterium retention in different carbon materials exposed in TEXTOR, J. of Phys.- Conf. Ser. 100 (2008) 062024.
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CFC NB31 deuterium depth profile in cleavage
j=σT4 Jožef Stefan Institute SEWG meeting Cadarache, June 2009
3. Conclusion
Fig.1: Lithium charge exchange channel with heather/TC separated from Li melt, installed within the project PWI-08-TA-06/MHEST/PS/01, for 3He beam production (Source: HVEE)
Ion Beam Analytical methods for hydrogen (deuterium) detection for PWI Studies were configured during the last three years and are now available for work within MHEST projects, as well as for Mobility visits.