Automatic measurements with the Pille-ISS thermoluminescent dosimeter system on board the International Space Station (2003-2021).

The health risk of staying in space is a well-known fact, and the radiation doses to the astronauts must be monitored. The Pille-ISS thermoluminescent dosimeter system is present on the International Space Station (ISS) since 2003. We present an analysis of 60000 data points over 19 years from the 90 min automatic measurements and show a 4-day-long segment of 15 min measurements.

The neutron dose equivalent rate measurements by R3DR/R2 spectrometers on the international space station.

The data from two Bulgarian-German instruments with the basic name "Radiation Risk Radiometer-Dosimeter" (R3D) are discussed. The R3DR instrument worked inside the ESA EXPOSE-R facility (2009-2010), while R3DR2 worked inside the ESA EXPOSE-R2 facility (2014-2016). Both were outside the Russian Zvezda module on the International Space Station (ISS).

Results of long-term radiation environment monitoring by the Russian RMS system on board Zvezda module of the ISS.

The Radiation monitoring system (RMS) continuously operated in various configurations since the launch of the Zvezda module of the International Space Station (ISS). The RMS consisted of 7 units, namely: the R-16 dosimeter, 4 DB-8 dosimeters, utility and data collection units. The obtained data covers a time of 22 years.

Comparison of the particle flux measured by Liulin-MO dosimeter in ExoMars TGO science orbit with those calculated by models.

The knowledge of the space radiation environment in spacecraft transition and in Mars vicinity is of importance for the preparation of the human exploration of Mars. ExoMars Trace Gas Orbiter (TGO) was launched on March 14, 2016 and was inserted into circular Mars science orbit (MSO) with a 400 km altitude in March 2018. The Liulin-MO dosimeter is a module of the Fine Resolution Epithermal Neutron Detector (FREND) aboard ExoMars TGO and has been measuring the radiation environment during the TGO interplanetary travel to Mars and continues to do so in the TGO MSO.

Observation of the radiation environment and solar energetic particle events in Mars orbit in May 2018- June 2022.

The dosimeter Liulin-MO for measuring the radiation environment onboard the ExoMars Trace Gas Orbiter (TGO) is a module of the Fine Resolution Epithermal Neutron Detector (FREND). Here we present results from measurements of the charged particle fluxes, dose rates and estimation of dose equivalent rates at ExoMars TGO Mars science orbit, provided by Liulin-MO from May 2018 to June 2022. The period of measurements covers the declining and minimum phases of the solar activity in 24th solar cycle and the rising phase of the 25th cycle.

Space agency-specific standards for crew dose and risk assessment of ionising radiation exposures for the International Space Station.

The Partner Agencies of the International Space Station (ISS) maintain separate career exposure limits and shared Flight Rules that control the ionising radiation exposures that crewmembers can experience due to ambient environments throughout their space missions. In low Earth orbit as well as further out in space, energetic ions referred to as galactic cosmic radiation (GCR) easily penetrate spacecraft and spacecraft contents and consequently are always present at low dose rates. Protons and electrons that are trapped in the Earth's geomagnetic field are encountered intermittently, and a rare energetic solar particle event (SPE) may expose crew to (mostly) energetic protons.

Radiation environment in high-altitude Antarctic plateau: Recent measurements and model studies.

Polar regions are the most exposed to secondary particles and radiation produced by primary cosmic rays in the atmosphere, because naturally they are with marginal geomagnetic shielding. In addition, the secondary particle flux contributing to the complex radiation field is enhanced at high-mountain altitudes compared to sea level because of the reduced atmospheric attenuation. At present, there are very few systematic experimental measurements of environmental dose at high southern latitudes, specifically at high-altitude region.

SPACEDOS: AN OPEN-SOURCE PIN DIODE DOSEMETER FOR APPLICATIONS IN SPACE.

A new Open-Source dosemeter, SPACEDOS, has been developed for measurements of cosmic radiation on board spacecraft and small satellites. Its main advantages are that it is small and lightweight with low power consumption. It can be adjusted for specific applications, e.

Solar modulation of the GCR flux and dose rate, observed in space between 1991 and 2019.

The paper presents the solar modulation of the long-term galactic cosmic rays (GCR) flux and dose rates variations, observed during 14 space experiments by 10 Bulgarian build Liulin-type spectrometers (LTS) (Dachev et al., 2015a). They worked in near Earth space and in the interplanetary radiation environment between January 1991 and January 2019.

ANGULAR DEPENDENCE OF TRACK-ETCH DETECTOR HARZLAS TD-1.

Track-etched detectors are commonly used also for radiation monitoring onboard International Space Station. To be registered in track-etched detectors, the particle needs to meet several criteria-it must have linear energy transfer above the detection threshold and strike the detector's surface under an angle higher than the so-called critical angle. Linear energy transfer is then estimated from calibration curve from the etch rate ratio V that is calculated from parameters of individual tracks appearing on the detector's surface after chemical etching.

Ray-tracing simulation of the radiation dose distribution on the surface of the spherical phantom of the MATROSHKA-R experiment onboard the ISS.

Space radiation is one of the main concerns for human space flights. The prediction of the radiation dose for the actual spacecraft geometry is very important for the planning of long-duration missions. We present a numerical method for the fast calculation of the radiation dose rate during a space flight.

MEASUREMENT OF DIFFERENT COMPONENTS OF SECONDARY RADIATION ONBOARD INTERNATIONAL SPACE STATION BY MEANS OF PASSIVE DETECTORS.

The evaluation of different components of secondary radiation (charged fragments and neutrons) onboard ISS is described. Solid-state nuclear track detectors CR-39™ were applied for the measurements of short-range nuclear fragments, while the measurements of neutrons were carried out by means of thermo-luminescent dosimeters with various concentrations of 6Li and 7Li. The flux of charged secondaries and the gamma-equivalent neutron dose are presented in function of the low-LET dose in various modules of the Russian segment of ISS.

CONTRIBUTION OF DIFFERENT PARTICLES MEASURED WITH TRACK ETCHED DETECTORS ONBOARD ISS.

Cosmic radiation consists of primary high-energy galactic and solar particles. When passing through spacecraft walls and astronauts' bodies, the spectrum becomes even more complex due to generating of secondary particles through fragmentation and nuclear interactions. Total radiation exposure is contributed by both these components.

[SUBSTANTIATION OF DOSE LIMITS FOR A NEW NORMATIVE DOCUMENT ON RADIATION SAFETY OF LONG-DURATION SPACE MISSIONS AT ORBIT ALTITUDES OF UP TO 500 KM].

Review of the data of experimental radiobiology and epidemiological follow-up of large groups of people subjected to radiation exposures on Earth has been undertaken to substantiate dose limits for critical organs of cosmonauts in order to ensure good performance and vitality while on long-duration orbital missions. The career dose limits for cosmonauts and astronauts established earlier in the USSR and USA amounted to nothing more but banning the risk of cancer death increase to 3%. To apply more rigorous criteria of delayed radiation risks, the Russian limits for cosmonauts were revised to substantiate a 4-fold reduction of the average tissue equivalent dose maximum to 1 Sv.

Galactic cosmic ray simulation at the NASA Space Radiation Laboratory.

Most accelerator-based space radiation experiments have been performed with single ion beams at fixed energies. However, the space radiation environment consists of a wide variety of ion species with a continuous range of energies. Due to recent developments in beam switching technology implemented at the NASA Space Radiation Laboratory (NSRL) at Brookhaven National Laboratory (BNL), it is now possible to rapidly switch ion species and energies, allowing for the possibility to more realistically simulate the actual radiation environment found in space.

[MODIFICATION OF THE PROTON BEAM PHYSICAL PARAMETERS AND RADIOBIOLOGICAL CHARACTERISTICS BY ELEMENTS OF SPACECRAFT RADIATION PROTECTION].

The experiment was performed with outbred ICR (CD-1). female mice (SPF). The animals were irradiated by 171 MeV protons at a dose of 20 cGy.

[CALCULATION OF RADIATION LOADS ON THE ANTHROPOMORPHIC PHANTOM ONBOARD THE SPACE STATION IN THE CASE OF ADDITIONAL SHIELDING].

The paper presents the results of calculating doses from space ionizing radiation for a modeled orbital station cabin outfitted with an additional shield aimed to reduce radiation loads on cosmonaut. The shield is a layer with the mass thickness of -6 g/cm2 (mean density = 0.62 g/cm3) that covers the outer cabin wall and consists of wet tissues and towels used by cosmonauts for hygienic purposes.

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 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.

[MEASUREMENT OF SPACE RADIATION DOSES AND LINEAR ENERGY TRANSFER SPECTRA INSIDE BIOLOGICAL SATELLITE BION-M1].

The paper presents the results of measuring biologically significant characteristics of space radiation (spectra of linear energy transfer (LET), absorbed and equivalent doses and averaged quality factors) inside the descend capsule of biosatellite Bion-M1 in space experiment Bioradiation. Measurements combined the use of thermoluminescent detectors DTG-4 (TDL) and solid state nuclear track detectors CR-39 (Tastrak) (SSNTD). Differential and integral LET spectra of high-LET space radiation were determined in 4 points inside spacecraft using passive detectors assembles (PDA).

Radiation environment at aviation altitudes and in space.

On the Earth, protection from cosmic radiation is provided by the magnetosphere and the atmosphere, but the radiation exposure increases with increasing altitude. Aircrew and especially space crew members are therefore exposed to an increased level of ionising radiation. Dosimetry onboard aircraft and spacecraft is however complicated by the presence of neutrons and high linear energy transfer particles.

Bubble-detector measurements of neutron radiation in the international space station: ISS-34 to ISS-37.

Bubble detectors have been used to characterise the neutron dose and energy spectrum in several modules of the International Space Station (ISS) as part of an ongoing radiation survey. A series of experiments was performed during the ISS-34, ISS-35, ISS-36 and ISS-37 missions between December 2012 and October 2013. The Radi-N2 experiment, a repeat of the 2009 Radi-N investigation, included measurements in four modules of the US orbital segment: Columbus, the Japanese experiment module, the US laboratory and Node 2.

NUNDO: a numerical model of a human torso phantom and its application to effective dose equivalent calculations for astronauts at the ISS.

The health effects of cosmic radiation on astronauts need to be precisely quantified and controlled. This task is important not only in perspective of the increasing human presence at the International Space Station (ISS), but also for the preparation of safe human missions beyond low earth orbit. From a radiation protection point of view, the baseline quantity for radiation risk assessment in space is the effective dose equivalent.

[Results of measuring neutrons doses and energy spectra inside Russian segment of the International Space Station in experiment "Matryoshka-R" using bubble detectors during the ISS-24-34 missions].

The paper presents the results of calculating the equivalent dose from and energy spectrum of neutrons in the right-hand crewquarters in module Zvezda of the ISS Russian segment. Dose measurements were made in the period between July, 2010 and November, 2012 (ISS Missions 24-34) by research equipment including the bubble dosimeter as part of experiment "Matryoshka-R". Neutron energy spectra in the crewquarters are in good agreement with what has been calculated for the ISS USOS and, earlier, for the MIR orbital station.