have rapidly found application in many areas and have been very successfully
adapted to detect X-rays and used extensively for imaging and diffraction experiments. A major advantage of this approach is that direct detection of photons is
possible, which is in contrast to the CCD detector that has to convert impinging
photons into light which is read out as an analogue signal and then transformed into a
digital signal. In this section we give brief illustrations of how this new technology
has been applied to university/home laboratory-based facilities. However, there is
further detail in the following section on synchrotron instrumentation.
Over a decade ago, the company Dectris launched the revolutionary Pilatus
detector [23], which took silicon HPC technology and applied it to the crystallographic technique, and it rapidly became the detection system of choice at macromolecular crystallography (MX) beamlines around the world. A modest number of
these detectors were installed in laboratory-based facilities; however, in the last
decade, this technology has moved on considerably and is now readily available
for chemical crystallography and the home laboratory. This is illustrated by the fact
that major diffractometer manufacturers now sell their own versions of this technology as an off-the-shelf package specifically for chemical crystallography. In fact,
Rigaku Oxford Diffraction has even gone as far as only selling HPC-based detectors
for their X-ray systems, and the HyPix-6000HE [24] is specifically designed for
single-crystal diffraction. The HyPix detector is readily paired with a rotating anode
generator, which, due to the low noise level and coupling of detection to readout
electronics, is particularly good at measuring diffraction from small and poorly
diffracting crystals. Alternatively, Bruker has developed the PHOTON series of
detectors [25], based on CMOS technology [26] which is a single monolithic charge
integrating pixel array which can simultaneously count and integrate incoming
photons and therefore has no count rate saturation point.
The combination of high flux sources and fast, noiseless detectors means that
copper-based systems are now much more viable for chemical crystallography in the
home laboratory. Due to the longer wavelength of copper radiation, it is necessary to
position the detector in many different locations to cover a suitable volume of
reciprocal space, and therefore a faster detector alleviates this time-consuming
problem. This combination is very powerful, due to the much higher brilliance of
copper radiation over the traditional molybdenum target.
1.2.2 Synchrotron Instrumentation
Sources
A ‘synchrotron’ is a particle accelerator, which is in fact something of a misnomer
for this type of light source as the X-ray producing component is the storage ring and
as such the particles are not accelerated and rather their energy is just maintained.
Light sources generally use electrons, but there are a few that use positrons,
e.g. PETRA-III in Hamburg. The electrons are generated in an electron gun and
then accelerated in a linear accelerator before being passed into the booster ring,
76
S. J. Coles et al.
adapted to detect X-rays and used extensively for imaging and diffraction experiments. A major advantage of this approach is that direct detection of photons is
possible, which is in contrast to the CCD detector that has to convert impinging
photons into light which is read out as an analogue signal and then transformed into a
digital signal. In this section we give brief illustrations of how this new technology
has been applied to university/home laboratory-based facilities. However, there is
further detail in the following section on synchrotron instrumentation.
Over a decade ago, the company Dectris launched the revolutionary Pilatus
detector [23], which took silicon HPC technology and applied it to the crystallographic technique, and it rapidly became the detection system of choice at macromolecular crystallography (MX) beamlines around the world. A modest number of
these detectors were installed in laboratory-based facilities; however, in the last
decade, this technology has moved on considerably and is now readily available
for chemical crystallography and the home laboratory. This is illustrated by the fact
that major diffractometer manufacturers now sell their own versions of this technology as an off-the-shelf package specifically for chemical crystallography. In fact,
Rigaku Oxford Diffraction has even gone as far as only selling HPC-based detectors
for their X-ray systems, and the HyPix-6000HE [24] is specifically designed for
single-crystal diffraction. The HyPix detector is readily paired with a rotating anode
generator, which, due to the low noise level and coupling of detection to readout
electronics, is particularly good at measuring diffraction from small and poorly
diffracting crystals. Alternatively, Bruker has developed the PHOTON series of
detectors [25], based on CMOS technology [26] which is a single monolithic charge
integrating pixel array which can simultaneously count and integrate incoming
photons and therefore has no count rate saturation point.
The combination of high flux sources and fast, noiseless detectors means that
copper-based systems are now much more viable for chemical crystallography in the
home laboratory. Due to the longer wavelength of copper radiation, it is necessary to
position the detector in many different locations to cover a suitable volume of
reciprocal space, and therefore a faster detector alleviates this time-consuming
problem. This combination is very powerful, due to the much higher brilliance of
copper radiation over the traditional molybdenum target.
1.2.2 Synchrotron Instrumentation
Sources
A ‘synchrotron’ is a particle accelerator, which is in fact something of a misnomer
for this type of light source as the X-ray producing component is the storage ring and
as such the particles are not accelerated and rather their energy is just maintained.
Light sources generally use electrons, but there are a few that use positrons,
e.g. PETRA-III in Hamburg. The electrons are generated in an electron gun and
then accelerated in a linear accelerator before being passed into the booster ring,
76
S. J. Coles et al.