Gamma-ray spectrometer calibration systems and methods
A gamma-ray spectrometer calibration system comprises a photomultiplier tube and analysis electronics. The photomultiplier tube provides one or more reference signals that are analyzed relative to a spectrum by the analysis electronics to calibrate a gamma-ray spectrometer. Additional apparatus, methods, and systems are disclosed.
1. A system, comprising:
a gamma-ray spectrometer;
a laser proximate to the gamma-ray spectrometer to generate light pulses to induce one or more reference signals;
a temperature sensor proximate to the laser; and
analysis electronics electrically coupled to the gamma-ray spectrometer, the analysis electronics configured to:
analyze the one or more reference signals relative to a spectrum;
calibrate the gamma-ray spectrometer based on analysis of the one or more reference signals; and
adjust power to the laser responsive to a signal provided by the temperature sensor.
2. The system of claim 1 , wherein the analysis electronics are configured to calibrate the gamma-ray spectrometer to compensate for changes in gain.
3. The system of claim 2 , wherein the analysis electronics are configured further to calibrate the gamma-ray spectrometer to compensate for channel offset.
4. The system of claim 1 , wherein the laser comprises a semiconductor laser.
5. The system of claim 1 , wherein the gamma-ray spectrometer comprises:
a scintillation crystal; and
a photomultiplier tube optically coupled to the scintillation crystal, wherein the photomultiplier tube is configured to detect photons from the scintillation crystal.
6. The system of claim 5 , further comprising a light guide coupled to the scintillation crystal, wherein the light guide is configured to direct photons to the photomultiplier tube.
7. The system of claim 5 , wherein the analysis electronics comprise:
a stabilization multichannel analyzer configured to generate the spectrum based on a signal produced by the photomultiplier; and
a stabilization processor configured to analyze the one or more reference signals relative to the spectrum generated by the stabilization multichannel analyzer.
8. The system of claim 7 , wherein the analysis electronics further comprise a preamplifier configured to process the signal produced by the photomultiplier for processing by the stabilization multichannel analyzer.
9. The system of claim 8 , wherein the analysis electronics further comprise a gain amplifier configured to amplify output pulses from the preamplifier.
10. The system of claim 1 , wherein:
the laser is embedded in a light guide; and
the light guide is configured to direct photons from the laser to the photomultiplier tube.
11. The system of claim 1 , wherein the analysis electronics further comprise a current driver configured to control the generation of light pulses from the laser.
12. A method, comprising:
generating light pulses with a laser to induce one or more reference signals in a spectrum;
calibrating a gamma-ray spectrometer based on an analysis of the one or more reference signals relative to a spectrum; and
adjusting power to the laser responsive to a signal provided by a temperature sensor proximate the laser.
13. The method of claim 12 , further comprising:
determining a gain change based on the one or more reference signals, wherein calibrating the gamma-ray spectrometer comprises adjusting parameters of the gamma-ray spectrometer based on the gain change.
14. The method of claim 13 , further comprising:
determining a channel offset based on at least two reference peaks resulting from the one or more reference signals, wherein calibrating the gamma-ray spectrometer further comprises adjusting parameters of the gamma-ray spectrometer based on the channel offset.