Radiation measurement using multiple parameters

• US 20080315110A1
• Filed: 06/19/2007
• Published: 12/25/2008
• Est. Priority Date: 06/19/2007
• Status: Active Grant

• Current Assignee: Thermo Fisher Scientific Incorporated
• Original Assignee: Thermo Fisher Scientific Incorporated
• Inventors: Trost, Norbert, Iwatschenko-Borho, Michael, Pijahn, Ralf
• Granted Patent: US 7,737,401 B2
• Time in Patent Office: Days
• US Class Current: 250/394
• CPC Class Codes: G01T 1/023 Scintillation dose-rate meters

Abstract

An improved radiation detection device measures a broad range of dose rate levels. According to one arrangement, the radiation detection device calculates a radiation value based on, gamma count information representing counts for different energy levels of radiation in a radiation field as well as a radiation intensity indicator value (e.g., photomultiplier tube anode DC current, measured directly by conventional Analog to Digital Converters or indirectly by power or current consumption information indicating how much energy is required to maintain a photomultiplier tube at a constant voltage) that is at least proportional to an amount of overall radiation energy detected in the radiation sample. Based on a combination of the gamma count information and the radiation intensity indicator value, a controller associated with a corresponding radiation detection device can calculate a radiation dose rate associated with the received radiation sample.

Claims

1. A method comprising:

receiving radiation count information representing counts for different energy levels of radiation in a monitored radiation field;

receiving a radiation intensity indicator value that is proportional to an amount of overall radiation energy detected in the monitored radiation field; and

based on a combination of the radiation count information and the radiation intensity indicator value, calculating a radiation dose rate associated with the monitored radiation field.

2. A method as in claim 1, wherein calculating the radiation dose rate associated with the monitored radiation field includes calculating the radiation dose rate based at least in part on the radiation intensity indicator value as well as amounts of respective gamma count values for amounts of radiation detected at each of the multiple different energy levels in the monitored radiation field.

3. A method as in claim 1, wherein calculating the radiation dose rate associated with the monitored radiation field includes calculating the radiation dose rate based at least in part on weighted amounts of respective gamma count values at the different energy levels.

4. A method as in claim 1, wherein calculating the radiation dose rate associated with the monitored radiation field includes calculating the radiation dose rate based at least in part on a distribution of detected radiation energies in the monitored radiation field at the different energy levels.

5. A method as in claim 1 further comprising:

converting the monitored radiation field into light pulses; and

counting the light pulses at different energy levels to produce the radiation count information.

6. A method as in claim 5 further comprising:

generating the radiation intensity indicator value as a value representing an overall amount of light energy produced as a result of converting the monitored radiation field into the light pulses.

7. A method as in claim 5, wherein receiving the radiation intensity indicator value includes receiving a power consumption value representing an amount of power consumed by a photomultiplier tube that is used to convert the light pulses into electrical pulses that are counted at the different energy levels to produce the radiation count information.

8. A method as in claim 1 further comprising:

converting the monitored radiation field into light pulses; and

generating the radiation intensity indicator value as a count value representing a number of oscillations associated with a switching power supply signal that varies depending on an amount of power required by a photo detector device to convert the light pulses into countable electronic signals at the different energy levels.

9. A system comprising:

a processor;

a memory unit that stores software code executed by the processor; and

an interconnect coupling the processor and the memory unit, enabling the system to execute the software code and perform operations of;

receiving radiation count information representing counts for different energy levels of radiation in a monitored radiation field;

receiving a radiation intensity indicator value that is proportional to an amount of overall radiation energy detected in the monitored radiation field; and

based on a combination of the radiation count information and the radiation intensity indicator value, calculating a radiation dose rate associated with the monitored radiation field.

10. A system as in claim 9, wherein calculating the radiation dose rate associated with the monitored radiation field includes calculating the radiation dose rate based at least in part on the radiation intensity indicator value as well as amounts of respective gamma count values for amounts of radiation detected at each of the multiple different energy levels in the monitored radiation field.

11. A system as in claim 9, wherein calculating the radiation dose rate associated with the received radiation includes calculating the radiation dose rate based at least in part on weighted amounts of respective gamma radiation count values at the different energy levels.

12. A system as in claim 9, wherein calculating the radiation dose rate associated with the monitored radiation field includes calculating the radiation dose rate based at least in part on a distribution of detected radiation energies in the monitored radiation field at the different energy levels.

13. A system as in claim 9 further comprising:

a scintillator configured to convert the monitored radiation field into light pulses; and

a plurality of counters configured to count the light pulses at different energy levels to produce the gamma count information.

14. A system as in claim 13 further comprising:

a resource configured to generate the radiation intensity indicator value to be proportional to an overall amount of light energy of the light pulses produced by the scintillator.

15. A system as in claim 13, wherein the radiation intensity indicator value is a power consumption value representing an amount of power consumed by a photomultiplier tube that is used to convert the light pulses into electrical pulses that are counted at the different energy levels to produce the radiation count information.

16. A system as in claim 9 further comprising:

a scintillator to convert the radiation field received into light pulses;

a photo detector device configured to convert the light pulses into countable electrical signals; and

a counter configured to generate the radiation intensity indicator value as a count value representing a number of oscillations associated with a switching power supply signal that varies depending on an amount of power required by the photo detector device to convert the light pulses into the countable electronic signals at the different energy levels.

17. A method comprising:

receiving radiation count information derived from monitoring a radiation field;

receiving power consumption information of a radiation detection device used to measure the radiation field, the power consumption information varying depending on an amount of energy present in the radiation field; and

based on a combination of the radiation count information and the power consumption information, calculating a radiation dose rate associated with the radiation field.

18. A method as in claim 17, wherein receiving the radiation count information includes receiving a respective radiation count value for each of multiple different energy levels of radiation present in the radiation received from the source.

19. A method as in claim 18, wherein calculating the radiation dose rate associated with the radiation received from the source includes calculating the radiation dose rate based at least in part on the power consumption information as well as amounts of respective gamma radiation count values for the multiple different energy levels.

20. A method as in claim 18, wherein calculating the radiation dose rate associated with the received radiation includes calculating the radiation dose rate based at least in part on weighted amounts of respective gamma radiation count values at the multiple different energy levels.

21. A method as in claim 17, wherein calculating the radiation dose rate includes calculating the radiation dose rate based at least in part on a distribution of detected radiation at different energy levels in the radiation field.

22. A computer-readable medium having instructions stored thereon for processing data information, such that the instructions, when carried out by a processing device, enable the processing device to perform the operations of:

receiving radiation count information representing counts for different energy levels of radiation in a monitored radiation field;

receiving a radiation intensity indicator value that is proportional to an amount of overall radiation energy detected in the monitored radiation field; and

based on a combination of the radiation count information and the radiation intensity indicator value, calculating a radiation dose rate associated with the monitored radiation field.

23. A computer-readable medium as in claim 22, wherein calculating the radiation dose rate associated with the monitored radiation field includes calculating the radiation dose rate based at least in part on the radiation intensity indicator value as well as amounts of respective radiation count values for amounts of radiation detected at each of the multiple different energy levels.

24. A computer-readable medium as in claim 22, wherein calculating the radiation dose rate includes calculating the radiation dose rate based at least in part on a distribution of radiation detected at the different energy levels.

25. A radiation detection device including:

means for receiving radiation count information representing counts for different energy levels of radiation in a monitored radiation field;

means for receiving a radiation intensity indicator value that is proportional to an amount of overall radiation energy detected in the monitored radiation field; and

means for calculating a radiation dose rate associated with the monitored radiation field based on a combination of the radiation count information and the radiation intensity indicator value.