Ionizing particle beam fluence and position detector array using Micromegas technology with multi-coordinate readout

• US 10,265,545 B2
• Filed: 05/08/2017
• Issued: 04/23/2019
• Est. Priority Date: 05/06/2016
• Status: Active Grant

• Current Assignee: Radiation Detection And Imaging Technologies, LLC
• Original Assignee: Radiation Detection And Imaging Technologies, LLC
• Inventors: Galyaev, Evgeny
• Primary Examiner(s): Johnston, Phillip A
• Application Number:
  US15/589,883
• Publication Number:
  US 20170319872A1
• Time in Patent Office: 715 Days
• Field of Search: 2504923
• CPC Class Codes: A61N 2005/1087 Ions; Protons
• CPC Class Codes: A61N 5/1048 Monitoring, verifying, controlling systems and methods
• CPC Class Codes: A61N 5/1049 for verifying the position of the patient with respect to the radiation beam
• CPC Class Codes: A61N 5/1065 Beam adjustment
• CPC Class Codes: A61N 5/1075 for testing, calibrating, or quality assurance of the radiation treatment apparatus
• CPC Class Codes: A61N 5/1077 Beam delivery systems
• CPC Class Codes: G01T 1/185 with ionisation chamber arrangements
• CPC Class Codes: G01T 1/2935 using ionisation detectors
• CPC Class Codes: H01J 37/08 Ion sources; Ion guns
• CPC Class Codes: H01J 37/244 Detectors; Associated components or circuits therefor
• CPC Class Codes: H01J 47/02 Ionisation chambers

Abstract

A particle beam detector system can comprise a particle beam generator, a particle beam fluence and position detector array based on Micromegas technology, and data readout electronics coupled to the position detector array. The particle beam fluence and position detector array can comprise a sealed, gas-filled, ionizing radiation detector chamber. A printed circuit board (PCB) can be disposed within the ionizing radiation detector chamber, the PCB comprising a multi-layer array arrangement of interconnected conductive sensor pads comprising three planar coordinate grids, X, Y, and ST (stereo) situated on separate layers of the PCB. The multi-layer array arrangement of interconnected conductive sensor pads can comprise a first footprint. A dielectric lattice structure can be disposed over the PCB and the multi-layer array arrangement of sensors. A conductive mesh structure can comprise a second footprint disposed over the dielectric lattice structure and extending over an entire area of the first footprint.

Claims

1. A particle beam detector system, comprising:

a particle beam generator;

a Micromegas particle beam fluence and position detector array comprising;

a sealed, gas-filled, ionizing radiation detector chamber,

a printed circuit board (PCB) disposed within the ionizing radiation detector chamber, the PCB comprising a multi-layer array arrangement of interconnected conductive sensor pads with the conductive sensor pads disposed on the PCB and coupled to an interconnected series of corresponding strips comprising three planar coordinate grids, X, Y, and ST (stereo), the interconnected series of corresponding strips being situated as separate layers within the PCB, the arrangement of interconnected conductive sensor pads comprising a first footprint,

wherein the interconnected conductive sensor pads form a plurality of interlocking three-coordinate detection clusters with each three-coordinate detection cluster coupled to the three planar coordinate grids, X, Y, and ST, such that the plurality of three-coordinate detection clusters extend across the PCB in a repeating pattern,

a dielectric lattice structure, disposed over the PCB and extending away from the multi-layer array arrangement of sensors, and

a conductive mesh structure comprising a second footprint disposed over the dielectric lattice structure and the PCB, the second footprint extending over an entire area of the first footprint;

electronic signal acquisition channels coupled to each of the conductive sensor pads and corresponding strips of the particle beam fluence and position detector array; and

data readout electronics coupled to the electronic signal acquisition channels.

2. The particle beam detector system of claim 1, wherein the plurality of interlocking three-coordinate detection clusters comprise a diamond shape X coordinate sensor, a diamond shape Y coordinate sensor, and a diamond shape ST coordinate sensor joined to form the interlocking three-coordinate detection clusters comprising a hexagonal shape.

3. The particle beam detector system of claim 1, wherein the dielectric lattice structure comprises openings of any shape through which a particle beam may pass to the multi-layer array arrangement of sensors.

4. The particle beam detector system of claim 1, wherein the electronic signal acquisition channels connected to each of the corresponding strips of the particle beam fluence and position detector array for resolving incoming flux intensity variations comprises fewer electronic signal acquisition channels than a second number of electronic signal acquisition channels using individual independent collector pads, wherein the second number of independent collector channels increases by a power law.

5. The particle beam detector system of claim 1, wherein the detector array comprises a curved surface to produce a cylindrical detector.

6. The particle beam detector system of claim 1, wherein the dielectric lattice structure comprises a wall thickness in a range of 0.003-0.5 millimeters (mm) and a height in a range of 50-300 micrometers (μ

m).

7. The particle beam detector system of claim 1, wherein:

the particle beam generator is adapted to send an ionizing particle beam to the detector array; and

the position detector array is oriented substantially perpendicular to a direction of a beam produced by the particle beam generator.

8. The particle beam detector system of claim 1, wherein the position detector array comprises a planar surface.

9. A particle beam detector array, comprising:

a sealed, gas-filled, ionizing radiation detector chamber;

a substrate disposed within the ionizing radiation detector chamber, the substrate comprising a multi-layer array arrangement of interconnected conductive sensor pads coupled to an interconnected series of corresponding strips comprising three planar coordinates X, Y, and ST (stereo), the sensor pads situated on the substrate, and the interconnected series of corresponding strips situated on three separate layers of the substrate;

wherein the interconnected conductive sensor pads form a plurality of interlocking three-coordinate detection clusters with each three-coordinate detection cluster coupled to the three planar coordinate grids, X, Y, and ST, such that the plurality of three-coordinate detection clusters extend across the PCB in a repeating pattern,

a dielectric lattice structure, disposed over the substrate and the plurality of interlocking three-coordinate detection clusters; and

a conductive mesh structure disposed over the dielectric lattice structure.

10. The particle beam detector array of claim 9, wherein the particle beam detector array comprises a Micromegas particle beam fluence and position detector array.

11. The particle beam detector array of claim 9, wherein the plurality of interlocking three-coordinate detection clusters comprise a a diamond shape X coordinate sensor, a diamond shape Y coordinate sensor, and a diamond shape ST coordinate sensor join to form a hexagonal shape.

12. The particle beam detector array of claim 9, wherein the dielectric lattice structure comprises openings of any shape through which a particle beam may pass to the multi-layer array arrangement.

13. The particle beam detector array of claim 9, wherein a first number of electronic signal acquisition channels for resolving incoming flux intensity variations is lower than a second number of electronic signal acquisition channels using individual independent collector pads for which the second number of independent collector channels increases by a power law.

14. The particle beam detector array of claim 9, wherein the multi-layer array arrangement comprises a curved surface to produce a cylindrical detector.

15. The particle beam detector array of claim 9, wherein the dielectric lattice structure comprises a wall thickness in a range of 0.003-0.5 millimeters (mm) and a height in a range of 50-300 micrometers (μ

m).

16. A method of using an ionizing particle beam detector system, comprising:

directing an ionizing particle beam from a particle beam generator to a particle beam fluence and position detector array, wherein the ionizing beam is directed in a direction substantially perpendicular to the position detector array;

measuring the ionizing particle beam fluence and position with a particle beam fluence and position detector array, the particle beam fluence and position detector array comprising interconnected conductive sensor pads that form a plurality of interlocking three-coordinate detection clusters; and

calibrating the particle beam generator by adjusting particle beam generator to generate an ionizing particle beam comprising a fluence and position within one percent of a desired fluence and position.

17. The method of claim 16, further comprising:

the particle beam fluence and position detector array comprising a Micromegas particle beam fluence and position detector array; and

directing the ionizing particle beam from the particle beam generator to a patient after uniquely calibrating the particle beam generator to radiate a tumor in the patient.

18. The method of claim 16, further comprising:

directing a first ionizing particle beam from the particle beam generator to a first position on the particle beam fluence and position detector array;

measuring a first an amount of radiation delivered by the first ionizing particle beam;

moving the particle beam generator;

directing a second ionizing particle beam from the particle beam generator to a second position on the particle beam fluence and position detector array;

measuring a second amount of radiation delivered by the second ionizing particle beam; and

generating a planar map of fluence for the radiation delivered by the first ionizing particle beam and the second ionizing particle beam.

19. The method of claim 16, further comprising generating the ionizing particle beam as a heavy ionizing particle beam or a proton beam with a fluence on the order of 10⁵-10¹⁴ ionizing particles per second.

20. The method of claim 16, further comprising resolving beam position and spot size to 0.8-1.2 mm, and measure of delivered dose radiation with an accuracy of less than or equal to 2% of a desired dose for beam monitoring of proton therapy.

21. The method of claim 16, wherein a particle beam fluence and position detector array comprise an active area greater than 10 centimeters squared (cm²), a coordinate resolution (X, Y) less than 200 micrometers (μ

m) (Isotropic in X-Y), a beam flux dynamic range 10⁶-10¹³ particles/cm²/s±

1%, a lifetime accumulated dose exposure greater than 50 kGy, a charge sensitivity less than 100 fC, and a response time less than 1 millisecond (ms).