Speaker
Mr
Stephane Aune
(DAPNIA, Centre d' Etudes de Saclay, Gif sur Yvette Cedex 91191, France)
Description
A new technique of fabrication of Micromegas (MM) using the PCB
technologies has been developed. A standard commercial wire mesh (19
m) was employed as cathode element and the amplification gap was
defined by using spacers (pillars) made out of a 100 m thick Solder
Mask (SM). After a three steps process, lamination, insulation and
development, the detector core is obtained as a single-compact piece
(Bulk Micromegas): In a first process the anode read-out, the SM and
the mesh are laminated at high temperature (100°C). The
polymerisation is done under UV insulation through a mask which
provides the required shape (edges and pillars). Finally the non
insulated part is removed by development in a chemical bath. The
result is a self-sustained unit containing the PCB board and the
mesh which is kept between two layers of SM : the outer border (2 mm
wide) and the pillars ( 0.4 mm every 2 mm) in the inner region are
left embracing the mesh. Several 10 cm x10 cm prototypes have been
fabricated and successfully tested. High gas gains up to 105 have
been reached in Argon mixtures and an energy resolution of 20%
(FWHM) was measured, using x-rays from a 55Fe source.
The advantage of this technique that allows large area detector
fabrication is the robustness, the reliability and the low cost. The
Bulk technology opens new perspectives: large MM mosaic detectors
with negligible dead space, double stage MM, curved shape MM (i.e.
cylinder of thin Kapton bulk)
Primary author
Mr
Stephane Aune
(DAPNIA, Centre d' Etudes de Saclay, Gif sur Yvette Cedex 91191, France)
Co-author
Ioannis Giomataris
(DAPNIA, Centre d' Etudes de Saclay, Gif sur Yvette Cedex 91191, France)
