Vashenyuk, E.V. and Miroshnichenko, L.I. and Gvozdevsky, B.B. (2000) Proton energy spectrum and source parameters of the September 29, 1989 event. Il nuovo cimento C, 23 C (3). pp. 285-292. ISSN 1826-9885
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Abstract
Ground Level Enhancement (GLE) of solar cosmic rays (SCR) widely observed on September 29, 1989 is studied. The event was remarkable for a number of unusual features. Among them were the double-peak increases observed at some neutron monitor (NM) stations and complicated behaviour of the proton energy spectrum and anisotropy at high rigidities (RF1 GV). Two-component structure of the proton intensity-time profiles in the event has been demonstrated. The first (prompt) component (PC) had a short duration and very hard energy spectrum. The second (delayed) component (DC), being ejected from the Sun A1-2 h later, was dominated by a particle population with the soft spectrum and gradual profiles. By fitting the observed proton spectrum to the calculated one in a computational model with a fast acceleration mechanism at the first, early stage of the event, we estimate parameters of the magnetic field and plasma in the source of the prompt component: B= 91 G; n = 1.23107 cm23 ; L= 109 cm (B, n and L are magnetic field intensity, plasma density at the acceleration site and length of the current sheet, respectively). Such values of B and n are characteristic for the trailing part of coronal transient (behind an eruptive filament) at the coronal heights of several tenths of solar radius, and the value of L is of the order of the filament length.
| Item Type: | Article |
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| Uncontrolled Keywords: | Cosmic rays |
| Subjects: | 500 Scienze naturali e Matematica > 550 Scienze della Terra > 551 Geologia, Idrologia, Meteorologia > 551.5 Meteorologia (Classificare qui l'atmosfera) (Classificare la previsione e le previsioni di specifici fenomeni meteorologici in 551.64; classificare la Micrometeorologia in 551.66) > 551.52 Termodinamica, interazioni atmosferiche con la superficie terrestre, temperature, radiazioni > 551.527 Radiazioni (per fenomeni ottici, vedi 551.565) > 551.5276 Radiazioni cosmiche (Include il rumore cosmico) (Classificare qui i raggi cosmici) |
| Depositing User: | Marina Spanti |
| Date Deposited: | 09 Mar 2020 14:58 |
| Last Modified: | 09 Mar 2020 14:58 |
| URI: | http://eprints.bice.rm.cnr.it/id/eprint/13906 |
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