121802001
Evaluation of prototype silicon drift detectors
Abstract Silicon drift detectors, of two elementary designs, have been fabricated and tested using β electrons and light pulses. Drift of electrons within the detectors has been observed over distances up to about 8 mm with high efficiency. Results are presented, some of which identify important design parameters of such devices.
110503904
Silicon detector tests with the RAL microplex readout chip
The design, construction and operation of a five-layer silicon microstrip detector is described. The detector consisted of silicon microstrip wafers bonded to the RAL Microplex MX2 readout chip. The readout chip provided amplification with double-correlated sampling for each microstrip channel and multiplexing of 128 signals. The circuitry controlling the chip, the readout electronics, the stage holding the microstrip wafers and their alignment, are also described. A single-layer resolution of 10±0.6 μm was obtained in a test beam. This work is part of a program to design a microvertex detector for UA1 at the CERN pp collider.
16901067
W Boson Physics at the Fermilab Tevatron
We present electroweak physics results from the D0 and CDF experiments using data from p \bar p collisions at \sqrt s = 1.8 TeV. Measurements of the cross sections times branching ratios for W and Z production, the inclusive width of the W boson and the W boson mass are presented. Direct tests of the WW\gamma and WWZ trilinear gauge boson couplings are also presented based on studies of diboson production.
122654690
Silicon microstrip wedge detectors for the DØ silicon tracker
Abstract The silicon tracking system proposed for the DO upgrade is discussed. The design of “wedge” modules for the forward disk section of the tracker is described. The wedge detectors are double-sided with a stereo angle of ± 15° and a strip pitch of 50 μm. Each strip includes an integrated ac-coupling capacitor and polysilicon bias resistor. First results from recently fabricated prototype wedge detectors are presented.
120475830
Physics capabilities of the DO upgrade detector
The D0 detector at Fermilab is being upgraded to meet the demands imposed by high luminosity Tevatron running planned to begin in 1998. The central tracking detectors will be replaced with silicon and scintillating fiber tracking systems inside a solenoidal magnetic field and a preshower detector will be added to aid in electron identification. The design and performance of these systems are described and detailed simulations of the physics capabilities of the upgraded detector are presented. In particular the authors focus on the study of electroweak boson properties and top quark physics and briefly describe the b-physics capabilities.
110084127
A silicon drift photodiode
A low-capacitance photodiode based on the principle of the solid-state drift chamber has been constructed and tested. The device is based on a cellular design with an anode at the center of each of five cells, allowing electrons liberated by ionization to drift up to 1 mm to the readout strip. Two designs were produced with p/sup +/ implant widths of 75 mu m and 85 mu m, respectively, using n-type material of 3.5-k Omega -cm resistivity. The opposite surface is a uniform p-type implant, features matching those of the other surface, and is unmetallized to ensure good photosensitivity. Results on the performance of the detector, including leakage current, capacitance, and drift properties, are presented and compared with simulation results. >
15671309
Construction of Large Period Symplectic Maps by Interpolative Methods
The goal is to construct a symplectic evolution map for a large section of an accelerator, say a full turn of a large ring or a long wiggler. We start with an accurate tracking algorithm for single particles, which is allowed to be slightly non-symplectic. By tracking many particles for a distance S one acquires sufficient data to construct the mixed-variable generator of a symplectic map for evolution over S, given in terms of interpolatory functions. Two ways to find the generator are considered: (1) Find its gradient from tracking data, then the generator itself as a line integral. (2) Compute the action integral on many orbits. A test of method (1) has been made in a difficult example: a full turn map for an electron ring with strong nonlinearity near the dynamic aperture. The method succeeds at fairly large amplitudes, but there are technical difficulties near the dynamic aperture due to oddly shaped interpolation domains. For a generally applicable algorithm we propose method (2), realized with meshless interpolation methods.
122661247
The super fixed target beauty facility at the SSC
Abstract The rationale for pursuing beauty physics at the SSC in a fixed target configuration is described. The increased beauty production cross section at the SSC, combined with high interaction rate capability of the proposed detector, results in 10 10–11 produced BB events per year. The long decay length of the B hadrons (≌10 cm) allows direct observation of B decays in the high resolution silicon microstrip vertex detector. To optimize the operation of the proposed beauty spectrometer and the SSC, parasitic extraction of attendant or artificially generated large amplitude protons using crystal channeling is proposed and explored. The large sample of fully reconstructed B events allows detailed studies various CP violating decays with requisite statistics to confront the standard model. The CP physics potentials of the proposed experiment is evaluated and compared with alternative approaches, such as asymmetric e + e − B Factories and specialized hadron colliders.
117418480
Reliability of numerical solutions of a diffusion equation modeling rf noise-induced dilution in particle beams
The dilution process in particle beams caused by noise in the rf accelerating system has been modeled using a diffusion equation. Particle tracking can also be undertaken to determine the effects of rf noise, through it is much more computationally extensive than integrating the diffusion equation. In this paper we present the integration results using the Method of Lines (MOL) for certain important classes of noise. We will describe the numerical algorithms in detail, including those that are made to remove anomalous solutions. Reliability of the numerical results will be checked using both finite-difference and finite-element (Galerkin) methods in discretization and applying the same algorithms to the cases of linear and quadratic diffusion coefficients where exact solutions are known.
10238716
From symplectic integrator to poincaré map: spline expansion of a map generator in Cartesian coordinates
Abstract Data from orbits of a symplectic integration can be interpolated so as to construct an approximation to the generating function of a Poincare map. The time required to compute an orbit of the symplectic map induced by the generator can be much less than the time to follow the same orbit by symplectic integration. The approximation has been constructed previously for full-turn maps of large particle accelerators, and a large saving in time (for instance a factor of 60) has been demonstrated. A shortcoming of our work to date arises from the use of canonical polar coordinates, which preclude map construction in small regions of phase space near coordinate singularities. Here, we show that Cartesian coordinates can be used, thus avoiding singularities. The generator is represented in a basis of tensor product B-splines. Under weak conditions, the spline expansion converges uniformly as the mesh is refined, approaching the generator of the Poincare map as defined by the symplectic integrator, in some parallelepiped of phase space centered at the origin.
125938618
Transverse beam dynamics with noise