First GiPS spectrum (lifetime spectrum obtained as projection of AMOC spectrum to lifetime axis)
We solved the ground loop problem of the detector sysrem at the slow positron beam
First sample to be measured by GiPS (Gamma-induced Positron Spectroscopy): pure, annealed iron
Andreas Wagner is mounting the ioron sample to the position in cross point of all 6 detectors
Left: vacuum tube for holding the sample; Middle: BaF detector; right: Ge detector
Vacuum system is going to be closed
The whole detector system in the nuclear physics cave 109
Ge detector is sourrounded by BGO detectors in anticoincidence to reduce Compton events in Ge detector (not used in our experiments)
Constant fractions being used
A part of the (analog) electronics
One of three racks ...
Gamma beam line entering cave 109
Vacuum system...
Instruction for use of vacuum system
A part of the crew: Marco Jungmann, Arnold Krille, Gerhard Brauer, Wolfgang Anwand, Andreas Wagner (from left)
Fast electronics ...
Door is going to be closed
Back in slow positron lab ...
An SCA was the solution for most of electronic noise problems
Ronald Schwengner with us in corridore in front of cave 109
Andreas playing with modules
RKR also there
Red light: ELBE beam running, door must stay closed
Yellow light: beam down, door may be opened
Re-adjustment of BaF to aline the single rates of all detectors to be roughly equal
The other BaF detector
Automatic LN2 filling system of Ge detectors
Look into the cave
Part of electronic system
Ronald and Andreas waiting for the ELBE beam to appear
4 single rates (2 Ge and 2 BaF detectors on top) and 4 coincidence rates
First lifetime GiPS spectra of iron are growing
Marco and Maik installing a board in slow positron lab
A mouse was observed in the ELBE hall
LN2 supply
The board boing to be ready soon...
The sample holder for liquids (here water) has two thin caton foils
... the same holder
Holder inside the sample tube
in the meantime: board finished
The gamma beam opening (center) and 2 Ge detectors (behind copper attenuator plates) and 2 BaF outside
sample in middle of wire ring to avoid the plastic tube
Iron sample within wire ring holder
Small champaign party for first positron spectra at ELBE
RKR giving some explanations
The ELBE crew
Prof. Möller from Inst. of Ion beam Physics
Andreas Wagner
Jörg Pawelke and Tom Cowan talking
RKR and Peter Michel