Electronic equipment for reading and recording signals from the microstrip vertex detector of the SVD-2 setup

Electronic equipment developed for reading, shaping, and recording signals from microstrip sensors of the vertex detector of the SVD-2 setup is described. The configuration of the vertex detector sensors, construction of signal-reading cards, and structure and functions of the recording modules are considered. The obtained characteristics are analyzed.     

Electronic equipment for readout and processing of data from the microstrip vertex detector of the SVD-2 setup

The electronic equipment for data processing and reading designed for the vertex detector of the SVD-2 setup is described. The structure of basic modules, their characteristics, and software for data acquisition are considered.     

A γ detector movement system of the spectrometer with a vertex detector setup

The system controlling movement of the γ detector in the spectrometer with a vertex detector (SVD) setup has been upgraded. The choice of circuitry components for designing the control interface, coordinate sensors, actuation mechanisms, and system of emergency shutdown is substantiated. The circuit designs allowing the reliability of the γ detector and its positioning accuracy to be increased are described. Commercially produced industrial controllers of asynchronous motors with frequency steering are used in the system. The software developed for controlling the γ detector movement is described. The system has been completely mounted and tested and now is ready for operation as a part of the SVD setup.     

A vertex detector to search for beauty

This paper describes a high resolution vertex detector designed to study heavy quarks and other rare phenomena at the FNAL Tevatron machine. Its performance is examined and discussed. This vertex detector will be used in the frame of experiment E-687, being set up at Fermilab.     

A silicon strip vertex detector for LEP

The Design of a silicon strip diode detector for use at LEP is described. It will use a custom-designed NMOS read-out chip, to reduce the size and cost of the associated electronics.     

A slow-control data detector for the ZEUS setup

The ZEUS experimental setup operating at DESY (German Electron Synchrotron) is a many-purpose detector aimed at studying high-energy interactions of electrons and protons. The ZEUS comprises 20 subdetectors (components). One of them is the slow-control data detector described in this paper.     

Conceptual design for a high resolution high rate vertex detector for charm and beauty experiments using scintillating fibre optics

A vertex detector is proposed for charm and beauty experiments using a simple arrangement of scintillating optical fibres to provide high resolution (∼10 μm) in a plane transverse to the event axis. Experience with the high resolution bubble chambers shows that this is optimal for the detection of heavy flavour decays in complex events. The aim is to provide a high rate triggerable charm/beauty track and vertex detector for fixed target or collider experiments.     

Computer simulation of the vertex detector of the CLAS12 facility

The CLAS International Collaboration is preparing the CLAS detector for updating in 2013, because the energy of the CEBAF electron accelerator will be raised to 12 GeV. The new facility will be called the CLAS 12. An SVT vertex detector will be one of new units of the CLAS 12. This paper presents the results of computer simulation of the vertex detector using the GEANT4 package. Estimates of the detector counting rate and the expected accuracy of determining coordinates and momenta are obtained. The dependence of the efficiency of operation of the vertex detector on different external conditions is studied.     

A data acquisition system of the SND detector for experiments on the BЭΠΠ-2000

A new data acquisition system for the SND detector is presented. The digitizing electronics, the detector triggering and monitoring subsystems, and the organization of the data transmission to the computer are described. The architecture of the software part of the data acquisition system, the operator’s interface, and the processes of event acquisition, processing, and monitoring are presented. The results of system testing on cosmic events and a random-triggering generator are described.     

Testing the electronic system for the γ-quantum detector of the SVD-2 setup

Firmware for checking the electronic equipment for recording signals of the hodoscope γ-quantum detector is described. The detector has 1344 channels for measuring charges of nanosecond pulses arriving from outputs of photomultiplier tubes. The testing system is intended to test the electronics at each level of its hierarchical structure and also to perform the initial check of the γ-quantum detector itself.     

Scaling Modules for the IHEP Experimental Setups

Multichannel scaling modules, which have a high response speed and meet the specific requirements of experiments conducted with the IHEP physical setups, are described. The scaling modules are made to SUMMA, MISS, and Euromechanics standards and use high-speed microcircuits of the 1500 family and programmable logic integrated circuits from Altera.     

A gated liquid-scintillator-based neutron detector for fast-ignitor experiments and down-scattered neutron measurements

The detection of neutrons in fast-ignitor experiments or down-scattered neutrons in inertial fusion experiments is very challenging since it requires the neutron detection system to recover within 10-100 ns from a high background orders of magnitude stronger than the signal of interest. The background is either the hard x-ray emission from short-pulse laser target interactions for the fast-ignitor experiments or the primary neutron signal for the down-scattered neutrons. A liquid-scintillator detector has been developed using a gated photomultiplier that suppresses the background signal and eliminates the afterglow present in conventional plastic scintillators.     

Testing the prototype of the NUCLEON setup on the pion beam of the SPS accelerator (CERN)

A technique for determining the energy of primary cosmic rays in the range of 10¹²–10¹⁵ eV has been developed. The idea behind this technique consists in measuring the spatial flux density of secondary particles produced in the first act of inelastic nuclear interaction inside a target and passed through a thin converter layer in which the electromagnetic component (photons from decays of neutral pions) is multiplied. This technique has been developed by generalizing the well-known Castagnoli method (for measuring the angular characteristics of tracks of secondary particles produced in the first act of inelastic nuclear interaction inside a target), and its application offers a chance to design instruments for scientific studies such that their mass is relatively low while their luminosity is high. It is proposed to use this technique in a satellite-based NUCLEON experiment. The technique has been tested on charged particle beams of the SPS accelerator at CERN. Results of these tests confirm that, using this method, it is possible to measure the particle energy and, therefore, perform an orbital scientific experiment with the proposed equipment.     

Development and application of setup for ac magnetic field in neutron scattering experiments

We report on a new setup developed for neutron scattering experiments in periodically alternating magnetic fields at the sample position. The assembly consisting of rf generator, amplifier, wide band transformer, and resonance circuit. It allows to generate homogeneous ac magnetic fields over a volume of a few cm(3) and variable within a wide range of amplitudes and frequencies. The applicability of the device is exemplified by ac polarized neutron reflectometry (PNR): a new method established to probe remagnetization kinetics in soft ferromagnetic films. Test experiments with iron films demonstrate that the ac field within the accessible range of frequencies and amplitudes produces a dramatic effect on the PNR signal. This shows that the relevant ac field parameters generated by the device match well with the scales involved in the remagnetization processes. Other possible applications of the rf unit are briefly discussed.     

A setup for thermodesorption measurements

An ultrahigh-vacuum setup for studying the interaction of ions with a solid by the thermodesorption spectroscopy method has been developed. The residual pressure achieved in the setup after heating is <2 × 10⁻⁷ Pa (the main component of the residual gas is H₂). A sample suspended by two tungsten wires is inserted into the main vacuum chamber through a lock chamber. The sample is heated by thermal radiation from the heater from room temperature to 1600–1700 K. The main features of the setup, the experimental technique, and the calibration of desorption flows are discussed. Examples of results obtained on the setup are presented.     

A linear accelerator for simulating micrometeorites

The theory, the estimated parameters, and the design features of the linear accelerator capable of accelerating charged dust particles 0.1–10 μm in diameter to velocities of 12 km/s are presented. The electrodynamical circuit of the accelerator is composed of 27 acceleration gaps, each of which is held at a potential of 20 kV. Particles are injected into the linear electrodynamical accelerator after preliminary acceleration in the linear electrostatic accelerator with an effective voltage of 145 kV. The total effective accelerating voltage is 670 kV. The total length of the accelerating sections is 3.62 m. The essential difference of this accelerator from the existing machines is that the drift tubes of the dynamical circuit are identical and that synchronism of particle motion with the voltage applied to the drift tubes is achieved by forming the accelerating voltage as a function of the particle velocity and specific charge. The measured performance data of the accelerator are presented.     

Fusion neutron detector for time-of-flight measurements in z-pinch and plasma focus experiments

We have developed and tested sensitive neutron detectors for neutron time-of-flight measurements in z-pinch and plasma focus experiments with neutron emission times in tens of nanoseconds and with neutron yields between 10(6) and 10(12) per one shot. The neutron detectors are composed of a BC-408 fast plastic scintillator and Hamamatsu H1949-51 photomultiplier tube (PMT). During the calibration procedure, a PMT delay was determined for various operating voltages. The temporal resolution of the neutron detector was measured for the most commonly used PMT voltage of 1.4 kV. At the PF-1000 plasma focus, a novel method of the acquisition of a pulse height distribution has been used. This pulse height analysis enabled to determine the single neutron sensitivity for various neutron energies and to calibrate the neutron detector for absolute neutron yields at about 2.45 MeV.     

A new electromagnetic calorimeter for the updated VES setup

A complex of the new electromagnetic calorimeter (ECAL-2) for the VES setup is described. It is composed of 1592 “shashlik” type counters consisting of a set of lead?scintillator plates, high-voltage supplies based on cascade voltage multipliers for FEU-84 photomultiplier tubes, an LED-based monitoring system, a slow control system, and a pulse-height analysis system. The procedures of ECAL-2 calibration and online monitoring are described.     

A trigger based on an active target for the MIS ITEP experimental setup

The use of a silicon photomultiplier (SiPM) has made it possible to produce a compact target composed of 16 active elements capable of measuring ionization losses in each element. The accuracy of a single ionization measurement is sufficient to allow discrimination between single- and three-track signals in 90% of events. A special ????-80 processor has been developed using the programmable decision lookup table method for trigger signal generation, which is implemented in Altera programmable logic devices. The time it takes for the special processor to produce a trigger signal is 80 ns or less. The possibility of separating reactions with neutral strange particles has been demonstrated using vast experimental statistics.     

A versatile low-temperature setup for the electrical characterization of single-molecule junctions

We present a modular high-vacuum setup for the electrical characterization of single molecules down to liquid helium temperatures. The experimental design is based on microfabricated mechanically controllable break junctions, which offer control over the distance of two electrodes via the bending of a flexible substrate. The actuator part of the setup is divided into two stages. The slow stage is based on a differential screw drive with a large bending range. An amplified piezoceramic actuator forms the fast stage of the setup, which can operate at bending speeds of up to 800 μm/s. In our microfabricated break junctions this is translated into breaking speeds of several 10 nm/s, sufficient for the fast acquisition of large statistical datasets. The bandwidth of the measurement electronics has been optimized to enable fast dI/dV spectroscopy on molecular junctions with resistances up to 100 MΩ. The performance of the setup is demonstrated for a π-conjugated oligo(phenylene-ethynylene)-dithiol molecule.