This article presents the design and characteristics of a multi-leaf collimator developed for the experimental clinical ion beam therapy system for the U‑70 accelerator of the Institute for High-Energy Physics, Kurchatov Institute National Research Center.

The RBS experimental set-up has been working in every accelerator session of the U-70 accelerator complex since 2015. The main users of the set-up are radiobiologists and physicians. The direction of research is radiobiological experiments with extracted beams of accelerated carbon ions and preclinical studies aimed at the development of domestic methods of ion therapy. The requirements for irradiation of samples with carbon ions are very high: irradiation uniformity is no worse than 95%, positioning accuracy is no worse than 0.1 mm, dose delivery accuracy is no worse than ±2.5%. The article describes the instruments and devices that are used to support radiobiological experiments at the RBS installation: a plane-parallel ionization chamber, a mosaic ionization chamber, a water phantom with a 3D movement system, a 6-axis table, a degrader, a laser positioning system, clinical dosimeters. Programs for working with this equipment and archiving the data obtained are described.

A PF-LDS CAMAC 8-channel programmable pulse shaper module has been developed for reception and preprocessing of information from low-channel detecting systems. The module can operate with input signals of both polarities. Output signals of the module are NIM-level signals. The module supports up to three output channels per input, and the output signals can be direct or inverse. The shaper module is designed in the CAMAC standard, has eight channels for pulse shaping, and takes two slots in a CAMAC crate. The average quantization-step duration of an output pulse is 6.52 ± 0.04 ns. The maximum pulse length of output signals is 404 ± 2 ns. The shaper delays signals by 18.85 ± 0.57 ns on average for all channels. The mean length of the leading edge of shaper output signals is 1.23 ± 0.20 ns. The relative change in the output-pulse duration under a full load of the module channels is at most 3%. The shaper threshold voltage is set in the range from –540 to +540 mV.

A detector consisting of four p-i-n silicon pad structures of size 6 × 6 mm2 and thickness 300 μm was developed for the rapid monitoring of carbon ion beam quality at the Temporary Radiobiology Facility at the Institute for High Energy Physics (TRBF IHEP) by measuring event-by-event energy release on passage of charged particles (ions) through it. This articles describes the detector design and the method used for identifying contaminants in the beam of carbon nuclei. The charge composition of the ion beam of the TRBF IHEP calculated using the amplitude spectra of signals from the p-i-n structures is presented.

The results obtained by estimating the contribution of Be and B nuclei to the coherent dissociation of C, B, and C relativistic nuclei in nuclear track emulsions (“white” stars) are presented. The selection of white stars accompanied by B leads to a distinct peak appearing in the distribution of the excitation energy of 2α2p ensembles and having a maximum at 4.1 ± 0.3 MeV. A Be nucleus manifests itself in the coherent-dissociation reaction B → 2He + H with a probability of (25 ± 5)%, (14 ± 3)% of it being due to B decays. The ratio of the branching fractions of the B + n and Be + p mirror channels is estimated at 6 ± 1. An analysis of the relativistic dissociation of C nuclei in a nuclear track emulsion revealed nine 3α events corresponding to the Hoyle state. DOI: 10.1134/S1063778817060047

The results obtained by estimating the contribution of 8Be and 9B nuclei to the coherent dissociation of 10 C, 10 B, and 12 C relativistic nuclei in nuclear track emulsions (“white” stars) are presented. The selection of white stars accompanied by 9B leads to a distinct peak appearing in the distribution of the excitation energy of 2α2 p ensembles and having a maximum at 4.1 ± 0.3 MeV. A 8Be nucleus manifests itself in the coherent-dissociation reaction 10 B → 2 He + H with a probability of (25 ± 5)%, (14 ± 3)% of it being due to 9B decays. The ratio of the branching fractions of the 9 B + n and 9 Be + p mirror channels is estimated at 6 ± 1. An analysis of the relativistic dissociation of 12 C nuclei in a nuclear track emulsion revealed nine 3α events corresponding to the Hoyle state.

Experimental and theoretical studies of direct photon production in hadronic collisions essentially expand our insights in multiparticle production mechanisms. These photons are useful probes to investigate nuclear matter at all stages of the interaction. Soft photons play a particular role in these studies. Until now we have no explanation for the experimentally observed excess of soft photons. These photons have low transverse momenta \( p_{T} < 0.1\) GeV/c, \( \vert x\vert < 0.01\) . In this domain their yield exceeds the theoretical estimates by 5-8 times. The registration of soft photons at Nuclotron (LHEP, JINR) has been carried out by the electromagnetic calorimeter built by the SVD-2 Collaboration. Soft photon electromagnetic calorimeter was tested at U-70, IHEP (Protvino). For the first time the soft photon yield at interactions of 3.5A GeV/c per nucleon deuterium and lithium beams has been measured. The obtained energy spectra confirm the increased yield of soft photons with their energy less than 50MeV (in the laboratory system) in comparison with theoretical predictions and agree with previous experiments at high-energy interactions. It is planned to continue soft photon study at the future accelerator complex NICA with heavy-ion beams.

First results of a soft photon yield in nucleus-nuclear interactions at 3.5 GeV per nucleon are presented. These photons have been registered at Nuclotron (LHEP, JINR) by an electromagnetic calorimeter built in the SVD Collaboration. The obtained spectra confirm the excess yield in the energy region less than 50 MeV in comparison with theoretical predictions and agree with previous experiments at high-energy interactions.

A system for control and data processing of a linear GaAs detector array of an X-ray scanner is described in detail. The control software processing the scanner data and algorithms for compensation of dark currents and adjustment of detector sensitivity to X-ray intensity are presented.

The scheme of the C ions beam production with energy 455 MeV/nucleon from the U-70 accelerator was described briefly. The equipment facilities for the radiobiology experiments were shown. Experimental parameters of the carbon beam were described. The first experimental results were shown.

The stages of development and the current status of the versatile “Spectrometer with a Vertex Detector” setup designed for physics experiments at the U-70 accelerator of the Institute for High Energy Physics (Protvino) is described. The main detectors of the setup are the vertex detector based on silicon microstrip detectors, the wide-aperture magnetic spectrometer based on multiwire proportional chambers, and the lead-glass hodoscope γ detector. In the setup, there is a fast two-level trigger system for selecting required particle interactions. The key characteristics of the setup systems are presented, and the physical results obtained on it are briefly listed.

A matrix gallium-arsenide detector for roentgenography and nondestructive monitoring is described in this work. The detector contains 128 × 128 sensitive elements with 50-μm pitch, an analog multiplexor, and a system for information acquisition. The detector is intended for use in low- or medium-dose medical X-ray apparatuses. It can also be used for nondestructive defectoscopy.

Описаны этапы развития и современное состояние многоцелевой установки “Спектрометр с вершинным детектором”, созданной для проведения физических экспериментов на ускорителе У-70 Института физики высоких энергий (Протвино). Основными детекторами установки являются: вершинный детектор на основе кремниевых микростриповых детекторов, широкоапертурный магнитный спектрометр на основе пропорциональных камер, годоскопический детектор -квантов, собранный из свинцовых стекол. Для отбора нужных взаимодействий частиц в установке имеется быстродействующая двухуровневая система запуска. Приведены основные характеристики созданных систем установки, кратко перечислены полученные физические результаты.

The widely growing interest to the digital diagnostics and analysis systems, that have many advantages in comparison with the traditional (film) systems, in data taking, data storing, and data transmitting, requires a new detection technology. One of the most promising system for medical radiography today is a scanning type apparatus with some linear array detectors. The constructed apparatus is a device with some semiconductor GaAs detectors as sensitive elements to form the image while scanning an object. GaAs detectors are the detectors of the direct transformation of X-ray radiation into the electrical. The present paper describes the results of the construction and testing of the portable X-ray unit for traumatic examination and orthopedic manipulation in stationer clinics and at the first aid in medicine of catastrophe.