title: A Dynamic Nuclear Polarization spectrometer at 95 GHz/144 MHz with EPR and NMR excitation and detection capabilities.
abstract: A spectrometer specifically designed for systematic studies of the spin dynamics underlying Dynamic Nuclear Polarization (DNP) in solids at low temperatures is described. The spectrometer functions as a fully operational NMR spectrometer (144 MHz) and pulse EPR spectrometer (95 GHz) with a microwave (MW) power of up to 300 mW at the sample position, generating a MW B(1) field as high as 800 KHz. The combined NMR/EPR probe comprises of an open-structure horn-reflector configuration that functions as a low Q EPR cavity and an RF coil that can accommodate a 30-50 μl sample tube. The performance of the spectrometer is demonstrated through some basic pulsed EPR experiments, such as echo-detected EPR, saturation recovery and nutation measurements, that enable quantification of the actual intensity of MW irradiation at the position of the sample. In addition, DNP enhanced NMR signals of samples containing TEMPO and trityl are followed as a function of the MW frequency. Buildup curves of the nuclear polarization are recorded as a function of the microwave irradiation time period at different temperatures and for different MW powers.
authors.affiliation: Department of Chemical Physics, Weizmann Institute of Science, Rehovot 76100, Israel. akiva.feintuch@weizmann.ac.il
authors.forename: Akiva
authors.initials: A
authors.lastname: Feintuch
authors.forename: Daphna
authors.initials: D
authors.lastname: Shimon
authors.forename: Yonatan
authors.initials: Y
authors.lastname: Hovav
authors.forename: Debamalya
authors.initials: D
authors.lastname: Banerjee
authors.forename: Ilia
authors.initials: I
authors.lastname: Kaminker
authors.forename: Yaacov
authors.initials: Y
authors.lastname: Lipkin
authors.forename: Koby
authors.initials: K
authors.lastname: Zibzener
authors.forename: Boris
authors.initials: B
authors.lastname: Epel
authors.forename: Shimon
authors.initials: S
authors.lastname: Vega
authors.forename: Daniella
authors.initials: D
authors.lastname: Goldfarb
mesh_terms: D003080:Cold Temperature; D004574:Electromagnetic Fields; D004578:Electron Spin Resonance Spectroscopy / Q000295:instrumentation / Q000379:methods*; D009682:Magnetic Resonance Spectroscopy / Q000295:instrumentation / Q000379:methods*; D008872:Microwaves; D012815:Signal Processing, Computer-Assisted; D013057:Spectrum Analysis