Optimal signal-to-noise ratio

PILATUS3 Hybrid Photon Counting detectors are inherently free of dark current and readout noise (Fig. 1). The absence of any detector noise guarantees data with an excellent signal-to-noise ratio. [A. Ben-Shem et al., Science 334, 1524 (2011), DOI: 10.1126/science.1212642]

Fig. 1: Absence of readout noise and dark current in PILATUS hybrid pixel detectors.
Images of a single PILATUS module without exposure to an X-ray source with 100 ms (a) or 1 hour (b) of acquisition time. a)  After a short acquisition time, all pixels have zero counts, since no noise is added onto the readout of the image. b) After a long acquisition time, most pixels still have zero counts, since no dark current accumulates during long exposure and no noise is added during readout. In addition to the absence of dark current, the low average count rate of 0.2 cts/h/pixel provides a further advantage over integrating detectors, i.e., that high energy cosmic radiation only contributes one single count per detected event.

Electronic gating and external trigger

Exposure times can be varied from a few nanoseconds to several hours and are controlled either internally or by applying an external gate signal. The external trigger input with a programmable delay function makes synchronization between the detector and other hardware very easy. [T. Ejdrup, H. T. Lemke, K. Haldrup, T. N. Nielsen, D. A. Arms, D. A. Walko, A. Miceli, E. C. Landahl, E. M. Dufresne, and M. M. Nielsen, J. Synchrotron Radiat. 16, 387 (2009)]

Shutterless operation

All PILATUS3 detectors are electronically gated and do not require a mechanical shutter; this is a noticeable simplification of any measurement setup. Combined with the noiseless readout of the PILATUS3 detectors, this enables acquisition of diffraction data in fine φ-slicing mode.

A multitude of applications

PILATUS3 X-ray detector systems offer ample performance for a wide range of synchrotron applications:

  • Macromolecular crystallography (MX)
  • Single crystal diffraction (SCD)
  • Surface diffraction
  • Small- and wide-angle X-ray scattering (SAXS/WAXS)
  • Coherent X-ray imaging
  • Pre-clinical X-ray imaging
  • Time-resolved experiments

High modularity

The basic element of every PILATUS3 detector is the detector module, which can be combined to form multi-module detector setups with different geometries. DECTRIS offers a standard line-up of PILATUS3 S and X detector systems covering a wide range of active areas and frame rates to perfectly suit your measurement needs. Moreover, DECTRIS possesses the expertise required to develop and manufacture application and customer-specific systems, such as in-vacuum detectors with cylindrical geometry.

High energy sensors

In addition to the standard 450 µm thick silicon sensors, you can customize your PILATUS3 detector with 1000 µm thick silicon sensors. This achieves high quantum efficiency at a wide range of X-ray energies  (Tab. 1). 

Photon energy 450 µm 1000 µm
5.4 keV  94 % > 80 %
8.0 keV 98 % 96 %
12.4 keV () 84 % 97 %
17.5 keV 47 % 76 %
22.2 keV 27 % 50 %

Table 1: Quantum efficiency of PILATUS sensors based on measurements at the PTB beamline at BESSY II.  

Optional vacuum compatibility

The water-cooled models PILATUS3 X 300K and 300K-W offer optional vacuum compatibility. This customization allows you to operate the detector in vacuum, e.g. in the flight tube of an SAXS instrument. In addition to the vacuum upgrade, the 300K and 300K-W are also available with special calibrations for low energy applications. Based on PILATUS3 technology, DECTRIS can build  Specific Solutions. In this case all detector modules are placed in vacuum and custom geometries can be realized. Contact us for more details.

 


Excellent Point-Spread Function

A sharp point-spread function smaller than one pixel offers a variety of benefits (Fig. 2). Closely spaced signals, even of largely differing intensity, can be accurately resolved and measured. Sharper signals reduce overlap with scattering or other background intrinsic to the experiment, thereby improving the signal-to-noise ratio. 

Due to the direct conversion of X-rays into charge pulses, PILATUS3 detectors spread virtually no intensity between pixels. The point-spread function of the PILATUS detector is thus significantly smaller than the pixel size (172 µm) and enables optimally sharp images to be created, which are free of artifacts (such as blur, intensity tails, blooming, or streaking) typical of other detectors.

Fig. 2: Superior dynamic range and point-spread function of PILATUS Hybrid Photon Counting detectors.
Details of diffraction images showing the same reflection of an insulin crystal. The images were acquired at a synchrotron beamline with identical parameters except for the detector distance, which was adjusted to achieve the same resolution at the detector edge, depending on the detector size. a) The 20-bit counter depth of the PILATUS Hybrid Photon Counting detector provides sufficient dynamic range to record 727,716 counts in the highest intensity pixel. With the excellent point-spread function, the spot is well confined to a small area. Furthermore, the sharp reflection profile of the low mosaicity crystal is accurately represented with a more than one-thousand-fold difference in intensity between neighboring pixels. b) The same reflection recorded with a CCD contains many overloaded pixels. The reflection intensity is smeared out over a large area.

High dynamic range

A counter depth of 20 bits (~ 1 million counts) combined with the absence of detector noise ensures unprecedented contrast and dynamic range, another hallmark of all PILATUS3 detectors, leading to excellent image and data quality (Fig. 2). Extremely strong and weak signals can be accurately detected on a single image. [Y. Sonntag et al., Nature communications | 2:304 | DOI: 10.1038/ncomms1307] 

Short readout times and high frame rates

PILATUS3 S and X systems feature short readout times and high frame rates which substantially reduce measurement time and maximize efficiency and throughput. Furthermore, in conjunction with versatile trigger and gating capabilities, dynamic processes on fast time scales can be investigated.

[Wim Bras and Andrew M. Beale. "Combined time-resolved X-ray scattering and spectroscopy methods." Spectroscopic Properties of Inorganic and Organometallic Compounds: Techniques, Materials and Applications 43 (2012): 257-288.]

High local and global count rates

All PILATUS3 detectors feature DECTRIS instant retrigger technology, which enables each pixel of a PILATUS3 to accurately detect up to ten million photons per second Furthermore, no global count rate limit is detected up to 6 × 106 photons per second and pixel. This enables global count rates of more than 2 × 108 photons per second and square millimeter. Both local and global count rates of PILATUS detectors are far superior to those of counting detectors based on gas discharge or similar technologies.

Fluorescence suppression

PILATUS3 S and X detectors provide an adjustable lower energy threshold to suppress fluorescence. Combining the high dynamic range with the excellent point-spread function, fast read-out and fluorescence suppression enables the pursuit of exciting new sciences, e.g. in diffuse scattering.

[A. Bosak et al., PRL 103, 076403 (2009), DOI:10.1103/ PhysRevLett.103.076403 and Ch. Bärlocher et al., Science 333, 1134 (2011); DOI: 10.1126/science.1207466].

Radiation tolerance

The PILATUS3 CMOS readout chips as well as the silicon sensors are designed using radiation-tolerant layout techniques developed for high-energy physics to prevent damage from incoming X-rays. The detectors are able to withstand the doses arising from long-term operation at modern synchrotrons.

[P. Kraft et al., J. Synchrotron Rad. (2009). 16, 368–375; doi:10.1107/S0909049509009911)]

Ease of operation

All PILATUS3 detector systems can be operated at room temperature and only require dry air or N2 for operation. They are easy to set up and require no regular maintenance or service.