XPDF (I15-1) is the dedicated X-ray Pair Distribution Function beamline. XPDF is applicable to a diverse range of disciplines such as materials chemistry, solid-state physics, earth sciences and pharmaceuticals.
Researchers are able to study the local structure of crystalline, semi-crystalline and amorphous solids and liquids with a speed and robustness which has not been possible at Diamond before. The beamline optics and endstation have been optimised to give the high X-ray energy, high flux and low background signal which are necessary for quality PDF data.
XPDF typically operates with two large area detectors, one placed close to the sample to the provide the large Q range required for quality PDF data (Qmax up to 40 Å–1 at 76.7 keV) and one mounted further from the sample for simultaneous higher-resolution Bragg data.
We still hope to have the wiggler running by the restart in January, so this is only about the next call for proposals and NOT cancelling any of the experiments currently scheduled for January and February. In the last update regarding new proposals we had suggested we would open the system in December but now wish to wait.
We have decided to hold off the opening of a call for proposals due to the continuing issues of the wiggler repair, it’s move back into the storage ring and the need to reschedule cancelled experiments from AP26 into the AP27 period. With more parts due to arrive in November, and visits scheduled from both the cooling system and wiggler manufacturers before Christmas we remain optimistic that operations will resume in January, but of course cannot yet be certain. Rather than have users submit proposals with this uncertainty we will reassess the situation in late January and decide the best course of action at that time. We will then update the web site and send out an email to all registered users.
We continue to be disappointed with these delays and wish to reassure users that Diamond Staff are doing all that they can to resolve the issue through vigorous and continous engagement with the external suppliers, as well as considering long-term options going forward
Following the second compressor failure in August, four new compressors were ordered so that all of them could be replaced, and leave a spare. These arrived in Oct and means that we have effectively completely replaced the He cooling system with new compressors and refurbished coolers on the superconducting magnet. However the company has now told us that one of the refurbished cold heads has failed, and even though we ordered spare parts for these back in August they cannot deliver until late November. We have pursued every option possible at this time, but the company are unable fix it in time for the run starting next week. We are thus having to cancel all beamtime during Nov and Dec. Beamtime scheduled for Jan through March will remain scheduled assuming the latest repairs planned in Dec are completed with no further issues. We are deeply disappointed that these problems have not been resolved despite vigorous and continuous engagement with the company. We are continuing to strive to fix the situation as soon as possible and are reconsidering our long-term options.
XPDF is commissioning two new in-situ environments focussed on time-resolved measurements in reacting solutions. Both environments allow for steady state measurements to be taken at time increments after two precursor solutions are passively mixed. The first cell is aimed at longer duration reactions, consisting of eight measurement positions. Here the first measurement is available for reaction times greater than ca. 0.5 seconds. The second cell is targeted at much faster reactions where data can be collected at times greater than ca. 0.05 seconds after mixing. It will be possible to run both cells at elevated temperature, to a maximum of 250 °C. If you are interested in using these sample environments for the current round of proposals please contact the beamline staff.
XPDF is operational and welcomes users to apply for beamtime by the standard DLS peer review process.
Some information on beamline equipment is listed below. Dedicated software is also being developed which will ultimately produce PDF data in real-time at the point of data collection, providing an unparalleled user-friendly X-ray PDF beamline and allowing non-expert users to use this powerful technique.
|Beam size at focus|| |
700 μm horizontal by 10 μm vertical
Standard size at sample 700 μm x 150 μm
|Bent-Laue monochromator|| |
40.0, 65.4 and 76.6 keV
700 μm horizontal focussing
|Multi-layer mirror||10 μm vertical focussing||Available|
|Primary detector|| |
Perkin Elmer XRD 1611 CP3
409.6 × 409.6 mm2 active area
100 μm pixel size, 4 Hz read-out
|Secondary detector||Perkin Elmer XRD 4343 CT |
432 × 432 mm2 active area
150 μm pixel size, 15 Hz read-out (TBC)
|XY sample stage|| |
250 mm (h) × 450 mm (v) travel
5 kg load capacity
|Single capillary spinner||10 Hz capillary spinner||Available|
|Multi-capillary spinner||15 position sample changer||Available (14 positions operational)|
|Hot air blower||350 - 1100 K||Available|
|Cryojet||90 - 500 K||Available|
|Hydrothermal cell|| |
Zero-background capillary cell for hydrothermal reactions
RT - 473 K
|Available (contact beamline staff for details)|
|Gas cell|| |
Capillary cell for flowing gas experiments.
A limited set of gasses is currently available.
Can be used with the hot air blower.
|Commissioning (contact beamline staff for details)|
|eChem system||8-channel Ivium-n-Stat electrochemical analyser for battery cycling, impedance analysis and more.||Available|
See the sample environment page for more details on the equipment available. New sample environment equipment is always in development. For more information about proposed experiments please contact email@example.com.
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