Apparatus for measuring the activity of nuclear isotopes using a self-powered detector

Abstract

A measurement device for measuring the activity of a sample of radioisotopes is disclosed. The sample of radioisotopes is contained within a capsule. The measurement device includes an inner enclosure, a gamma radiation-sensitive self-powered detector (SPD) positioned around the inner enclosure, and an outer enclosure positioned around the SPD and the inner enclosure. The inner enclosure includes an internal cavity configured to receive the capsule containing the sample. The inner enclosure defines a longitudinal axis. The outer enclosure secures the SPD to the inner enclosure so that the SPD does not move during operation and storage of the measurement device.

Description

[Background technology]

[0001] REFERENCE TO RELATED APPLICATIONS This application claims the benefit of U.S. Provisional Patent Application No. 63 / 003,610, filed April 1, 2020, the contents of which are incorporated herein by reference in their entirety.

[0002] Accurate measurement of the amount of gamma radiation emitted from a volume of a radioisotope in a sample, such as Cobalt-60 (Co-60), is necessary to ensure that the total activity level of the radioisotope in the sample meets the desired total activity level. The total activity of a sample is the number of decays per unit time and the volume of the radioisotope. A radioisotope sample, or specimen, may be contained within a capsule, tube, and / or enclosure. Measuring the activity of a sample is necessary to ensure that the activity of the sample meets the approved activity limits of the cask used to ship the sample to its final destination, and to ensure that the activity of the sample meets the requirements of commercial suppliers. Radioisotopes such as Co-60 are used commercially in the medical industry, particularly for irradiation of cancerous tumors, sterilization of medical equipment, and sterilization of food. A rapid and accurate means of making activity measurements of a sample is needed to minimize the uncertainties and labor costs associated with the aforementioned operations. Summary of the Invention

[0003] In various embodiments, a measurement device for measuring activity of a sample of a radioisotope is disclosed. The sample of the radioisotope is contained within a capsule. The measurement device comprises an inner enclosure, a gamma radiation sensitive self-powered detector (SPD) positioned around the inner enclosure, and an outer enclosure positioned around the SPD and the inner enclosure. The inner enclosure comprises an internal cavity configured to receive the capsule containing the sample. The inner enclosure defines a longitudinal axis. The outer enclosure secures the SPD to the inner enclosure such that the SPD does not move during operation and storage of the measurement device.

[0004] In various embodiments, a method is disclosed for measuring the activity of a target sample containing a radioisotope. The method comprises positioning a plurality of test samples of the radioisotope, one at a time, in a measurement device comprising a gamma-sensitive self-powered detector (SPD), where the activity of each of the test samples is known. The method further comprises measuring the current in the SPD when each of the test samples is positioned in the measurement device, and positioning a target sample of the same radioisotope as the test samples in the measurement device, where the activity of the target sample is unknown. The method further comprises measuring the current in the SPD when the target sample is positioned in the measurement device, and comparing the measured current of the test samples to the measured current of the target sample to determine the activity of the target sample.

[0005] In various embodiments, a method for measuring the activity of a target sample containing a radioisotope is disclosed. The method comprises positioning the target sample of the radioisotope in a measurement device comprising a gamma-sensitive self-powered detector (SPD), the activity of the target sample is unknown, and the SPD comprises a known sensitivity level and a known length. The method further comprises measuring the current of the SPD when the target sample is positioned in the measurement device, and determining the activity of the target sample using the measured current of the SPD, the known sensitivity level of the SPD, and the known length of the SPD. [Brief description of the drawings]

[0006] The various features of the embodiments described herein, together with their advantages, may be understood by reference to the following description taken in conjunction with the accompanying drawings, in which:

[0007] [Figure 1] FIG. 1 is a plan view of a measurement apparatus for measuring the activity of a sample of a radioisotope in accordance with at least one embodiment of the present disclosure.

[0008] [Diagram 2] 2 is a cross-sectional view of the measurement device of FIG. 1 taken along line 2-2 of FIG.

[0009] [Diagram 3] FIG. 3 illustrates a logic diagram of a control system for use with a measurement device in accordance with at least one embodiment of the present disclosure. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0010] 1 and 2 show a measurement device 100 for measuring the activity of a sample of a radioisotope. The sample may be contained within a tube, enclosure, or capsule. In at least one embodiment, the radioisotope of the sample includes Co-60. However, other embodiments are envisioned with different samples having different radioisotopes, such as Molybdenum-99, Iodine-131, and other beta particle emitters useful for nuclear medicine applications. In any case, the measurement device 100 includes an inner enclosure or inner tube 110, a self-powered detector 120 (SPD) positioned around the inner tube 110, and an outer enclosure or outer tube 130 positioned around the SPD 120 and the inner tube 110. In at least one embodiment, the inner tube 110 and the outer tube 130 are attached to each other with the SPD 120 located midway between the inner tube 110 and the outer tube 130. The inner tube 110 may be attached to the outer tube 130 via welding, bolting, fasteners, and / or any other suitable attachment method. In any case, the inner tube 110 includes an opening or cavity 112 configured to receive a capsule containing a sample. The outer tube 130 is positioned around the SPD 120 and the inner tube such that the SPD 120 is held and / or secured to the inner tube 110 so that the SPD does not change position during operation and / or storage. The position of the SPD relative to the sample is important to accurately measure activity levels. If the SPD shifts relative to the outer tube 130, the sample will not be properly aligned with the SPD and the accuracy of the activity measurement may be affected.

[0011] Further to the above, the inner tube 110 includes an inner diameter and an outer diameter. The inner diameter of the inner tube 110 defines the cavity 112 of the inner tube 110. In at least one embodiment, the inner diameter of the inner tube 110 is, for example, between 0.24 inches and 0.45 inches. The outer tube 130 includes an inner diameter and an outer diameter. The inner diameter of the outer tube 130 is configured to receive the SPD and the inner tube 110. In at least one embodiment, the inner diameter of the outer tube 130 is determined based on, for example, the outer diameter of the inner tube and the outer diameter of the SPD 120. In the illustrated embodiment, the inner tube 110 and the outer tube 130 are of the same length EL. However, other embodiments are contemplated in which the inner tube 110 and the outer tube 130 are of different lengths. In at least one embodiment, the length EL of the inner tube 110 and the outer tube 130 is, for example, between 7 inches and 10 inches. In any event, the inner tube 110 and the outer tube 130 are concentric and define a longitudinal axis LA. A capsule containing a sample is inserted into the cavity 112 of the inner tube 110 along the longitudinal axis LA through an opening at one end of the measurement device 100. One end of the inner tube 110 and the outer tube 130 is open to allow the sample to be loaded into the cavity 112, and the other end 114 of the inner tube 110 and the outer tube 130 is closed to prevent the sample from falling out of the cavity 112. However, other embodiments contemplate a lid on the open end of the measurement device 100. Additionally, other embodiments contemplate such an arrangement with both ends of the measurement device 100 open, with the measurement device 100 including internal features within the cavity 112 to secure and / or hold the capsule containing the sample.

[0012] Further to the above, in the illustrated embodiment, the inner enclosure or inner tube 110 and the outer enclosure or outer tube 130 are tubular in shape. However, other embodiments are envisioned in which the inner and outer enclosures are rectangular or square in cross section, although any suitable enclosure can be used to receive the sample and position the SPD around the sample.

[0013] In the nuclear industry, SPDs are configured to measure the amount of activity of a radioisotope based on the current induced in the SPD by the radioisotope. The SPD is designed to generate a current when the SPD is exposed to radiation, such as gamma radiation. The current of an SPD exposed to radiation can be measured in several ways. Additionally, SPDs are typically provided in a wire configuration with an inner core and an outer sheath, and the manufacturer of the SPD, through testing, can calculate the sensitivity value of the SPD. The sensitivity value of the SPD is based on the amount of current generated in a given length of the SPD for a given amount and type of radiation exposure. As mentioned above, to ensure accurate activity level measurements, the position of the SPD relative to the sample should remain constant throughout the life of the measurement device 100.

[0014] Further to the above, although the SPD 120 includes a gamma radiation sensitive SPD, other embodiments are envisioned in which the SPD 120 is sensitive to different types of radiation other than gamma radiation. In any event, the SPD 120 illustrated in FIGS. 1 and 2 includes a wire including an inner core 122 and an outer sheath 124 surrounding the inner core 122. In at least one embodiment, the inner core 122 includes platinum and the outer sheath 124 includes a metallic material that is an electrical conductor including a material or materials having an atomic number lower than platinum. In at least one embodiment, the outer sheath 124 may include an iron-based material such as stainless steel, Inconel, and / or any other suitable material. In at least one embodiment, the SPD 120 includes a platinum emitter that is not depleted when measurements are made outside of a nuclear reactor, thereby ensuring that the operating characteristics of the SPD 120 do not change significantly over time. The measurement device 100 may be used to measure the activity of multiple radioisotopes by developing radioisotope specific calibration constants.

[0015] Further to the above, in the illustrated embodiment, the SPD 120 is wound around the outer diameter of the inner tube 110 in a helical configuration. More specifically, the SPD 120 is wound around the inner tube 110 around the longitudinal axis LA of the inner tube 110 such that the SPD 120 covers the outer diameter of the inner tube 110 along the length DL of the inner tube 110. In at least one embodiment, the length of the capsule and / or test sample is the same as the length DL. The capsule and / or test sample is positioned along the longitudinal axis LA such that the capsule and / or test sample is positioned within the length DL. In other words, the location of the capsule and / or test sample along the longitudinal axis overlaps with where the SPD 120 is wound around the inner tube 110. In any case, the SPD 120 is tightly wound around the outer surface of the inner tube 110 such that there are no and / or minimized gaps between adjacent portions of the SPD 120 along the length DL. If gaps exist between adjacent portions of SPD 120 along the length DL, radiation emitted from the sample may escape without irradiating SPD 120; therefore, preventing and / or reducing these gaps may increase the accuracy of activity measurements.

[0016] In addition to the above, when the SPD 120 is exposed to radiation, such as gamma radiation from a radioisotope, the gamma radiation penetrates the outer sheath 124 of the SPD 120, displacing electrons in the inner core 122, which in turn displaces electrons in the outer sheath 124 of the SPD 120, ultimately inducing a current in the SPD 120 that can be measured at the electrical output 140. The current induced in the SPD 120 corresponds to the total activity of the radioisotope. In at least one example, the current induced in the SPD 120 is directly proportional to the total activity of the radioisotope. Thus, a constant of proportionality between the current output of the SPD 120 and the activity of a sample of unknown activity (i.e., a target sample) can be determined via calibration to a current output measured by the device 100 of a sample containing known radioisotope activity (i.e., a test sample), as discussed in more detail below.

[0017] Once a current is induced in the SPD 120, the current can be measured at the electrical output 140 using a DC measurement device on either the inner core 122 and / or outer sheath 124 of the SPD 120. Additionally, the voltage difference between the inner core 122 and the outer sheath 124 can be measured and if the resistance is known, the current can be calculated using the law of resistance (i.e., V=IR). In either case, the current in the SPD 120 can be measured and / or calculated for a given target sample (i.e., the activity of the target sample is unknown) and compared to the predetermined current measurement of the SPD 120 for a radioisotope of known activity (i.e., a test sample). In other words, a test sample with known activity can be placed in the measurement device 100 and the current generated in the SPD 120 can be measured at the electrical output 140. Thus, current values ​​of the SPD 120 may be generated for several radioisotope test samples with various known activities and then compared to the current generated in the SPD 120 by the target sample to determine the activity of the target sample. In at least one embodiment, the radioisotope in the test sample and the radioisotope in the target sample are the same type of radioisotope, such as, for example, Co-60.

[0018] In addition to the above, another method of determining the activity of a target sample in the measurement device 100 includes using the sensitivity level of the SPD 120 of the measurement device 100. More specifically, the length of the SPD 120 is known or can be calculated, and the sensitivity of the SPD 120 is known (i.e., a sensitivity value from the manufacturer, as described above). The length of the SPD 120 is the total length of the wound wire, regardless of its configuration (i.e., not the height or length that the SPD 120 encompasses). Furthermore, as discussed above, the current generated by the SPD 120 can be measured when a target sample (e.g., a radioisotope of unknown activity) is introduced into the measurement device 100. Thus, the activity of the target sample can be determined by calculation using the measured current of the SPD, the known sensitivity level of the SPD, and the known length of the SPD. In such an arrangement, a test sample of known activity is not required to determine the activity of the target sample.

[0019] In addition to the above, the total activity of the specimen / sample can be measured by at least one of two methods. The first method uses a linear relationship between the measured SPD current (I) and the sample activity (A) of the following form: A=KI

[0020] K is determined from the measured slope of the linear relationship between the measured SPD current and a sample of the desired radioisotope having known total activity, such that the slope of the line is determined from at least two measured activity values, including zero activity, and corresponding measured currents having substantially zero background gamma radiation.

[0021] A second method for measuring the total activity of a sample inserted into the device over its entire length L uses the measured SPD gamma sensitivity (S), which is determined by exposing a typical SPD element to one or more known activities of gamma radiation and measuring the output current (I) to produce a relationship where the slope of the relationship (i.e., sensitivity (S)) has units of (measured current) / (Curie) / (unit length). With this information for a particular SPD design, the measured activity (A) is determined from the measured current using the relationship: A=IL / S

[0022] The above approach allows for the measurement of sample activity for all SPD elements of a given design without the need to calibrate each device individually.

[0023] FIG. 3 illustrates a logic diagram of a control system 200 for use with a measurement device such as those described herein, according to one or more aspects of the present disclosure. For example, the control system 200 may be used to calculate a total activity level of the measurement device utilizing the equations discussed herein. The control system 200 comprises a control circuit including a microcontroller 210 including a processor 220 and a memory 230. The control system 200 is in signal communication with a sensor 240. The sensor 240 provides real-time feedback to the processor 220. In at least one embodiment, the sensor 240 is a current sensor configured to measure a current in an SPD of the measurement device, such as, for example, the SPD 120 of the measurement device 100. In at least one embodiment, the sensor 240 is a voltage sensor configured to measure a voltage in an SPD of the measurement device, such as, for example, the SPD 120 of the measurement device 100. In at least one embodiment, the sensor 240 is a resistance sensor configured to measure a resistance of an SPD of the measurement device, such as, for example, the SPD 120 of the measurement device 100. Other embodiments are contemplated where sensor 240 measures any suitable characteristic of the SPD of the measurement device. Control system 200 includes a display 270 that displays various conditions or status of the measurement device and may include touch screen capabilities for data entry. For example, display 270 may display the total activity level of a sample of a radioisotope, after it has been calculated by control system 200.

[0024] In one embodiment, the microcontroller 210 may be any single core or multi-core processor, such as those known under the trade name ARM Cortex from Texas Instruments. In one embodiment, the main microcontroller 210 may be an LM4F230H5QR ARM Cortex-M4F processor core available from Texas Instruments, including on-chip memory, for example 256KB of single cycle flash memory or other non-volatile memory up to 40MHz, a pre-fetch buffer to improve performance above 40MHz, 32KB single cycle SRAM and built-in ROM loaded with StellarisWare® software, 2KB of EEPROM, one or more PWM modules, one or more QEI analogs, and / or one or more 12-bit ADCs with 12 analog input channels, as further details may be found in the product data sheet.

[0025] In one embodiment, the microcontroller 210 may include a safety controller, including two controller-based families such as TMS570 and RM4x, known by Texas Instruments under the trade name Hercules ARM Cortex R4. The safety controller may provide advanced integrated safety features while providing scalable performance, connectivity, and memory options, specifically configured for IEC 61508 and ISO 26262 safety critical applications. The microcontroller 210 may be programmed to perform a variety of functions. For example, the microcontroller 210 may be configured to calculate a total activity level of a radioactive sample in a measurement device, such as the measurement devices described herein, store the calculated activity level in memory 230, and then display the calculated activity level on the display 270.

[0026] The microcontroller 210 can be configured to calculate the response in software of the microcontroller 210. The calculated response is compared to measurements of the actual system to obtain an "observed" response that is used in the actual feedback decision. The observed response is a preferred adjusted value that balances the smooth, continuous nature of the simulated response with a measured response that can detect external influences on the system.

[0027] In one aspect, the power supply assembly provides power to the control system 200. The power supply assembly may include a battery, which may include multiple battery cells connected in series that can be used as a power source to power the control system 200. In certain circumstances, the battery cells of the power supply assembly may be replaceable and / or rechargeable. In at least one embodiment, the battery cells may be lithium ion batteries that are coupleable and detachable from the power supply assembly. However, other embodiments are contemplated in which the control system 200 is powered by current generated by an SPD of a measurement device, such as, for example, SPD 120 of measurement device 100.

[0028] In addition to the above, the control system 200 may be provided on any of the measurement devices described herein, however, other embodiments are envisioned in which the control system 200 is separate from the measurement device and in signal communication with the measurement device via a wired or wireless connection. EXAMPLES

[0029] Various aspects of the subject matter described herein are illustrated in the following examples.

[0030] Example 1 - A measurement device for measuring the activity of a sample of a radioisotope, the sample of the radioisotope being contained within a capsule. The measurement device comprises an inner enclosure, a gamma radiation sensitive self-powered detector (SPD) positioned around the inner enclosure, and an outer enclosure positioned around the SPD and the inner enclosure. The inner enclosure comprises an internal cavity configured to receive the capsule containing the sample. The inner enclosure defines a longitudinal axis. The outer enclosure secures the SPD to the inner enclosure such that the SPD does not move during operation and storage of the measurement device.

[0031] Example 2 - The measurement device of Example 1, wherein the radioisotope is Co-60.

[0032] Example 3 - The measurement device of example 1 or 2, wherein at least a portion of the SPD comprises platinum.

[0033] Example 4 - The measurement apparatus of any of Examples 1-3, wherein the inner enclosure defines a first length along the longitudinal axis and the sample defines a second length along the longitudinal axis, the first length and the second length being the same.

[0034] Example 5 - The measurement apparatus of Example 4, wherein the sample is positioned relative to the inner enclosure such that the first length and the second length overlap along the longitudinal axis.

[0035] Example 6 - The measurement device of example 4 or 5, wherein the inner enclosure includes an outer surface, and the SPD is positioned around the outer surface of the inner enclosure such that the entire outer surface is covered by the SPD.

[0036] Example 7 - The measurement device of any of Examples 1-6, wherein the inner enclosure includes an outer surface and the SPD is wrapped in a spiral configuration around the outer surface of the inner enclosure.

[0037] Example 8 - The measurement device of Example 7, where the spiral configuration of the SPD is configured to cover the entire outer surface of the inner enclosure.

[0038] Example 9 - The measurement device of any of Examples 1-8, wherein the inner enclosure includes an outer surface and the SPD is wrapped in a spiral configuration around the outer surface of the inner enclosure.

[0039] Example 10 - The measurement device of Example 9, wherein the helical configuration of the SPD is configured to cover the entire outer surface of the inner enclosure.

[0040] Example 11 - The measurement apparatus of any of Examples 1-10, wherein the sample includes a sample length defined along a longitudinal axis, the inner enclosure includes an outer surface, and the SPD is wrapped around the inner enclosure such that it covers the entire outer surface along the sample length.

[0041] Example 12 - A method for measuring activity of a target sample containing a radioisotope. The method comprises positioning a plurality of test samples of the radioisotope, one at a time, in a measurement device comprising a gamma-sensitive self-powered detector (SPD), where the activity of each of the test samples is known. The method further comprises measuring the current in the SPD when each of the test samples is positioned in the measurement device, and positioning a target sample of the same radioisotope as the test samples in the measurement device, where the activity of the target sample is unknown. The method further comprises measuring the current in the SPD when the target sample is positioned in the measurement device, and comparing the measured current of the test sample to the measured current of the target sample to determine the activity of the target sample.

[0042] Example 13 - The method of Example 12, further comprising using a linear calibration between the measured current of the test sample and the measured current of the target sample.

[0043] Example 14 - The method of Example 12 or 13, wherein the radioisotope is Co-60.

[0044] Example 15 - The method of any of Examples 12-14, wherein at least a portion of the SPD comprises platinum.

[0045] Example 16 - The method of any of Examples 12-15, wherein the SPD is positioned helically within the measurement device.

[0046] Example 17 - A method of measuring activity of a target sample containing a radioisotope. The method comprises positioning a target sample of the radioisotope in a measurement device comprising a gamma-sensitive self-powered detector (SPD), the activity of the target sample being unknown, the SPD comprising a known sensitivity level and a known length. The method further comprises measuring a current of the SPD when the target sample is positioned in the measurement device, and determining the activity of the target sample using the measured current of the SPD, the known sensitivity level of the SPD, and the known length of the SPD.

[0047] Example 18 - The method of Example 17, wherein the radioisotope is Co-60.

[0048] Example 19 - The method of example 17 or 18, wherein at least a portion of the SPD comprises platinum.

[0049] Example 20 - The method of any of Examples 17-19, wherein the SPD is disposed within the measurement device in a spiral configuration.

[0050] As used in any embodiment herein, the term "control circuitry" may refer to, for example, hardwired circuitry, programmable circuitry (e.g., a computer processor, including one or more individual instruction processing cores, processing units, processors, microcontrollers, microcontroller units, controllers, digital signal processors (DSPs), programmable logic devices (PLDs), programmable logic arrays (PLAs), or field programmable gate arrays (FPGAs)), state machine circuitry, firmware that stores instructions executed by the programmable circuitry, and any combination thereof. The control circuitry may be embodied, collectively or individually, as circuitry that forms part of a larger system, e.g., an integrated circuit (IC), an application specific integrated circuit (ASIC), a system on a chip (SoC), a desktop computer, a laptop computer, a tablet computer, a server, a smartphone, etc. Thus, "control circuitry" as used herein includes, but is not limited to, electrical circuitry having at least one discrete electrical circuit, electrical circuitry having at least one integrated circuit, electrical circuitry having at least one application specific integrated circuit, electrical circuitry forming a general purpose computing device configured by a computer program (e.g., a general purpose computer configured by a computer program to at least partially execute a process and / or a device described herein, or a microprocessor configured by a computer program to at least partially execute a process and / or a device described herein), electrical circuitry forming a memory device (e.g., in the form of random access memory), and / or electrical circuitry forming a communication device (e.g., a modem, a communication switch, an optoelectronic device).Those skilled in the art will recognize that the subject matter described herein may be implemented in an analog or digital fashion or some combination thereof.

[0051] As used in any aspect herein, the term "logic" may refer to an application, software, firmware, and / or circuitry configured to perform any of the aforementioned operations. Software may be embodied as a software package, code, instructions, instruction sets, and / or data recorded on a non-transitory computer-readable storage medium. Firmware may be embodied as hard-coded (e.g., non-volatile) code, instructions, or instruction sets, and / or data within a memory device.

[0052] As used in any aspect of this specification, the terms "component," "system," "module," etc. may refer to a computer-related entity, i.e., either hardware, a combination of hardware and software, software, or software in execution.

[0053] As used in any aspect of the present specification, an "algorithm" refers to a self-consistent sequence of steps leading to a desired result, where the "steps" refer to the manipulation of physical quantities and / or logical states, although not necessarily in the form of electrical or magnetic signals that can be stored, moved, combined, compared, and otherwise manipulated. These signals are commonly referred to as bits, values, elements, symbols, characters, terms, numbers, or the like. These and similar terms may be associated with the appropriate physical quantities and are merely convenient labels applied to these quantities and / or states.

[0054] Although particular embodiments of the invention have been described in detail, it will be appreciated by those skilled in the art that various modifications and alternatives to those details may be developed in light of the overall teachings of the present disclosure, and that selected elements of one or more of the exemplary embodiments may be combined with one or more elements from other embodiments without departing from the scope of the disclosed concepts. Accordingly, the particular embodiments disclosed are intended to be illustrative only and not limiting with respect to the scope of the invention, which is to be given the full scope of the appended claims and any and all equivalents thereof.

[0055] Those skilled in the art will recognize that the terms used in the specification, generally, and in the appended claims, particularly (e.g., the body of the appended claims), are generally intended as "open" terms (e.g., the term "including" should be interpreted as "including, but not limited to," the term "having" should be interpreted as "having at least," the term "include" should be interpreted as "including, but not limited to," etc.). It will be further understood by those skilled in the art that if a specific number of claim recitations to be introduced are intended, such intent will be expressly recited in the claims, and that in the absence of such recitation, no such intent exists. For example, as an aid to understanding, the following appended claims may contain the use of the introductory phrases "at least one" and "one or more" to introduce the claim recitations. However, the use of such phrases should not be construed as implying that the introduction of a claim recitation with the indefinite article "a" or "an" limits any particular claim containing such an introduced claim recitation to those claims that include only one such recitation, even when that same claim includes the introductory phrases "one or more" or "at least one" and an indefinite article such as "a" or "an" (e.g., "a" and / or "an" should typically be construed to mean "at least one" or "one or more"), nor should the use of definite articles used to introduce claim recitations.

[0056] Moreover, even when a particular number of introduced claim recitations is explicitly recited, one of ordinary skill in the art will recognize that such recitation should typically be interpreted to mean at least the recited number (e.g., an explicit recitation of "two recitations" without other modifiers typically means at least two recitations, or more than two recitations. Furthermore, in such cases where a convention similar to "at least one of A, B, and C, etc." is used, such structure is generally intended in the sense that one of ordinary skill in the art would understand the convention (e.g., "a system having at least one of A, B, and C" would include, but is not limited to, systems having A alone, B alone, C alone, A and B together, A and C together, B and C together, and / or A, B, and C together). Conventions similar to "at least one of A, B, or C, etc." In such cases where is used, generally, such structure is intended in the sense that one of ordinary skill in the art would understand the convention (e.g., "a system having at least one of A, B, or C" would include, but is not limited to, systems having A alone, B alone, C alone, A and B together, A and C together, B and C together, and / or A, B, and C together, etc.). It will be further understood by those of ordinary skill in the art that typically disjunctive words and / or phrases presenting two or more alternative terms, whether in the description, claims, or drawings, should be understood to contemplate the possibility of including one of the terms, either of the terms, or both terms, unless the context dictates otherwise. For example, the phrase "A or B" would typically be understood to include the possibilities of "A" or "B" or "A and B."

[0057] With respect to the appended claims, those skilled in the art will understand that the operations recited therein may generally be performed in any order. Also, while various operational flow diagrams are presented in sequences, it should be understood that various operations may be performed in other orders than those illustrated, or may be performed simultaneously. Examples of such alternative orderings may include overlapping, interleaving, interrupting, reordering, incremental, preparatory, supplementary, simultaneous, reverse, or other various orderings, unless the context dictates otherwise. Moreover, unless the context dictates otherwise, terms such as "responsive to," "related to," or other past tense adjectives are generally not intended to exclude such variations.

[0058] It should be noted that any reference to "one embodiment," "one aspect," "one example," "one example," etc. means that a particular feature, structure, or characteristic described in connection with an embodiment is included in at least one embodiment. Thus, the appearances of the phrases "in one embodiment," "in one embodiment," "in one example," and "in one example" in various places throughout this specification are not necessarily all referring to the same embodiment. Furthermore, particular features, structures, or characteristics may be combined in any suitable manner in one or more embodiments.

[0059] Any patent application, patent, non-patent publication, or other disclosure material referenced herein and / or listed in any application data sheet is incorporated herein by reference to the extent that such material is not inconsistent with this specification. Thus, and to the extent necessary, the present disclosure as expressly set forth herein supersedes any conflicting material incorporated herein by reference. Any material, or portion thereof, that is referred to as being incorporated herein by reference but that conflicts with existing definitions, descriptions, or other disclosure material set forth herein, is incorporated only to the extent that there is no conflict between the incorporated material and the existing disclosure material.

[0060] The terms "comprise" (and any form of comprise, such as "comprises" and "comprising"), "have" (and any form of have, such as "has" and "having"), "include" (and any form of include, such as "includes" and "including"), and "contain" (and any form of contain, such as "contains" and "containing") are open-ended linking verbs. As a result, a system that "comprises," "has," "contains," or "contains" one or more elements possesses those one or more elements, but is not limited to possessing only those one or more elements. Similarly, an element of a system, device, or apparatus that "comprises," "has," "contains," or "contains" one or more features possesses those one or more features, but is not limited to possessing only those one or more features.

[0061] In summary, numerous benefits resulting from employing the concepts described herein are described. The above description of one or more embodiments is presented for purposes of illustration and description. It is not intended to be exhaustive or limited to the precise form disclosed. Modifications or variations are possible in light of the above teachings. The one or more embodiments have been selected and described in order to illustrate the principles and practical applications, thereby enabling those skilled in the art to utilize the various embodiments and with various modifications suitable for the particular use contemplated. The claims submitted herein are intended to define the overall scope.

Claims

1. 1. A measuring device for measuring the activity of a sample of a radioisotope, said sample of said radioisotope being contained within a capsule; The measuring device comprises: an inner enclosure including an interior cavity configured to receive the capsule containing the sample, the inner enclosure defining a longitudinal axis; gamma radiation sensitive self-powered detectors (SPDs) positioned about the inner enclosure; an outer enclosure positioned around the SPD and the inner enclosure, the outer enclosure securing the SPD to the inner enclosure so that the SPD does not move during operation and storage of the measurement device.

2. The measuring device according to claim 1 , wherein the radioisotope is Co-60.

3. The measurement device of claim 1 or 2, wherein at least a portion of the SPD comprises platinum.

4. the inner enclosure defines a first length along the longitudinal axis; the sample defines a second length along the longitudinal axis; The measuring device according to any one of claims 1 to 3, wherein the first length and the second length are the same.

5. The measurement device of claim 4 , wherein the sample is positioned relative to the inner enclosure such that the first length and the second length overlap along the longitudinal axis.

6. the inner enclosure includes an outer surface; 6. The measurement device of claim 4 or 5, wherein the SPDs are positioned around the outer surface of the inner enclosure such that the entire outer surface is covered by the SPDs.

7. the inner enclosure includes an outer surface; The measurement device of any one of claims 1 to 6, wherein the SPD is wrapped in a spiral configuration around the outer surface of the inner enclosure.

8. The measurement device of claim 7 , wherein the spiral configuration of the SPD is configured to cover the entire outer surface of the inner enclosure.

9. the inner enclosure includes an outer surface; The measurement device of any one of claims 1 to 8, wherein the SPD is wound in a spiral configuration around the outer surface of the inner enclosure.

10. The measurement device of claim 9 , wherein the helical configuration of the SPD is configured to cover the entire outer surface of the inner enclosure.

11. the sample includes a sample length defined along the longitudinal axis; the inner enclosure includes an outer surface; A measurement apparatus according to any one of claims 1 to 10, wherein the SPD is wrapped around the inner enclosure such that the SPD covers the entire outer surface along the sample length.

12. 1. A method for measuring the activity of a target sample containing a radioisotope, comprising: placing a plurality of test samples of a radioisotope, one at a time, into a measurement device comprising a gamma sensitive self-powered detector (SPD), the activity of each of the test samples being known; measuring the current in the SPD when each of the test samples is positioned in the measurement device; positioning a target sample of the same radioisotope as the test sample in the measurement device, the activity of the target sample being unknown; measuring a current in the SPD when the target sample is located in the measurement device; comparing the measured current of the test sample with the measured current of the target sample to determine an activity of the target sample.

13. The method of claim 12 , further comprising using a linear calibration between the measured current of the test sample and the measured current of the target sample.

14. The method of claim 12 or 13, wherein the radioisotope is Co-60.

15. The method of any one of claims 12 to 14, wherein at least a portion of the SPD comprises platinum.

16. The method according to any one of claims 12 to 15, wherein the SPD is positioned helically within the measurement device.

17. 1. A method for measuring the activity of a target sample containing a radioisotope, comprising: positioning a target sample of a radioisotope in a measurement device comprising a gamma sensitive self-powered detector (SPD), the activity of the target sample being unknown, the SPD comprising a known sensitivity level and a known length; measuring the current of the SPD when the target sample is located within the measurement device; determining an activity of the target sample using the measured current of the SPD, the known sensitivity level of the SPD, and the known length of the SPD.

18. 18. The method of claim 17, wherein the radioisotope is Co-60.

19. 19. The method of claim 17 or 18, wherein at least a portion of the SPD comprises platinum.

20. The method of any one of claims 17 to 19, wherein the SPDs are positioned within the measurement device in a helical configuration.

Images