Fig.1

T1 relaxation values of hyperpolarized 129Xe as functions of (a) oxygen partial pressure, and (b) magnetic field gradients (T = 300 K, p = 2.068 bar, B0=0.356 T)

Fig.2

Model of accumulation of hyperpolarized Xe ice in a cold trap

Fig.3

Automatic accumulation-thawing device: (a) Framework; (b) Model of core part; (c) Graphical user interface (GUI) of the control program

Fig.4

The setup of gas channel for hyperpolarized 129Xe in NMR experiment

Fig.5

Typical results of NMR experiments. (a) NMR signal of proton (Average of 200 sampling); (b) NMR signal of hyperpolarized 129Xe gas before accumulation-thawing (single sampling); NMR signal of hyperpolarized 129Xe gas after thawing using (c) manual and (d) automatic accumulation-thawing device (single sampling)

Fig.6

Recovery ratios of polarization (a) and their corresponding pressure curves of the gas (b) for automatic and manual accumulation (1 psi≈6 895 Pa)

Fig.7

Comparison of recovery ratios of polarization among three accumulation-thawing methods (automatic accumulation-thawing, manual accumulation-manual thawing in different/the same field)

Fig.8

Comparison of recovery ratios of polarization between the PFA and glass spiral cold traps for automatic accumulation-thawing

Fig.9

Recovery ratios of polarization using the PFA spiral cold trap for (a) different volumes and (b) different time with the homebuilt device for the accumulation-thawing