The PERCIVAL detector: first user experiments

Abstract

The PERCIVAL detector is a CMOS imager designed for the soft X-ray regime at photon sources. Although still in its final development phase, it has recently seen its first user experiments: ptychography at a free-electron laser, holographic imaging at a storage ring and preliminary tests on X-ray photon correlation spectroscopy. The detector performed remarkably well in terms of spatial resolution achievable in the sample plane, owing to its small pixel size, large active area and very large dynamic range; but also in terms of its frame rate, which is significantly faster than traditional CCDs. In particular, it is the combination of these features which makes PERCIVAL an attractive option for soft X-ray science.

Soft X-ray Fluorescence and Near-Edge Absorption Microscopy for Investigating Metabolic Features in Biological Systems: A Review

“…As for other analytical methods, the accessible chemical elements are intrinsically limited as they are determined by the specific energy range. Moreover, in the soft X-ray regime, restrictions do exist in terms of sample size, sample thickness and acquisition time, even if there is a global trend to overcome these limitations both improving the experimental environment [ 51 , 53 ], the light sources [ 68 ] and the detectors [ 69 , 70 , 71 , 72 , 73 , 74 ], and employing some expedients to reduce the sampling frequency or to automatize the acquisition process [ 75 , 76 ].…”

Detector developments for photon science at DESY

“…It is the combination of these features that makes Percival an especially well-suited detector for soft X-ray scattering experiments. Detailed description of the system and its performance can be found in [11][12][13][14][15][16][17][18].…”

“…Even though the current first version of the sensor has a number of shortcomings [16] it has been used in a number of proof-ofprinciple user experiments, including Holography and XPCS of magnetic skyrmions at Petra III's soft X-ray beamline P04, and single-shot Ptychography at FLASH. These exploratory experiments showed the great potential of the large dynamic range and high frame rates of Percival [18]. The shortcomings of the first version sensor-crosstalk between ADC and digital control lines, and insufficient ground connections for the pixel array that resulted in uneven biasing-are understood and are corrected in a second version of the sensor which was recently submitted to the foundry.…”