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.
15193392
The D0 detector upgrade and physics program
The D0 detector at Fermilab is in the final stages of an extensive upgrade. It is designed to meet the demands imposed by high luminosity Tevatron running planned to begin March 2001. The design and performance of the detector subsystems are described and a brief outline of the physics potential is presented.
110541630
Punch-through currents and floating strip potentials in silicon detectors
Punch-through currents flowing between adjacent p/sup +/ strips on the surface of silicon microstrip drift detectors have been observed. Measurements of the floating strip potential have shown that a p/sup +/ strip acquires a voltage such that the punch-through current and the leakage current are equal and opposite. The factors influencing the threshold for the punch-through effect have been compared with a simple computer model, and the predicted variation with the interstrip gap is found to be in reasonable agreement with measured values for a variety of detectors. >
122003047
Silicon drift photodiodes
Abstract Low capacitance photodiodes based on the principle of the solid state drift chamber have been constructred and tested. The devices are based on a cellular design with an anode at the centre of each of five cells allowing electrons liberated by ionisation to drift up to 1 mm to the readout strip. Results on the performance of the detectors, including leakage current, capacitance and drift properties, are presented and compared with simulations. A second series drift photodiodes have been processed which incorporate improvements based on results acquired from the first design. They have leakage currents of a few nA and shorter drift times at the periphery of the drift cells. We present measurements showing the performance of the new devices.
53491810
Searches for the Higgs Boson at the Tevatron
We report on direct searches for Higgs bosons carried out by the CDF and DO Collaborations in proton‐antiproton collisions at a center‐of‐mass energy of 1.96 TeV. Limits on the production cross section times branching fraction will be presented and a brief discussion of searches for supersymmetric Higgs bosons will be given. We will focus mainly on recent results only (those released in 2006), based on data sets of 260 – 950 fb−1 of data collected between 2004 – 2006.
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.
119726162
First operation with a crystal septum to replace a magnet in a charged particle beam
Abstract Particle channeling in a bent crystal at Fermilab has been used to replace a magnet in a secondary charged particle beam. The maximum momentum of particles that could be transmitted to an experimental location was raised from the magnetic septum limit of 225 GeV/ c to the full primary beam momentum of 400 GeV/ c .
17542978
CSR EFFECTS IN A BUNCH COMPRESSOR: INFLUENCE OF THE TRANSVERSE FORCE AND SHIELDING ∗
We studytheinsuenceofcoherentsynchrotronradiation(CSR) on particle bunches traveling on arbitrary planar or-bits betweenparallelconductingplates whichrepresentthevacuum chamber. Our ultimate goal is to follow the timeevolution of the phase space density distribution by solv-ing the 2D Vlasov-Maxwell (VM) system in the time do-main. In contrast to macroparticle methods, the VM ap-proach has no statistical noise and is better suited to thestudy of microbunching. The Þelds excited by the bunchare computed in the lab frame, while the nonlinear Vlasovequation, formulated in interaction picture, is integrated inthe beam frame using the method of local characteristics(Perron-Frobenius (PF) method). The interaction pictureallows a relatively large step using the Euler method. De-tails of our method can be found in [1] and [2]. The majordifÞculty here is the need for a detailed understanding ofthe support of the phase space density. Here we show re-cent numerical results obtained in our Liouville-Maxwellapproximation (LMA) for the benchmark bunch compres-sor at 5 GeV studied in [3]. We analyze the role played bythe transverse force and the effect of shielding and studythe supportof the phase space density.
122016249
Vlasov treatment of coherent synchrotron radiation from arbitrary planar orbits
We study the influence of coherent synchrotron radiation (CSR) on particle bunches traveling on arbitrary planar orbits between parallel conducting plates which represent the vacuum chamber. Our goal is to follow the time evolution of the phase space distribution by solving the Vlasov–Maxwell equations in the time domain. This should provide simulations with lower numerical noise than the macro-particle method, and allow one to study such issues as emittance degradation and microbunching due to CSR in bunch compressors. The fields excited by the bunch are computed in the laboratory frame from a new formula that leads to much simpler computations than usual methods. The nonlinear Vlasov equation, formulated in the interaction picture, is integrated in the beam frame by approximating the Perron–Frobenius operator. For application to a chicane bunch compressor we take steps to deal with energy chirp.
118063820
HERA-B and halo control using noise
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.