arXiv subjects

Debashis Bhowmick

Publications and source records attributed to Debashis Bhowmick.

6 recordsLinked to original sources

arXiv2019

Detection of Crab radiation with a meteorological balloon borne phoswich detector

We use existing light weight balloon facility of Indian Centre for Space Physics to detect the X-ray radiation from Crab pulsar with a phoswich detector. We present the design considerations and characterization of the detector used for this purpose. We model the background radiation in the detector environment at various altitudes and use this in spectral analysis. The background radiation level and limitations on the detector allowed us to calculate minimum detection limit for extrasolar radiation sources with our set up.

astro-ph.IM↗

arXiv2019

Development of Instruments for Space Exploration Using Meteorological-balloons

Indian Centre for Space Physics is engaged in studying terrestrial and extra-terrestrial high energy phenomena from meteorological balloon borne platforms. A complete payload system with such balloons is at the most about five kilograms of weight. One has to adopt innovative and optimal design for various components of the experiment, so that the data can be procured at decent heights of ~ 35-42 km and at the same time, some scientific goals are achieved. In this paper, we mainly describe the instruments in detail and present their test and calibration results. We discuss, how we implemented and tested three major instruments, namely, a Geiger-M\"uller counter, a single crystal scintillator detector and a phoswich type scintillator detector for our missions. We also present some flight data of a few missions to demonstrate the capability of such experiments.

astro-ph.IM↗

arXiv2017

Study of high energy phenomena from near space using low-cost meteorological balloons

Indian Centre for Space Physics has taken a novel strategy to study low energy cosmic rays and astrophysical X-ray sources which involve very light weight payloads up to about five kilograms on board a single or multiple balloons which are usually used for meteorological purposes. The mission duration could be anywhere from 3-12 hours. Our strategy provides extreme flexibility in mission preparation and its operation using a very economical budget. There are several limitations but our innovative approach has been able to extract significant amount of scientific data out of these missions. So far, over one hundred missions have been completed by us to near space and a wealth of data has been collected. The payloads are recovered and are used again. Scientific data is stored on board computer and the atmospheric data or payload location is sent to ground in real time. Since each mission is different, we present here the general strategy for a typical payload and provide some results we obtained in some of these missions.

astro-ph.IM↗

arXiv2017

Measurement of secondary cosmic ray intensity at Regener-Pfotzer height using low-cost weather balloons and its correlation with solar activity

Cosmic ray flux in our planetary system is primarily modulated by solar activity. Radiation effects of cosmic rays on the Earth strongly depend on latitude due to the variation of the geomagnetic field strength. To study these effects we carried out a series of measurements of the radiation characteristics in the atmosphere due to cosmic rays from various places (geomagnetic latitude: ~ 14.50 deg N) in West Bengal, India, located near the Tropic of Cancer, for several years (2012-2016) particularly covering the solar maximum in the 24th solar cycle. We present low energy ($15-140$ keV) secondary radiation measurement results extending from the ground till the near space (~ 40 km) using a scintillator detector on board rubber weather balloons. We also concentrate on the cosmic ray intensity at the Regener-Pfotzer maxima and find a strong anti-correlation between this intensity and the solar activity even at low geomagnetic latitudes.

astro-ph.EP↗

arXiv2013

A New Paradigm in Space Based Experiments Using Rubber Balloons

Indian Centre for Space Physics is engaged in long duration balloon borne experiments with typical payloads less than ~ 3kg. Low cost rubber balloons are used. In a double balloon system, the booster balloon lifts the orbiter balloon to its cruising altitude where data is taken for a long time. Here we present results of muon detections and recent solar activities, including the light curves and flare spectra in the 20-100keV range. We not only show that we have successfully obtained several flares and there spectra at different altitudes, we also found that the high energy X-ray flux of strong flares at altitudes of 10-13 km (the flight altitude of commercial planes) could be more than the contribution due to cosmic rays.

astro-ph.IM↗

arXiv2011

First VLF detections of ionospheric disturbances due to Soft Gamma ray Repeater SGR J1550-5418 and Gamma Ray Burst GRB 090424

We present the first report of the detection of sudden ionospheric disturbances (SIDs) due to a Soft Gamma Ray Repeater (SGR) SGR J1550-5418 and a Gamma Ray Burst (GRB) GRB 090424. These detections were made with receiving stations of Indian Centre for Space Physics which were monitoring Very Low Frequency signals (VLFs) from the VTX transmitter located at the southern tip of Indian sub-continent. These positive detections add to the list of a handful of similar detections of other GRBs and SGRs throughout the world.

astro-ph.GA↗