1 research outputs found
PixFEL: development of an X-ray diffraction imager for future FEL applications
A readout chip for diffraction imaging applications at new generation X-ray FELs (Free Electron
Lasers) has been designed in a 65 nm CMOS technology. It consists of a 32 Ă— 32 matrix, with
square pixels and a pixel pitch of 110 µm. Each cell includes a low-noise charge sensitive amplifier
(CSA) with dynamic signal compression, covering an input dynamic range from 1 to 104 photons
and featuring single photon resolution at small signals at energies from 1 to 10 keV. The CSA
output is processed by a time-variant shaper performing gated integration and correlated double
sampling. Each pixel includes also a small area, low power 10-bit time-interleaved Successive
Approximation Register (SAR) ADC for in-pixel digitization of the amplitude measurement. The
channel can be operated at rates up to 4.5 MHz, to be compliant with the rates foreseen for future
X-ray FEL machines. The ASIC has been designed in order to be bump bonded to a slim/active
edge pixel sensor, in order to build the first demonstrator for the PixFEL (advanced X-ray PIXel
cameras at FELs) imager