Detectors

The detector has been custom-designed by Canberra-Eurisys for the IXS beamlines at the ESRF. The five individual silicon detectors as well as their pre-amplifiers are integrated on a single monolithic silicon chip, which is Peltier cooled in order to reduce the electronic background. Thanks to the increased thickness of the silicon detector with respect to the previous model, the signal losses even at the highest operating phonon energy of 25.7 keV remain modest (< 10 %). Other main detector specifications are:

• resistive feedback mode
• sensitive area of individual diode: 3 mm wide x 8 mm height
• spacing in between individual diodes: 4.5 mm
• diode inclination with respect to horizontal plane: 20º (=> resulting apparent detector size: 3 mm horizontal x 2.7 mm vertical)
• leak current 1-7 nA ( 7 nA guaranteed)
• dark count rate with standard discriminator settings for all operating energies 1 counts in one hour.

   

  Picture 1 : View of the single element normally used as a S(Q) detector.

   

  Picture 2 : View of the Si pin diodes normally used to monitor the beam intensity.

   

  Picture 3 : View of the 5-element detector used with the horzontal spectrometer.