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A Deeper Look at B1 and Modulation Field Distribution in a Resonator

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Quantitative EPR

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Abstract

The EPR signal is proportional to the microwave B1 at the sample, which is proportional to √P. Consequently, it is important to carefully examine the distribution of B1 over a sample of finite size, such as a standard liquid or powdered sample in a 4 mm o.d. quartz sample tube. In the typical EPR experiment that uses magnetic field modulation and phase-sensitive detection, the integrated signal intensity is proportional to the modulation amplitude at the sample. Therefore, it is also important to consider the distribution of modulation amplitude over the sample. The details of these two factors are discussed in this chapter. This chapter also includes discussion of sample size, issues related to automatic frequency control (AFC) for very narrow signals, and cell geometries for aqueous samples.

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Authors and Affiliations

  1. Department of Chemistry & Biochemistry, University of Denver, Denver, CO, USA

    Dr. Gareth R. Eaton & Dr. Sandra S. Eaton

  2. Bruker BioSpin Corporation, Billerica, MA, USA

    Dr. David P. Barr & Dr. Ralph T. Weber

Authors
  1. Dr. Gareth R. Eaton
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  2. Dr. Sandra S. Eaton
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  3. Dr. David P. Barr
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  4. Dr. Ralph T. Weber
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Eaton, G.R., Eaton, S.S., Barr, D.P., Weber, R.T. (2010). A Deeper Look at B1 and Modulation Field Distribution in a Resonator. In: Quantitative EPR. Springer, Vienna. https://doi.org/10.1007/978-3-211-92948-3_6

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