http://192.168.1.40:8080/xmlui/handle/123456789/1099 2026-05-31T12:08:34Z http://192.168.1.40:8080/xmlui/handle/123456789/2563 Bose Institute : A Historical Perspective,1917-47 Siddiqi, Maqsood; Raha, Sibaji 2011-01-01T00:00:00Z http://192.168.1.40:8080/xmlui/handle/123456789/2301 Characterization of some commercial polymers for the detection of massive cosmic ray particles Basu, Basudhara; Mazumdar, A.; Raha, Sibaji; Saha, S.; Saha, Swapan K.; Syam, D. A particular brand (CENTURY de'Smat, India) of overhead projector (OHP) film has been exposed to α-particle and fission fragments from 252Cf natural source in order to investigate its detection efficiency and charge sensitivity in comparison to the standard detector CR39, applying solid state nuclear track detection (SSNTD) technique. The results obtained indicate that these OHP films cannot detect particles with Z / β ≤ 35, but particles with Z/β ∼ 900 -1600 can be detected. The composition of the OHP film was determined. The high detection threshold identifies this particular material as a suitable candidate for setting up a large area array of detectors, aiming at the search of rare massive cosmic ray particles at mountain altitudes. 2005-03-01T00:00:00Z http://192.168.1.40:8080/xmlui/handle/123456789/2290 Characterization of a polymer as a heavy ion detector Basu, B.; Fischer, B.; Mazumdar, A.; Raha, Sibaji; Saha, S.; Saha, Swapan K.; Syam, D. A particular brand of polymer, commonly used as overhead projector transparencies, has been used as a solid state nuclear track detector with Z/beta > 35. From the infra-red transmission spectrum by FTIR Spectrophotometer, the polymer was identified to be polyethylene terepthalate (PET). The charge response of this PET detector has been studied using 11.3 MeV/n U-238-ion and 11.4 MeV/n Ni-58-ions from GSI, Germany and 53.6 MeV O-16-ions from Nuclear Science Centre, India. 2005-01-01T00:00:00Z http://192.168.1.40:8080/xmlui/handle/123456789/2288 A highly unusual cosmic ray event at mountain altitude Basu, B.; Biswas, S.; Dey, S.; Mazumdar, A.; Raha, Sibaji; Saha, Swapan K. Search of rare massive particles in cosmic rays became an active field of research for several years. A recent theoretical study suggested the possible existence of strangelets in cosmic rays even at the mountain altitude. A common polymer, generally used as overhead projector transparencies, was identified as a solid state nuclear track detector (SSNTD) with a detection threshold Z/beta > 35. Those polymer detectors were exposed to cosmic rays at an altitude of 2.2 km as a trial experiment for setting up a large area array of detectors, aiming at the search of rare massive cosmic ray particles at mountain altitude. During the analysis of one such OHP detector we have found a highly unusual event. In the present paper we report our observation. 2005-01-01T00:00:00Z