HALL PROBE, EPR COIL DRIVER AND EPR RAPID SCAN DECONVOLUTION

• US 20150185255A1
• Filed: 09/13/2013
• Published: 07/02/2015
• Est. Priority Date: 09/14/2012
• Status: Active Grant

• Current Assignee: University of Denver
• Original Assignee: University of Denver
• Inventors: Tseitlin, Mark, Eaton, Gareth R., Quine, Richard Quine
• Granted Patent: US 12,000,920 B2
• Time in Patent Office: Days
• US Class Current: 1/1
• CPC Class Codes: G01N 24/10 by using electron paramagnetic resonance G01N24/12 takes precedence
• CPC Class Codes: G01R 1/203 Resistors used for electric measuring, e.g. decade resistors standards, resistors for comparators, series resistors, shunts resistors in general H01C; microwave or radiowave terminations H01P1/26; coupling devices H01R
• CPC Class Codes: G01R 33/60 using electron paramagnetic resonance G01R33/24, G01R33/62 take precedence

Abstract

Systems and methods are disclosed to simulate a Hall probe, provide EPR coil driver, and/or perform a time-domain full scan sinusoidal deconvolution of EPR signals. The simulated Hall probe can return a Hall Effect voltage from a coil current that creates a magnetic field within a coil magnet and the reference current that would be fed to an actual Hall probe. From these values, the Hall Effective voltage can be determined which can be used to determine the magnetic field flux, which can then be used to regulate the magnetic field. Embodiments of the invention also disclose a coil driver and a new technique for EPR deconvolution.

Claims

1. A Hall Probe simulator comprising:

a reference current input configured to receive the reference current for a Hall Probe;

a current sensor configured to sense the coil current in a coil magnet that produces a magnetic field; and

a controller coupled with the reference current input and the current sensor, wherein the controller is configured to determine a Hall Effect voltage from a function of the coil current and the reference current.

2. The Hall probe simulator according to claim 1, wherein the controller is further configured to determine the magnitude of the magnetic field produced by the coil magnet from the Hall Effect voltage.

3. The Hall probe simulator according to claim 1, further comprising a reference resistor,

wherein the reference current input inputs a reference voltage across the reference resistor, and

wherein the Hall Effect voltage is determined from a function of the reference voltage and the coil current.

4. The Hall probe simulator according to claim 3, further comprising a temperature regulator coupled at least partially with the reference resistor and configured to regulate the temperature of the reference resistor.

5. The Hall probe simulator according to claim 1, further comprising a current sense resistor,

wherein the current sensor is configured to sense a current sense voltage across the current sense resistor, wherein the current sense voltage is proportional to the coil current, and

wherein the Hall Effect voltage is determined from a function of the current sense voltage and the reference current.

6. The Hall probe simulator according to claim 5, further comprising a temperature regulator coupled at least partially with the current sense resistor and configured to regulate the temperature of the current sense resistor.

7. The Hall probe simulator according to claim 1, further comprising:

a reference resistor, wherein the reference current input inputs a reference voltage across the reference resistor; and

a current sense resistor, wherein the current sensor is configured to sense a current sense voltage across the current sense resistor, wherein the current sense voltage is proportional to the coil current, and

wherein the Hall Effect voltage is determined from a function of the reference voltage and the coil current.

8. The Hall probe simulator according to claim 1, wherein the function of the coil current and the reference current comprises a product of the coil current and the reference current.

9. The Hall probe simulator according to claim 1, wherein the function of the coil current and the reference current further comprises a function of the coil current, the reference current, and a Hall Effect constant.

10. The Hall probe simulator according to claim 1, wherein the controller is further configured to regulate the coil current in response to the Hall Effect voltage.

11. A method for simulating a Hall Probe, the method comprising:

sensing a coil current in a coil magnet that produces a magnetic field;

sensing a reference current sent to a Hall Probe;

determining a Hall Effect voltage from a function of the coil current and the reference current; and

outputting the Hall Effect voltage.

12. The method for simulating a Hall Probe according to claim 11, further comprising, determining the magnitude of the magnetic field produced by the coil magnet from the Hall Effect voltage.

13. The method for simulating a Hall Probe according to claim 11, wherein sensing the coil current comprises sensing a current sense voltage across a current sense resistor in series with the coil magnet, and wherein the Hall Effect voltage is determined from a function of the current sense voltage and the reference current, wherein the current sense voltage is proportional to the coil current.

14. The method for simulating a Hall Probe according to claim 13, further comprising regulating the temperature of the current sense resistor.

15. The method for simulating a Hall Probe according to claim 11, wherein sensing the reference current comprises sensing a reference voltage across a reference resistor in place of the Hall Probe, and wherein the Hall Effect voltage is determined from a function of the reference voltage and the coil current.

16. The method for simulating a Hall Probe according to claim 15, further comprising regulating the temperature of the reference resistor.

17. The method for simulating a Hall Probe according to claim 11, wherein the function of the coil current and the reference current comprises a product of the coil current and the reference current.

18. The method for simulating a Hall Probe according to claim 11, wherein the function of the coil current and the reference current further comprises a function of the coil current, the reference current, and a Hall Effect constant.

19. The method for simulating a Hall Probe according to claim 11, further comprising regulating the coil current in response to the Hall Effect voltage.

20. A method for deconvoluting an EPR signal, the method comprising:

receiving an EPR signal from an EPR device;

determining a free induction decay signal from the EPR signal using a Tikhonov regularization; and

determining the EPR spectrum from the free induction decay signal.

21. The method for deconvoluting an EPR signal according to claim 20, wherein the EPR signal is a rapid scan EPR signal such that transition through resonance occurs in a time that is short relative to electron spin relaxation time.

22. The method for deconvoluting an EPR signal according to claim 20, wherein the free induction decay signal can be determined using (you cannot minimize regularization, if you do, it is like you do not use it) using ∥

{circumflex over (D)}fid−

rs*d∥

²+λ

∥

{circumflex over (R)}fid∥

², wherein D is a Toeplitz matrix, fid is the free induction decay signal, R is a regularization matrix, rs is the rapid scan signal, λ

is the regularization parameter, and d is the driving function.

23. The method for deconvoluting an EPR signal according to claim 20, wherein the free induction decay signal can be determined from fid=({circumflex over (D)}{circumflex over (D)}^T+{circumflex over (λ

)}{circumflex over (R)}{circumflex over (R)}^T(rs*d), wherein D is a Toeplitz matrix, fid is the free induction decay signal, R is a regularization matrix, rs is the rapid scan signal, λ

is the regularization parameter, and d is the driving function.