公开(公告)号：US10796876B2

公开(公告)日：2020-10-06

申请号：US15983967

申请日：2018-05-18

Applicant: Colorado State University Research Foundation

Inventor： Bao Gia Nguyen ,  John D. Williams ,  Desiree D. Williams ,  Casey C. Farnell ,  Ryan Kenneth Ham ,  Kathryn Elizabeth Greiner

IPC: H01J29/48 ,  H01J9/04 ,  H01J37/02 ,  B33Y40/00 ,  H05H1/48 ,  H01J1/28 ,  H01J37/065 ,  B33Y30/00 ,  H01J29/04 ,  H01J3/02 ,  B22F3/105 ,  H01J27/20

Abstract: A filament assembly can include: a button having a planar emitter region with one or more apertures extending from an emission surface of the planar emitter region to an internal surface opposite of the emission surface; an inlet electrical lead coupled to the button at a first side; an outlet electrical lead coupled to the button at a second side opposite of the first side; and a low work function object positioned adjacent to the internal surface of the planar emitter region and retained to the button. The planar emitter region can include a plurality of apertures. The low work function object can include a porous ceramic material having the barium, and may have a polished external surface. An electron gun can include the filament assembly. An additive manufacturing system can include the electron gun having the filament assembly.

公开(公告)号：US20180269024A1

公开(公告)日：2018-09-20

申请号：US15983967

申请日：2018-05-18

Applicant: Colorado State University Research Foundation

Inventor： Bao Gia Nguyen ,  John D. Williams ,  Desiree D. Williams ,  Casey C. Farnell ,  Ryan Kenneth Ham ,  Kathryn Elizabeth Greiner

IPC: H01J29/48 ,  H01J3/02 ,  H01J9/04 ,  H01J37/02

Abstract: A filament assembly can include: a button having a planar emitter region with one or more apertures extending from an emission surface of the planar emitter region to an internal surface opposite of the emission surface; an inlet electrical lead coupled to the button at a first side; an outlet electrical lead coupled to the button at a second side opposite of the first side; and a low work function object positioned adjacent to the internal surface of the planar emitter region and retained to the button. The planar emitter region can include a plurality of apertures. The low work function object can include a porous ceramic material having the barium, and may have a polished external surface. An electron gun can include the filament assembly. An additive manufacturing system can include the electron gun having the filament assembly.

公开(公告)号：US10002738B1

公开(公告)日：2018-06-19

申请号：US15466768

申请日：2017-03-22

Applicant: Colorado State University Research Foundation

Inventor： Casey Farnell ,  Cody Farnell ,  John Williams ,  Desiree Williams ,  Bao Gia Nguyen ,  Kathryn Elizabeth Greiner ,  Ryan Kenneth Ham

IPC: H01J9/04 ,  H05H1/24 ,  B22F3/11 ,  H01J29/04 ,  B22F3/24

Abstract: In an example, a method to form a low work function insert includes preparing a mixture that includes a first powder that contains barium, a second powder that contains calcium, a third powder that contains at least one of aluminum, samarium, or magnesium, and a fourth powder that contains a refractory metal. The method may also include heating the mixture, contained in a crucible, in a furnace. Oxygen concentration in the furnace may be maintained at a low partial pressure during heating of the mixture in the furnace. The low work function of the insert allows electrons to be readily extracted from its surface.