Feb 11 – 15, 2013
Vienna University of Technology
Europe/Vienna timezone

GridPix Characterisation and Development

Feb 12, 2013, 5:45 PM
EI8 (Vienna University of Technology)


Vienna University of Technology


Willem Koppert (NIKHEF (NL))


The innovative GridPix detector is a micro TPC, read out with a Timepix pixelchip. Each individual element of the 256x256 pixel-matrix is connected to a preamplifier, discriminator and TDC (100MHz) for time of arrival measurements. By using wafer post processing techniques an aluminium grid is placed on top of the chip. When operated, the electric field in between the grid and the chip is sufficient to create single electron induced avalanches which are measured by the pixels. The digital counter is used to record the relative time enabling reconstruction of high precision 3D track segments. A SiRN protection layer protects the chip from discharges. Gossips are GridPix detectors proposed as inner tracker detectors in ATLAS. Because of the LHC frequency a drift gap of 1 mm is required. Low diffusion and sufficient ionisations are essential for accurate 3D tracking. Currently, time walk is the dominant error in the drift direction. In a detailed study, recent test beam data gave insight into the contribution of both diffusion and time walk to the positional and angular resolutions of a Gossip detector. In addition long term tests show that the protection layer successfully quenches discharges preventing harm to the chip. Recently, GridPix detectors were successfully made on full wafer scale, to meet the demand for more reliable and cheaper devices in large quantities. Wafer scale production opens a large variety of new possibilities and novel applications for GridPix.
quote your primary experiment Gossip, GridPix, MPGD

Primary author

Willem Koppert (NIKHEF (NL))


Fransen Martin (NIKHEF (NL)) Frederik Hartjes (NIKHEF (NL)) Harry Van Der Graaf (NIKHEF (NL)) Jan Timmermans (NIKHEF Amsterdam) Jurriaan Schmitz (University of Twente) Klaus Desch (Universitaet Bonn (DE)) Niels Van Bakel (NIKHEF) Paul Colas (CEA - Centre d'Etudes de Saclay (FR)) Rolf Schon (NIKHEF) Yevgen Bilevych (Universitaet Bonn (DE))

Presentation materials