Energy fluence meter for x-rays

Claim 2

In a portable X-ray detector system for determining energy fluence of an X-ray field comprising: a first assembly, said first assembly made of a material for absorbing incident X-radiation totally only for the low-energy part of the spectrum; first detector means embedded within said first assembly at its center for producing an output signal proportional to X-radiation energy deposited in said first assembly by incident primary X-radiation; a second assembly; second detector means embedded within said second assembly on a longitudinal axis for producing an output signal proportional to X-radiation energy deposited in said second assembly by incident primary X-radiation; said second assembly made of materials which modify the X-radiation spectrum as it penetrates said materials to said second detector means such that said second detector means responds only to a portion of incident X-radiation greater than said low energy part; and a thermal insulating housing, said first and second assemblies embedded within said thermal insulating housing, said first assembly being positioned relative to said second assembly to receive incident X-radiation prior its receipt by said second assembly.

Claim 3

In a system as claimed in claim 1 wherein: said first and second detector means are temperature sensors.

Claim 4

In a system as claimed in claim 2 wherein: said first and second detector means are thermistors.

Claim 5

In a system as claimed in claim 1 wherein: said first and second detector means are semiconductors.

Claim 6

In a system as claimed in claim 4 wherein: said semiconductors are silicon and germanium.

Claim 7

In a system as claimed in claim 1 wherein said system has a total response function which varies very little with respect to X-radiation in the energy range of 10 keV to 100 MeV.

Claim 8

In a system as claimed in claim 1 in which: said first assembly is made of iron.

Claim 9

In a system as claimed in claim 7 wherein: said second assembly is formed by cylinders of graphite and aluminum separated by a disc of iron, and said second detector means is positioned in said aluminum cylinder on the linear axis thereof.

Claim 10

In a system as claimed in claim 8 wherein: said system has a total response function which varies very little with respect to X-radiation in the energy range of 10 kev to 100 MeV.

Claim 11

In a system as claimed in claim 1 wherein; said second assembly is formed by cylinders of graphite and aluminum separated by a disc of iron, and said second detector means is positioned in said aluminum cylinder on the linear axis thereof.

Claim 12

In a system as claimed in claim 1 wherein: the ratio of the output signal of said first detector means to that of said second detector means determines the quality of the energy spectrum.

Claim 13

In a system as claimed in claim 1 wherein: the outputs of said first and second detector means are adjusted and combined to achieve an overall response proportional to an incident X-ray energy fluence which does not depend strongly upon the incident spectrum.

Claim 14

A portable X-ray detector system for determining energy fluence of an X-ray field comprising: a first assembly; said first assembly made of a material for absorbing incident X-radiation totally only for the low energy part of the spectrum; first detector means embedded within said first assembly at its center for producing an output signal proportional to X-radiation energy deposited in said first assembly by incident primary X-radiation; a second assembly; second detector means embedded within said second assembly on a longitudinal axis for producing an output signal proportional to X-radiation energy deposited in said second assembly by incident primary X-radiation, said second assembly made of materials which modify the X-radiation spectrum as it penetrates said materials to said second detector means such that said second detector means responds only to a portion of incident X-radiation; a thermal insulating housing, said first and second assemblies embedded within said thermal insulating housing such that said first assembly is positioned relative to said second assembly to receive indicent X-radiation prior to that of said second assembly, amplifier means for amplifying the output signals from said first and second detector means; analog-to-digital converter means for receiving said amplified output signals from said first and second detector means and producing a digital output; a microcomputer base programmed to solve the equation ψ = D 1 + (D m /K) during processing said digital output from the output of said first and second detector means where ψ is the energy fluence, D 1 is the change in the digital output from said second detector means, D m is the change in the digital output from said second detector means and K is a constant stored in said computer; and a recorder for recording the output from said computer which output is the energy fluence of the X-radiation indicent on said first and second assemblies.

Claim 15

A portable X-ray detector system for determining energy fluence of an X-ray field comprising: a first assembly; said first assembly made of a material for absorbing incident X-radiation totally only for the low energy part of the spectrum; first detector means embedded within said first assembly at its center for producing an output signal proportional to X-radiation energy deposited in said first assembly by incident primary X-radiation; a second assembly; second detector means embedded within said second assembly on a longitudinal axis for producing an output signal proportional to X-radiation energy deposited in said second assembly by incident primary X-radiation, said second assembly made of materials which modify the X-radiation spectrum as it penetrates said materials to said second detector means such that said second detector means responds only to a portion of incident X-radiation; a thermal insulating housing, said first and second assemblies embedded within said thermal insulating housing such that said first assembly is positioned relative to said second assembly to receive indicent X-radiation prior to that of said second assembly, amplifier means for amplifying the output signals from said first and second detector means; analog-to-digital converter means for receiving said amplified output signals from said first and second detector means and producing a digital output; a microcomputer base programmed to solve the equation ψ = D 1 + (D m /K) during processing said digital output from the output of said first and second detector means where ψ is the energy fluence, D 1 is the change in the digital output from said second detector means, D m is the change in the digital output from said second detector means and K is a constant stored in said computer; and a recorder for recording the output from said computer which output is the energy fluence of the X-radiation indicent on said first and second assemblies.

Claim 16

A system as claimed in claim 13 wherein: said first and second detector means are temperature sensors.

Claim 17

A system as claimed in claim 14 wherein: said first and second detector means are thermistors.

Claim 18

A system as claimed in claim 13 wherein: said first and second detector means are semiconductors.

Claim 19

A system as claimed in claim 16 wherein: said semiconductors are silicon and germanium.

Claim 20

A system as claimed in claim 13 wherein: said first assembly is made of iron.

Claim 21

A system as claimed in claim 18 wherein: said second assembly is formed by cylinders of graphite and aluminum separated by a disc of iron, and said second detector means is embedded in said aluminum cylinder on the linear axis thereof.

Claim 22

A system as claimed in claim 13 wherein: said second assembly is formed by cylinders of graphite and aluminum separated by a disc of iron, and said second detector means is embedded in said aluminum cylinder on the linear axis thereof.