Characteristic X-ray computed laminography system for home made explosives (HME) detection
View Patent ↗A homemade explosives (HME) detection system provides a coded-source, x-ray computed laminography imaging system which detects material composition by the ratio of the transmitted characteristic X-rays within a coded x-ray beam. Motion-free 3-Dimensional geometrical details are obtained through computed laminography imaging techniques.
1. A homemade explosives (HME) detection system comprising:
a coded X-ray source to illuminate an object with a coded X-ray beam;
an X-ray detector array which receives said coded X-ray beam, the object located between the coded X-ray source and the X-ray detector array such that characteristic X-rays emerge from the object for discrimination by the X-ray detector array; and
a microprocessor system in communication with the X-ray detector array which measures transmission of the characteristic X-rays through the object to reveal an elemental composition of the object.
2. The system as recited in claim 1 , wherein said coded X-ray source produces said coded X-ray beam with a shield mask.
3. The system as recited in claim 2 , wherein said shield mask contains apertures arranged in a uniformly redundant array (URA).
4. The system as recited in claim 2 , wherein said shield mask contains apertures arranged in a modified uniformly redundant array (MURA).
5. The system as recited in claim 2 , wherein said microprocessor system determines a ratio R of the low-energy and high-energy x-ray attenuation coefficients directly from the ratio of the transmitted low-energy and high energy characteristic X-rays according to the formula as follows:
R
=
μ
le
μ
he
=
ln
(
I
le
/
I
le
0
)
ln
(
I
he
/
I
he
0
)
where μ is the mass attenuation coefficient, I is characteristic X-ray intensity and the subscripts le and he are for low energy and high-energy characteristic X-rays respectively.
6. The system as recited in claim 5 , wherein said microprocessor system utilizes said ratio R as a discriminator for different classes of materials.
7. The system as recited in claim 1 , wherein said coded X-ray source produces said coded X-ray beam by an internal arrangement.
8. The system as recited in claim 1 , wherein the coded X-ray source produces said coded X-ray beam with a shield mask having apertures arranged in an array.
9. A method of determining a material composition of an object comprising the steps of:
(A) illuminating an object with a coded X-ray beam; and
(B) detecting a material composition of the object by a ratio of transmitted characteristic X-rays passed through the object.
10. A method as recited in claim 9 , further comprising the step of:
(C) determining geometrical details of the object through a computed laminography imaging technique from the coded x-ray beam.
11. A method as recited in claim 9 , wherein said step (B) further comprises:
(a) detecting selected compositions within the object.
12. A method as recited in claim 9 , wherein said step (B) further comprises:
(a) utilizing a ratio R as a discriminator for different classes of materials, a ratio R of the low-energy and high-energy x-ray attenuation coefficients directly from the ratio of the transmitted low-energy and high energy characteristic X-rays according to the formula as follows:
R
=
μ
le
μ
he
=
ln
(
I
le
/
I
le
0
)
ln
(
I
he
/
I
he
0
)
where μ is the mass attenuation coefficient, I is characteristic X-ray intensity and the subscripts le and he are for low energy and high-energy characteristic X-rays respectively.
13. A method as recited in claim 9 , wherein the coded X-ray beam is provided utilizing a shield mask having an array of apertures.
14. A method of determining a homemade explosive (HME) comprising the steps of:
(A) illuminating an object with a coded X-ray beam; and
(B) detecting a material composition of the object by a ratio of transmitted characteristic X-rays passed through the object; and
(C) utilizing the ratio R as a discriminator for the material composition within the object.
15. The method of claim 14 , wherein the coded X-ray beam is provided utilizing a shield mask having an array of apertures.