System and method for characterizing a sample by low-frequency spectra
First Claim
1. Apparatus for interrogating a sample that exhibits molecular rotation, comprising:
- a container adapted for receiving the sample, the container having both magnetic and electromagnetic shielding;
a source of noise for injection into the sample, with the sample in the container;
a detector for detecting an electromagnetic time-domain signal composed of sample source radiation superimposed on the injected Gaussian noise;
a storage device for storing the time-domain signal and a second time-domain signal separately detected from the same or a similar sample; and
an electronic computer which is adapted to receive the stored signal from the storage device, and to process the signal by;
(i) cross correlating the time-domain signal detected with the second time-domain signal, to produce a frequency-domain spectrum in a frequency range within DC to 50 KHz, and(ii) generating an output that includes information relating to spectral components in the spectrum that are characteristic of the sample.
2 Assignments
0 Petitions
Accused Products
Abstract
A method and apparatus for interrogating a sample that exhibits molecular rotation are disclosed. In practicing the method, the sample is placed in a container having both magnetic and electromagnetic shielding, and Gaussian noise is injected into the sample. An electromagnetic time-domain signal composed of sample source radiation superimposed on the injected Guassian noise is detected, and this signal is cross-correlated with a second time-domain signal produced by the same or similar sample, to produce a cross-correlated signal with frequency domain components. The latter is plotted in the frequency domain by a fast Fourier transform to produce a frequency domain spectrum in a frequency range within DC to 50 KHz. From this spectrum, one or more low-frequency signal components that are characteristic of the sample being interrogated are identified.
-
Citations
27 Claims
-
1. Apparatus for interrogating a sample that exhibits molecular rotation, comprising:
-
a container adapted for receiving the sample, the container having both magnetic and electromagnetic shielding; a source of noise for injection into the sample, with the sample in the container; a detector for detecting an electromagnetic time-domain signal composed of sample source radiation superimposed on the injected Gaussian noise; a storage device for storing the time-domain signal and a second time-domain signal separately detected from the same or a similar sample; and an electronic computer which is adapted to receive the stored signal from the storage device, and to process the signal by; (i) cross correlating the time-domain signal detected with the second time-domain signal, to produce a frequency-domain spectrum in a frequency range within DC to 50 KHz, and (ii) generating an output that includes information relating to spectral components in the spectrum that are characteristic of the sample. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13)
-
-
14. A method for interrogating a sample that exhibits molecular rotation, comprising:
-
placing the sample in a container having both magnetic and electromagnetic shielding; injecting noise into the sample; recording an electromagnetic time-domain signal composed of sample source radiation superimposed on the injected noise; comparing the time-domain signal recorded with a second time domain signal separately recorded from the same or similar sample, to produce a frequency domain spectrum in a frequency range within DC to 50 Khz; and identifying in the frequency-domain spectrum, one or more low-frequency signal components that are characteristic of the sample being interrogated. - View Dependent Claims (15, 16, 17, 18, 20, 21, 22, 23, 24, 25, 26)
-
-
19. The method of 18, wherein the container is an attenuation tube having a sample-holding region, a magnetic shielding cage surrounding the region, and a Faraday cage contained within the magnetic shielding cage and also surrounding the region, the noise is injected from a Gaussian noise generator and a Helmholz coil which is contained within the magnetic cage and the Faraday cage, and which receives a noise output signal from the noise generator, and which further includes, for use in removing stationary noise components in the time-dependent signal, a signal inverter operatively connected to the the noise source and to the SQUID, for receiving Gaussian noise from the noise source and outputting into the SQUID, Gaussian noise in inverted form with respect to the Gaussian noise injected into the sample.
-
27. A time-domain signal associated with a material of interest, produced by:
-
placing the sample of the material in a container having both magnetic and electromagnetic shielding, injecting Gaussian noise into the sample; and recording an electromagnetic time-domain signal composed of sample source radiation superimposed on the injected Gaussian noise, correlating the time-domain signal recorded with a second time domain signal separately recorded from the same or similar sample, to produce a correlated time-domain signal, and transforming the time-domain signal to a frequency domain spectrum in a frequency range within DC to 50 Khz, and identifying in the frequency-domain spectrum, one or more low-frequency signal components that are characteristic of the sample being interrogated.
-
Specification