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 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

j=σT 4 Jo ž ef 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=σT 4 Jo ž ef Stefan Institute SEWG meeting Cadarache, June 2009

j=σT 4 Jo ž ef Stefan Institute SEWG meeting Cadarache, June 2009 RBS/ERDA : Beam: 4230 keV 7 Li 2+, Sample tilted 75° RBS detector at 160°, ERDA detector at 30° ERDA detector equipped with 11 µm Al foil Dose 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=σT 4 Jo ž ef Stefan Institute SEWG meeting Cadarache, June 2009 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=σT 4 Jo ž ef 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 7 Li beam (In collaboration with Th. Schwartz-Seliger, IPP Garching, sept. 2008)

j=σT 4 Jo ž ef Stefan Institute SEWG meeting Cadarache, June High Energy Focused Ion Beam: micro-ERDA and micro-NRA Focused beam formation: Magnet quadrupole triplet lens is focusing the beam at the analyzing object. Example: beam envelope for the focusing of 7 Li 2+ beam to 3x3 µm 2 Blue: horizontal plane Red: vertical plane

j=σT 4 Jo ž ef Stefan Institute SEWG meeting Cadarache, June 2009

j=σT 4 Jo ž ef Stefan Institute SEWG meeting Cadarache, June 2009 Areal distribution of molybdenum (islands) measured by Li-beam excited X-ray emmision (LIXE) and simultaneously measured hydrogen lateral distribution by Li-beam ERDA over an area of 1240 x 450 µm2. Sensitivity of the method is 0.1 at. % 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 , 917 (2005).

j=σT 4 Jo ž ef 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 3 He 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 µm 2 with 500 pA. Beam size limited by the brightness of the ion source for neg. 3 He beam production. Ion source reliability problem solved in Micro:NRA with 3 He beam and D( 3 He,p) 4 He formation

j=σT 4 Jo ž ef 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)

j=σT 4 Jo ž ef Stefan Institute SEWG meeting Cadarache, June 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 3 He 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.