@article{e2912a316f444af894c545801edaa4c9,
title = "Pulsed Electron-Nuclear Double Resonance (ENDOR) at 140 GHz",
abstract = "We describe a spectrometer for pulsed ENDOR at 140 GHz, which is based on microwave IMPATT diode amplifiers and a probe consisting of a TE011 cavity with a high-quality resonance circuit for variable radiofrequency irradiation. For pulsed EPR we obtain an absolute sensitivity of 3 × 109 spins/Gauss at 20 K. The performance of the spectrometer is demonstrated with pulsed ENDOR spectra of a standard bis-diphenylene-phenyl-allyl (BDPA) doped into polystyrene and of the tyrosyl radical from E. coli ribonucleotide reductase (RNR). The EPR spectrum of the RNR tyrosyl radical displays substantial g-anisotropy at 5 T and is used to demonstrate orientation-selective Davies-ENDOR.",
author = "M. Bennati and Farrar, {C. T.} and Bryant, {J. A.} and Inati, {S. J.} and V. Weis and Gerfen, {G. J.} and P. Riggs-Gelasco and J. Stubbe and Griffin, {R. G.}",
note = "Funding Information: Thanks are accorded to Professor D.J. Singel for conversations pointing out the advantages of high frequency ENDOR. We are grateful to K. Kreischer for the loan of the frequency sweeper used in the cavity quality measurements and to Jan Henrik Ardenkjaer-Larsen (NYCOMED Innovation AB) for the gift of the trityl radical. We would like to acknowledge P. H{\"o}fer for helpful discussions and comments on this manuscript. M. Bennati thanks the Deutsche Forschungsgemeinschaft for a postdoctoral fellowship. C.T. Farrar was supported by a National Institutes of Health postdoctoral fellowship (GM-18790). This research was supported by the National Institutes of Health (grants GM-38352 and RR-00995).",
year = "1999",
month = jun,
doi = "10.1006/jmre.1999.1727",
language = "English (US)",
volume = "138",
pages = "232--243",
journal = "Journal of Magnetic Resonance",
issn = "1090-7807",
publisher = "Academic Press Inc.",
number = "2",
}