The time evolution of the low-energy deuteron fluxes measured in Cosmic Rays with the PAMELA experiment from the 23rd solar minimum to the 24th solar maximum

• Published in: Astroparticle physics Vol. 168; p. 103089
• Main Authors: Lenni, A., Boezio, M., Munini, R., Menn, W., Marcelli, N., Ngobeni, M.D., Ndiitwani, D.C., Ramokgaba, I.I., Potgieter, M.S., Adriani, O., Barbarino, G.C., Bazilevskaya, G.A., Bellotti, R., Bogomolov, E.A., Bongi, M., Bonvicini, V., Bruno, A., Cafagna, F., Campana, D., Carlson, P., Casolino, M., Castellini, G., De Santis, C., Galper, A.M., Koldashov, S.V., Koldobskiy, S., Kvashnin, A.N., Leonov, A.A., Malakhov, V.V., Marcelli, L., Martucci, M., Mayorov, A.G., Mergè, M., Mocchiutti, E., Monaco, A., Mori, N., Mikhailov, V.V., Osteria, G., Panico, B., Palma, F., Papini, P., Picozza, P., Ricci, M., Ricciarini, S.B., Simon, M., Sotgiu, A., Sparvoli, R., Spillantini, P., Stozhkov, Y.I., Vacchi, A., Vannuccini, E., Voronov, S.A., Yurkin, Y.T., Zampa, G., Zampa, N.
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 01.06.2025
• Subjects: Cosmic rays; Deuterons; Heliosphere; Solar activity cycle; Solar modulation; Heliosphere; Deuterons; Solar modulation; Solar activity cycle; Cosmic rays
• ISSN: 0927-6505; 1873-2852
• DOI: 10.1016/j.astropartphys.2025.103089

The space-borne PAMELA experiment was launched on the 15th of June 2006 on board the Russian satellite Resurs-DK1 from the Baikonur Cosmodrome. The PAMELA instrument performed high-precision measurements of cosmic rays over a wide energy range until January 2016. We present the yearly average deuteron spectra for the 23rd solar minimum (July 2006 – January 2009) and the first part of the 24th solar maximum (until September 2014). The deuterons were selected with a rigidity between 0.75 and 2.6 GV by combining the Time of Flight (ToF) and the tracker systems. The measured spectra display a rising trend toward the solar minimum followed by a decreasing trend as the solar maximum approaches. The corresponding deuteron-to-proton flux ratios show time dependence at the lowest rigidities, as expected due to the different charge-to-mass ratios and the different shapes of the respective local interstellar spectra. These results are significant for the fine-tuning of propagation and modulation models of cosmic rays through the heliosphere.