Constant Current Source for resistivity measurement

A characterization technique by slightly modifying the UV-Visible spectrophotometer Shimadzu model 160 has been developed to characterize the solar sensors to be used for the development and fabrication of Ozone detector/Solar spectrophotometer by SAMEER Mumbai.  The technique consists of placing the solar sensor to be characterized in place of the spectrophotometer detector and recording its intensity vs. wavelength spectra in the manual mode. A typical spectra is  as  shown below. This test procedure has considerably helped SAMEER for optimizing the usage of solar sensors in the fabrication of their Ozone detector / Solar spectrophotometer. Further collaborative work has been planned in this regard.

Design & Fabrication of an Experimental set-up for the Solar Corona Studies during Total Solar Eclipse :

An experimental set-up consisting of i) Fabry-Perot Interferometer with an interference filter with 7 A0 bandwidth centered at l = 5303 A0, ii) a lens (L1) to recollimate light passing through the filter (D = 66.66 mm, F = 80mm, f/1.2), iii) Camera lens (L2) for imaging. (D = 45.833 mm, F = 55mm, f/1.2), iv) Mercury lamp to calibrate instrument and to determine instrumental profile, was designed and fabricated to (a) measure the Large scale Mass flows in Solar Corona by using Doppler shift, (b) determine the temperature distribution and velocity field in solar corona during the total solar eclipse of 22nd July 2009, for the M.Sc. students of Department of Astro-Physics, University of Mumbai and Helios Astronomy Group, Mumbai. The set up was found to be extremely useful by these students in performing their experiments on Solar Corona studies. The experiment was conducted in Hawgzhou & Wuhan cities of China. Prof. A.M. Narsale and Dr. R.D. Tewari delivered invited talks in this regard at the Cultural Centre of Russia on 10th July 2009.