Forward scintillation hodoscope for nuclear fragment detection at the high acceptance dielectron spectrometer (HADES) setup

The main characteristics of the forward scintillation hodoscope and readout electronics of the high acceptance dielectron spectrometer (HADES) at GSI (Darmstadt, Germany) are presented. Methods for adjustment and amplitude-time calibration of hodoscope detectors using cosmic rays and results of measurements of the Au + Au reaction at a beam energy of 1.24 GeV/nucleon are described. The use of the forward hodoscope for tagging the n + p reaction by means of the deuteron beam incident on a liquid hydrogen target is discussed. A procedure for determining the reaction plane angle in event-by-event analysis of the Au + Au reaction data (at 1.24 GeV/nucleon) is presented.     

Entropy Approach in the Analysis of Anisotropy of Digital Images

Anisotropy is assumed to be the difference of a plane object observed in different dimensions. For digital images, anisotropy is determined in two ways. The first one is based on the comparison of mosaics bearing rectangular smalts developed in different (perpendicular, to be exact) directions. The comparison is provided through an intermediate mosaic called palette, that is the mosaic with the frequency of smalts equal to arithmetic mean of the frequency of smalts of compared mosaics. The latter is based on the calculation of the information capacity of the mosaics developed in different directions. The information capacity is the specific entropy of real mosaic calculated against the reconstructed one bearing the most probable expansions of smaller smalts. The problem of test object is discussed.     

Information Capacity of Symbol Sequences

The information capacity of sequences is considered through the calculation of specific entropy of their frequency dictionary. The specific entropy was calculated against the reconstructed dictionary which bears the most probable continuations of shorter strings. The measure developed allows to distinguish the sequences both from the random ones, and those with high level of (rather simple) order. Some applications of the developed methodology to genetics, bioinformatics, and linguistics are discussed.     

The Prototype for a Monitoring System for a Photon Spectrometer Based on Lead-Tungstate Crystals

A monitoring system for the prototype of a Photon Spectrometer based on the lead-tungstate crystals of the ALICE experiment at the LHC collider. Light-emitting diodes are used as a source of light test signals simulating scintillations in crystals. The system provides individual control of the spectrometer's 64 channels. A relative channel monitoring stability of 1.2 × 10^–3 was achieved upon exposing the spectrometer to a beam for a period of 100h.     

A comparison of sonographic growth curves of triplet and twin fetuses

Sonographic growth curves of 47 normal triplet pregnancies were compared with those of 71 uncomplicated twin gestations. Starting from the 25th week, the biparietal diameter in triplets was found to lag progressively compared with that of twins, reaching a mean difference of 2 weeks at 36 weeks gestation. Similarly, a significant difference was found between the femur length and head to abdomen circumference ratio growth curves of triplets and twins. It is concluded that as pregnancy continues from the 25th to the 36th gestational week, there is a significant delay in the growth patterns of normal triplet pregnancies compared with twin gestations.     

Methods of Coordinate Reconstruction in Gaseous Detectors with Cathode Readout

The methods for reconstructing the coordinates of charged particles in gaseous detectors with cathode readout are analyzed in detail. The spatial resolution is investigated using spatial-reconstruction procedures based on the known relations and the new formulas proposed in the paper. The use of this method is illustrated by processing the beam-test data of the charged-particle veto detector of the proton spectrometer for the ALICE experiment at the Large Hadron Collider (CERN). The spatial resolution of the detector based on the multiwire proportional chamber with cathode-pad readout (pad dimensions are 22 × 10.7 mm, the anode-wire pitch is 5.65 mm, and the anode–cathode gap is 5.5 mm), measured along and across the anode wires, is _x 0.14 cm and _y 0.15 cm, respectively.