FAQ

Yes! We welcome applications from other research centres, universities, and commercial/industrial partners. Please contact us with your enquiry.

NOTE: In light of the current guidelines relating to Covid-19, we are only accepting virtual meetings/emails for project discussions.

There are numerous ways to get in touch to discuss your enquiry including via phone, email and virtual meeting. Once the pandemic is over, we will be holding regular open days which will allow you the opportunity to speak with the STC management team in person and to see the instruments for yourself.

Please get in touch if you would like to organise a (virtual) meeting.

It depends on the sample. To maximise resolution, you should cut your sample so it is as small as possible. Samples should also ideally be cylindrical in shape. Biological samples may need to be fixed or stained. Correct sample mounting is also critical to prevent movement during scanning - please contact us to discuss potential mounting options and any preparation you may need.

As much as possible! You will need to tell us various things including sample composition, sample size, why you want to do what you want to do, associated COSHH and health and safety aspects, number of samples, billing information, etc. The more you tell us, the easier the scan set-up process will be. This can all be inputted to the scan proposal form which you will be notified about once you have discussed your project with us.

The reported minimum spatial resolution on the 620 Versa is 500nm whereas the smallest voxel size is ~100nm. This means that, in theory, the minimum separation at which a feature pair can be resolved (spatial resolution) is 500nm, and the smallest 3D pixel (voxel) can be 100nm. This however depends on numerous factors including sample size, density, composition, and other imaging set-up conditions. We can realistically see features that are ~1 micron using the 40x objective.

Previous knowledge of the size of any subsurface features you wish to image will be useful and will help determine whether the 620 Versa is the correct instrument for you to use.

Ideally the smaller the better to maximise resolution, however the large cabinet in the 620 Versa enables tall samples up to 15cm (however you certainly wont fit this in the entire field of view - the max field of view is 5cm x 5cm). The smaller your sample, the higher resolution we can get to. Ideally the sample will be cylindrical in geometry, and isotropic.

Yes, we encourage users to perform text/proof of concept scans initially. Please get in touch to find out what we can offer - we will be having one or two weeks of proof of concept scans each call quarter, depending on numbers.

Again, this totally depends on the sample and the experiment. Simple scans of relatively low resolution and low density material can take 30 mins -2 hours (plus scan set-up time), however denser/thicker material requiring a high exposure time can be 20+ hours, and in-situ experiments can take numerous days. Performing a test scan will enable us to predict this better.

Again, this totally depends on the sample and the experiment. If the sample has been scanned previously and previous settings can be used as a guide, then this process can be relatively quick, however some samples are more challenging and require a bit of 'trial and error' to get the conditions spot on. This process can be 20 -90 minutes, or longer (particularly for rig set up).

This depends on the length of the scan(s), but we aim to give users their data as quickly as possible. It helps if you have an external hard drive with at least 500GB memory. Currently we are uploading data to a cloud based system and sharing with users due to limited access.

The Versa automatically creates a .txm/.txrm file during the reconstruction process, however there is also the option to create a .tiff stack. We suggest you create a .tiff stack as not all post-processing software recognises the .txm format.

Once scanning is completed, you will need to have your own external hard drive to take away your data. You can arrange data transfer with Ria Mitchell. If you are internal the University of Sheffield, it is also possible to share your data using a cloud based system (we are only sharing via this method during the pandemic).

This totally depends on what you want to do with your data. We have a number of software options on our PC workstations, and you should discuss your needs with Ria Mitchell. Avizo, Dragonfly and Fiji/ImageJ are commonly used for analysis, whereas Dragonfly and Drishti are commonly used for visualisation and figure creation. But this will vary from person to person.

You can if you have a powerful enough computer, RAM and graphics card (most generic laptops are not powerful enough). A general rule of thumb is RAM should be 10x your volume size (e.g. if your scan volume is 5GB you'll need 50GB+ RAM) for segmentation, and a GPU of at least 10GB textural memory for volume rendering. There are numerous open-source/free versions of software in existence (e.g. Fiji, Dragonfly, Drishti) so they are accessible without a licence. Fiji(ImageJ) however will usually work on generic laptops and PCs to do simple tasks. Avizo is operated through a paid-for licence system, so we'd expect you to use the Centre PCs for this.

We will be running numerous (virtual) training sessions in software visualisation and analysis - please get in touch to find out more, or check out the events page. Because of the wide variety of tasks that users want to complete, it's unrealistic for everyone to to have one-to-one training and assistance - there is however a virtual drop-in session specific to software questions every week - please get in touch for more details.

Once you have enquired about your proposed scanning project with a member of the Centre team, you will be provided with a link to a form which will be your proposal. Make sure you have all of the details ready for the form - there is a guide about designing a X-ray CT experiment on Blackboard. Once you have submitted your proposal, we will let you know the outcome once the deadline passes, usually within ~10 days.

For external submissions, please get in touch with Ria Mitchell to discuss the application process - we will operate this via a similar proposal-based application system.