|JKMRS Volume 21, No 4, pp 114 Solid State Dynamic Nuclear Pola...|
|2017년 12월 21일 / 조회수: 231|
Solid State Dynamic Nuclear Polarization of 1H Nuclear Spins at 0.3 T and 4.2 K
Jeong Hyun Shim*
Korea Research Institute of Standards and Science, Daejeon 34113, Republic of Korea
Abstract Here, I report solid state Dynamic Nuclear Polarization (DNP) of 1H nuclear spins at 0.3 T and 4.2 K. The DNP polarizer was developed based on a commercial X-band Electron Spin Resonance (ESR) modified for DNP, in combination with a NMR console and a liquid-Helium cryostat. By detuning magnetic field, DNP spectrum was measured to find the optimal condition. At +3 mT detuned from on-resonance field, 1H NMR signal of 60:40 glycerol/water frozen solution doped with 20 mM perdeuterated-Tempone was amplified 43 times. The 1H spin polarization obtained at 4.2 K is over 3100 times higher than that at 300 K. The width of the DNP spectrum, which is five times broader than ESR spectrum, is inconsistent with solid effect or thermal mixing, and presumably suggests a different DNP mechanism.