US 12,002,648 B2
Interruption-ring in an x-ray tube
Todd S. Parker, Kaysville, UT (US); and Kasey Otho Greenland, South Jordan, UT (US)
Assigned to Moxtek, Inc., Orem, UT (US)
Filed by Moxtek, Inc., Orem, UT (US)
Filed on May 3, 2023, as Appl. No. 18/311,683.
Application 18/311,683 is a continuation of application No. 17/500,403, filed on Oct. 13, 2021, granted, now 11,688,578.
Claims priority of provisional application 63/112,216, filed on Nov. 11, 2020.
Prior Publication US 2023/0274904 A1, Aug. 31, 2023
Int. Cl. H01J 35/16 (2006.01)
CPC H01J 35/16 (2013.01) [H01J 2235/02 (2013.01); H01J 2235/16 (2013.01)] 18 Claims
OG exemplary drawing
 
1. An x-ray tube comprising:
a cathode and an anode electrically insulated from one another, the cathode configured to emit electrons towards the anode, and the anode configured to emit x-rays out of the x-ray tube in response to impinging electrons from the cathode;
an enclosure attached to the cathode and the anode, the enclosure electrically-insulating the cathode from the anode;
the enclosure, the cathode, and the anode form a housing that is hermetically sealed;
a coating-ring on and adjoining an inner-face of the enclosure, the coating-ring encircling a longitudinal-axis of the enclosure, the longitudinal-axis extending between the cathode and the anode;
an interruption-ring located at the inner-face of the enclosure, the interruption-ring encircling the longitudinal-axis, the interruption-ring being distinct from the coating-ring;
the coating-ring and the interruption-ring each have a circular shape;
a series electric-current-path through the coating-ring and the interruption-ring between the anode and the cathode;
RI>RC, where RI is electrical resistance per unit length through the interruption-ring and RC is electrical resistance per unit length through the coating-ring, both measured parallel to the longitudinal-axis;
ρC<ρE, where ρC is a bulk electrical resistivity of the coating-ring and PE is a bulk electrical resistivity of the enclosure;
the enclosure includes a cylinder with a hole extending through a core of the cylinder;
the inner-face of the enclosure is an inner-face of the cylinder;
the interruption-ring encircles the longitudinal-axis at a different location along the longitudinal-axis than the coating-ring;
material of the coating-ring coats at least part of an exterior of the cylinder;
the material of the coating-ring is continuous from the coating-ring to the exterior of the cylinder;
a triple-point is formed at a junction of the cylinder, an internal vacuum inside of the cylinder, and the cathode; and
the material of the coating-ring extends between the cathode and the cylinder, thus helping to protect the triple point.