Development micropattern gaseous detectors produced by a multilayer printed circuit technology

I. Proposal

We suggest exploring a new approach in designing micropattern gaseous detectors (MPGD): a multilayer printed circuit technology widely used now in microelectronics. In this essential modification a network of additional internal strips/pads electrodes is located inside the dielectric sheets supporting the conductive or semi conductive electrodes of the MPGD.

These additional inner electrodes have at least two important roles in the MPGD operation:

1) they are decoupled from the active electrode and can be used for the detection of induce signals and hence for position-sensitive readout. At the same time the active electrodes can be made of resistive materials or from metal strips loaded on a screen printed resistors. Both these measures ensuring spark protection and adjustable high rate characteristics

2) They can be used for the optimization the electric field in the multiplication region in order to achieve higher gas gain and better stability: by applying voltages on the internal electrodes one can influence on the actual electric filed and also on the charging up effect

II. Preliminary experience:

Several prototypes of various MPGD based om a multilayer printed circuit technology were already built and successfully tested (see, for example http://indico.cern.ch/contributionDisplay.py?sessionId=6&contribId=49&confId=186337). They were oriented on such applications as : RICH, flame detection, noble liquid TPCs, Rn detection etc.

Recently we start experimenting with an electric filed correction possibility by applying voltages on inner strips. First results will be presented at the RD-51 meeting, Febr. 2014.These developments include, for example a multilayer TGEM with cone holes for ion back flow suppression.

III. Technical capability and supports

1) We have a fully equipped former ALICE VHMPID lab. at CERN having a gas system, tests chambers, electronics etc.

2) We have an access to the RD-51 facilities at CERN

3) We are closely collaborating with Oliveira workshop. R. Oliveira is informed about the present proposal and is interested in participation

4) Some developments , for example multilayer TGEM with conical holes, probably could be supported by ALICE TPC upgrade collaboration

-- BernhardKetzer - 11 Feb 2014