Pictures of the experiment

Here we have some scanned images of various aspects of our experiment. Each picture is available in an enlarged version by clicking on the small thumbnail pictures.

Some members of our collaboration:

Pictures taken during the beam time of 1994.

An overview of the PiE1 area at PSI.

The beam is entering the area through the green magnet in the wall. It is focused to a lead collimator before it enters the red quadrupole triplet. After the small concrete wall it hits a stopping counter. Particles from the pion decay enter the wooden box filled with CsI crystals which is positioned beam-left. The second wooden box behind the CsI box is part of the air conditioning system which keep the CsI temperature at a constant level.

A detail photograph of the beamline with the intermediate focus and the lead collimator in the middle. Besides the big green and red magnets at the left and the right side, ther are also two tiny steering magnets (one horizontal, one vertical) attached to the silver beam pipe.

Various views of the wooden box with 26 CsI crystals. Left side from the frot (where the particles are entering), middle and right side from the back. Each hexagonal or pentagonal shaped CsI crystal is read out by a 3 inch photomultiplier. The crystals are wrapped with a thin golden or sivel mylar foil to minimize loss of light. The crystals are designed in such a way that they can form a complete self-supporting sphere without gaps.

The cosmic tomography setup to measure the homogeneithy of the CsI crystals.

For a description see tomography

The distance measurement of the CsI crystals.

For a description see distance measurements

The wire chambers of the Pion Beta Detector.

Only a few channels are read out for testing. The inner cylindrical wire chamber is mostly obscured by the outer chamber.

The wire chambers, prepared for a testrun (Nov-97):

The plastic veto of the Pion Beta Detector.

The plastic veto consists of twenty scintillator staves surrounding the cylindrical wire chamber. They are read out from both sides.

An article in a local newspaper about our spherical housing for the calorimeter.

"Die Botschaft", unt. Aaretal, Bezirk Zurzach, vom 12. Oktober 1996

The mechanical housing which will contain the CsI calorimeter.

Test assembly, Nov. 1997

S. Ritt, 20 March 1997