Neutron detector system

Claim 2

A neutron detector system including a first neutron detector of a given type and a second neutron detector of a different type; means for receiving signals from said first and second neutron detectors including means for comparing the magnitudes of said signals and including a variable gain device for receiving the signal from said first neutron detector; and means for adjusting the gain of said device in proportion to the relative magnitudes of said signals from said first and second detectors.

Claim 3

adjusting the level of the signal from said ion chamber in proportion to the relative magnitudes of said signals from said detectors.

Claim 4

adjusting the level of the signal from said ion chamber in proportion to the relative magnitudes of said signals from said detectors.

Claim 5

A neutron detector system including an ion chamber detector and a self-powered detector; means for receiving signals from said detectors including means for comparing the magnitudes of said signals and including a variable gain amplifier for receiving the signal from said ion chamber; and means for adjusting the gain of said amplifier in proportion to the relative magnitudes of said signals from said detectors.

Claim 6

A neutron detector system including an ion chamber detector and a self-powered detector; means for receiving signals from said detectors including means for comparing the magnitudes of said signals and including a variable gain amplifier for receiving the signal from said ion chamber; and means for adjusting the gain of said amplifier in proportion to the relative magnitudes of said signals from said detectors.

Claim 7

measuring subsequent signals from said fission chamber and said self-powered detector at a time t and providing a second indication R(t) which is proportional to the ratio of said subsequent signal from said fission chamber to said subsequent signal from said self-powered detector; and

Claim 8

measuring subsequent signals from said fission chamber and said self-powered detector at a time t and providing a second indication R(t) which is proportional to the ratio of said subsequent signal from said fission chamber to said subsequent signal from said self-powered detector; and

Claim 9

measuring subsequent signals from said fission chamber and said self-powered detector at a time t and providing a second indication R(t) which is proportional to the ratio of said subsequent signal from said fission chamber to said subsequent signal from said self-powered detector; and

Claim 10

measuring subsequent signals from said fission chamber and said self-powered detector at a time t and providing a second indication R(t) which is proportional to the ratio of said subsequent signal from said fission chamber to said subsequent signal from said self-powered detector; and

Claim 11

at time t receiving subsequent signal current If(t) from said fission chamber portion and subsequent signal current Is(t) from said self-powered portion;

Claim 12

at time t receiving subsequent signal current If(t) from said fission chamber portion and subsequent signal current Is(t) from said self-powered portion;

Claim 13

receiving subsequent signals from said fission chamber and self-powered portions in said neutron field and determining a ratio R(t) at time t which is proportional to the ratio of said subsequent signal from said fission chamber portion to said subsequent signal from said self-powered portion;

Claim 14

receiving subsequent signals from said fission chamber and self-powered portions in said neutron field and determining a ratio R(t) at time t which is proportional to the ratio of said subsequent signal from said fission chamber portion to said subsequent signal from said self-powered portion;

Claim 15

determining the sensitivity Sf(t) at time t of said fission chamber portion in accordance with the relationship: Sf(t) Sf(0) exp ((- sigma f/ sigma f - sigma s) (Ln R(0) - Ln R(t))) where sigma f is the burn-up cross section of the fissile material in said fission chamber portion, sigma s is the burn-up cross section of the emitter material of said self-powered portion, and Sf(0) is the initial sensitivity of said fission chamber portion; and

Claim 16

determining the sensitivity Sf(t) at time t of said fission chamber portion in accordance with the relationship: Sf(t) Sf(0) exp ((- sigma f/ sigma f - sigma s) (Ln R(0) - Ln R(t))) where sigma f is the burn-up cross section of the fissile material in said fission chamber portion, sigma s is the burn-up cross section of the emitter material of said self-powered portion, and Sf(0) is the initial sensitivity of said fission chamber portion; and

Claim 17

determining the sensitivity Sf(t) at time t of said fission chamber portion in accordance with the relationship: Sf(t) Sf(0) exp (- sigma f/ sigma f - sigma s (Ln R(0) - Ln If(t) -Ln Is(t))) where Sf(0) is the initial snesitivity of said fission chamber portion, sigma f is the burn-up cross section of the fissile material in said fission chamber and sigma s is the burn-up cross section of the emitter material of said self-powered detector.

Claim 18

determining the sensitivity Sf(t) at time t of said fission chamber portion in accordance with the relationship: Sf(t) Sf(0) exp (- sigma f/ sigma f - sigma s (Ln R(0) - Ln If(t) -Ln Is(t))) where Sf(0) is the initial snesitivity of said fission chamber portion, sigma f is the burn-up cross section of the fissile material in said fission chamber and sigma s is the burn-up cross section of the emitter material of said self-powered detector.

Claim 19

determining the neutron exposure phi t according to the relationship; sigma t (1/ sigma f - sigma s) (Ln R(0) - Ln R(t)) where sigma f is the neutron burn-up cross section of the fissile material in said fission chamber, and sigma s is the neutron burn-up cross section of the emitter material of said self-powered detector.

Claim 20

determining the neutron exposure phi t according to the relationship; sigma t (1/ sigma f - sigma s) (Ln R(0) - Ln R(t)) where sigma f is the neutron burn-up cross section of the fissile material in said fission chamber, and sigma s is the neutron burn-up cross section of the emitter material of said self-powered detector.

Claim 21

In a nuclear reactor having a fuel core: a plurality of neutron detector units distributed in said core, each of said units including an ion chamber portion and a self-powered portion; for each of said detector units a respective variable gain amplifier for receiving the signal from the ion chamber portion thereof; means for comparing the magnitudes of the signals from the ion chamber and self-powered portions of each said detector unit; and means for adjusting the gain of each of said amplifiers in proportion to the relative magnitudes of the signals from the ion chamber and self-powered portions of the respective detector unit.

Claim 22

In a nuclear reactor having a fuel core: a plurality of neutron detector units distributed in said core, each of said units including an ion chamber portion and a self-powered portion; for each of said detector units a respective variable gain amplifier for receiving the signal from the ion chamber portion thereof; means for comparing the magnitudes of the signals from the ion chamber and self-powered portions of each said detector unit; and means for adjusting the gain of each of said amplifiers in proportion to the relative magnitudes of the signals from the ion chamber and self-powered portions of the respective detector unit.

Claim 23

determining the neutron flux phi according to the relationship: phi (1/t ( sigma f - sigma s) (Ln R(0) - Ln R(t)) where sigma f is the neutron burn-up cross section of the fissile material in said fission chamber, and sigma s is the neutron burn-up cross sEction of the emitter material of said self-powered detector.

Claim 24

determining the neutron flux phi according to the relationship: phi (1/t ( sigma f - sigma s) (Ln R(0) - Ln R(t)) where sigma f is the neutron burn-up cross section of the fissile material in said fission chamber, and sigma s is the neutron burn-up cross sEction of the emitter material of said self-powered detector.

Claim 27

adjusting the level of the signal from said fission chamber portion in proportion to the sensitivity Sf(t).

Claim 28

adjusting the level of the signal from said fission chamber portion in proportion to the sensitivity Sf(t).

Claim 41

The method of claim 10 including the further step of adjusting the level of the signal from said fission chamber portion in proportion to the sensitivity Sf(t).

Claim 42

A neutron detector device including combined ion chamber and self-powered detectors comprising: first, second and third spaced electrodes; a neutron sensitive material disposed between said first and second electrodes and producing ionizing radiation upon neutron irradiation; an ionizable medium filling a space between said first and second electrodes, said first and second electrodes, said neutron sensitive material and said ionizable medium constituting said ion chamber detector; a dielectric material filling a space between said second and third electrodes, one of said electrodes of said second and third electrodes having a substantially greater thermal neutron absorption cross section than the other electrode of said second and third electrodes said second and third electrodes and said dielectric material constituTing said self-powered detector; a source of voltage and a first signal responsive means connected in series to said first and second electrodes; and a second signal responsive means connected to said second and third electrodes.

Claim 43

A neutron detector device including combined ion chamber and self-powered detectors comprising: first, second and third spaced electrodes; a neutron sensitive material disposed between said first and second electrodes and producing ionizing radiation upon neutron irradiation; an ionizable medium filling a space between said first and second electrodes, said first and second electrodes, said neutron sensitive material and said ionizable medium constituting said ion chamber detector; a dielectric material filling a space between said second and third electrodes, one of said electrodes of said second and third electrodes having a substantially greater thermal neutron absorption cross section than the other electrode of said second and third electrodes said second and third electrodes and said dielectric material constituTing said self-powered detector; a source of voltage and a first signal responsive means connected in series to said first and second electrodes; and a second signal responsive means connected to said second and third electrodes.

Claim 44

A neutron detector device comprising: a sealed chamber, first, second and third spaced electrodes in said chamber; a fissionable material disposed between said first and second electrodes; a dielectric material filling the space between said second and third electrodes, one of said electrodes of said second and third electrodes having a substantially lower thermal-neutron absorption cross section than the other electrode of said second and third electrodes; an ionizable gas filling the voids in said chamber including a space between said first and second electrodes said first and second electrodes with said fissionable material and said ionizable gas therebetween forming an ion chamber detector portion of said device and said second and third electrodes with said dielectric material therebetween forming a self-powered detector portion of said device; a source of voltage and a first signal responsive means connected in series to said first and second electrodes; and a second signal responsive means connected to said second and third electrodes.

Claim 45

A neutron detector device comprising: a sealed chamber, first, second and third spaced electrodes in said chamber; a fissionable material disposed between said first and second electrodes; a dielectric material filling the space between said second and third electrodes, one of said electrodes of said second and third electrodes having a substantially lower thermal-neutron absorption cross section than the other electrode of said second and third electrodes; an ionizable gas filling the voids in said chamber including a space between said first and second electrodes said first and second electrodes with said fissionable material and said ionizable gas therebetween forming an ion chamber detector portion of said device and said second and third electrodes with said dielectric material therebetween forming a self-powered detector portion of said device; a source of voltage and a first signal responsive means connected in series to said first and second electrodes; and a second signal responsive means connected to said second and third electrodes.

Claim 46

A neutron detector device comprising; a sealed chamber; first, second and third spaced electrodes in said chamber; a fissionable material disposed between said first and second electrodes; a dielectric material filling the space between said second and third electrodes, one of said electrodes of said second and third electrodes producing fewer electrons in a neutron flux as compared to the other of said second and third electrodes; an ionizable gas filling the voids in said chamber including a space between said first and second electrodes said first and second electrodes with said fissionable material and said ionizable gas therebetween forming an ion chamber detector portion of said device and said second and third electrodes with said dielectric material therebetween forming a self-powered detector portion of said device; a source of voltage and a first signal responsive means connected in series to said first and second electrodes; and a second signal responsive means connected to said second and third electrodes.

Claim 47

A neutron detector device comprising; a sealed chamber; first, second and third spaced electrodes in said chamber; a fissionable material disposed between said first and second electrodes; a dielectric material filling the space between said second and third electrodes, one of said electrodes of said second and third electrodes producing fewer electrons in a neutron flux as compared to the other of said second and third electrodes; an ionizable gas filling the voids in said chamber including a space between said first and second electrodes said first and second electrodes with said fissionable material and said ionizable gas therebetween forming an ion chamber detector portion of said device and said second and third electrodes with said dielectric material therebetween forming a self-powered detector portion of said device; a source of voltage and a first signal responsive means connected in series to said first and second electrodes; and a second signal responsive means connected to said second and third electrodes.

Claim 48

A neutron detector unit comprising: a sealable chamber containing an ionizable gas; a first electrode, tubular in form, the inner surface of said first electrode being within said chamber; a second electrode, tubular in form, positioned concentrically within said first electrode and spaced therefrom; a third electrode having a cylindrical outer surface positioned concentrically within said second electrode and spaced therefrom; a solid dielectric material filling the space between said first and second electrodes to form therewith a self-powered detector portion of said detector unit, one of said electrodes of said first and second electrodes producing fewer electrons in a neutron flux compared to the other of said first and second electrodes; an amount of neutron sensitive material producing ionizing radiation in response to neutron radiation disposed between said second and third electrode together with an amount of said ionizable gas to form an ion chamber detector portion of said detector unit; a first signal responsive means connected to said first and second electrodes; and a source of voltage and a second signal responsive means connected to said second and third electrodes.

Claim 49

A neutron detector unit comprising: a sealable chamber containing an ionizable gas; a first electrode, tubular in form, the inner surface of said first electrode being within said chamber; a second electrode, tubular in form, positioned concentrically within said first electrode and spaced therefrom; a third electrode having a cylindrical outer surface positioned concentrically within said second electrode and spaced therefrom; a solid dielectric material filling the space between said first and second electrodes to form therewith a self-powered detector portion of said detector unit, one of said electrodes of said first and second electrodes producing fewer electrons in a neutron flux compared to the other of said first and second electrodes; an amount of neutron sensitive material producing ionizing radiation in response to neutron radiation disposed between said second and third electrode together with an amount of said ionizable gas to form an ion chamber detector portion of said detector unit; a first signal responsive means connected to said first and second electrodes; and a source of voltage and a second signal responsive means connected to said second and third electrodes.

Claim 50

The neutron detector unit of claim 15 wherein said neutron sensitive material is fissionable material.

Claim 51

The neutron detector unit of claim 15 wherein said first electrode is formed of material from the group consisting of aluminum, cadmium, cobalt, rhodium, silver, vanadium, and alloys thereof.

Claim 52

The neutron detector unit of claim 15 wherein said second electrode is formed of material from the group consisting of aluminum, cadmium, cobalt, rhodium, silver, vanadium, and alloys theReof.

Claim 53

The neutron detector unit of claim 15 wherein said dielectric material is formed of an oxide of light metal.

Claim 54

The neutron detector unit of claim 19 wherein said light metal oxide is a material from the group consisting of aluminum oxide, magnesium oxide, zirconium oxide, silicon oxide, beryllium oxide, yttrium oxide, and mixtures thereof.

Claim 55

A neutron detector unit comprising: a sealable chamber containing an ionizable gas; a first electrode, tubular in form, the inner surface of said first electrode being within said chamber; a second electrode, tubular in form, positioned concentrically within said first electrode and spaced therefrom; a third electrode having a cylindrical outer surface positioned concentrically within said second electrode and spaced therefrom; a solid dielectric material filling the space between said second and third electrodes to form a self-powered detector portion of said detector unit, one of said electrodes of said second and third electrodes producing fewer electrons in a neutron flux compared to the other of said second and third electrodes; and an amount of neutron sensitive material producing ionizing radiation in response to neutron radiation disposed between said first and second electrodes together with an amount of said ionizable gas to form an ion chamber portion of said detector unit; a first signal responsive means connected to said second and third electrodes; and a source of voltage and a second signal responsive means connected to said first and second electrodes.

Claim 56

A neutron detector unit comprising: a sealable chamber containing an ionizable gas; a first electrode, tubular in form, the inner surface of said first electrode being within said chamber; a second electrode, tubular in form, positioned concentrically within said first electrode and spaced therefrom; a third electrode having a cylindrical outer surface positioned concentrically within said second electrode and spaced therefrom; a solid dielectric material filling the space between said second and third electrodes to form a self-powered detector portion of said detector unit, one of said electrodes of said second and third electrodes producing fewer electrons in a neutron flux compared to the other of said second and third electrodes; and an amount of neutron sensitive material producing ionizing radiation in response to neutron radiation disposed between said first and second electrodes together with an amount of said ionizable gas to form an ion chamber portion of said detector unit; a first signal responsive means connected to said second and third electrodes; and a source of voltage and a second signal responsive means connected to said first and second electrodes.

Claim 57

The neutron detector unit of claim 21 wherein said neutron sensitive material is fissionable material.

Claim 58

The neutron detector unit of claim 21 wherein said second electrode is formed of material from the group consisting of aluminum, cadmium, cobalt, rhodium, silver, vanadium, and alloys thereof.

Claim 59

The neutron detector unit of claim 21 wherein said third electrode is formed of material from the group consisting of aluminum, cadmium, cobalt, rhodium, silver, vanadium, and alloys thereof.

Claim 60

The neutron detector unit of claim 21 wherein said dielectric material is formed of an oxide of light metal.

Claim 61

The neutron detector unit of claim 25 wherein said light metal oxide is a material from the group consisting of aluminum oxide, magnesium oxide, zirconium oxide, silicon oxide, beryllium oxide, yttrium oxide, and mixtures thereof.