Where the three contributing terms are for collisional relaxation (CR), magnetic field inhomogeneity (MFI) relaxation, and relaxation caused by the presence of paramagnetic oxygen (O2). The T 1 duration could be anywhere from minutes to several hours, depending on how much care is put into lessening the effects of CR, MFI, and O 2. The last term has been quantified to be 0.360 s amagat, but the first and second terms are hard to quantify since the degree of their contribution to the overall T 1 is dependent on how well the experimental setup and cell are optimized and prepared.