Journal ArticleProperties of Cosmic Deuterons Measured by the Alpha Magnetic SpectrometerAguilar, M; Alpat, B; Ambrosi, G; Anderson, H; Arruda, L; Attig, N; Bagwell, C; Barao, F; Barbanera, M; Barrin, L; Bartoloni, A; Battiston, R; Bayyari, A; Belyaev, N; Bertucci, B; Bindi, V; Bollweg, K; Bolster, J; Borchiellini, M; Borgia, B; Boschini, M J; Bourquin, M; Brugnoni, C; Burger, J; Burger, W J; Cai, X D; Capell, M; Casaus, J; Castellini, G; Cervelli, F; Chang, Y H; Chen, G M; Chen, G R; Chen, H; Chen, H S; Chen, Y; Cheng, L; Chou, H Y; Chouridou, S; Choutko, V; Chung, C H; Clark, C; Coignet, G; Consolandi, C; Contin, A; Corti, C; Cui, Z; Dadzie, K; D’Angelo, F; Dass, A; Delgado, C; Della_Torre, S; Demirköz, M B; Derome, L; Di_Falco, S; Di_Felice, V; Díaz, C; Dimiccoli, F; von_Doetinchem, P; Dong, F; Donnini, F; Duranti, M; Egorov, A; Eline, A; Faldi, F; Fehr, D; Feng, J; Fiandrini, E; Fisher, P; Formato, V; Gámez, C; García-López, R J; Gargiulo, C; Gast, H; Gervasi, M; Giovacchini, F; Gómez-Coral, D M; Gong, J; Grandi, D; Graziani, M; Guracho, A N; Haino, S; Han, K C; Hashmani, R K; He, Z H; Heber, B; Hsieh, T H; Hu, J Y; Huang, B W; Ionica, M; Incagli, M; Jia, Yi; Jinchi, H; Karagöz, G; Khan, S; Khiali, B; Kirn, Th; Klipfel, A P; Kounina, O; Kounine, A; Koutsenko, V; Krasnopevtsev, D; Kuhlman, A; Kulemzin, A; La_Vacca, G; Laudi, E; Laurenti, G; LaVecchia, G; Lazzizzera, I; Lee, H T; Lee, S C; Li, H L; Li, J Q; Li, M; Li, M; Li, Q; Li, Q; Li, Q Y; Li, S; Li, S L; Li, J H; Li, Z H; Liang, M J; Liao, P; Lin, C H; Lippert, T; Liu, J H; Liu, P C; Lu, S Q; Lu, Y S; Luebelsmeyer, K; Luo, J Z; Luo, Q; Luo, S D; Luo, Xi; Mañá, C; Marín, J; Marquardt, J; Martínez, G; Masi, N; Maurin, D; Medvedeva, T; Menchaca-Rocha, A; Meng, Q; Mikhailov, V V; Molero, M; Mott, P; Mussolin, L; Jozani, Y Najafi; Nicolaidis, R; Nikonov, N; Nozzoli, F; Ocampo-Peleteiro, J; Oliva, A; Orcinha, M; Palmonari, F; Paniccia, M; Pashnin, A; Pauluzzi, M; Pensotti, S; Pietzcker, P; Plyaskin, V; Poluianov, S; Pridöhl, D; Qu, Z Y; Quadrani, L; Rancoita, P G; Rapin, D; Conde, A Reina; Robyn, E; Rodríguez-García, I; Romaneehsen, L; Rossi, F; Rozhkov, A; Rozza, D; Sagdeev, R; Savin, E; Schael, S; Schultz_von_Dratzig, A; Schwering, G; Seo, E S; Shan, B S; Shukla, A; Siedenburg, T; Silvestre, G; Song, J W; Song, X J; Sonnabend, R; Strigari, L; Su, T; Sun, Q; Sun, Z T; Tabarroni, L; Tacconi, M; Tang, Z C; Tian, J; Tian, Y; Ting, Samuel_C C; Ting, S M; Tomassetti, N; Torsti, J; Urban, T; Usoskin, I; Vagelli, V; Vainio, R; Valencia-Otero, M; Valente, E; Valtonen, E; Vázquez_Acosta, M; Vecchi, M; Velasco, M; Wang, C X; Wang, L; Wang, L Q; Wang, N H; Wang, Q L; Wang, S; Wang, X; Wang, Z M; Wei, J; Weng, Z L; Wu, H; Wu, Y; Wu, Z B; Xiao, J N; Xiong, R Q; Xiong, X Z; Xu, W; Yan, Q; Yang, H T; Yang, Y; Yelland, A; Yi, H; You, Y H; Yu, Y M; Yu, Z Q; Zhang, C; Zhang, F Z; Zhang, J; Zhang, J H; Zhang, Z; Zhao, P W; Zheng, C; Zheng, Z M; Zhuang, H L; Zhukov, V; Zichichi, A; Zuccon, PAMS_Collaboration<p>Precision measurements by the Alpha Magnetic Spectrometer (AMS) on the International Space Station of the deuteron (<math display='inline'><mrow><mi>D</mi></mrow></math>) flux are presented. The measurements are based on<math display='inline'><mrow><mn>21</mn><mo>×</mo><msup><mrow><mn>10</mn></mrow><mrow><mn>6</mn></mrow></msup></mrow></math><math display='inline'><mrow><mi>D</mi></mrow></math>nuclei in the rigidity range from 1.9 to 21 GV collected from May 2011 to April 2021. We observe that over the entire rigidity range the<math display='inline'><mrow><mi>D</mi></mrow></math>flux exhibits nearly identical time variations with the<math display='inline'><mrow><mi>p</mi></mrow></math>,<math display='inline'><mrow><mmultiscripts><mrow><mi>He</mi></mrow><mprescripts/><none/><mrow><mn>3</mn></mrow></mmultiscripts></mrow></math>, and<math display='inline'><mrow><mmultiscripts><mrow><mi>He</mi></mrow><mprescripts/><none/><mrow><mn>4</mn></mrow></mmultiscripts></mrow></math>fluxes. Above 4.5 GV, the<math display='inline'><mrow><mi>D</mi><mo>/</mo><mrow><mmultiscripts><mrow><mi>He</mi></mrow><mprescripts/><none/><mrow><mn>4</mn></mrow></mmultiscripts></mrow></mrow></math>flux ratio is time independent and its rigidity dependence is well described by a single power law<math display='inline'><mrow><mo>∝</mo><msup><mrow><mi>R</mi></mrow><mrow><mi mathvariant='normal'>Δ</mi></mrow></msup></mrow></math>with<math display='inline'><mrow><msub><mrow><mi mathvariant='normal'>Δ</mi></mrow><mrow><mi>D</mi><mo>/</mo><mrow><mmultiscripts><mrow><mi>He</mi></mrow><mprescripts/><none/><mrow><mn>4</mn></mrow></mmultiscripts></mrow></mrow></msub><mo>=</mo><mo>−</mo><mn>0.108</mn><mo>±</mo><mn>0.005</mn></mrow></math>. This is in contrast with the<math display='inline'><mrow><mrow><mmultiscripts><mrow><mi>He</mi></mrow><mprescripts/><none/><mrow><mn>3</mn></mrow></mmultiscripts></mrow><mo>/</mo><mrow><mmultiscripts><mrow><mi>He</mi></mrow><mprescripts/><none/><mrow><mn>4</mn></mrow></mmultiscripts></mrow></mrow></math>flux ratio for which we find<math display='inline'><mrow><msub><mrow><mi mathvariant='normal'>Δ</mi></mrow><mrow><mrow><mmultiscripts><mrow><mi>He</mi></mrow><mprescripts/><none/><mrow><mn>3</mn></mrow></mmultiscripts></mrow><mo>/</mo><mrow><mmultiscripts><mrow><mi>He</mi></mrow><mprescripts/><none/><mrow><mn>4</mn></mrow></mmultiscripts></mrow></mrow></msub><mo>=</mo><mo>−</mo><mn>0.289</mn><mo>±</mo><mn>0.003</mn></mrow></math>. Above<math display='inline'><mrow><mo stretchy='false'>∼</mo><mn>13</mn><mtext> </mtext><mtext> </mtext><mi>GV</mi></mrow></math>we find a nearly identical rigidity dependence of the<math display='inline'><mrow><mi>D</mi></mrow></math>and<math display='inline'><mrow><mi>p</mi></mrow></math>fluxes with a<math display='inline'><mrow><mi>D</mi></mrow><mo>/</mo><mrow><mi>p</mi></mrow></math>flux ratio of<math display='inline'><mn>0.027</mn><mo>±</mo><mn>0.001</mn></math>. These unexpected observations indicate that cosmic deuterons have a sizable primarylike component. With a method independent of cosmic ray propagation, we obtain the primary component of the<math display='inline'><mrow><mi>D</mi></mrow></math>flux equal to<math display='inline'><mn>9.4</mn><mo>±</mo><mn>0.5</mn><mo>%</mo></math>of the<math display='inline'><mrow><mmultiscripts><mrow><mi>He</mi></mrow><mprescripts/><none/><mrow><mn>4</mn></mrow></mmultiscripts></mrow></math>flux and the secondary component of the<math display='inline'><mrow><mi>D</mi></mrow></math>flux equal to<math display='inline'><mn>58</mn><mo>±</mo><mn>5</mn><mo>%</mo></math>of the<math display='inline'><mrow><mmultiscripts><mrow><mi>He</mi></mrow><mprescripts/><none/><mrow><mn>3</mn></mrow></mmultiscripts></mrow></math>flux.</p> <sec><supplementary-material><permissions><copyright-statement>Published by the American Physical Society</copyright-statement><copyright-year>2024</copyright-year></permissions></supplementary-material></sec>Physical Review Letters2024-06-0110604082Physical Review Letters132260031-9007https://doi.org/10.1103/PhysRevLett.132.2610012149809; 2013228National Science Foundation