The SAGE spectrometer

The SAGE Spectrometer

The electrons are transported away from the hostile target region and towards the silicon detector by a magnetic field. The field is induced by three solenoid coils designed in a way which maximizes electron transmission without compromising γ-ray efficiency.
	Nearly collinear geometry between the solenoid coil and beam axes reduces Doppler broadening. Positioning the silicon detector upstream of the target reduces the δ-electron flux which reaches the detector.
A high-voltage barrier positioned between the target and detector further reduces the δ-electron flux.
	A dual carbon-foil system is used to separate the high-vacuum region of the high-voltage barrier from the target region. For target cooling purposes the target chamber is in the same vacuum as RITU, which operates with helium pressures up to 1mbar.
Up to six targets can be positioned simultaneously on a target wheel. The same target wheel offers the possibility to use a larger rotating target.
	The electrons are detected by a 1mm thick silicon detector segmented into 90 individual pixels.
The detector is mounted on a PCB which also accommodates the preamplifiers.
	Each detector pixel is connected to a CAEN A1422 charge sensitive hybrid preamplifier.
The γ rays are detected by the JUROGAM II array which consists of 24 four-fold segmented clover detectors and 15 Eurogam Phase I-type detectors. When used with SAGE, 5 of the Phase I-type detectors are removed. All the germanium detectors are Compton-suppressed. Further information on JUROGAM II can be found here.