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 paper. In the last section of the paper some of the most significant scientific results obtained in space and on aircraft, balloon and rocket flights since 1989 are presented.

Для оценки радиационного риска в космическом полете необходимо определить дозовые нагрузки, получаемые критическими органами тела человека. Для этой цели на борту космических кораблей проводятся эксперименты с моделями человеческого тела – фантомами, оснащенными пассивными и активными радиационными детекторами, которые измеряют распределения дозы в местах расположения критических органов. Дозиметрический телескоп “Люлин-5” создан с использованием трех кремниевых детекторов для исследования радиационной обстановки в шаровом тканеэквивалентном фантоме на Российском сегменте Международной космической станции. Цель эксперимента с прибором “Люлин-5” – исследование динамики дозы и потока частиц в фантоме, а также вариаций радиационной обстановки на МКС на продолжительных временных интервалах в зависимости от фазы цикла солнечной активности, параметров орбиты и наличия солнечных энергичных частиц. Дозиметр “Люлин-5” измеряет одновременно мощность дозы и потоки заряженных частиц на трех разных глубинах в радиальном канале фантома, а также спектр линейной передачи энергии. В данной работе представлены результаты измерений мощности дозы и потоков частиц, обусловленных различными компонентами радиационного поля на МКС, в период с июня 2007 года по декабрь 2009 года.

For estimating radiation risk in space flights it is necessary to determine radiation dose obtained by critical organs of a human body. For this purpose the experiments with human body models are carried out onboard spacecraft. These models represent phantoms equipped with passive and active radiation detectors which measure dose distributions at places of location of critical organs. The dosimetric Liulin-5 telescope is manufactured with using three silicon detectors for studying radiation conditions in the spherical tissue-equivalent phantom on the Russian segment of the International space station (ISS). The purpose of the experiment with Liulin-5 instrument is to study dynamics of the dose rate and particle flux in the phantom, as well as variations of radiation conditions on the ISS over long time intervals depending on a phase of the solar activity cycle, orbital parameters, and presence of solar energetic particles. The Liulin-5 dosimeter measures simultaneously the dose rate and fluxes of charged particles at three depths in the radial channel of the phantom, as well as the linear energy transfer. The paper presents the results of measurements of dose rate and particle fluxes caused by various radiation field components on the ISS during the period from June 2007 till December 2009.

Long-term analysis of data from two radiation detection instruments on the International Space Station (ISS) shows that the docking of the Space Shuttle drops down the measured dose rates in the region of the South Atlantic Anomaly (SAA) by a factor of 1.5–3. Measurements either by the R3DE detector, which is outside the ISS at the EuTEF facility on the Columbus module behind a shielding of less than 0.45gcm−2, and by the three detectors of the Liulin-5 particle telescope, which is inside the Russian PEARS module in the spherical tissue equivalent phantom behind much heavier shielding demonstrate that effect. Simultaneously the estimated averaged incident energies of the incoming protons rise up from about 30 to 45MeV. The effect is explained by the additional shielding against the SAA 30–150MeV protons, provided by the 78 tons Shuttle to the instruments inside and outside of the ISS. An additional reason is the ISS attitude change (performed for the Shuttle docking) leading to decreasing of dose rates in two of Liulin-5 detectors because of the East–West proton fluxes asymmetry in SAA. The Galactic Cosmic Rays dose rates are practically not affected.