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One of the most important activities of the IBR-2 DSC is the development of detector technologies, which will be used as a basis in designing detectors for future experiments. Detector systems developed by the IBR-2 DSC are described. Today they are used to good effect in research facilities or are prepared for application in the foreseeable future. [ABSTRACT FROM AUTHOR]

Abstract—This article discusses the results of parallel measurements with two-coordinate position-sensitive He3 detectors with a delay line, which are installed on REFLEX and GRAINS neutron spectrometers of the IBR-2 pulsed reactor with the simultaneous use of three data acquisition systems: DeLiDAQ-1, DeLiDAQ-2, and a system based on the N6730 digitizer produced by CAEN. [ABSTRACT FROM AUTHOR]

The article reviews thermal neutron detector developments in the Department of the IBR-2 Spectrometer Complex of the Frank Laboratory of Neutron Physics, Joint Institute for Nuclear Research (FLNP JINR). A variety of detector types are considered: neutron monitors, ring detectors, position-sensitive detectors (PSD), and scintillation detectors. The experience of exploitation of these detectors at the research facilities of the FLNP JINR is presented. [ABSTRACT FROM AUTHOR]

The modernization of the detector system and control system of the neutron powder diffractometer (NPD) in the GEK-5 channel of the VVR-c reactor (Obninsk Branch, Karpov Institute of Physical Chemistry) is described. The PC-connected hardware and software complex, which ensures data acquisition and storage and control of the experiments, is created. The main modules of the NPD automation system and Sonix+ control software package, designed at the Frank Laboratory of Neutron Physics at JINR, are briefly described. The modernization has made it possible to increase the luminosity of the diffractometer and completely automatize the measurement process. [ABSTRACT FROM AUTHOR]

Development of new high-flux-intensity neutron sources and the need to equip them with efficient spectrometers raises the problem of designing special-purpose direct-beam monitors-detectors. These detectors feature an extremely low efficiency and a very low attenuation of the incident neutron beam. In this work, a two-coordinate position-sensitive monitor-detector is described that was developed for real-time recording of the profile of neutron beams generated by both steady and pulsed neutron sources. The basic parameters of this device are the following: a coordinate resolution of 4 × 4 mm2, a sensitive area of 100 × 100 mm2, and a recording efficiency of 10−6−10−2. Use of nitrogen as a converter makes it possible to achieve a record low efficiency and still maintain other parameters at a desired level. The device can be combined not only with high-flux-intensity neutron sources already in use worldwide but also with next-generation sources being developed in the United States (SNS) and Japan (JPARC). [ABSTRACT FROM AUTHOR]

A one-dimensional position-sensitive detector of thermal neutrons has been developed to equip high-efficiency neutron spectrometers at the ИБР-2 research reactor. The detector is based on a multiwire proportional chamber filled with a mixture of 3He + CF4 and has an active area of 200 × 80 mm and a spatial resolution of 2 mm. The detector has been used to good effect in the REFLEX and HRFD spectrometers of the ИБР-2 reactor, as well as in the diffraction facility of the ИВВ-2M research reactor (Zarechnyi, Russia). [ABSTRACT FROM AUTHOR]

Two LiInSe2 single crystals, grown under different conditions, have been studied. Characteristics of these crystals for neutron detection have been compared using scintillation detection method due to the neutron capture by lithium nuclei and subsequent emission of charged particles and the conventional method of charge extraction from single-crystal surfaces due to the same nuclear reaction. Prospects of application of LiInSe2 single crystals for neutron detectors of different types are discussed. [ABSTRACT FROM AUTHOR]

The article discusses the development of a new gas multi-section ring-shaped detector (MSRD) at the Frank Laboratory of Neutron Physics (FLNP) of the Joint Institute for Nuclear Research (JINR) in Dubna, Russia. The MSRD, which was developed for the study of samples in small quantities at high pressures, has 16 sections with equal gas volume distribution. It also cites the advantages of MSRD such as large working volume and efficiency.

Three neutron instruments at the Neutron Physics Laboratory (NPL) in Řež near Prague — small-angle scattering (SANS) MAUD, strain scanner SPN-100 and strain diffractometer TKSN-400 — have been modernized recently with new 2D position-sensitive detectors (PSDs) from JINR, Dubna. Here we report on the progress made in relation to the possibilities of the diffractometers due to the improved performance of the detectors. The first part of the paper is dedicated to a detailed description of the hardware and software of the PSDs, as well as its integration with the in-house experimental control software. Then practical examples of neutron scattering experiments for each of the upgraded facilities are presented. [ABSTRACT FROM AUTHOR]

The design and main characteristics of a test setup for studying the serviceability of the bead cryogenic neutron moderator and determining its optimal operating conditions on the fast pulsed IBR-2 reactor are presented. Using the test setup, the possibility has been demonstrated of filling the moderator chamber with the working medium-beads of a mixture of aromatic hydrocarbons, delivered to the chamber by a cold ( T < 85 K) helium gas flow over an intricately shaped cryogenic pipeline system. [ABSTRACT FROM AUTHOR]

A user interface that provides the means for scheduling an experiment and controlling its performance is described. The current state of a spectrometer, the programs, and the experimental results can now be presented on the Internet as dynamically formed protocols and graphs. After giving a password, an experiment may be controlled via the Internet. The client can use the Internet without the need for any applied programs. The software package is designed for experiments in the field of condensed matter and nuclear physics and is ready for immediate use. [ABSTRACT FROM AUTHOR]

The high-resolution Fourier diffractometer (HRFD) operates at the IBR-2 pulsed reactor, on which the correlation method of data registering has been implemented using a fast Fourier chopper and specialized electronics. A wide-aperture ring back-scattering detector for HRFD has been developed. The detector consists of six Z n S (A g) / 6 L i F -scintillation rings, each one of which is divided into 12 sections. Main parameters of this detector: covered solid angle 2 θ = (133 − 175) ∘ ; Ω d ≈ 2.0 sr; average absorption efficiency 85 % , geometric contribution to resolution Δ d / d < 0.0005. The concept of a detector and its data acquisition system are presented. [ABSTRACT FROM AUTHOR]

Abstract The High Resolution Fourier Diffractometer (HRFD) is a neutron time-of-flight spectrometer with a fast Fourier chopper and a correlation mode of data acquisition designed to study atomic and magnetic structures of crystalline materials with high resolution in reciprocal space. The HRFD was constructed in the early 1990s by a collaboration of JINR (Dubna), PNPI (Gatchina) and VTT (Espoo) and began operating routinely in 1994 at the IBR-2 pulsed reactor in Dubna. If correlation analysis is used, the HRFD Δ d / d resolution is determined by the maximum rotational speed of the Fourier chopper. For V max = 6000 rpm, "high-resolution" patterns are measured by backscattering detectors with Δ d / d ≈ 0.0015 despite a very short flight path (L ≈ 20 m) between chopper and sample. Switching to a regular TOF-mode (without Fourier chopper) makes HRFD one of the world's best high-intensity diffractometers, capable of measuring diffraction patterns in the range of ∼1 min and less. In this paper, the experience of using HRFD at IBR-2 is considered and a possible solution for some technical and methodical problems of Fourier diffractometry at a long-pulse neutron source recognized during its operation is discussed. New possibilities appearing after the recent substantial HRFD upgrade and further perspectives on the method are also presented. [ABSTRACT FROM AUTHOR]