Atomic physics techniques for studying nuclear ground state properties, fundamental interactions and symmetries: status and perspectives

The international workshop on “Application of Lasers and Storage Devices in Atomic Nuclei Research” held during 2009 in Poznan gave an excellent overview on the latest experimental and theoretical results regarding the investigation of radionuclides by atomic physics techniques and the extraction of ground state properties of exotic nuclei. This publication intends to summarize the progress recently achieved by laser spectroscopy and mass spectrometry as well as by weak interaction studies using atomic physics techniques. Furthermore, it tries to point to some areas requiring urgent improvements and to indicate some routes of future research and challenging opportunities.     

Using plastic track detectors to solve radiation safety problems at nuclear reactor facilities

Three options of the method to determine microconcentrations of fissile materials in water solutions are developed. They utilize plastic track detectors to measure concentrations. The options are as follows a “wet” method, “thin-layer inorganic sorbent-plastic track detectors”, and a method of selective extraction and coprecipitation. These methods are used to check up fuel cladding integrity at the research reactor IVV-2M and liquid radioactive waste contamination by uranium and plutonium at the Beloyarskaya Nuclear Power Plant (BNPP).     

Targets for studying the dynamic and radiative properties of material with laser facilities

The technology of target preparation for direct and indirect laser irradiation is developed to study the shock compressibility of materials on the Sokol-2 and Iskra-5 laser facilities. Copper and aluminum films with a density close to that of the bulk materials are prepared by ion-beam deposition. The difference in the densities of the film and bulk materials is 0.8–1.7%, and the accuracy of density measurement is 0.4–1.5%. Processes for the preparation of porous materials (aluminum, copper, nickel, gold, etc.) are also devised. Porous cop-per samples of thickness 10–50 μm, pore size 0.1–5.0 μm, mean density 0.065–0.4 g/cm³, and porosity 20–140 are obtained. The preparation of freely suspended film targets 0.1–0.2 μm thick that are irradiated by picosecondlaser shots on the Progress-P and élas-PS facilities is described.     

High-pressure facilities at the ESRF

Abstract

Several beamlines at the European Synchrotron Radiation Facility in Grenoble are being designed with high-pressure experiments in mind. Among the first seven beamlines the Microfocus Beamline, the Materials Science Beamline, the Laue White Beamline and the High Energy Beamline are of particular interest for high-pressure diffraction experiments. These experimental stations are outlined and their characteristics are compared.

Presented at the IUCr Workshop on ‘Synchrotron Radiation Instrumentation for High Pressure Crystallography’, Daresbury Laboratory 20-21 July 1991     

Neutron-deuteron breakup reaction as a tool for studying neutron-neutron interactions

An analysis of the most recent data on the reaction nd → pnn revealed a serious discrepancy between theoretical predictions and cross sections measured for this reaction in various configurations where the role of neutron-neutron interactions is important. In view of this, it seems necessary both to develop theoretical approaches and to obtain new experimental data. For this purpose, a setup for studying the neutron-deuteron breakup reaction was created at the Institute for Nuclear Research on the basis of the neutron beam in the RADEX channel and deuterium targets. This facility makes it possible to perform experiments over a broad region of primary-neutron energies (10–60 MeV) and in various (final-state interaction, quasifree scattering, and spatial-star) configurations. Preliminary results of the respective experiment were obtained for configurations of final-state neutron-neutron interaction and quasifree neutron-neutron scattering.     

A unified conformal model for fundamental interactions without dynamical Higgs field

A Higgsless model for strong, electroweak and gravitational interactions is proposed. This model is based on the local symmetry group SU(3)×SU(2)_L×U(1)×C,where C is the local conformal symmetry group. The natural minimal conformally invariant form of total Lagrangian is postulated. It contains all standard model fields and gravitational interaction. Using the unitary gauge and the conformal scale fixing conditions, we can eliminate all four real components of the Higgs doublet in this model. However, the masses of vector mesons, leptons, and quarks are automatically generated and are given by the same formulas as in the conventional standard model. In this manner one gets the mass generation without the mechanism of spontaneous symmetry breaking and without the remaining real dynamical Higgs field. The gravitational sector is analyzed, and it is shown that the model admits in the classical limit the Einsteinian form of gravitational interactions.     

Noncommutative geometry and fundamental interactions: the first ten years

This is the full text of a survey talk for nonspecialists, delivered at the 66th Annual Meeting of the German Physical Society in Leipzig, March 2002. We have not taken pains to suppress the colloquial style. References are given only insofar as they help to underline the points made; this is not a full‐blooded survey. The connection between noncommutative field theory and string theory is mentioned, but deemphasized. Contributions to noncommutative geometry made in Germany are emphasized.     

Wireless-electrodeless quartz-crystal-microbalance biosensors for studying interactions among biomolecules: A review

The mass sensitivity of quartz-crystal microbalance (QCM) was drastically improved by removing electrodes and wires attached on the quartz surfaces. Instead of wire connections, intended vibrations of quartz oscillators were excited and detected by antennas through electromagnetic waves. This noncontacting measurement is the key for ultrahigh-sensitive detection of proteins in liquids as well as quantitative measurements. This review shows the principle of wireless QCMs, their applications to studying interactions among biomolecules and aggregation reactions of amyloid β peptides, and the next-generation MEMS QCM, the resonance acoustic microbalance with naked embedded quartz (RAMNE-Q).     

New version of the integrated method for measuring small effects in experiments on beams extracted from a nuclear reactor at the effect sign switching frequency above the fundamental frequencies of the reactor power fluctuation spectrum

The principles of construction and the results of testing of a system for measuring P-odd asymmetries in nuclear reactions with polarized cold neutrons by the integrated method of recording events at the neutron polarization switching frequency above the fundamental frequencies of the reactor power fluctuation spectrum are presented. It is shown experimentally that if the signal under investigation is characterized by the spectral density of power decreasing with increasing frequency, switching of the equipment at a higher frequency decreases the measuring error. The dependence of the error of measurements of P-odd asymmetry in the emission of γ quanta in the ¹⁰B(n, α)⁷Li* ⟹ γ ⟹ ⁷Li(g.s.) reaction on the neutron polarization switching frequency is derived. The system described here is implemented experimentally for the first time.     

A new tool for the study of fundamental interactions: Parity-odd correlations in quark fragmentation

Parity-odd correlations among the fragmentation products of quarks should reveal the longitudinal polarization of these quarks. Possible applications of this idea include a new way to determine the Weinberg angle from data on neutrino reactions, a sensitive test of the quark-antiquark creation picture in e⁺e^? annihilation, a way to determine the weak coupling of hypothetical heavy particles to light quarks and a test for the parton-parton scattering model with elementary gluon exchange for high p⊥ events in nucleon-nucleon collisions.     

Antineutrino-deuteron experiment at the Krasnoyarsk reactor

The investigation of antineutrino interaction with matter at the Krasnoyarsk reactor is described. The characteristics of the “Deuteron” detector, the results obtained, and prospects are discussed.     

Precision X-ray optics for fundamental interactions in atomic physics,resolving discrepancies in the X-ray regime

Reliable knowledge of the complex X-ray form factor (Re(f) and f) is required for many fields including crystallography, medical diagnosis and XAFS studies. However, there are discrepancies between theory and theory, experiment and experiment and theory and experiment of 10% and more, over central X-ray energies. Discrepancies exist for most elements, despite claimed experimental accuracies of 1%. This paper summarises the current variation between experimental and theoretical results, and outlines key issues for obtaining experimental accuracies of 1% in critical wavelength ranges for selected elements to address these issues. This paper critically surveys available experimental data for attenuation coefficients and suggests a procedure for obtaining significantly higher accuracy measurements in the future.     

Fast-neutron-flux measurements in the underground facilities at Baksan

The fast-neutron flux in one of the deep underground facilities situated at a depth of 4900 mwe in the Baksan Neutrino Observatory are measured. The relative neutron-shielding properties of several commonly available natural materials are also investigated. Preliminary results obtained with a highly sensitive fast-neutron spectrometer at a sensitivity level of about 10^?7 neutron cm^?2 s^?1 are presented and discussed.     

Instrumentation for PSD-based neutron diffractometers at Dhruva reactor

Linear position sensitive detectors (PSDs) are widely used to configure neutron diffractometers and other instruments. Necessary front-end electronics and a data acquisition system [1] is developed to cater to such instruments built around the Dhruva research reactor in BARC. These include three diffractometers with multiple PSDs and four with single PSD. The front-end electronics consists of high voltage units, preamplifiers [2],shaping amplifiers, ratio ADCs (RDC) [3]. The data acquisition system consists of an interface card and software. Commercially available hardware like temperature controller or stepper motor controller connected over GPIB or RS232 are also integrated in the data acquisition system. The data acquisition is automated so that it can continue unattended for control parameter like temperature, thus enabling optimum utilization of available beam time. The instrumentation is scalable and can be easily configured for various instrumental requirements. The front-end electronics and the data acquisition system are described here.     

Transverse electroreflectance of GaSe at the fundamental absorption edge

The transverse electroreflectance of GaSe has been measured near the fundamental edge at 4.2 K. The observed structures have been interpreted in terms of the Franz-Keldysh oscillations, the exciton ground state, the first excited state of exciton, and the phonon replica of the exciton ground state.