119863129
Performance of the H1 lead/scintillating-fibre calorimeter
Abstract In the winter-shutdown 1994/95 the backward region of the H1 detector has been equipped with a new lead/scintillating-fibre calorimeter. The purpose of the calorimeter is to perform precise measurements of the energy and the position of scattered electrons in ep collisions at HERA. In addition, the calorimeter determines the hadronic energy flow in the backward region and provides detailed trigger information and efficient background rejection exploiting the difference of impact times for physics events and beam related background events. The first data-taking experience with the new device is described.
54868784
Series tests of fine mesh photomultiplier tubes in magnetic fields of up to 1.2 Tesla
Abstract The new lead/scintillating-fibre calorimeter (“SpaCal”) for the backward region of the H1 experiment at HERA (DESY) is equipped with fine mesh phototubes which operate in a magnetic field close to 1 T. A large sample of these tubes of the types Hamamatsu R5505 and R5506, and Hamamatsu R2490-05, have been tested in fields of up to 1.2T. We have investigated the cathode homogeneity with and without magnetic field, the gain loss under the influence of the magnetic field, and stability with time. For a subsample of tubes, we have performed additional studies on stability with respect to temperature changes, variation of gain as a function of the magnetic field, high voltage discharges, single photo-electron response, and linearity. We finally summarize the experience with these tubes after one year of operation in the experiment.
110779087
The SVX4 integrated circuit
Abstract A first prototype of the SVX4 readout IC with enclosed transistor layout for radiation tolerance has been fabricated in a commercial 0.25 μm bulk CMOS process. The SVX4 is intended to instrument the CDF and D0 Run IIB silicon strip detector upgrades at Fermilab. The design and test results are discussed.
7496605
Serial Powering for Silicon Strip Detectors at SLUC
Serial powering of silicon sensors is a novel powering scheme that would reduce the total power, the number of cables, the passive detector material, and the costs of future silicon trackers by large factors. Modules are chained in series and are served by a single current source. Serial powering is of great interest for future large-scale silicon tracking detectors for particle physics with many thousands of densely packed detector modules. Tests with six ATLAS semiconductor tracker (SCT) modules using both serial powering and the conventional independent powering have been carried out. The electrical performance of SCT modules powered in series is excellent. We present selected results and discuss the system aspects of a serial powering.
38852891
Shielding and electrical performance of silicon detector supermodules
A large detector structure, called a supermodule, was developed for the CDF Run IIb silicon strip detector. The supermodule is a compact mechanical, thermal, and electrical unit, which is ideally suited for construction and assembly of large volume detector systems. Its dense packaging requires careful suppression of possible electromagnetic interference due to power, clock, control, and data bus activity. We study the coupling of the magnetic fields caused by a clock signal through an aluminum shield into the silicon strips. Analytical and numerical calculations of the resulting interference signal are presented, and its shape and size are estimated. The calculations are in fair agreement with electrical performance measurements taken with final design supermodules. Calculations and measurements show that the interference effect can be effectively suppressed by a thin aluminum shield.
111420431
Ideas on DC-DC Converters for Delivery of Low Voltage and High Currents for the SLHC / ILC Detector Electronics in Magnetic field and Radiation environments
For more efficient power transport to the electronics embedded inside large colliding beam detectors, we explore the feasibility of supplying 48 Volts DC and using local DCDC conversion to 2 V (or lower, depending upon on the lithography of the embedded electronics) using switch mode regulators located very close to the front end electronics. These devices will be exposed to high radiation and high magnetic fields, 10 – 100 Mrads and 2 4 Tesla at the SLHC, and 20 Krads and 6 Tesla at the ILC.
16334731
Higgs Production by Gluon initiated Weak Boson Fusion
The gluon-gluon induced terms for Higgs production through weak-boson fusion are calculated. They form a finite and gauge-invariant subset of the NNLO corrections in the strong coupling constant. This is also the lowest order with sizeable t-channel colour exchange contributions, leading to additional hadronic activity between the outgoing jets.
122225376
An investigation of the antinuclei and nuclei production mechanism in Pb + Pb collisions at 158 A GeV
We investigate the production mechanisms of p, d, t, 3He, 4He, 6Li, , and in Pb+Pb collisions at 158 A GeV measured near zero transverse momentum with the NA52 experiment at the CERN SPS. We find evidence that nuclei and antinuclei in Pb+Pb collisions are mainly produced via the coalescence mechanism out of a thermalized source of hadrons, at a time close to the thermal freeze-out of hadrons corresponding to a temperature of ~120 MeV.
123173797
Calibration, alignment and tracking performance of the CMS silicon strip tracker
Abstract After its installation in the CMS experiment, the CMS silicon tracker has been commissioned, calibrated and aligned based on several million reconstructed tracks, recorded during extended cosmic ray data-taking in 2008 and 2009. The collision data at 900 GeV and 2.36 TeV which were recorded by the CMS experiment in December 2009 allowed to repeat the calibration measurements and derive compatible results. Calibration results are shown for the silicon strip detector only, whereas alignment and tracking performance are given for the complete CMS tracker, including the silicon pixel system.
107061988
Design and assembly of double-sided silicon strip module prototypes for the ATLAS upgrade strip tracker
The LHC foresees a peak luminosity increase of up to ∼5×1034cm−2s−1 from ∼2022 with an integrated luminosity of ∼3000fb−1 before 2030. The current ATLAS Inner Detector will not stand the predicted radiation levels nor the expected large increase in the hit occupancy rates. A new inner tracker must therefore be designed, built and installed in a relatively short time-scale. The current layout assumes an all-silicon tracker with pixel detectors for the innermost layers and strip modules at higher radii. Major constraints are the requirements of radiation-hard sensors, efficient power distribution, minimum material budget, affordable cost, and fast and reliable production. This note reports on the design of double-sided silicon strip modules for the short-strip region of the upgraded ATLAS inner tracker. The different components of the module are described. The thermal performance is discussed. The assembly sequence of first module prototypes is explained in detail.
56244151
Experience with the L3 vertex drift chamber at LEP
The vertex drift chamber of the L3 Experiment at LEP, based on the time expansion principle, was in operation from the start-up of LEP in 1989 until the shutdown of LEP in 2000. The gas mixture used was 80% CO2 and 20% i-C4H10 at a pressure of . We present the design of the chamber, the infrastructure and the performance during the 11 years of operation. The total radiation received on the anode wires was ~10-4 C/cm. No degradation of the anode pulse amplitude, wire efficiencies and resolution was observed for the whole running period.