X-ray radiation sources with low neutron emissions for radiation scanning

• US 7,783,010 B2
• Filed: 10/14/2008
• Issued: 08/24/2010
• Est. Priority Date: 06/24/2005
• Status: Expired due to Fees

• Current Assignee: Varex Imaging Corporation
• Original Assignee: Varian Medical Systems Incorporated (Siemens AG)
• Inventors: Clayton, James E.
• Primary Examiner(s): Yun; Jurie
• Application Number:
  US12/287,730
• Publication Number:
  US 20090041197A1
• Time in Patent Office: 679 Days
• Field of Search: 378/119, 378/121, 378/122, 378/142, 378/143, 378/144, 378/203, 250/505.1, 250/506.1, 250/515.1
• US Class Current: 378/119
• CPC Class Codes: G01N 23/005 by using neutrons G01N23/02 - G01N23/227 take precedence
• CPC Class Codes: Y10T 29/531 Nuclear device

Abstract

A method of manufacturing a radiation source in one example comprises selecting at least one of a target, a collimator, or target shielding consisting essentially of at least one isotope having a neutron production threshold greater than a peak acceleration energy of the source, and assembling the source including the selected material. A simulation may be used to assist in design a radiation source meeting neutron production requirements and optionally other requirements.

Claims

1. A method of manufacturing a low neutron emitting radiation source, the method comprising

selecting a peak acceleration energy for a radiation source;

selecting at least one of a target, a collimator, or target shielding consisting essentially of at least one isotope having a neutron production threshold greater than the peak acceleration energy of the source; and

assembling the source including the selected isotope.

2. The method of claim 1, further comprising:

selecting housing shielding consisting essentially of at least one isotope having a neutron production threshold greater than the peak acceleration energy; and

assembling the source with the selected housing shielding.

3. The method of claim 1, further comprising:

defining neutron production requirements for the source;

preparing a preliminary design for the radiation source the preliminary design being based, at least in part, on the defined neutron production requirements at the selected peak acceleration energy;

inputting the preliminary design into a simulation to predict neutron production; and

receiving an output of the simulation, including predicted neutron production.

4. The method of claim 3, wherein, if the output does not meet requirements, the method further comprises:

adjusting the design; and

inputting the adjusted design into the simulation to predict neutron production.

5. The method of claim 3, comprising:

preparing the preliminary design based on at least one of size requirements and X-ray radiation generation requirements.

6. The method of claim 3, comprising:

preparing the preliminary design comprising a target consisting essentially of copper.

7. The method of claim 6, further comprising:

preparing the preliminary design comprising at least one of a collimator, target shielding, or housing shielding comprising tungsten.

8. The method of claim 3, comprising:

preparing the preliminary design comprising a collimator comprising tungsten.

9. The method of claim 3, comprising:

preparing the preliminary design comprising a target assembly shielding comprising tungsten.

10. The method of claim 3, comprising:

preparing the preliminary design comprising an upstream target assembly shielding comprising tungsten.

11. The method of claim 3, comprising:

preparing the preliminary design comprising housing shielding comprising tungsten.

12. The method of claim 3, further comprising:

preparing the design based on weight or cost requirements.

13. The method of claim 1, comprising:

selecting a peak acceleration energy of less than about 9.910 MeV;

selecting a target consisting essentially of copper;

selecting a collimator comprising tungsten; and

selecting target shielding comprising tungsten.

14. A method of manufacturing a low neutron emitting radiation source, the method comprising;

selecting a peak acceleration of less than about 9.910 MeV for a radiation source;

defining neutron production requirements for the radiation source;

preparing a preliminary design for the radiation source, the preliminary design being based, at least in part, on the selected peak acceleration energy requirement and the defined neutron production requirement, the preliminary design comprising a target consisting essentially of at least one isotope having a peak acceleration energy greater than the selected peak acceleration energy, so that the target will not generate neutrons;

inputting the preliminary design into a simulation to predict neutron production;

receiving an output of the simulation, including predicted neutron production; and

if the neutron production requirements are met, assembling the source based on the preliminary design.

15. The method of claim 14, wherein the target consists essentially of copper.

16. The method of claim 14, further comprising:

if the neutron production requirement is not met, adjusting the design;

inputting the adjusted design into the simulation to predict neutron production; and

if the neutron production requirement is met, assembling the source based on the adjusted design.

17. The method of claim 14, wherein the preliminary design comprises a collimator comprising at least one isotope having a neutron production threshold less than the peak acceleration energy of the preliminary design, the method comprising;

if the neutron production requirement is not met, adjusting the preliminary design by providing the collimator with a first section comprising the at least one isotope having a neutron production threshold less than the predetermined peak acceleration energy and a second section consisting essentially of at least one isotope having a neutron production threshold greater than the peak acceleration energy.

18. The method of claim 17, wherein the first section comprises tungsten and the second section consists essentially of copper.

19. The method of claim 14, wherein the preliminary design comprises target shielding comprising at least one isotope having a neutron production threshold less than the peak acceleration energy of the preliminary design, the method comprising;

if the neutron production requirement is not met, adjusting the preliminary design by providing the target shielding with a first section comprising the at least one isotope having a neutron production threshold less than the predetermined peak acceleration energy and a second section consisting essentially of at least one isotope having a neutron production threshold greater than the peak acceleration energy.

20. The method of claim 19, wherein the first section comprises tungsten and the second section consists essentially of copper.

21. The method of claim 14, wherein the preliminary design comprises a housing shielding comprising at least one isotope having a neutron production threshold less than the peak acceleration energy of the preliminary design, the method comprising;

if the neutron production requirement is not met, adjusting the preliminary design by providing the housing shielding with a first section comprising the at least one isotope having a neutron production threshold less than the predetermined peak acceleration energy and a second section consisting essentially of at least one isotope having a neutron production threshold greater than the peak acceleration energy.

22. The method of claim 14, further comprising;

defining additional requirements comprising at least one of a predetermined size, predetermined weight, or a predetermined cost;

preparing the preliminary design based, at least in part, on the additional requirements; and

adjusting the preliminary design if any additional requirement is not met.

23. The method of claim 14, wherein the selected peak acceleration energy is at least about 6.2 MeV.