This page contains a list of Frequently Asked Questions. If your question isn't answered here, feel free to submit it using the form above. Your name and email address are optional, but if you provide these details, beamline staff will respond to you directly.
Previous FAQs:
Q: How can I decide the camera length and the energy of X-ray for my expeirments?
A: The measurable q-range is defined by the combination between the camera length and the X-ray energy (wavelength). Thus, these 2 parameters must be chosen carefuly depending on the period length, lattice size or molecular size of your sample. I22 staff can help and give some ideas for this question, please ask the I22 staff before making the beamtime application or your beamtime! A useful guide can be found elsewhere in this manual.
Q: I have a large vertical black streak on the CCD detector, and it's impossible to see my data in the image.
A: The fast shutter is set up incorrectly. Please refer to the section of the user manual about setting up the fast shutter for directions to solve the problem. Once the fast shutter is opening at the correct time, the streak should disappear.
Q: The lab is out of a consumable item, such as gloves/wipes/tips. How do I get more?
A: During office hours, let your local contact know. Beamline staff extensions are posted in the control room and the data reduction room (Zone 2 pod). Out of hours (after 6 PM, before 9 AM and on the weekends), please contact the EHCs on 8787 for assistance.
Q: What file format is my data? How do I analyse it?
A: We aim to provide data reduction and analysis instructions on this website. If you need any further guidance, please ask your local contact. Presently, I22 data is saved in the Nexus format (.nxs), but legacy files in the BSL format are also generated from each scan or set of frames, so if you have older or custom software that is designed to analyze BSL files, these will still work.
Q: I need help modifying a custom sample environment. Can Diamond staff assist me?
A: It depends on what you need. Often we help users with custom spacers or other adapter sections to make an existing sample environment match with the space envelope available on the beamline- if this is a concern for your experiment, please ask, as we may already have the necessary part from a previous setup! Our technicians have also assisted users with custom sample cells and other small designs on occasion. We do not do elaborate machining on site, however, and this assistance is limited to smaller tasks. We also require significant (at least four weeks) advance notice that you will need technical or shop assistance with your sample environment. Please contact beamline staff if you intend to bring a custom sample environment, so we can begin to assist you as soon as possible.
Q: What camera length and energy did my experiment use last time?
A: These parameters are crucial for your data analysis, so it's important to make a note. Usually, we have set up the requirements you have requested, so the camera length and energy are probably recorded in the original proposal, beamline log book, or in email exchanges we've had with you prior to the experiment.
Q: In each dataset directory there are 5 files. What are they?
A: In the dataset directory, the files are stored in BSL format that provides 5 files following this filename format.
*0.* file is the header file containing information on the sample, the number of frame you have collected etc… It is an ASCII file
*1.* file is the file containing the intensity of the SAXS data
*2.* file contains the normalisation channel. By default, it is number 2 on I22.
*3.* file contains the WAXS data
*4.* contains some other information about the detector but it is used for debugging.
The last 4 files are binary files.