Title: New Results from GridPixes

Authors: Yevgen Bilevych, Klaus Desch, Jean-Paul Fransen, Harry van der Graaf, Markus Gruber, Fred Hartjes, Bas van der Heijden, Kevin Heijhof, Charles Ietswaard, Dimitri John, Jochen Kaminski, Peter Kluit, Naomi van der Kolk, Auke Korporaal, Cornelis Ligtenberg, Oscar van Petten, Gerhard Raven, Joop RĂśvekamp, Tobias Schiffer and Jan Timmermans


Abstract: GridPix detectors consist of a high granularity readout based on a pixel ASIC with a Micromegas gas amplification stage, which is produced by photolithographic postprocessing. This technique allows for good alignment of each grid hole with one readout pixel. Therefore, each single primary electron guided into one hole and multiplied in the amplfication gap can be detected separately. This leads to an excellent spatial and energy resolution based on the primary electron statistics only.

To improve the performance of detectors the production has switched from using Timepix to Timepix3 as a basis for the GridPix detectors. In 2017 a first testbeam with 2.5 GeV electrons from the ELSA accelerator at Bonn was performed. The good results encouraged the development of a Quad featuring four GridPix detectors in one readout unit. The optimized design of the Quads leads to an active area of 69 % and good alignment of the GridPixes with respect to each other. A first Quad was tested in 2018 in the same test beam showing equally good results.

In this presentation the results of the two test beams as well as the status of the readout systems will be discussed along with possible applications in the ILD-TPC and the IAXO experiment.