This is the world’s largest public database of material radio-purity measurements. These measurements are used by members of the low-background particle/nuclear physics community to build experiments that search for neutrinos, neutrinoless double-beta decay, WIMP dark matter, and other exciting physics.

The project is maintained by an international collaboration of scientists from North America, Europe, and China, who are responsible for developing the database application (Persephone), defining the material assay data format (MADF), and helping people contribute their data.

The project originated at LBNL but has only grown through the generous support of the wider low-background community. Special thanks go to the AARM collaboration and to SNOLAB, which hosts the site.

Get in touch if you’d like to help the project. In particular, we’d love to include your data.

Contact James Loach or Jodi Cooley for more information.


Searches are case-insensitive and OR by default. Examples:

  • "ofhc copper"
  • copper AND ofhc
  • copper OR lead
  • coppe?
  • cop*
  • name:copper
  • grouping:EXO

Enter all to see all entries. The results are presented in random order.

Click on a measurement to see more detail, and then on the magnifying glass to see everything. Click on the X icon to remove results from the display and drag-and-drop results into different orders to help make comparisons. Click on the wrench icon to report an error or export data. Note that only administrators can log in and edit entries.

A more technical description of the database application and instructions on how to install you own version can be found in the project's github repository.


These data sets are available online (click on the name to view the entries):

These are in preparation:


The collaboration consists of:

We've been assisted by a number of undergraduate students: Keith Adler (SMU), Matthew Bruemmer (SMU), Khang Nguyen (LBNL), Zheng Li (SJTU), and Ben Wise (SMU).


If you find the database helpful, you can cite our publication:

J.C. Loach et al., A Database for Storing the Results of Material Radiopurity Measurements, Nucl. Instr. Meth. A 839 (2016).


This is the full acknowledgments statement from our publication:

This work was supported by: the U.S. Department of Energy, Office of Science, Office of Nuclear Physics, under Con- tract No. DE-AC02-05CH11231; by the Shanghai Key Lab for Particle Physics and Cosmology (SKLPPC), Grant No. 11DZ2260700; by the Helmholtz Alliance for Astroparticle Physics (HAP) funded by the Initiative and Networking Fund of the Helmholtz Association; and by the National Science Foundation under Grant No. PHY 124260 awarded to the AARM (Assay and Acquisition of Radiopure Materials) collaboration. We acknowledge the support of IBM Cloudant in hosting an early version of our community database and to SNOLAB for their ongoing hosting and management of the site. We acknowledge support and guidance from colleagues in the underground science community, including from the AARM, ILIAS, EXO, XENON100, SuperCDMS and Majorana collaborations.