A prototype particle tracking telescope has been constructed using Timepix and Medipix ASIC hybrid pixel assemblies as the six sensing planes. Each telescope plane consisted of one 1.4 cm 2 assembly, providing a 256×256 array of 55 µm square pixels. The telescope achieved a pointing resolution of 2.3 µm at the position of the device under test. During a beam test in 2009 the telescope was used to evaluate in detail the performance of two Timepix hybrid pixel assemblies; a standard planar 300 µm thick sensor, and 285 µm thick double sided 3D sensor. This paper describes a detailed charge calibration study of the pixel devices, which allows the true charge to be extracted, and reports on measurements of the charge collection characteristics and Landau distributions. The planar sensor achieved a best resolution of 4.0 ± 0.1 µm for angled tracks, and resolutions of between 4.4 and 11 µm for perpendicular tracks, depending on the applied bias voltage. The double sided 3D sensor, which has significantly less charge sharing, was found to have an optimal resolution of 9.0 ± 0.1 µm for angled tracks, and a resolution of 16.0 ± 0.2 µm for perpendicular tracks. Based on these studies it is concluded that the Timepix ASIC shows an excellent performance when used as a device for charged particle tracking.2

20The Timepix particle tracking telescope has been developed as part of the LHCb VELO Upgrade project, supported by the Medipix Collaboration and the AIDA framework. It is a primary piece of infrastructure for the VELO Upgrade project and is being used for the development of new sensors and front end technologies for several upcoming LHC trackers and vertexing systems. The telescope is designed around the dual capability of the Timepix ASICs to provide information 25 about either the deposited charge or the timing information from tracks traversing the 14×14 mm matrix of 55 × 55 µm pixels. The rate of reconstructed tracks available is optimised by taking advantage of the shutter driver readout architecture of the Timepix chip, operated with existing readout systems. Results of tests conducted in the SPS North Area beam facility at CERN show that the telescope typically provides reconstructed track rates during the beam spills of 30 between 3.5 and 7.5 kHz, depending on beam conditions. The tracks are time stamped with 1 ns resolution with an efficiency of above 98% and provide a pointing resolution at the centre of the telescope of ∼1.6 µm . By dropping the time stamping requirement the rate can be increased to ∼15 kHz, at the expense of a small increase in background. The telescope infrastructure provides CO 2 cooling and a flexible mechanical interface to the device under test, and has been used for 35 a wide range of measurements during the 2011-2012 data taking campaigns.

Abstract-The DEPFET collaboration develops highly granular, ultra-transparent active pixel detectors for high-performance vertex reconstruction at future collider experiments. The characterization of detector prototypes has proven that the key principle, the integration of a first amplification stage in a detector-grade sensor material, can provide a comfortable signal to noise ratio of over 40 for a sensor thickness of 50-75 µm. ASICs have been designed and produced to operate a DEPFET pixel detector with the required read-out speed. A complete detector concept is being developed, including solutions for mechanical support, cooling and services. In this paper the status of DEPFET R & D project is reviewed in the light of the requirements of the vertex detector at a future linear e + e − collider.

Abstract-LHCb is one of the experiments of the Large HadronCollider at CERN, dedicated to B-physics and CP-violation measurements. To fully exploit the physics potential, a good tracking performance with high efficiency in a high particle density environment close to the beam pipe is required. Silicon strip detectors with large read-out pitch and long strips will be used for the LHCb Inner Tracker after the magnet and the Trigger Tracker station in front of the magnet. We report here about the design of the Silicon Tracker, test beam results and the electrical tests foreseen during module production.

The LHCb detector at the LHC has shown a very successful initial operation and it is expected that the experiment will accumulate an integrated luminosity in proton-proton collisions of around 1 fb −1 in 2011. The data already collected are being used to pursue the experiment's primary physics goal that is the search for New Physics via the measurement of CP asymmetries and rare decays in the b and c sector. The LHC is already capable of delivering higher luminosity than is currently used at LHCb, and an LHCb upgrade is planned for 2018 which will allow the detector to exploit higher luminosity running, and at the same time to enhance the trigger efficiencies, particularly in the hadronic decay modes. This upgrade will allow the experiment to accumulate an integrated luminosity of ∼ 50 fb −1 over the following decade, and acquire enormous samples of b and c hadron decays to allow for more precise measurements and a deeper exploration of the flavour sector. In addition, the flexibility of the new proposed trigger together with the unique angular coverage of the LHCb experiment opens up possibilities for interesting discoveries beyond the flavour sector, and will allow LHCb to focus on the physics channels which will be of most interest in the light of the discoveries of the coming decade.