Dual-mode microwave resonator device and method of electron spin resonance measurement

Patent metadata

Field	Value
Publication number	US-9287606-B2
Application number	US-201013502777-A
Country	US
Kind code	B2
Filing date	Jul 27, 2010
Priority date	Jul 27, 2010
Publication date	Mar 15, 2016
Grant date	Mar 15, 2016

Abstract

A microwave resonator device ( 1 ), being configured in particular for electron spin resonance measurements, comprises a resonator being resonant with first and second microwave field modes and including first and second resonance sections ( 7, 8 ) arranged along a longitudinal axis ( 2 ) of the resonator, and a coupling unit being arranged between the first and second resonance sections, wherein the coupling unit includes a conducting plate ( 16 ) being arranged on the longitudinal axis ( 2 ) and covering a central portion of a cross-sectional area of the resonator, the conducting plate ( 16 ) is adapted to adjust a first mode frequency of the first microwave field mode, and the conducting plate ( 16 ) is arranged at a field minimum of the second microwave field mode. Furthermore, a method of conducting an electron spin resonance measurement with a sample to be investigated is described.

First claim

The invention claimed is:

1. A microwave resonator device, that is configured for electron spin resonance measurements, comprising:
a resonator being simultaneously resonant with first and second microwave field modes and including a first and second resonance sections arranged along a longitudinal axis of the resonator, and
a coupling unit being arranged between the first and second resonance sections, said coupling unit including a conducting plate being arranged on the longitudinal axis and covering a central portion of a cross-sectional area of the resonator,
wherein:
the conducting plate is arranged in order to adjust a first mode frequency of the first microwave field mode,
the conducting plate is also arranged at a position corresponding to a field minimum of the second microwave field mode,
whereby one of the first and second resonance sections is capable of accommodating a sample, and
wherein the microwave resonator device is configured in order to allow an excitation of the sample at one frequency and a detection of an electron spin resonance response of the sample at another frequency.

2. The microwave resonator device according to claim 1 , wherein the coupling unit further includes lateral conducting slabs surrounding the conducting plate so that a ring-shaped slit is formed between the first and second resonance sections.

3. The microwave resonator device according to claim 2 , wherein the lateral conducting slabs are movable such that a radial width of the ring-shaped slit is adjustable.

4. The microwave resonator device according to claim 3 , further comprising a drive unit that causes a synchronous adjustment movement of the lateral conducting slabs.

5. The microwave resonator device according to claim 1 , further comprising at least one of
a first adjustment piston arranged in the first resonance section, wherein frequencies of the first and second microwave field modes of the resonator depend on an adjustment position of the first adjustment piston in the first resonance section, and
a second adjustment piston arranged in the second resonance section, wherein the frequencies of the first and second microwave field modes of the resonator depend on an adjustment position of the second adjustment piston in the second resonance section.

6. The microwave resonator device according to claim 5 , further comprising a frequency setting device being arranged and configured for setting the adjustment position of at least one of the first and second adjustment pistons.

7. The microwave resonator device according to claim 6 , wherein the frequency setting device is configured for a synchronous setting of the adjustment positions of both of the first and second adjustment pistons such that a frequency separation of the first and second microwave modes is a constant.

8. The microwave resonator device according to claim 5 , wherein the first adjustment piston has a concentric opening in order to introduce a sample into the first resonance section.

9. The microwave resonator device according to claim 1 , wherein one of the first or the second resonance sections includes a coupling iris being arranged and configured for connecting an incoupling waveguide with the first or second resonance section, wherein the coupling iris is located at a point where a microwave magnetic field strength induced in the first or second resonance section is at a maximum and has the same orientation as the magnetic field of a dominant mode in the incoupling waveguide.

10. The microwave resonator device according to claim 1 , wherein the resonator has a cylindrical shape and the first and second resonance sections are cylindrical sections.

11. The microwave resonator device according to claim 1 , wherein the conducting plate is arranged at a half longitudinal length of the resonator.

12. The microwave resonator device according to claim 1 , wherein the conducting plate is arranged perpendicular to the longitudinal axis of the resonator.

13. The microwave resonator device according to claim 1 , wherein the conducting plate has a diameter of at least 2.2 mm.

14. The microwave resonator device according to claim 1 , wherein the conducting plate has a thickness below 200 μm.

15. A method of conducting an electron spin resonance measurement with a sample to be investigated, comprising the steps of:
positioning the sample in the first resonance section of the microwave resonator device according to claim 1 ,
adjusting a first mode frequency of the first microwave field mode,
adjusting a second mode frequency of the second microwave field mode, the second mode frequency being separated from the first mode frequency by a predetermined frequency spacing,
exciting electron spin resonance signals in the sample, and
collecting the electron spin resonance signals excited in the sample.

16. The method according to claim 15 , further comprising the steps of:
varying the frequency spacing between first and second different microwave modes, and
simultaneously collecting electron spin resonance signals from each of the first and second different microwave modes as the frequency spacing is varying.

Assignees

• Tkach Igor
• Bennati Marina
• Max Planck Gesellschaft

Inventors

• Tkach Igor
• Bennati Marina

Classifications

• G01R33/60

  using electron paramagnetic resonance (G01R33/24, G01R33/62 take precedence) · CPC title

• G01R33/345 Primary

  of waveguide type (G01R33/343 takes precedence) · CPC title

• H01P7/00 Primary

  Resonators of the waveguide type · CPC title