Microwave frequency modulation to enhance Dissolution Dynamic Nuclear Polarization

Aurélien Bornet (1) , Jonas Milani (1) , Basile Vuichoud , Angel J. Perez Linde , Geoffrey Bodenhausen (2, 3) , Sami Jannin (1)

1 ISIC - Institut des sciences et d'ingénierie chimiques
2 Institut des Sciences et Ingénierie Chimiques
3 UPMC - Université Pierre et Marie Curie - Paris 6

Hyperpolarization by Dissolution Dynamic Nuclear Polarization is usually achieved by monochromatic microwave irradiation of the ESR spectrum of free radicals embedded in glasses at 1.2 K and 3.35 T. Hovav et al. (2014) have recently shown that by using frequency-modulated (rather than monochromatic) microwave irradiation one can improve DNP at 3.35 T in the temperature range 10-50 K. We show in this Letter that this is also true under Dissolution-DNP conditions at 1.2 K and 6.7 T. We demonstrate the many virtues of using frequency-modulated microwave irradiation: higher polarizations, faster buildup rates, lower radical concentrations, less paramagnetic broadening, more efficient cross-polarization, and less critical frequency adjustments.

Domaines: Biochimie, Biologie Moléculaire

Aurélien Bornet, Jonas Milani, Basile Vuichoud, Angel J. Perez Linde, Geoffrey Bodenhausen, et al.. Microwave frequency modulation to enhance Dissolution Dynamic Nuclear Polarization. Chemical Physics Letters, 2014, 602, pp.63-67. ⟨10.1016/j.cplett.2014.04.013⟩. ⟨hal-01366398⟩