FAQ - Frequently Asked Questions

What will be analyzed?

We have different generations of XRF scanners in operation. Depending on sediment composition the whole suite of elements between Potassium (K) and Strontium (Sr) can be analyzed.
The new generation scanners can measure light elements beginning with Aluminium (Al) and heavy elements between Rubidium (Rb) and Barium (Ba), each within a separate measurement run.

In which resolution can be measured?

Measurements can be taken down to mm or even micron scale resolution (down to even 200 micron at the "Superslit Scanner"). However, for "normal" marine, bioturbated sediments usually it does not make sense to scan at a resolution higher than 1cm (standard resolution).

Depending on the sediment composition one measurement takes between 15 to 60 seconds. It strongly depends on the wavelength of the fluorescent radiation (varies for different elements according to their position in the periodic system).
Please note that at the start up to 3 hours will be needed for a general introduction to the instrument and operation, preparing of the core sections, and defining the settings ("dead time") for light elements.
Please also take into account that some time is needed for data processing, backups, cleaning, and properly returning the core sections in the reefer and the core racks afterward.
The table below shows an approximate time estimation for measuring a core section with a length of 1m in different resolutions.

Step size	Minutes	Hours	Days
2 mm	278	4,63	0,58
5 mm	74	1,23	0,15
1 cm	37	0,62	0,08
2 cm	19	0,31	0,04

How should the cores look like?

It is possible to scan cores with diameters between 30 to 150 mm and a maximum length of 1800 mm.
Liners should be filled with sediment. For optimal results the sediment surface should be ideally flat.

Is it possible to measure U-channels?

In principle yes. However, as they are taken by pushing the U-channel into a core half some distortion at the edges of the channel could affect the data quality. Also, U-channel samples more easily crack, dry out, or crumble. Therefore, it is always preferred to scan the intact core if available.

Is there any fee for using the XRF Scanner?

Yes, there is a consumables fee. For details please email Dr. Ursula Röhl.

What do I have to do when I want to make use the XRF-Scanner?

Contact the lab manager Dr. Ursula Röhl by email.
Please include the following information

why you need XRF scanner data for your research,
which chemical elements would be important.
which cores (project, core #no.),
how many meters of core,
in which resolution (step size) you envisage to measure.

Helpful information for travel arrangements:

Accomodation options see link above

Private Apartments in Bremen
Teerhof58 (Guesthouse in the city center)

How to find us