Physical properties of ices present in TNOs? Density of nitrogen and methane Physical properties of ices present in TNOs? Good afternoon First of all I want to thank the comité for let me expose our work The goal of my talk is show you some results of the experiments performed in our laboratory in Alcoi in order to get comments and suggestions for apply in these interesting objects. With is mind we select 3 molecules. Two of them are detected in TNOs as Nitrogen and CH4. As can be seen from the list of 32 TNOs presented by Barucci, Merlin, Dotto, Doressoundiram and de Bergh. The third molecule we studied is CO2 because it is detected on the surface of Triton (Cruikshank 93) that can be considered as “relative” of TNOs. Strazzulla (03) And supported by the capture hypothesis for Triton proposed by McKinnon (95) reinforced by the idea of a zone of common origin Morbidelli and Levison (04). On the other hand the variability in the spectra obtained from the same object in different periods (Barucci et al 05) suggest the possibility of different zones due, among other reasons to differential sublimation (Sedna can have atmosphere in certain conditions). Then the situation exposed by Quirico et al 99 refering to different terrains with volatile dominated molecules. And the possibility of a CO2 dominated terrain open to us the possibility of study the effect on the characteristic temperature of sublimation of N2 and CH4 due to the structure of CO2. M.A. Satorre, M. Domingo, R. Luna, C. Millán, J. Cantó Escola Politècnica Superior d’Alcoi Universitat Politècnica de València 04/05/2019

Density of nitrogen and methane Contents Experimental set-up and procedure Results n, , pure molecules (N2, CH4, CO2) (Double laser and QCMB) n for CO2 from ~ 270 to 650 nm (UV-Vis) Tsubl for pure molecules and CO2 dominated (95 %) binary mixtures (TPD) Summary 04/05/2019

Experimental Set-up and procedure Interference register Si diodes (a) chamber squematic side view (b) chamber squematic top view CO2 mixture prechamber CH4 N2 Other ceravac center three Laser 1 Laser 2 α β Closed He-cycle Cold finger Au substrat QCMB Cryostat ITR 90 secuvac turbo pump rotary pump gas inlet window Interference register 04/05/2019

Experimental Set-up and procedure 04/05/2019

Double laser technique and Quartz Crystal Microbalance (QCMB) 04/05/2019

Density of nitrogen and methane Results: n, , pure molecules CH4 (20K) N2 (20K) CO2 (77K) 1 Roux, J.A. et al. ours Roux, J.A. et al 2 Tempelmeyer, K.E, et al. 3 Warren, S.G. (g/cm3) 0.42 0.43 0.83 0.85 1.50 n 1.35 1.25 1.45 1.41 1.40 Infrared Optical Properties of Thin film CO, NO, CH4; HCl, N2O, O2, N2, Ar and Air Cryofilms J.A. Roux; B.E. Wood; A. M. Smith and R.R. Plyer Roux, J.A.; Wood, B.E.; Smith, A.M.; Plyer, R.R., (1979), Report Nº AEDC-TR-78-81, Defense Technical Information Center. Tempelmeyer, K.E.; Mills, Jr., D.W., (1968), J. Appl. Phys., 39 (6), 2968-2969. Warren, S.G. (1986), Applied Optics, 25, 16, 2650-2674. 04/05/2019

Nitrogen Results: n, , nitrogen 04/05/2019 * Roux, J.A.; Wood, B.E.; Smith, A.M.; Plyer, R.R., (1979), Report Nº AEDC-TR-78-81, Defense Technical Information Center. 04/05/2019

Methane Results: n, , methane 04/05/2019 * Roux, J.A.; Wood, B.E.; Smith, A.M.; Plyer, R.R., (1979), Report Nº AEDC-TR-78-81, Defense Technical Information Center. 04/05/2019

Results: n, , carbon dioxide 04/05/2019

Interference with UV-Vis spectrometer 04/05/2019

Results: n, carbon dioxide at different  04/05/2019

Density of nitrogen and methane Results: n, carbon dioxide at different  Infrared Optical Propertiees of Thin film CO, NO, CH4; HCl, N2O, O2, N2, Ar and Air Cryofilms J.A. Roux; B.E. Wood; A. M. Smith and R.R. Plyer 04/05/2019

Temperature Programmed Desorption with the mass spectrometer 04/05/2019

Results: Tsubl 04/05/2019

Results: Tsubl, CH4-CO2, N2-CO2 mixtures 04/05/2019

Summary The index of refraction and density of pure Methane, Nitrogen and Carbon Dioxide is obtained at different deposition temperatures Variation on the index of refraction at wavelengths from 250 till 650 nm are obtained Changes on the characteristic temperature of sublimation for both methane and nitrogen codeposited with carbon dioxide are identified Acknowledgements -This research has been supported by “Ministerio de Ciencia y Tecnología” (AYA2004-05382) and FEDER founds 04/05/2019

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