Beamline description

Pagina 4 di 7

X-Ray Monitoring Detectors


The vertical arm - attached to the “2theta” rotational axis - can accommodate up to six slots for photodiodes and miniaturized detectors.

A miniaturized SDD (Amptek, USA) is available for XRR measurements. This SDD has a crystal area of 25 mm2, a Be window with 8.5 µm thickness, 131 eV resolution @MnKa, thickness 500 µm and internal multilayer as collimator. The chip is mounted on a special UHV assembly with the preamplifier placed outside the vacuum. This SDD is currently under commissioning.

Currently the following four detectors (three photodiodes and one miniaturized SDD) are installed.
  1. Hamamatsu Si-photodiode S3590-09 (10x10 mm2, 300µm thickness, no slit);
  2. Hamamatsu Si-photodiode S3590-09 (vertical slit of 100 µm, 300 µm thickness);
  3. Hamamatsu Si-photodiode S3590-09 (vertical slit of 200 µm, 300 µm thickness);
  4. Miniaturized SDD (Amptek, USA) with vertical slit of 200 µm.

The incoming beam is monitored by a Beam Monitoring System (BMS) developed by the detector group of Elettra Sincrotrone Trieste. The system is based on a 4-channel solid state sensor composed of a 12-μm thick free standing polycrystalline Chemical Vapour Deposit (pVCD) diamond plate (Dectris, Rigi). Its total active area is 9mm x 3mm subdivided into four electrodes of 4.5 mm x 1.5 mm area each (separated by a gap of about 20 µm) connected with individual UHV feedthroughs to the signal processing and acquisition system. The BMS allows good transmission at low energies (67.4% at 3.0 keV). It can be inserted or retracted from the beam path using a manually controlled linear stage. The individual currents from the four sensors are registered by a 4-channel picoammeter (Elettra, AH501B). 

 

Ultima modifica il Mercoledì, 13 Novembre 2024 16:22