Author/Authors :
Campbell، نويسنده , , M. and Heijne، نويسنده , , E.H.M. and Llopart، نويسنده , , X. and Colas، نويسنده , , P. and Giganon، نويسنده , , A. and Giomataris، نويسنده , , Y. and Chefdeville، نويسنده , , M. and Colijn، نويسنده , , A.P. and Fornaini، نويسنده , , Gea A. and van der Graaf، نويسنده , , H. and Kluit، نويسنده , , P. and Timmermans، نويسنده , , J. and Visschers، نويسنده , , J.L. and Schmitz، نويسنده , , J.، نويسنده ,
Abstract :
A small TPC has been read out by means of a Medipix2 chip as direct anode. A Micromegas foil was placed 50 μ m above the chip, and electron multiplication occurred in the gap. With a He/isobutane 80/20 mixture, gas multiplication factors up to tens of thousands were achieved, resulting in an efficiency for detecting single electrons of better than 90%. With this new readout technology for gas-filled detectors we recorded many image frames containing 2D images with tracks from cosmic muons. Along these tracks, electron clusters were observed, as well as δ -rays. With a gas layer thickness of only 1 mm, the device could be applied as vertex detector, outperforming all Si-based detectors.
