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Thermo chromatography: Experimental data

Thermo chromatography: Experimental data. Surface chemistry investigations for higher yields Hanna Frånberg. Chemical properties of the product. Volatility Reactivity Molecular formation Adsorption/desorption Production rates Half-lives Etc etc …. Target unit. Transfer line

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Thermo chromatography: Experimental data

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  1. Thermo chromatography:Experimental data Surface chemistry investigations for higher yields Hanna Frånberg

  2. Chemical properties of the product • Volatility • Reactivity • Molecular formation • Adsorption/desorption • Production rates • Half-lives • Etc etc …

  3. Target unit Transfer line Reactions  delay Target material Production Diffusion Reactions Ion source Efficiency Reactions Target container Reactions

  4. What and how? • Diffusion studies • Inplantations into target material samples. • Effusionout from the target, through the transfer line and in the ion source. • Study of adsorption/desorption  enthalpy • THERMO CHROMATOGRAPHY • Ionizationefficiency in the ion source

  5. Thermo chromatography

  6. PET or any other charge particle detection method. 511 keV 511 keV 511 keV 511 keV

  7. Carbon Z N

  8. Yield comparisons between calculations and experiment Target: MgO Transfer line: Ta Ion source: FEBIAD

  9. Vapour pressure

  10. Picking out materials. MgO Al2O3 SiO2 CaO TiO2 CeO2 HfO2

  11. PSI and PROTRAC 13N : T(1/2) = 9.96 min 11C : T(1/2) = 20.39 min 11CO2 11CO Warm converter 11 MeV 16O(p,α)13N 16O(p,αpn)11C 14N(p,α)11C

  12. Two analysers helps determination of the gases. CsI scintillation detectors helps to determine the half-lives of the species in the traps. Carrier gas (N2) 600 cm3/min Chemical trap

  13. Technical demands • Right temperature for the reactions to occur. • The target needs to ”leak” a certain amounts of Oxygen oxygen rich target for the molecular formation of CO2 and CO. • Target container and transport line in materials that do not thermodynamically favour adsorption. • Ion source with the possibility to handle a molecule. ECRIS

  14. Diluted PROTRAC gas Oxidised PROTRAC gas Oxidised PROTRAC gas + elimination of CO2 with KOH trap Diluted PROTRAC gas + elimination of CO2 with KOH trap Counts in coins.

  15. Actual results

  16. MgO, CO2 ∆H = -154 kJ/mol CO ∆H = -127 kJ/mol CaO CO ∆H ≤ - 200 kJ/mol CO2 ∆H ≤ - 200 kJ/mol SiO2 CO ∆H = -16 kJ/mol CO2 ∆H = -27 kJ/mol TiO2 CO2 ∆H = -146 kJ/mol CO ∆H = -123 kJ/mol Al2O3 , coating CO ∆H = -68 kJ/mol CO2∆H = -70 kJ/mol Al2O3 , felt CO ∆H = -77 kJ/mol CO2∆H = -69 kJ/mol HfO2 CO2 ∆H = -66 kJ/mol CO ∆H = ≥ -8 kJ/mol NO2 ∆H = ≥ -8 kJ/mol NO ∆H = ≥ -8 kJ/mol CeO2 CO ∆H = -154 kJ/mol CO2 ∆H =-156 kJ/mol Enthalpies

  17. Retention times.

  18. Target solution

  19. Thank you for your attention Thanks to: Markus Ammann and Ulli Köster, Prof. Heinz Gäggeler, the ISOLDE collaboration, Thorsten Bartel-Rausch for introduction in gas thermochromatography, Bernd and Robert Eichler for introduction and discussion about analysis and interpretation of gas thermochromatography data. Supported by the EU-RTD project TARGISOL (HPRI-CT-2001-50033) and by PSI.

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