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titleRead more about the ERA

The Experimental Risk Assessment (ERA) is the place to record and address any hazards that may arise from your experiment. It is critical to complete the ERA for all experiment types at Diamond.

Samples

One of the most common hazards for an experiment at Diamond is the samples themselves. Every sample that you bring to Diamond must be covered by one of the sample entries in the ERA.

Equipment

If you’re bringing your own equipment to I15-1 (i.e. your own in situ environment) then you need to risk assess it here.

Experimental Methods

Here you should specify all of the processes which are going to occur on the beamline during your experiment. For even the simplest experiment, you will still be mounting and unmounting samples from the beamline so you should describe here how that is going to be done, and any precautions you need to take.

Lab Access

If your experiment involves you coming to Diamond (i.e. it’s not an easy access experiment); you should request lab access. This is required for you work in our side labs, irrespective of how non-hazardous your samples are.

Even if you are planning on loading your capillaries before you come to Diamond, you may need some lab space to reload capillaries in the event that one of them gets broken.

Sample Information

In order to get a PDF from your sample, we need to know a few things about it, including the composition, density, and packing fraction.

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titleRead more about the required sample information

It is important to characterise the samples for a PDF experiment as comprehensively as possible before your beamtime. The three key properties that are required are;

  1. Sample composition - Quantitative analysis should be performed to identify the most accurate composition possible for the samples. This is the full composition for the sample, including any water, binder or support materials that may be present, not just the composition of the material of interest.

  2. Density - The density of the sample should be known, preferably in g cm-3

  3. Packing fraction - This is a value between 0-1 and is often estimated to be ca. 0.6.

The sample composition, density and packing fraction are essential parameters that should be known as accurately as possible in order to perform the data reduction step and generate the PDFs.

A range of suitable analysis methods should be performed such as XRF, TGA/DSC-MS etc. to characterise the sample in advance of the beamtime.

Additional information such as amorphous content, concentration of impurity phases etc. will also be useful during analysis.

Additional Factors

There are additional factors that should be considered regarding the samples, such as:

  • Are there any peaks at low Q? This may require the beam stop to be moved further from the sample. If you have a peak at Q ≤ 1 Å-1 then your local contact should be made aware before the experiment. Q is defined as:

Mathblock
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Q=4\pi\sin\theta/\lambda = 2\pi/d

  • Have you simulated the pdf and the scattering data for comparison?

  • Do you have .cif files that you can bring with you?

  • Which of your samples are likely to be the most strongly scattering? This can be effected by the concentration of highly scattering elements, the crystallinity of the sample and the presence of large crystallites in your powder.

  • Is your sample a "good" powder? Are there likely to be larger crystallites that need further grinding to give a good powder average?

  • Have you packed as many capillaries as you can at your home institution? We will post empty capillaries to you where necessary. Please refer to the "Know Your Setup" section and discuss with your local contact.

All samples should be labelled with the visit number, date, name of the investigator/group and a suitable description of the material (i.e. the full composition including any support materials/binders)

Laboratory Information Management System

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