Nationaal instituut voor subatomaire fysica

New detector prototype designed by Nikhef shipped to CERN for investigation in a particle beam


The Gossip set-up. Pictures by Marco Kraan.

A Gossip (Gas On Slimmed SIlicon Pixels) detector set-up that was designed and built at Nikhef was shipped to CERN today. It will be used at CERN’s SPS pre-accelerator. 

The Nikhef Detector R&D group designs new detector prototypes, builds them with the help of Nikhef's Electronics and Mechanical departments, and studies their performance to improve them further. The GridPix detector is one of those new prototypes, a pixelated readout chip with a
gas amplification grid on top. A thin version of GridPix, the Gossip, has a 1 mm gas layer over the GridPix structure. This family of detectors allows a 3-D track reconstruction of ionising radiation. The X-Y position is given by the chip's fine pixel structure and the Z position is calculated with the time of arrival of the drifting ionisation charge.

The set-up as shown in the pictures is a so-called beam telescope consisting of four Gossip detectors in a row. Each detector is mounted on an individual stage that can be rotated about all axes while keeping every detector's centre perfectly aligned. The telescope will be used in next week's beam test at CERN's SPS pre-accelerator. To measure and verify important properties of the Gossip detectors muons with a constant energy of 150 GeV/c^2 will transverse the telescope. These well-defined conditions will allow the researchers to measure the position and angular resolution of the reconstructed muon tracks. The Gossip's gas region is so thin to guarantee that the charge created by a traversing particle can be collected within 25 ns, the time between two consecutive
collisions in the interaction points of the upgraded LHC.

These studies form an integral part for the research of Wilco Koppert, a fourth year graduate student working in the Detector R&D group at Nikhef. He will operate the set-up at CERN together with his colleagues Francesco Zappon, Rolf Schön (both also PhD candidates), Fred Hartjes, Harry van der Graaf, Joris van Heijningen, Niels van Bakel, and Nigel Hessey.