21012160
Tests of A Roman Pot Prototype for the Totem Experiment
The TOTEM collaboration has developed and tested the first prototype of its Roman Pots to be operated in the LHC. TOTEM Roman Pots contain stacks of silicon detectors with strips oriented in two orthogonal directions. To measure proton scattering angles of a few microradians, the detectors will approach the beam centre to a distance of 10σ + 0.5 mm (= 1.3 mm). Dead space near the detector edge is minimised by using two novel "edgeless" detector technologies. The silicon detectors are used both for precise track reconstruction and for triggering. The first full-sized prototypes of both detector technologies as well as their read-out electronics have been developed, built and operated. The tests took place in the proton beam-line of the SPS accelerator ring. In addition, the pot's shielding against electromagnetic interference and the longitudinal beam coupling impedance have been measured with the wire method.
119975839
Impact parameter structure derived from elastic collisions
Impact parameter profiles derived from elastic scattering data within the framework of standard model cannot be regarded as definite being burdened by two defficiences: influenced strongly by an a priori (physically non-reasoned) assumption and by non-unique relation to elastic hadron amplitude. A mathematically consistent general model providing a unique relation is presented and some new formulas allowing to evaluate mean-square values of corresponding impact parameters (for elastic and inelastic processes directly from the t dependent amplitude) are introduced. Critical arguments against the mentioned a priori assumption are discussed as well.
469908
Performance of the Totem Detectors at the LHC
The TOTEM Experiment is designed to measure the total proton–proton cross-section with the luminosity-independent method and to study elastic and diffractive pp scattering at the LHC. To achieve optimum forward coverage for charged particles emitted by the pp collisions in the interaction point IP5, two tracking telescopes, T1 and T2, are installed on each side of the IP in the pseudorapidity region 3.1≤|η|≤6.5, and special movable beam-pipe insertions — called Roman Pots (RP) — are placed at distances of ±147 m and ±220 m from IP5. This article describes in detail the working of the TOTEM detector to produce physics results in the first three years of operation and data taking at the LHC.
122588297
Elastic partial-wave amplitude and poles of higher order
Starting from the usual formula for the elastic partial-wave scattering amplitude a new formal decomposition of the phase shift is given which leads to a new more general expression for energy-dependence exhibiting poles of higher order. This decomposition is in agreement with a multichannel decay model of unstable particles, which stands behind this approach.
44874120
Momentum-transfer dependence of the elastic-amplitude phase in high-energy hadron scattering.
The phase of the elastic-scattering amplitude is responsible for the probability distribution of events in the impact-parameter space. A rather steep increase of it around t = 0 can lead to a peripheral behavior of elastic collisions. The experimental data from the interference regions of hadronic and Coulomb scatterings have been shown to be fully consistent with such a peripherality. Other reasons supporting peripherality have been mentioned, also.
121853587
Predictions on the total cross-section and real part at LHC and SSC
Abstract An overall fit to the data on the total cross section and on the real part of the forward amplitude for p p and pp was performed using dispersion relations. The energy dependence of the total cross section was studied up to s = 100 TeV . Numerical predictions are presented for LHC and SSC energies.
186674866
The First Three TILECAL Submodule Assembly in Prague
110037616
The results of mass testing of the plastic streamer tubes for the DELPHI hadron calorimeter
Abstract The procedure and results of mass testing of plastic streamer tubes for the DELPHI hadron calorimeter are described in detail. The mass testing includes three stages: high voltage test and conditioning, X-ray test on radiation load capability and wire tension control in ready detectors. The productivity of the test workshop was 240 detectors per day at maximum. After testing of about 25 000 streamer tubes, 8% have been rejected on the ground of severe rejection criteria which exceed significantly the working conditions in the DELPHI experiment.
121692314
Test of a compact Si-strip detector for the forward region in DELPHI
Abstract The DELPHI detector will be upgraded by a new silicon detector in the very forward region to fulfil the physics demands of the LEP200 program. This detector will cover the angular region between 10° and 25° with respect to the beam pipe and will have a two dimensional readout. The severe space restrictions in this region lead us to develop a new arrangement of detectors and electronic hybrids. In beam tests the layout of the detectors was optimised. Special attention was given to the charge loss in intermediate strips for detectors with large strip pitch. Beam test results obtained with different detector layouts, e.g. various implant widths, and different angle of the incident particles will be shown.
120268916
Experimental tests of neutron shielding for the ATLAS forward region
Abstract Experimental tests devoted to the optimization of the neutron shielding for the ATLAS forward region were performed at the CERN-PS with a 4 GeV/ c proton beam. Spectra of fast neutrons, slow neutrons and gamma rays escaping a block of iron (40×40×80 cm 3 ) shielded with different types of neutron and gamma shields (pure polyethylene – PE; borated polyethylene – BPE; lithium filled polyethylene – LiPE; lead; iron) were measured by means of plastic scintillators, a Bonner spectrometer, a HPGe detector and a slow neutron detector. Effectiveness of different types of shielding against neutrons and γ-rays were compared. The idea of a segmented outer layer shielding (iron, BPE, iron, LiPE) for the ATLAS forward region was also tested.
125171490
CROSS-SECTIONS, AVERAGE MULTIPLICITIES AND ENERGY FRACTIONS OF NEUTRAL pi- AND K MESONS IN anti-p p ANNIHILATIONS AT 22.4-GeV/c