Borislav Tomov - Academia.edu (original) (raw)

Papers by Borislav Tomov

Research paper thumbnail of A Comparison Between Models of the Moon Radiation Environment and the Data from the RADOM Experiment Onboard the Indian Chandrayaan-1 Satellite

De Angelis G. Dachev Ts. P. Tomov B. Matviichuk Yu. Dimitrov P. Spurny F. A Comparison Between Mo... more De Angelis G. Dachev Ts. P. Tomov B. Matviichuk Yu. Dimitrov P. Spurny F. A Comparison Between Models of the Moon Radiation Environment and the Data from the RADOM Experiment Onboard the Indian Chandrayaan-1 Satellite [#1711] Models of radiation environment due to Galactic Cosmic Rays (GCR) and Solar Particle Events (SPE) on the Moon have been developed, and compared with data from the RADOM investigation onboard the ISRO Chandrayaan-1 spacecraft.

Research paper thumbnail of High dose rates obtained outside ISS in June 2015 during SEP event

Life Sciences in Space Research, 2016

The R3DR2 instrument performed measurements in the European Space Agency (ESA) EXPOSE-R2 platform... more The R3DR2 instrument performed measurements in the European Space Agency (ESA) EXPOSE-R2 platform outside the Russian "Zvezda" module of the International Space Station (ISS) in the period 24 October 2014-11 January 2016. It is the Liulin-type deposited energy spectrometer (DES) (Dachev et al., 2015a). Took place in November 2014, this was the first attempt to monitor a small solar energetic particle (SEP) event outside ISS using the Liulin-type DES (Dachev et al., 2015d). In this study, we describe the dosimetric characteristics of the largest SEP event, observed on 22 June 2015 with the R3DR2 instrument outside ISS. The main finding of this study is that SEP protons with a minimum energy of approximately 7MeV at the surface of the R3DR2 detector produced high dose rates, reaching >5000µGyh(-1), while the inner radiation belt maximum dose was at the level of 2200µGyh(-1). If a virtual external vehicle activity (EVA) was performed in the same period of the SEP maximum on 22 June 2015, the doses obtained in the skin of cosmonauts/astronauts can reach 2.84mGy after 6.5h, which is similar to the average absorbed dose inside ISS for 15days (Reitz et al., 2005). A comparison with other extreme events measured with Liulin-type instruments shows that SEPs similar to that observed on 22 June 2015 could be one of the most dangerous events for the cosmonauts/astronauts involved in EVA.

Research paper thumbnail of The Field Luminosity Function and Nearby Groups of Galaxies

The Large Scale Structure of the Universe, 1978

Research paper thumbnail of Space Radiation Peculiarities in the Extra Vehicular Environment of the International Space Station (ISS)

Research paper thumbnail of Fine Resolution Neutron Detector for ExoMars Trace Gas Orbiter. Instrument and science goals

Research paper thumbnail of Space Shuttle drops down the SAA doses on ISS

Advances in Space Research, 2011

Research paper thumbnail of Relativistic electron fluxes and dose rate variations during April–May 2010 geomagnetic disturbances in the R3DR data on ISS

Advances in Space Research, 2012

Research paper thumbnail of Time serial analysis of the induced LEO environment within the ISS 6A

Advances in Space Research, 2007

Anisotropies in the low Earth orbit (LEO) radiation environment were found to influence the therm... more Anisotropies in the low Earth orbit (LEO) radiation environment were found to influence the thermoluminescence detectors (TLD) dose within the (International Space Station) ISS 7A Service Module. Subsequently, anisotropic environmental models with improved dynamic time extrapolation have been developed including westward and northern drifts using AP8 Min & Max as estimates of the historic spatial distribution of trapped protons in

Research paper thumbnail of Overview of the Liulin type instruments for space radiation measurement and their scientific results

Ionizing radiation is recognized to be one of the main health concerns for humans in the space ra... more Ionizing radiation is recognized to be one of the main health concerns for humans in the space radiation environment. Estimation of space radiation effects on health requires the accurate knowledge of the accumulated absorbed dose, which depends on the global space radiation distribution, solar cycle and local shielding generated by the 3D mass distribution of the space vehicle. This paper presents an overview of the spectrometer-dosimeters of the Liulin type, which were developed in the late 1980s and have been in use since then. Two major measurement systems have been developed by our team. The first one is based on one silicon detector and is known as a Liulin-type deposited energy spectrometer (DES) (Dachev et al., 2002, 2003), while the second one is a dosimetric telescope (DT) with two or three silicon detectors. The Liulin-type instruments were calibrated using a number of radioactive sources and particle accelerators. The main results of the calibrations are presented in the...

Research paper thumbnail of Charged particles radiation measurements with Liulin-MO dosimeter of FREND instrument aboard ExoMars Trace Gas Orbiter during the transit and in high elliptic Mars orbit

ExoMars is a joint ESA—Rosscosmos program for investigating Mars. Two missions are foreseen withi... more ExoMars is a joint ESA—Rosscosmos program for investigating Mars. Two missions are foreseen within this program: one consisting of the Trace Gas Orbiter (TGO), that carries scientific instruments for the detection of trace gases in the Martian atmosphere and for the location of their source regions, plus an Entry, Descent and landing demonstrator Module (EDM), launched on March 14, 2016; and the other, featuring a rover and a surface platform, with a launch date of 2020. On October 19, 2016 TGO was inserted into high elliptic Mars’ orbit. The dosimetric telescope Liulin-MO for measuring the radiation environment onboard the ExoMars 2016 TGO is a module of the Fine Resolution Epithermal Neutron Detector (FREND). Here we present first results from measurements of the charged particle fluxes, dose rates, Linear Energy Transfer (LET) spectra and estimation of dose equivalent rates in the interplanetary space during the cruise of TGO to Mars and first results from dosimetric measurements...

Research paper thumbnail of Mir" radiation dosimetry results during the solar proton events in September-October 1989

Advances in space research : the official journal of the Committee on Space Research, 1992

Using data from dosimetry-radiometry system "Liulin" on board of "Mir"-space ... more Using data from dosimetry-radiometry system "Liulin" on board of "Mir"-space station the particle flux and doserate during September-October, 1989 has been studied. The orbit of the station was 379 km perigee, 410 km apogee and 51.6 degrees inclination. Special attention has been paid to the flux and doserate changes inside the station after intensive solar proton events (SPE) on 29 of September, 1989. The comparison between the doses before and after the solar flares shows increase of the calculated mean dose per day by factor of 10 to 200. During the SPE on the 29 of September the additional dose was 310 mrad. The results of the experiment are compared with the data for the solar proton fluxes obtained on the GOES-7 satellite.

Research paper thumbnail of Analysis of the Cyclotron Facility calibration and aircraft dosimetry results from the LIULIN-3M instrument

The LIULIN-3M instrument is a further development of the LIULIN dosimeter-radiometer, used on the... more The LIULIN-3M instrument is a further development of the LIULIN dosimeter-radiometer, used on the MIR spacestation during the 1988-1994 time period. The LIULIN-3M is designed for continuous monitoring of the radiation environment during the BION-12 satellite flight in 1999. A semiconductor detector with 1 mm thickness and cm2 area is contained in the instrument. Pulse high analysis technique is used to determine the energy losses in the detector. The final data from the instrument are the flux and the dose rate for the exposure time and 256 channels of absorbed dose spectra based on the assumption that the particle flux is normal to the detector. The LIULIN-3M instrument was calibrated by proton fluxes with different energies at the Indiana University Cyclotron Facility in June 1997 and had been used for radiation measurements during commercial aircraft flights. The calibration procedure and some flight results are presented in this paper.

Research paper thumbnail of Superclustering of Galaxies

Research paper thumbnail of Solar wind modulation of galactic cosmic rays observed on board of ExoMars TGO

Research paper thumbnail of Overview of the ISS Radiation Environment Observed during the ESA EXPOSE-R2 Mission in 2014-2016

Research paper thumbnail of Construction of complete sets of Gaussian smoothing and filtering functions for discrete fields of galaxies and clusters of galaxies

Research paper thumbnail of BION-M" No. 1 spacecraft radiation environment as observed in April-May 2013. Comparison with ISS data

ABSTRACT Space radiation has been monitored using the РД3-Б3 (in the following we use the Latin t... more ABSTRACT Space radiation has been monitored using the РД3-Б3 (in the following we use the Latin transcription RD3-B3) spectrometer-dosimeter on board a recent space flight of the Russian recoverable satellite “BION-M” No. 1. The instrument was mounted inside the satellite in a pressurized volume together with biological objects and samples. The RD3-B3 instrument is a battery operated version of the spare model of the R3D-B3 instrument developed and built for the ESA BIOPAN-6 facility on Foton M3 satellite launched on September 2007 (Häder et al., 2009). It is a low mass, small dimension automated device that measures solar radiation in four channels and ionizing radiation in 256 channels of a Liulin-type energy deposition spectrometer (Dachev et al., 2002). Cosmic ionizing radiation has been monitored and separated in 256 deposited energy spectra, which were further used for determination of the absorbed dose rate and flux. The paper summarizes the results for the Earth radiation environment at the altitude of 253-585 km.

Research paper thumbnail of Monitoring of the Earth and Moon radiation environment by the RADOM instrument on Indian Chandrayyan-1 satellite. Preliminary results

Research paper thumbnail of “Mir” radiation dosimetry results during the solar proton events in September – October 1989

Advances in Space Research, 1992

Using data from dosimetry-radiometry system "Liulin" on board o... more Using data from dosimetry-radiometry system "Liulin" on board of "Mir"-space station the particle flux and doserate during September-October, 1989 has been studied. The orbit of the station was 379 km perigee, 410 km apogee and 51.6 degrees inclination. Special attention has been paid to the flux and doserate changes inside the station after intensive solar proton events (SPE) on 29 of September, 1989. The comparison between the doses before and after the solar flares shows increase of the calculated mean dose per day by factor of 10 to 200. During the SPE on the 29 of September the additional dose was 310 mrad. The results of the experiment are compared with the data for the solar proton fluxes obtained on the GOES-7 satellite.

Research paper thumbnail of Tissue equivalent detector data obtained recently on Mir space station. Comparison with Solid State Detector data

Advances in Space Research, 1996

... Siegrist,** E. Duvivier,*** B. Almarcha,*** TP Dachev,t JV Semkova,t YN Matviichuk,t RT Kolev... more ... Siegrist,** E. Duvivier,*** B. Almarcha,*** TP Dachev,t JV Semkova,t YN Matviichuk,t RT Koleva,t BT Tomov,t PT Baynov,t VM Petrov,t VV ... 2. Map of H and Q aboard the MIR station on 31 July 1992 (quiet solar activity) : the dose rate increases and the quality factor decreases in ...

Research paper thumbnail of A Comparison Between Models of the Moon Radiation Environment and the Data from the RADOM Experiment Onboard the Indian Chandrayaan-1 Satellite

De Angelis G. Dachev Ts. P. Tomov B. Matviichuk Yu. Dimitrov P. Spurny F. A Comparison Between Mo... more De Angelis G. Dachev Ts. P. Tomov B. Matviichuk Yu. Dimitrov P. Spurny F. A Comparison Between Models of the Moon Radiation Environment and the Data from the RADOM Experiment Onboard the Indian Chandrayaan-1 Satellite [#1711] Models of radiation environment due to Galactic Cosmic Rays (GCR) and Solar Particle Events (SPE) on the Moon have been developed, and compared with data from the RADOM investigation onboard the ISRO Chandrayaan-1 spacecraft.

Research paper thumbnail of High dose rates obtained outside ISS in June 2015 during SEP event

Life Sciences in Space Research, 2016

The R3DR2 instrument performed measurements in the European Space Agency (ESA) EXPOSE-R2 platform... more The R3DR2 instrument performed measurements in the European Space Agency (ESA) EXPOSE-R2 platform outside the Russian "Zvezda" module of the International Space Station (ISS) in the period 24 October 2014-11 January 2016. It is the Liulin-type deposited energy spectrometer (DES) (Dachev et al., 2015a). Took place in November 2014, this was the first attempt to monitor a small solar energetic particle (SEP) event outside ISS using the Liulin-type DES (Dachev et al., 2015d). In this study, we describe the dosimetric characteristics of the largest SEP event, observed on 22 June 2015 with the R3DR2 instrument outside ISS. The main finding of this study is that SEP protons with a minimum energy of approximately 7MeV at the surface of the R3DR2 detector produced high dose rates, reaching >5000µGyh(-1), while the inner radiation belt maximum dose was at the level of 2200µGyh(-1). If a virtual external vehicle activity (EVA) was performed in the same period of the SEP maximum on 22 June 2015, the doses obtained in the skin of cosmonauts/astronauts can reach 2.84mGy after 6.5h, which is similar to the average absorbed dose inside ISS for 15days (Reitz et al., 2005). A comparison with other extreme events measured with Liulin-type instruments shows that SEPs similar to that observed on 22 June 2015 could be one of the most dangerous events for the cosmonauts/astronauts involved in EVA.

Research paper thumbnail of The Field Luminosity Function and Nearby Groups of Galaxies

The Large Scale Structure of the Universe, 1978

Research paper thumbnail of Space Radiation Peculiarities in the Extra Vehicular Environment of the International Space Station (ISS)

Research paper thumbnail of Fine Resolution Neutron Detector for ExoMars Trace Gas Orbiter. Instrument and science goals

Research paper thumbnail of Space Shuttle drops down the SAA doses on ISS

Advances in Space Research, 2011

Research paper thumbnail of Relativistic electron fluxes and dose rate variations during April–May 2010 geomagnetic disturbances in the R3DR data on ISS

Advances in Space Research, 2012

Research paper thumbnail of Time serial analysis of the induced LEO environment within the ISS 6A

Advances in Space Research, 2007

Anisotropies in the low Earth orbit (LEO) radiation environment were found to influence the therm... more Anisotropies in the low Earth orbit (LEO) radiation environment were found to influence the thermoluminescence detectors (TLD) dose within the (International Space Station) ISS 7A Service Module. Subsequently, anisotropic environmental models with improved dynamic time extrapolation have been developed including westward and northern drifts using AP8 Min & Max as estimates of the historic spatial distribution of trapped protons in

Research paper thumbnail of Overview of the Liulin type instruments for space radiation measurement and their scientific results

Ionizing radiation is recognized to be one of the main health concerns for humans in the space ra... more Ionizing radiation is recognized to be one of the main health concerns for humans in the space radiation environment. Estimation of space radiation effects on health requires the accurate knowledge of the accumulated absorbed dose, which depends on the global space radiation distribution, solar cycle and local shielding generated by the 3D mass distribution of the space vehicle. This paper presents an overview of the spectrometer-dosimeters of the Liulin type, which were developed in the late 1980s and have been in use since then. Two major measurement systems have been developed by our team. The first one is based on one silicon detector and is known as a Liulin-type deposited energy spectrometer (DES) (Dachev et al., 2002, 2003), while the second one is a dosimetric telescope (DT) with two or three silicon detectors. The Liulin-type instruments were calibrated using a number of radioactive sources and particle accelerators. The main results of the calibrations are presented in the...

Research paper thumbnail of Charged particles radiation measurements with Liulin-MO dosimeter of FREND instrument aboard ExoMars Trace Gas Orbiter during the transit and in high elliptic Mars orbit

ExoMars is a joint ESA—Rosscosmos program for investigating Mars. Two missions are foreseen withi... more ExoMars is a joint ESA—Rosscosmos program for investigating Mars. Two missions are foreseen within this program: one consisting of the Trace Gas Orbiter (TGO), that carries scientific instruments for the detection of trace gases in the Martian atmosphere and for the location of their source regions, plus an Entry, Descent and landing demonstrator Module (EDM), launched on March 14, 2016; and the other, featuring a rover and a surface platform, with a launch date of 2020. On October 19, 2016 TGO was inserted into high elliptic Mars’ orbit. The dosimetric telescope Liulin-MO for measuring the radiation environment onboard the ExoMars 2016 TGO is a module of the Fine Resolution Epithermal Neutron Detector (FREND). Here we present first results from measurements of the charged particle fluxes, dose rates, Linear Energy Transfer (LET) spectra and estimation of dose equivalent rates in the interplanetary space during the cruise of TGO to Mars and first results from dosimetric measurements...

Research paper thumbnail of Mir" radiation dosimetry results during the solar proton events in September-October 1989

Advances in space research : the official journal of the Committee on Space Research, 1992

Using data from dosimetry-radiometry system "Liulin" on board of "Mir"-space ... more Using data from dosimetry-radiometry system "Liulin" on board of "Mir"-space station the particle flux and doserate during September-October, 1989 has been studied. The orbit of the station was 379 km perigee, 410 km apogee and 51.6 degrees inclination. Special attention has been paid to the flux and doserate changes inside the station after intensive solar proton events (SPE) on 29 of September, 1989. The comparison between the doses before and after the solar flares shows increase of the calculated mean dose per day by factor of 10 to 200. During the SPE on the 29 of September the additional dose was 310 mrad. The results of the experiment are compared with the data for the solar proton fluxes obtained on the GOES-7 satellite.

Research paper thumbnail of Analysis of the Cyclotron Facility calibration and aircraft dosimetry results from the LIULIN-3M instrument

The LIULIN-3M instrument is a further development of the LIULIN dosimeter-radiometer, used on the... more The LIULIN-3M instrument is a further development of the LIULIN dosimeter-radiometer, used on the MIR spacestation during the 1988-1994 time period. The LIULIN-3M is designed for continuous monitoring of the radiation environment during the BION-12 satellite flight in 1999. A semiconductor detector with 1 mm thickness and cm2 area is contained in the instrument. Pulse high analysis technique is used to determine the energy losses in the detector. The final data from the instrument are the flux and the dose rate for the exposure time and 256 channels of absorbed dose spectra based on the assumption that the particle flux is normal to the detector. The LIULIN-3M instrument was calibrated by proton fluxes with different energies at the Indiana University Cyclotron Facility in June 1997 and had been used for radiation measurements during commercial aircraft flights. The calibration procedure and some flight results are presented in this paper.

Research paper thumbnail of Superclustering of Galaxies

Research paper thumbnail of Solar wind modulation of galactic cosmic rays observed on board of ExoMars TGO

Research paper thumbnail of Overview of the ISS Radiation Environment Observed during the ESA EXPOSE-R2 Mission in 2014-2016

Research paper thumbnail of Construction of complete sets of Gaussian smoothing and filtering functions for discrete fields of galaxies and clusters of galaxies

Research paper thumbnail of BION-M" No. 1 spacecraft radiation environment as observed in April-May 2013. Comparison with ISS data

ABSTRACT Space radiation has been monitored using the РД3-Б3 (in the following we use the Latin t... more ABSTRACT Space radiation has been monitored using the РД3-Б3 (in the following we use the Latin transcription RD3-B3) spectrometer-dosimeter on board a recent space flight of the Russian recoverable satellite “BION-M” No. 1. The instrument was mounted inside the satellite in a pressurized volume together with biological objects and samples. The RD3-B3 instrument is a battery operated version of the spare model of the R3D-B3 instrument developed and built for the ESA BIOPAN-6 facility on Foton M3 satellite launched on September 2007 (Häder et al., 2009). It is a low mass, small dimension automated device that measures solar radiation in four channels and ionizing radiation in 256 channels of a Liulin-type energy deposition spectrometer (Dachev et al., 2002). Cosmic ionizing radiation has been monitored and separated in 256 deposited energy spectra, which were further used for determination of the absorbed dose rate and flux. The paper summarizes the results for the Earth radiation environment at the altitude of 253-585 km.

Research paper thumbnail of Monitoring of the Earth and Moon radiation environment by the RADOM instrument on Indian Chandrayyan-1 satellite. Preliminary results

Research paper thumbnail of “Mir” radiation dosimetry results during the solar proton events in September – October 1989

Advances in Space Research, 1992

Using data from dosimetry-radiometry system "Liulin" on board o... more Using data from dosimetry-radiometry system "Liulin" on board of "Mir"-space station the particle flux and doserate during September-October, 1989 has been studied. The orbit of the station was 379 km perigee, 410 km apogee and 51.6 degrees inclination. Special attention has been paid to the flux and doserate changes inside the station after intensive solar proton events (SPE) on 29 of September, 1989. The comparison between the doses before and after the solar flares shows increase of the calculated mean dose per day by factor of 10 to 200. During the SPE on the 29 of September the additional dose was 310 mrad. The results of the experiment are compared with the data for the solar proton fluxes obtained on the GOES-7 satellite.

Research paper thumbnail of Tissue equivalent detector data obtained recently on Mir space station. Comparison with Solid State Detector data

Advances in Space Research, 1996

... Siegrist,** E. Duvivier,*** B. Almarcha,*** TP Dachev,t JV Semkova,t YN Matviichuk,t RT Kolev... more ... Siegrist,** E. Duvivier,*** B. Almarcha,*** TP Dachev,t JV Semkova,t YN Matviichuk,t RT Koleva,t BT Tomov,t PT Baynov,t VM Petrov,t VV ... 2. Map of H and Q aboard the MIR station on 31 July 1992 (quiet solar activity) : the dose rate increases and the quality factor decreases in ...