High-pressure magnetic resonance imaging up to 40 MPa

A high-pressure vessel designed for use with commercial magnetic resonance imaging equipment at up to 40 MPa of pressure was used and tested. Special features of the vessel are the following: 1) 12.6 mm sample chamber i.d.; 2) only non-magnetic parts; 3) visible sample from the outside; 4) resistant to corrosive chemicals, and; 5) sample could be manually translated and rotated in situ. This apparatus was demonstrated through observation of CO2 clathrate-hydrate growth in a water droplet injected into liquid CO2 at 20 MPa.