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.
117231264
Development of readout system for double-sided silicon strip modules
Y. Takubo ∗,a S. Gonzalez-Sevilla, c A. Clark, c M. Endo, b D. Ferrere, c K. Hanagaki, b Y. Ikegami, a S. Terada,a Y. Unno a and M. Weber c a High Energy Accelerator Research Organization (KEK) 1-1 Oho, Tsukuba, Ibaragi, Japan b Department of Physics, Osaka University 1-1 Machikaneyama Toyonaka Osaka, Japan c DPNC, University of Geneva 24, quai Ernest-Ansermet CH-1211 Geneva 4, Switzerland E-mail: yosuke.takubo@kek.jp
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.
116623294
EndCap Module Production for the ATLAS Silicon Tracker (SCT) at CERN and the University of Geneva
This note describes the infrastructure, procedure and quality assurance for the construction of approximately one third of the endcap modules for the ATLAS Semiconductor Tracker (SCT) by groups from the University of Geneva and CERN.
109729787
Development of a silicon-microstrip super module prototype for the high luminosity LHC
Following the Phase II upgrade of the CERN Large Hadron Collider (LHC) currently foreseen in 2022–2023, the High Luminosity LHC (HL-LHC) is expected to deliver a peak luminosity in excess of 5×1034cm−2s−1 and an integrated luminosity of order 3000fb−1 until 2033. The ATLAS Collaboration plans to replace the existing Inner Tracking Detector by a new tracker, with readout electronics as well as silicon pixel and strip sensor technology capable of maintaining the excellent tracking performance of the existing tracker in the severe radiation and high collision rate environment of the HL-LHC. The promising super-module integration concept extends the proven design of the existing barrel silicon strip tracker to the HL-LHC, with double-sided stereo silicon micro-strip modules assembled into a low mass local support structure. The Super-Module R&D program is described, with reference to HL-LHC requirements, and key prototype results are summarized.
120399805
Gluon Initiated Vector Boson Fusion
The gluon-gluon induced terms for Higgs production through vector-boson fusion are calculated. They are a finite and gauge-invariant subset of the NNLO corrections in the strong coupling constant. This is also the lowest order with t-channel colour exchange between the scattering quarks, leading to additional hadronic activity between the outgoing jets.
16250559
Determination of the local dark matter density in our Galaxy
Context. The rotation curve, the total mass and the gravitational potential of the Galaxy are sensitive measurements of the dark matter halo profile. Aims. Cuspy and cored DM halo profiles are analysed with respect to recent astronomical constraints in order to constrain the shape of the Galactic DM halo and the local DM density. Methods. All Galactic density components (luminous matter and DM) are parametrized. Then the total density distribution is constrained by astronomical observations: 1) the total mass of the Galaxy, 2) the total matter density at the position of the Sun, 3) the surface density of the visible matter, 4) the surface density of the total matter in the vicinity of the Sun, 5) the rotation speed of the Sun and 6) the shape of the velocity distribution within and above the Galactic disc. The mass model of the Galaxy is mainly constrained by the local matter density (Oort limit), the rotation speed of the Sun and the total mass of the Galaxy from tracer stars in the halo. Results. We showed from a statistical χ 2 fit to all data that the local DM density is strongly positively (negatively) correlated with the scale length of the DM halo (baryonic disc). Since these scale lengths are poorly constrained the local DM density can vary from 0.2 · �
119389130
Electroweak corrections to e+ e- -> nu anti-nu H and e+ e- -> t anti-t H
The most interesting Higgs-production processes at future e+ e- colliders belong to the process class e+ e- ->f anti-f H. We study the full O(alpha) corrections to this reaction in the Standard Model for neutrinos and top quarks in the final state. Leading higher-order corrections from initial-state radiation and QCD corrections are also taken into account. Although cancellations between the different kinds of corrections occur, the full corrections are of the order of +/-10% and thus important ingredients in the theoretical predictions for future e+ e- colliders.
120765978
Silicon Trackers for the Super-LHC
The Large Hadron Collider (LHC) will be upgraded to the Super-LHC in 2015 to provide a tenfold 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 technical challenges and possible solutions for the SLHC silicon trackers are described.
121724105
Serial Power Protection for ATLAS Silicon Strip Staves
Abstract Upgrades to the inner tracking detectors at the Super Large Hadron Collider (SLHC) will require more efficient methods of power delivery. Serial power is one architecture that delivers power efficiently by powering a chain of front-end circuits (hybrids) with a common current. A major concern with serial power is the loss of the full hybrid chain due to an open circuit failure of a single hybrid. We propose a method to protect a serial chain of hybrids with emphasis on application to the ATLAS silicon strip upgrade. A prototype protection circuit and its discrete component implementation are described. Results from tests of the protection circuit used with individual “dummy” hybrids and in a system test with a collection of dummy hybrids are given. Finally, a path towards a radiation-hard ASIC implementation is discussed. This work demonstrates that the protection of a serial chain is viable and is not an obstacle to the implementation of serial power.