XIA Alpha Counter Information
The BUGS lab currently hosts two UltraLo-1800 alpha counters to compliment the screening facilities of the germanium detector array. The UltraLo-1800 is a negative ion drift surface alpha counter which allows for the determination of the background contribution from the top few millimetres of a material or, with sufficient run time, a bulk contribution measurement. This information is of particular significance when considering the next generation of dark matter detectors as, due to their increasing dimensions, they incur a sizeable background contribution from the larger surface areas of their design. With this accounted for, a better simulation of detector capability and a more precise limit is possible.
For any additional information not found on this page, please email us at boulby@stfc.ac.uk
To book in a sample for assay, please use the sample request form.
Sample dimensions
The UltraLo can accommodate two sample sizes:
Wafer - a circle 12" (30cm) in diameter
Full - a square 17"x17" (43cmx43cm)
The absolute maximum size is 19.75" (50cm), this is the size of the outer frame of the sample tray
It is better to stay within the 17"x17" square in order to improve sensitivity
Max sample thickness - 6.3mm
Thicker samples can be accommodated if absolutely necessary by removing the top part of the detector and inserting the sample vertically. However, this is time consuming and disruptive, and should be avoided if possible.
Preparing the Sample
Sending a sample to Boulby is simple.
Samples can be sent totally unprepared and the Boulby team will prepare the sample for you. This must be discussed before hand and a plan agreed.
Alternatively the sample can be sent prepped for screening.
We recommend carefully packaging all samples before sending. Using radon barriers is essential for prepared samples. There are two companies we recommend, where these can be purchased (others may be available):
Assay and Reporting
Assays generally take no more than a week
Some samples will be screened on both the UltraLo and a Ge detector. If this is something you require please make sure that is mentioned in the sample booking form.
Samples can be screened before and after cleaning if understanding surface contamination or cleaning techniques is of interest. Again this should be discussed and highlighted in the sample request form.
Bulk measurements can also be carried out on the UltraLo and would require a prolonged run time. This should be discussed with the team prior to booking samples in.
Reports are generated for all samples and will be sent to the sender upon completion.
