Control of imaging assembly with interchangeable radiation shielding

1. An imaging assembly comprising:

a housing having a cavity;

a sensor placed in the cavity and configured to detect radiation impinging on the sensor from a plurality of directions;

one or more shields arranged relative to the sensor, including a first internal shield having a first annular body between a first inner surface and a first outer surface;

a dual-function fixed shield operatively connected to the sensor and configured to at least partially attenuate a back radiation striking the dual-function fixed shield;

a first temperature regulator operatively connected to the sensor and configured to maintain the sensor at a predefined critical temperature, the dual-function fixed shield being configured to conduct heat away from the first temperature regulator;

wherein the first internal shield is configured to be placed in the housing such that the first inner surface at least partially surrounds the sensor;

wherein the sensor is configured to receive a first central zone radiation through a first field of view, and a first peripheral zone radiation through a first peripheral view, when the first internal shield is placed in the housing; and

wherein the assembly is configured to provide at least one of a controllable field of view and reduced background contamination in an image domain.

2. The assembly of claim 1 , wherein:

the first peripheral zone radiation travels through the first annular body to reach the sensor; and

the first outer surface is tapered relative to the first inner surface such that the first peripheral zone radiation travels a first fixed distance (d 1 ) through the first annular body.

3. The assembly of claim 2 , wherein:

the first internal shield defines a first edge line connecting an outermost edge point of the first inner surface and the sensor;

the first internal shield defines a first normal line extending from the sensor and perpendicular relative to the first inner surface;

the first field of view extends inside the first edge line; and

the first peripheral view extends between the first edge line and the normal line.

4. The assembly of claim 2 , wherein:

the one or more shields includes a second internal shield interchangeably used with the first internal shield, the second internal shield having a second annular body between a second inner surface and a second outer surface;

the second internal shield is configured to be placed in the housing such that the second inner surface at least partially surrounds the sensor;

the sensor is configured to receive a second central zone radiation through a second field of view and a second peripheral zone radiation through a second peripheral view when the second internal shield is placed in the housing; and

the second field of view is smaller than the first field of view.

5. The assembly of claim 4 , wherein:

the second peripheral zone radiation travels through the second annular body to reach the sensor;

the second outer surface of the second internal shield is tapered relative to the second inner surface such that the second peripheral zone radiation travels a second fixed distance (d 2 ) through the second annular body;

the second fixed distance (d 2 ) is greater than the first fixed distance (d 1 );

the second internal shield defines a second edge line connecting an outermost edge point of the second outer surface and the sensor;

the second internal shield defines a second normal line extending from the sensor and perpendicular relative to the second inner surface;

the second field of view extends inside the second edge line; and

the second peripheral view extends between the second edge line and the normal line.

6. The assembly of claim 2 , further comprising:

a removable sleeve having a sleeve annular body between a sleeve inner surface and a sleeve outer surface and configured to be placed over the first internal shield such that the sleeve inner surface is adjacent to and co-extensive with the first outer surface; and

wherein the removable sleeve is composed of a non-attenuating material.

7. The assembly of claim 6 , wherein:

the first inner surface defines a first inner diameter (ID 1 ) and the second inner surface defines a second inner diameter (ID 2 );

the removable sleeve, the first internal shield and the second internal shield define a sleeve lateral width (L), a first shield width (W 1 ) and a second shield width (W 2 ), respectively; and

a first summation (S 1 =ID 1 +2L+2W 1 ) of the first inner diameter (ID 1 ), twice the sleeve lateral width and twice the first shield width is equal to a second summation (S 1 =S 2 ) of the second inner diameter (ID 2 ) and twice the second shield width (S 2 =ID 2 +2W 2 ).

8. The assembly of claim 1 , further comprising:

a second temperature regulator operatively connected to the first temperature regulator.

9. The assembly of claim 1 , wherein:

the one or more shields include a field of view (FOV) blocker positioned in the housing such that a combination of the first internal shield and the FOV blocker provides shielding in all directions.

10. The assembly of claim 1 , wherein:

the one or more shields include a field of view (FOV) adjuster having an opening defined by interior walls and positioned in the housing; and

a combination of the first internal shield and the FOV adjuster limits the first field of view to an FOV angle.

11. The assembly of claim 10 , wherein:

the FOV adjuster is composed of tungsten or an alloy of tungsten; and

the interior walls of the FOV adjuster are shaped as an hourglass.

12. A method of controlling an imaging assembly having a sensor placed in a housing, the method comprising:

positioning a first internal shield in the housing, the first internal shield having a first annular body between a first inner surface and a first outer surface such that the first inner surface at least partially surrounds the sensor;

wherein the sensor is configured to receive a first central zone radiation through a first field of view, and a first peripheral zone radiation through a first peripheral view, when the first internal shield is placed in the housing;

generating a first image with the first internal shield placed in the housing;

removing the first internal shield and positioning a second internal shield in the housing;

re-positioning the assembly based at least partially on the first image and generating a second image with the second internal shield in the housing;

wherein the sensor is configured to receive a second central zone radiation through a second field of view and a second peripheral zone radiation through a second peripheral view when the second internal shield is placed in the housing;

wherein the second field of view is smaller than the first field of view and the second peripheral zone radiation travels through a second annular body to reach the sensor;

wherein a second outer surface of the second internal shield is tapered relative to a second inner surface such that the second peripheral zone radiation travels a second fixed distance (d 2 ) through the second annular body;

wherein the first peripheral zone radiation travels through the first annular body to reach the sensor; and

wherein the first outer surface is tapered relative to the first inner surface such that the first peripheral zone radiation travels a first fixed distance (d 1 ) through the first annular body, the second fixed distance (d 2 ) being greater than the first fixed distance (d 1 ).

13. The method of claim 12 , further comprising:

prior to generating the first image, generating an initial image with no shield in the housing.

14. The method of claim 12 , further comprising:

prior to generating the first image, positioning a removable sleeve over the first internal shield, the removable sleeve having a sleeve annular body between a sleeve inner surface and a sleeve outer surface such that the sleeve inner surface is adjacent to and co-extensive with the first outer surface; and

wherein the removable sleeve is composed of a non-attenuating material.

15. The method of claim 14 , wherein:

the first inner surface defines a first inner diameter (ID 1 ) and the second inner surface defines a second inner diameter (ID 2 );

the removable sleeve, the first internal shield and the second internal shield define a sleeve lateral width (L), a first shield width (W 1 ) and a second shield width (W 2 ), respectively; and

a first summation (S 1 =ID 1 +2L+2W 1 ) of the first inner diameter (ID 1 ), twice the sleeve lateral width and twice the first shield width is equal to a second summation (S 2 =ID 2 +2W 2 ) of the second inner diameter (ID 2 ) and twice the second shield width (S 1 =S 2 ).

16. The method of claim 12 , further comprising:

positioning a field of view (FOV) blocker in the housing such that a combination of the first internal shield and the FOV blocker provides shielding in all directions; and

generating a first image of a scene with the FOV blocker and the first internal shield in place.

17. The method of claim 16 , further comprising:

removing the FOV blocker and generating a second image of the scene with the first internal shield but not the FOV blocker;

wherein the first and the second images are each divided into respective bins having respective numeric values; and

generating a third image by subtracting the second image from the first image.

18. The method of claim 16 , further comprising:

removing the FOV blocker and positioning a field of view (FOV) adjuster in the housing, the FOV adjuster having an opening defined by interior walls configured to limit the first field of view to an FOV angle;

generating a second image of the scene with the FOV adjuster and the first internal shield but not the FOV blocker;

wherein the first and the second images are each divided into respective bins having respective numeric values; and

generating a third image by subtracting the second image from the first image.

19. The method of claim 18 , wherein:

the FOV adjuster and the FOV blocker are each composed of tungsten or an alloy of tungsten; and

the interior walls of the FOV adjuster are shaped as an hourglass.

20. An imaging assembly comprising:

a housing having a cavity;

a sensor placed in the cavity and configured to detect radiation impinging on the sensor from a plurality of directions;

one or more shields arranged relative to the sensor, including a first internal shield and a second internal shield interchangeably used with the first internal shield;

wherein the first internal shield has a first annular body between a first inner surface and a first outer surface such that the first inner surface at least partially surrounds the sensor when the first internal shield is placed in the housing;

wherein the sensor is configured to receive a first central zone radiation through a first field of view, and a first peripheral zone radiation through a first peripheral view, when the first internal shield is placed in the housing;

wherein the first peripheral zone radiation travels through the first annular body to reach the sensor;

wherein the first outer surface is tapered relative to the first inner surface such that the first peripheral zone radiation travels a first fixed distance (d 1 ) through the first annular body;

wherein the second internal shield has a second annular body between a second inner surface and a second outer surface such that the second inner surface at least partially surrounds the sensor when the second internal shield is placed in the housing;

wherein the sensor is configured to receive a second central zone radiation through a second field of view and a second peripheral zone radiation through a second peripheral view when the second internal shield is placed in the housing;

wherein the second field of view is smaller than the first field of view and the second peripheral zone radiation travels through the second annular body to reach the sensor;

wherein the second outer surface of the second internal shield is tapered relative to the second inner surface such that the second peripheral zone radiation travels a second fixed distance (d 2 ) through the second annular body; and

the second fixed distance (d 2 ) is greater than the first fixed distance (d 1 ).