DECTRIS has introduced EIGER R 1M, an advanced Hybrid Photon Counting detector that integrates high resolution with popular single-photon sensitivity. The EIGER R 1M is a versatile tool and features a mega-pixel sensor with just 75µm pixel size. This ensures ultimate resolution and makes the detector system suitable for X-ray detection in a wide range of laboratory applications.
The EIGER R 1M enables users to record powder diffraction patterns from textured samples or to exploit the single-pixel point-spread function to determine large unit-cell protein crystal axes. In addition, the signal-to-noise ratio can be improved for the most complex samples by leveraging an image depth of 32 bit as well as the continuous energy threshold.
Strongest Bragg spots from tiny molecule crystals can be precisely measured, thanks to count-rate capabilities of up to 5•108phts/s/mm2. The system has a compact housing which makes it easy to accommodate it into small laboratory environments.
Continuous Readout and Auto-Summation
Continuous readout and auto-summation enables kilohertz frame rates with duty cycles better than 99%. Each pixel of an EIGER ASIC features a digital counter for noise-free counting of the sample photons during an exposure. A readout buffer is provided with the digital counter in each pixel. After an exposure is acquired, the state of the counter is passed on to the readout buffer almost instantly. A following exposure can begin after just 3 microseconds, while the preceding exposure is being read out from the buffer. The continuous readout of EIGER with counter and buffer in every pixel increases duty cycle and simultaneously allows for an electronic global shutter. This ensures that the data for all pixels of an image are gathered at the same time, in comparison to a rolling shutter that causes distorted images.
The auto-summation mode in EIGER is an additional advantage of the continuous readout with high duty cycle. A regular single exposure is restricted to the 12 bits of the digital counter however, auto-summation allows the data depth to be extended up to 32 bits or more than 4.2 billion counts per pixel based on the number of summed exposures in an image.
Image credit: Dectris Ltd.
At frame rates of more than a few hundred Hertz and higher, all counts are seized in the digital counter of a pixel. If lower frame rates are needed, exposures are still procured at high rates on the pixel level, thus effectively preventing any overflows. Exposures are summed to images with the requested frame rate on the fly; lengthening the bit depth of the data by the number of summed exposures. The auto-summation mode in EIGER helps to maintain a duty cycle higher than 99.7% at all times due to continuous readout with 3µs dead time.
No Readout Noise
EIGER hybrid photon counting detectors are fully free of dark current and readout noise. The majority of the pixels exhibit zero counts as the EIGER detectors do not display any dark current and the readout does not cause any noise to the data. Only the basic background radiation gives rise to a single count per event, thus the noise from background radiation is maintained at a less rate. The average background on an EIGER module is only 0.07 counts per hour and pixel.
Image credit: Dectris Ltd.
Excellent Count-Rate Performance
EIGER integrates advanced design for fast single-photon counting with small pixel size, which helps realize excellent count-rate performance per area. EIGER can precisely measure count rates of over 500 million counts per second and square millimeter or 3 million counts per second and pixel.
The main features of the EIGER R 1M are:
- Small pixels and excellent point-spread function for highest spatial resolution
- No dark current or readout noise for best signal-to-noise ratio
- Compact housing
- Frame rates up to 10Hz with duty cycle > 99.7%
- Continuous readout with global shutter
- Continuous threshold for fluorescence suppression
- Hybrid photon counting: Direct detection of X-rays in single-photon-counting mode
- Room temperature operation of all detector components
- Count rates up to 5•108phts/sec/mm2
- Service-free systems with minimal maintenance
The applications of the EIGER R 1M are:
- X-ray imaging
- Powder diffraction
- Surface diffraction
- Diffuse scattering
- Macromolecular crystallography
- Single crystal diffraction
- Small- and wide-angle X-ray scattering