A passive neutron dosemeter (PND) for high-energy accelerators is described. The slide of the DVGN-01 personal dosemeter, which is placed at the center of a polyethylene moderator, is used as a thermal-neutron detector. The moderator includes a lead insert, which increases the sensitivity of the dosemeter to high-energy neutrons, and a cadmium filter. Optimization calculations of the dosemeter design parameters have been performed with respect to the energy dependence of the response in the range from the thermal energy to 1 GeV. The results of the calculations are in good agreement with the experimental data obtained in low-energy neutron reference fields. Comparative measurements using the PND and a low-energy passive dosemeter have been performed in the neutron fields outside the shield of the 70-GeV U-70 proton accelerator at the Institute for High Energy Physics.

It is shown that there exists an optimal thickness of a rubidium target, dependent on the proton energy at its ingress, for reaching a compromise between the maximum yield of 82Sr and a minimum relative yield of the impurities 83Sr and 85Sr. The optimal irradiation regime and holding time are determined for a target to chemical separation of strontium from it during operation with no accelerator downtime. Recommendations are made for operating with partial loads.

New neutron reference fields, based on a 239Pu–Be source, intended for increasing the accuracy of measurements of neutron dosimeters and radiometers in the IHEP accelerator complex are described. A Bonner SB-RSU-01 spectrometer was used to measure the spectra of the neutron reference fields. The BON95 code was used to reconstruct the spectra; the initial spectra for the iteration procedure were determined by parameterization or by a calculation using the FAN15 code. Good agreement was obtained between the neutron spectra and the integral characteristics of the reference fields reconstructed by the two methods.

The first results of Proton Radiographic Facility operation on the beam with energies of 50–70 GeV extracted from the U-70 synchrotron at the Institute for High Energy Physics are presented. This facility is capable of forming proton radiographic images of samples with an optical thickness as large as 450 g/cm2 and a field of view of 220 mm or more.

Different versions of the design of a neutron dosemeter for high energy accelerators based on a fast scintillation lithium glass detector of thermal neutrons are considered. The detector is placed at the center of a polyethylene moderator shaped as a sphere, a cylinder, or a truncated cylinder with a lead insert used to increase the dosemeter sensitivity to neutrons with energies above 20 MeV. Calculations of the design parameters have been performed to optimize the angular and energy dependences of the response at energies ranging from the thermal energy to 1 GeV. The best results have been obtained for dosemeter versions comprising a boron filter along with the lead insert. In this case, the instrument has the lowest mass. The dosemeter has been developed for use in the radiation monitoring systems of the IHEP U-70 accelerator complex and other accelerators. It can also be used outside shields of reactors and other low-energy facilities.

A radiographic facility, placed in the initial rectilinear part of the injection channel, which is intended for transporting a proton beam from U-70 into an accelerator-storage complex, is described. It is designed for energy 50 GeV with field of view 60 mm and makes it possible to obtain an image of objects with optical thickness to 400 g/cm2 with resolution 100 μm. The first static and dynamic experiments performed in our country at 50 GeV have shown the advantages of pulsed radiography in studying fast processes in ultradense media.

In the present work, the delayed effects of chronic high linear energy transfer (LET) radiation in polychromatic erythrocytes (PCEs) of mice bone marrow were investigated in vivo. Irradiation of the two-month-old SHK white mongrel random-bred male mice was performed in the radiation field behind the concrete shield of the accelerator of 70 GeV protons to accumulate doses of 0.005-0.16 Gy. The dependence of the biological response on dose, adaptive response (AR) and genomic instability (GI) in F(1) and F(2) generations from males irradiated with doses of 0.005 and 0.16 Gy and from males exposed to combined action of immunomodulator-bendazol hydrochloride (BH) and of 0.16 Gy irradiation, were examined using the micronucleus formation test. The data demonstrated that irradiation of mice with these doses lead to an increase in the level of cytogenetic damage and induces no AR. With analysis of the bone marrow radiosensitivity to 1.5 Gy of X rays and the capacity to AR it was found that the chronic high-LET irradiation of parents induced the GI at least two generations. The combined exposure to BH and the dose of 0.16 Gy induces no AR in F(0) generation but induces AR in F(1) and F(2) offspring.

Описана радиографическая установка ускорителя протонов с энергией 70 ГэВ ГНЦ ИФВЭ. Установка создана с использованием имеющейся инфраструктуры в начальной прямолинейной части канала инжекции. Линзы канала инжекции предназначены для транспортировки протонного пучка из У-70 в ускорительно-накопительный комплекс и имеют диаметр 100 мм. Установка рассчитана только на энергию 50 ГэВ с полем обзора 60 мм и позволяет получать при наличии некоторых потерь в канале изображение объектов с оптической толщиной свыше 300 г/см2. Оптическое разрешение установки составляет 0.25 мм. В период 2004–2008 гг. на установке проведен ряд экспериментов с многокадровой регистрацией быстропротекающих процессов. При проведении динамических экспериментов использовались малогабаритные взрывозащитные камеры, а также измерительная система мониторинга состояния камеры и окружающей среды.

A radiographic facility for the 70-GeV proton a ccelerator of the Institute for High Energy Physics is described. The available infrastructure in the initial straight part of the injection channel is used in the facility. The 100-mm-diameter lenses of the injection line ar e intended for transportation of the proton beam from the U-70 accelerator to the accelerating-storage complex. The facility has been designed only for an energy of 50 GeVwith a viewfield of 60 mm and used for imaging of samples with an optical density of > 300 g/cm(2) in the presence of some losses in the line. The optical resolution of the facility is 0.25 mm. A set of experiments aimed at multiframe recording of fast processes were conducted on the facility in 2004-2008. Small-sized explosion-proof chambers, as well as the measuring system for monitoring the state of the chamber and environment, were used in the dynamic experiments.

A facility for studying the radioactivity of structural materials exposed to high-energy protons is described. Experimental data on the nuclide composition of different structural materials are presented. The data obtained are important for the radiological safety of proton accelerators and they can also be used as reference data for verifying computational codes.

The technique and results of measurements performed of the neutron spectrum behind the top shielding of the U-70 experimental hall using a Bonner spectrometer based on indium and carbon activation detectors are presented. The integral characteristics of the neutron field are presented; such a field could be useful in various areas of dosimetry, radiation physics, and radiobiology, in assuring radiological safety during flights in airplanes and in space, as well as in the study of malfunctions induced in microelectronics by high-energy neutrons.

In present work, we investigated the peculiarities of the effect of a low-dose rate high-LET radiation that simulates the spectral and component composition of the radiation field formed in the atmosphere at a height of 10 km on mice in vivo. The dose dependence and adaptive response were examined. Irradiation of mice was performed for 24 h a day in the radiation field behind the concrete shield of the Serpukhov accelerator of 70 GeV protons for the time (15-31 days) necessary to accumulate the required doses. The experiments demonstrated that irradiation of mice in vivo in the dose range of 11.5-31.5 cGy leads to an increase in cytogenetic damage to bone marrow cells and induces no adaptive response in bone marrow cells.

The purpose of this work was to study the chronic influence of the high-energy radiation field formed in the atmosphere at an altitude of 10 to 30 km on the level of DNA damage in leukocytes of peripheral blood in mice. The external radiation field (behind the concrete shield) of the U-70 accelerator (Serpukhov, Russia) was used for these studies. This radiation field simulates the components and spectral composition of the high-energy radiation field formed in the atmosphere at an altitude of 10 to 30 km. Two groups of SHK line mice were chronically irradiated with a total dose equivalent to 21.5 and 31.5 cGy. The state of the genome of nucleated blood cells was assessed by the Comet assay (alkaline version) 72 h after completion of chronic irradiation. The level of genome damage in individual peripheral blood leukocytes of irradiated animals was compared with the basal level of DNA lesions in peripheral blood leukocytes of unirradiated control mice. The damage was expressed in %TDNA (the amount of DNA found in the "comet tail" in percent of total DNA in the "comet"). It was found that in mice exposed to the radiation field of the accelerator, the mean value of DNA damage was: %TDNA = 3.88 +/- 0.35% for a dose of 21.5 cGy and % TDNA = 6.00 +/- 0.82% for a dose of 31.5 cGy. In mice irradiated at an X-ray therapeutic device with a dose of 150 cGy 24 h before the examination, %TDNA was 2.27 +/- 0.34% and this did not differ from %TDNA in unirradiated mice, 2.68 +/- 0.56%. We suggest that the increased level of DNA damage observed in mice irradiated with 31.5 cGy from the mixed radiation field at the Serpukhov accelerator points to the development of genetic instability in their leukocytes as a result of chronic exposure of animals to this particular radiation field.