The experimental setup KOLKHIDA has been designed to study the interactions of polarized neutrons with polarized nuclei, in particular to study the neutron nuclear precession (nuclear pseudomagnetism) and also for studying magnetic properties of crystals. The investigation has been performed at the Frank Laboratory of Neutron Physics, JINR.

Standardized means of experiments description and of operations sequence control, which do not require editing system components, when experiment is changed, are proposed.

In the paper “Nuclear neutron precession” [1], which marked the beginning of a new research area – neutron optics of polarized media, it has been theoretically shown that the dependence of the refractive index of a neutron wave on mutual orientation of spins of the neutron and nucleus determines the neutron spin rotation around the direction of the target polarization. The precession frequency  depends on nuclear spin I, density of nuclei N and difference f + – f – of amplitudes of neutron scattering by this nucleus corresponding to the states with total momentum of the

Equipment and software for recording time-of-flight spectra with a small channel width (10 ns) in precision experiments under conditions of low neutron beam intensities or recording rare events have been designed. An eight-input time encoder operates without losses when the signal intensity is up to 10 5 s −1 at any of the eight inputs. The use of the USB interface ensures the system mobility. The developed system integration procedure from components in the executed format allows one to obtain a distributed system, ensures a higher succession of the software, and the possibility of assembling the system by the user.

In connection with commissioning of the IREN pulsed resonance neutron source new electronics and appropriate software are developed for registration of time-of-flight spectra with small width of the channel (21 ns). The hardware-software system is intended for research of the IREN neutron beam characteristics, properties of new detectors, and also for performance of precision experiments under conditions of low intensity or registration of rare events.

In JINR at the IBR-2 pulsed reactor [Ananiev, Blokhincev, Bulkin, et al., IET(ras.) 5 (1977) 17.] the “Kolkhida” setup intended for studies of neutron optics phenomena in interactions of polarized neutrons with polarized nuclei has been constructed. In particular, studies of nuclear precession of neutron spin in a wide energy range from thermal to neutron resonance energies are planned. The setup also makes it possible to investigate magnetic properties using polarized neutrons.

Some precision experiments require several tens of hours for measurements. In this case, it is important to take into account possible drift of the detection system parameters in time. An express analysis program has been developed for early detection of significant distortions in recorded spectra, their filtration, and correction of results.

The yield of delayed neutrons, v d , from thermal-neutron-induced fission of 245 Cm is measured. Experiments aimed at studying the properties of delayed neutrons from the fission of some reactor isotopes and initiated in 1997 were continued at the upgraded Isomer-M facility by a method according to which a periodic irradiation of a sample with a pulsed neutron beam from the IBR-2 reactor was accompanied by recording emitted neutrons in the intervals between the pulses. The accuracy of the resulting total delayed-neutron yield v d = (0.64 ± 0.02)% is two times higher than that in previous measurements. This work was performed at the Frank Laboratory of Neutron Physics at the Joint Institute for Nuclear Research (JINR, Dubna).

The delayed-neutron yield from thermal-neutron-induced fission of the 237 Np nucleus was measured using a sample periodically exposed to a pulsed neutron beam with subsequent detection of neutrons during the time intervals between pulses. The experiment was realized on an Isomer-M setup mounted in the IBR-2 pulsed reactor channel equipped with a mirror neutron guide. The setup and the experimental procedure are described, the background sources are thoroughly analyzed, and the experimental data are presented. The total delayed-neutron yield from 237 Np fission induced by thermal neutrons is ν d = 0.0110 ± 0.0009. This study was performed at the Frank Laboratory of Neutron Physics (JINR, Dubna).

This paper reflects the evolution of the principles published in the No. 5, 2004, issue of Instruments and Experimental Techniques for creating new software for spectrometers. The development of the technique and software complex that allow a distributed experiment automation system (EAS) to be assembled from ready-made modules is described. Attention is devoted primarily to ensuring the invariance of programs with respect to variations of the experimental technique, the possibility of the user controlling the configuration of the spectrometer without involving the programmers, and to minimizing the driver development costs. The complex uses universal base programs and drivers for controlling particular devices. The drivers can be written in any programming language, and their functional code is minimized. The control computer, frontend computers, and observer computers are distinguished logically in the EAS structure on the basis of their functionality. The main function of the frontend computer is to control the equipment incorporated into the spectrometer. The complex allows one to easily scale the EAS, increase the number of frontend computers and drivers, and use frontend computers that run under any operating system. During operational testing on the DN2 spectrometer, the predicted characteristics of the described technique were confirmed. The interactive control program can be used on various setups without making any modifications.

A special structure and operating algorithm for a data acquisition subsystem have been developed for spectrometric experiments in which data are buffered in the memory. Universal basic software and driver-level programs for each particular spectrometer are both used in this subsystem. It is proposed that the experimental technique be taken into account in every measurement by specifying the spectrometer-state vector in terms of the variable parameters. Without any modification, such data acquisition subsystem programs are suitable for use with different spectrometers and impose no restrictions on the application of any experimental technique. A structure has been developed for the software used in a system for automating experiments, in which it is possible to perform the preliminary (and complete) on-line mathematical processing of experimental data and to realize a mode of processing that would permit the automatic cyclic execution of such operations as editing the composition of experimental data, computing, and analyzing the results.

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.