The PRIOR-II ("Proton Microscope for FAIR") is the only user facility for charged particle radiography in Europe, accessible to a broad international scientific community for experiments on high energy density states of matter (HED) and beyond. It is based on a high-gradient normal-conducting quadrupole quadruplet and is capable of imaging high-speed processes in dense matter up to 100g/cm² with a spatial resolution performance in the µm range and a temporal resolution in the nanosecond range. Depending on the experiment and individual requirements, the facility can be operated with protons from 0.4GeV to 4.5GeV or with light ions (up to nitrogen) from 0.2GeV/u to 1.5GeV/u.

Proton radiography is a non-invasive diagnostic method that is particularly suited for probing extreme states of matter that can be achieved by shock compression. It is therefore suitable for probing the material strength or dynamic behavior of functional materials, or for equation of state (EOS) measurements of composite materials. This is possible because, in addition to high speed and high resolution imaging, a 2D areal density map of the target can be reconstructed. While the relative areal density reconstruction accuracy is typically <1% depending on the experimental geometry, absolute density reconstruction is possible with an accuracy of 2%+. More information about PRIOR-II can be found in [1].

The facility is in operation at GSI since 2021 and has already completed several campaigns in the research fields of plasma physics, materials science and medical physics.

Proposals for PRIOR-II can be submitted via the GSI PPAC (gate.gsi.de). Before submitting a proposal, please first read the „How-To-PRIOR“ manual and contact our staff members.

Small brass watch imaged with PRIOR-II at GSI using 4.5GeV protons. The image illustrates the image quality and density contrast that PRIOR-II can provide.