InGaAsSb/GaSb lasers and photodetectors integrated on a silicon-on-insulator waveguide circuit for spectroscopic applications

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GaSb-based integrated lasers and photodetectors on a silicon-on-insulator waveguide circuit for sensing applications in the shortwave infrared

We report our results on GaSb photodiodes and lasers integrated on a Silicon-On-Insulator waveguide circuit. The photodiodes operate at room temperature with 0.4A/W responsivity for grating-assisted coupling and >1 A/W for an evanescent design. On the other hand, integrated Fabry-Perot lasers operate in continuous wave at room temperature with a threshold current of 49.7mA

Energy Deposition Patterns in the LHC Inner Triplet and Their Impact on the Phase II Luminosity Upgrade

Recent studies show that the energy deposition for the LHC Phase I luminosity upgrade, aiming at a peak luminosity 2.5×10**34 cm**-2s**-1, can be handled by appropriate shielding. The Phase II upgrade aims at a further increase of peak luminosity by a factor 4, possibly using Nb$_{3}$Sn quadrupoles. This paper describes how the main features of the triplet layout, such as quadrupole lengths, gaps between magnets, and aperture, affect the energy deposition in the insertion. We demonstrate how the energy deposition patterns depend on the triplet lay-out. An additional variable which is taken into account is the choice of conductor, i.e. solutions with Nb-Ti and Nb$_{3}$Sn are compared. Nb$_{3}$Sn technology gives possibilities for increasing the magnet apertures and space for new shielding solutions. Our studies give an indication on the possibility of managing energy deposition for the Phase II upgrade

Parametric Study of Energy Deposition in the LHC Inner Triplet for the Phase 1 Upgrade

To be able to make a global parametric analysis and to have some basic understanding of the influence of critical parameters, scaling laws may be of help. For the design of the LHC insertion regions triplets, among the critical parameters the energy deposited in the superconducting triplet plays a fundamental role in avoiding magnet quench, too heavy load on the cryogenic system, and degradation of the materials due to radiation. The influence on energy deposition of the lay-out key parameters, such as the magnet apertures, the magnet lengths and positions, has been studied for beta* = 0.25

Study of Energy Deposition and Activation for the LINAC4 Dump

This document provides estimates of energy deposition and activation for the dump of the future LINAC4 accelerator. Detailed maps of power density deposited in the dump are given, allowing to perform further thermo mechanical studies. Residual dose rates at a few cooling times for different irradiation scenarios have been calculated. Moreover, the air activation has been evaluated and doses to the reference population group and to a worker intervening in the cave at the shutdown have been predicted. Calculations were performed with the Monte Carlo particle transport and interaction code FLUKA

Energy Deposition Studies for the LHC Insertion Region Upgrade Phase-I

While the Large Hadron Collider (LHC) at CERN is starting operation with beam, aiming to achieve nominal performance in the shortest term, the upgrade of the LHC interaction regions is actively pursued in order to enhance the physics reach of the machine. Its first phase, with the target of increasing the LHC luminosity to 2-3 1034cm-2s-1, relies on the mature Nb-Ti superconducting magnet technology and is intended to maximize the use of the existing infrastructure. The impact of the increased power of the collision debris has been investigated through detailed energy deposition studies, considering the new aperture requirements for the low-ß quadrupoles and a number of other elements in the insertions. Effective solutions in terms of shielding options and design/layout optimization have been envisaged and the crucial factors have been pointed out

LHC Luminosity Upgrade: Protecting Insertion Region Magnets from Collision Debris

The Large Hadron Collider built at CERN now enters a starting-up phase where the present design luminosity up to 1034 cm-2 s-1 will be reached after the running in phase. A possible upgrading of the machine to luminosity up to 10^35 cm^-2 s^-1 requires a new insertion region design, and will be implemented in essentially two phases. The energy from collision debris is deposited in the insertion regions and in particular in the superconducting magnet coils with a possible risk of quench. We describe here how to protect the interaction region magnets against this irradiation to keep the energy deposition below critical values estimated for safe operation. The constraint is to keep the absorber size as small as possible to leave most of the magnet aperture available for the beam. This can be done by choosing a suitable material and design minimizing the load on the cryogenic system. Here we will describe design proposals for the phase I upgrade lay-out, i.e. luminosity up to 2.5 10^34 cm^-2 s^-1