INDIAN JOURNAL OF SCIENCE AND TECHNOLOGY RESEARCH ARTICLE OPEN ACCESS Received: 13.12.2020 Accepted: 14.01.2021 Published: 28.01.2021 Citation: Pareek D, Sengar P (2021) Decrement of secondary gamma radiation flux during lunar eclipse June 16, 2011. Indian Journal of Science and Technology 14(3): 245-250. https://doi.org/ 10.17485/IJST/v14i3.2232 ∗ Corresponding author. Tel: 9413954886 deven.pareek69@gmail.com Funding: None Competing Interests: None Copyright: © 2021 Pareek & Sengar. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited. Published By Indian Society for Education and Environment (iSee) ISSN Print: 0974-6846 Electronic: 0974-5645 Decrement of secondary gamma radiation flux during lunar eclipse June 16, 2011 Devendra Pareek 1∗ , Pallavi Sengar 1 1 Department of Physics, Bhupal Nobles’ University, Udaipur, 313001, India. Tel.: 9413954886 Abstract The lunar eclipse at Udaipur (27 ◦ 43’ 12.00” N, 75 ◦ 28’ 48.01” E), India was experimentally observed on June16, 2011 using ground based NaI (Tl) Scintillation detector. We interpret such decrement of secondary gamma radiation flux (SGRF) on the basis of obstruction effect produced by Earth and Moon during lunar eclipse on radiation. Objective: To observe secondary gamma radiation flux during lunar eclipse day on comparison to pre and post eclipse days. Methods: For this experimental study we used ground based NaI (Tl) Scintillation detector. The data files were stored in computer for thirty minutes duration from 1.00 AM to 2.00 AM (Indian Time) on pre-eclipse normal days June 14 and 15, 2011 as well as on post eclipse normal day June 17 and also on eclipse day June 16, 2011. Finding: The analyzed data reveal significant decrement of secondary gamma radiation flux (SGRF) on lunar eclipse day about 6% on comparison to pre and post lunar eclipse days. Novelty: In this experimental study first time we reported about 6% decrement of secondary gamma radiation flux on lunar eclipse day on comparison to pre and post lunar eclipse days. Keywords: Lunar eclipse; cosmic radiation; reflected solar radiation; secondary gamma radiation; obstruction effect by Earth and Moon 1 Introduction Charged particles cosmic radiation travels at nearly the speed of light and coming towards the Earth from all directions. Composition of such radiation is about 89% of these nuclei are protons, 10% of helium, and 1% of others heavier elements (1) . Tere is another class of radiation called solar radiation (SR) corresponded with energetic events on the sun. Te cosmic radiation (CR) almost isotropically distributed and propagates through space while arriving on the Earth (2) . When both radiations reach towards the earth atmosphere and strikes with atoms of the upper atmosphere of the Earth then there is production of “secondary” radiation. Tis secondary radiation has electromagnetic component which consist of gamma radiation, electrons. Produced secondary radiation can be detected using appropriate detector on ground (3,4) . On 15 th and 16 th June 2011 Lunar eclipse was witnessed over much of Europe, much of Asia, Australia, Africa, South America, Pacifc, Atlantic, Indian Ocean and Antarctica as shown in Figure 1. https://www.indjst.org/ 245