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.
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.
73602518
Radiation Resistant DC- DC Power Conversion with Voltage Ratios > 10 Capable of Operating in High Magnetic Field for LHC Upgrade Detectors
Commercial power converters that have voltage ratios greater than ten and are capable of running near the LHC collision region would increase the efficiency of the power distribution system of the ATLAS Silicon Tracker high luminosity upgrade. The devices must operate in a high magnetic field (2 T) and be radiation hard to ~50-100 Mrad and ~10 15 Neq/cm 2 . These converters are to be mounted on the same multi-chip modules as the ASIC readout chips or in close vicinity without introducing any additional readout noise due to the high switching frequencies. Such devices will permit higher voltage power delivery to the tracker and thus increase overall power efficiency by limiting the ohmic losses in the stretch of cable (about 100 meters) between the tracker and the power sources.
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.
55139157
SLHC tracker upgrade: challenges and strategies in ATLAS
The Large Hadron Collider (LHC) will be upgraded to the Super-LHC in ≈2016 to provide a ten-fold increased luminosity and data rate. The inner silicon tracking detectors of the ATLAS and CMS experiments will be replaced by even more powerful devices. The new detectors will face unprecedented particle densities and radiation levels. Limiting the power consumption of the front-end electronics, distributing power efficiently and minimizing detector mass, while keeping the costs of the detector affordable, are key challenges. Possible design solutions and the status of R&D for ATLAS are described.
121603383
Performance of an electromagnetic lead/scintillating-fibre calorimeter for the H1 detector
Abstract The properties of final modules of a high resolution lead/scintillating-fibre calorimeter to upgrade the backward region of the H1 detector were studied with electrons in the energy range from 2–60 GeV. The electromagnetic calorimeter consists of scintillating fibres with a diameter of 0.5 mm embedded in a lead matrix. This small fibre radius, in combination with a lead-to-fibre ratio of 2.27:1, ensures excellent energy resolution which has been measured to be δ/E=7.1%/ E/GeV ⊕ 1.0% . The spatial resolution as a function of energy for impact points at the center of a cell is given by 4.4 mm/ E/GeV + 1.0 mm . The time resolution was found to be better than 0.4 ns.
109654831
Electrical performance of a silicon micro-strip super-module prototype for the High-Luminosity LHC collider
A major luminosity upgrade for the Large Hadron Collider (LHC) proton–proton collider at CERN is planned for ∼2022 to allow for peak luminosities of ∼5×1034cm−2s−1. The current inner tracker of the ATLAS experiment will be completely replaced to guarantee excellent tracking capabilities in an environment characterized by much higher detector occupancies and harsher radiation backgrounds as compared with the current LHC. The new tracker will be an all-silicon based system, with pixel detectors in the innermost layers and silicon micro-strip layers at outer radii. The so-called super-module concept is an integration solution proposed for the strip barrel region of the future ATLAS internal tracker. It consists of several double-sided silicon micro-strip modules assembled into a common light-weight support structure. A first electrical prototype of a super-module has been produced, aimed to exercise the readout chain and to investigate the noise performance of such a complex system. In this paper the super-module prototype is described and first electrical results are presented.
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.
8016343
Testing coupling relations in SUSY QCD at a linear collider
Supersymmetry predicts that gauge couplings are equal to the corresponding gaugino-sfermion-fermion Yukawa couplings. This prediction can be tested for the QCD sector of the MSSM by studying the processes eplus+eminus -> squark+antisquark+gluon and eplus+eminus -> squark+antiquark+gluino at a future linear collider. We present results for these processes at next-to-leading order in alpha_s in the framework of the MSSM. We find sizable SUSY-QCD corrections. The renormalization scale dependence is significantly reduced at next-to-leading order.
115688949
Tests of supersymmetric couplings at high-energy colliders
55821746
Trilepton final state from neutralino-chargino production in mSUGRA.
The direct production of neutralino-chargino pairs in the mSUGRA scenario with decays into pure trilepton final states has a significant cross section for low neutralino masses. The trilepton signature was studied with the full and fast CMS detector simulations. The 5 signal can be observed in the dilepton invariant mass distribution at the integrated luminosity of L 30 fb for GeV.