Apparatus comprising a semiconductor-based photomultiplier and method regarding gain stabilization

1. An apparatus comprising a semiconductor-based photomultiplier, the apparatus being configured to:

inject a first input pulse into the semiconductor-based photomultiplier, wherein injecting the first input pulse increases a magnitude of the first input pulse by one or more steps until the first input pules is pushed above a breakdown threshold at a current operating temperature;

determine a revised bias voltage for the semiconductor-based photomultiplier based at least in part on a first output pulse corresponding to the first input pulse and a second output pulse from the semiconductor-based photomultiplier that is obtained at another time as compared to the first output pulse; and

adjust a bias voltage for the semiconductor-based photomultiplier to the revised bias voltage.

2. The apparatus of claim 1 , further being configured to determine a temperature change based at least on a comparison of the revised bias voltage to a prior bias voltage used during the first input pulse.

3. The apparatus of claim 1 , wherein the one or more steps have an increase in voltage between 2 mV to 500 mV.

4. The apparatus of claim 1 , further being configured to generate an output pulse in the form of an electronic pulse that is transmitted by the semiconductor-based photomultiplier.

5. The apparatus of claim 1 , further being configured to generate derivative information based at least in part on the output pulse from the semiconductor-based multiplier.

6. The apparatus of claim 1 , wherein injecting the first input pulse into the semiconductor-based photomultiplier is performed in response to a predetermined schedule.

7. The apparatus of claim 1 , wherein injecting the first input pulse into the semiconductor-based photomultiplier is performed in response to a predetermined event.

8. The apparatus of claim 7 , wherein the predetermined event is selected from the group consisting of a reboot, a start-up, a shutdown, a power outage, and any combination therein.

9. A method, comprising:

providing an apparatus comprising a semiconductor-based photomultiplier;

setting a first bias voltage to a desired gain;

supplying the first bias voltage to the semiconductor-based photomultiplier;

injecting a first input pulse into the semiconductor-based photomultiplier based on the first bias voltage;

determining a revised bias voltage for the semiconductor-based photomultiplier based at least in part on a first output pulse corresponding to the first input pulse and a second output pulse from the semiconductor-based photomultiplier that is obtained at another time as compared to the first output pulse; and

adjusting a second bias voltage for the semiconductor-based photomultiplier to the revised bias voltage.

10. The method of claim 9 , wherein the biased voltage is between 20 VDC and 30 VDC.

11. The method of claim 9 , further comprising determining a temperature change based at least on a comparison of the revised bias voltage to the first bias voltage used during the first input pulse.

12. The method of claim 11 , wherein temperature information from a temperature sensor can be used at least in part for setting the first bias voltage.

13. The method of claim 12 , wherein the temperature sensor is located within 9 cm of the semiconductor-based photomultiplier.

14. The method of claim 9 , wherein the first input pulse corresponds to a first temperature and a second input pulse corresponds to a second temperature, wherein the second temperature is between 20° C. and 25° C., and wherein the first temperature is at least 1.1° C. different from the second temperature.

15. The method of claim 9 , wherein the semiconductor-based photomultiplier is between 1° C. and 11° C. away from the temperature of the initial temperature of the first bias voltage.

16. The method of claim 9 , further comprising adjusting the revised bias voltage based at least in part on temperature information from a temperature sensor.

17. The method of claim 9 , further comprising injecting a second input pulse into the semiconductor-based photomultiplier after injecting the first input pulse, wherein injecting the second input pulse is performed on a predetermined schedule or in response to an occurrence of a predetermined event.

18. A method comprising:

injecting a first input pulse into a semiconductor-based photomultiplier within an apparatus;

determining a revised bias voltage for the semiconductor-based photomultiplier based at least in part on a first output pulse corresponding to the first input pulse and a second output pulse from the semiconductor-based photomultiplier that is obtained at another time as compared to the first output pulse, wherein determining the revised bias voltage comprises determining the revised bias voltage that is within 9% of V B1 , wherein:

V B1 =V B2 +N *( S 2 −S 1 )

V B1 is a bias voltage corresponding to the first output pulse,

V B2 is a bias voltage corresponding to the second output pulse,

N is a conversion factor,

S 1 is the first integrated signal; and

S 2 is the second integrated signal; and

adjusting a bias voltage for the semiconductor-based photomultiplier to the revised bias voltage.

19. The method of claim 18 , wherein adjusting the bias voltage for the semiconductor-based photomultiplier is adjusted after a threshold value is reached.

20. The method of claim 18 , wherein the threshold value is greater than 0.1% of VB 1 .