^1H-DNP Experiments and High Power Sub-Terahertz Wave Irradiation Effect on BDPA-Doped Toluene Solution

In order to investigate the experimental technique and the high magnetic field effect in the dynamical nuclear polarization (DNP) experiments,the X-band ^1H-DNP and the high power sub-THz wave irradiation experiments have been performed on a toluene solution of α,γ-bisdiphenylene-β-phyenylallyl (BDPA) radical at room temperature. We have established the sample-shuttle X-band DNP experimental system,and investigated the external magnetic field,the microwave power and ^1H-T1^-1 dependences of Overhauser enhancement factor ε. A maximal signal enhancement of approximately -19 has been observed. As for the sub-THz wave experiments,we have constructed the NMR and ESR measurement system for the experiments under the magnetic field of ～10.7 Ｔ,with a high power light source gyrotron CW-I (TE22,8 mode,ƒ～299.23 GHz). When the high power sub-THz wave of a gyrotron was irradiated on the toluene solution in order to confirm the evidence of DNP,the sample has evaporated due to the electromagnetic wave heating