arXiv subjects

Jaap Velthuis

Publications and source records attributed to Jaap Velthuis.

4 recordsLinked to original sources

arXiv2021

Development of muon scattering tomography for a detection of reinforcement in concrete

Inspection of ageing, reinforced concrete structures is a world-wide challenge. Existing non-destructive evaluation techniques in civil and structural engineering have limited penetration depth and don't allow to precisely ascertain the configuration of reinforcement within large concrete objects. The big challenge for critical infrastructure (bridges, dams, dry docks, nuclear bioshields etc.) is understanding the internal condition of the concrete and steel, not just the location of the reinforcement. In most new constructions the location should be known and recorded in the as-built drawings, where these might not exist due to poor record keeping for older structures. Muon scattering tomography is a non-destructive and non-invasive technique which shows great promise for high-depth 3D concrete imaging. Previously, we have demonstrated that individual bars with a diameter of 33.7 +- 7.3 mm at 50 cm depth can be located using muon scattering tomography. Here we present an improved method that exploits the periodicity of bar structures. With this new method, reinforcement with bars down to 6 mm thickness can be detected and imaged.

physics.ins-det↗

arXiv2019

LHCb VELO Timepix3 Telescope

The LHCb VELO Timepix3 telescope is a silicon pixel tracking system constructed initially to evaluate the performance of LHCb VELO Upgrade prototypes. The telesope consists of eight hybrid pixel silicon sensor planes equipped with the Timepix3 ASIC. The planes provide excellent charge measurement, timestamping and spatial resolution and the system can function at high track rates. This paper describes the construction of the telescope and its data acquisition system and offline reconstruction software. A timing resolution of 350~ps was obtained for reconstructed tracks. A pointing resolution of better than 2~\mum was determined for the 180~GeV/c %\gevc mixed hadron beam at the CERN SPS. The telescope has been shown to operate at a rate of 5 million particles~\unit{s^{-1}\cdot cm^{-2}} without a loss in efficiency.

physics.ins-det↗

arXiv2013

The Timepix Telescope for High Performance Particle Tracking

The 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 about either the deposited charge or the timing information from tracks traversing the 14 x 14mm matrix of 55 x 55 um pixels. The rate of reconstructed tracks available is optimised by taking advantage of the shutter driven 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 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 um . 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 CO2 cooling and a flexible mechanical interface to the device under test, and has been used for a wide range of measurements during the 2011-2012 data taking campaigns.

physics.ins-det↗

arXiv2009

The LCFIVertex package: vertexing, flavour tagging and vertex charge reconstruction with an ILC vertex detector

The precision measurements envisaged at the International Linear Collider (ILC) depend on excellent instrumentation and reconstruction software. The correct identification of heavy flavour jets, placing unprecedented requirements on the quality of the vertex detector, will be central for the ILC programme. This paper describes the LCFIVertex software, which provides tools for vertex finding and for identification of the flavour and charge of the leading hadron in heavy flavour jets. These tools are essential for the ongoing optimisation of the vertex detector design for linear colliders such as the ILC. The paper describes the algorithms implemented in the LCFIVertex package, as well as the scope of the code and its performance for a typical vertex detector design.

physics.ins-det↗