An emitter according to the present disclosure includes: first and second heaters generating heat by energization; an electron source comprising a first material emitting an electron by being heated by the first and second heaters; and an intermediate member interposed between the electron source, and the first and second heaters, the intermediate member comprising a second material lower in thermal conductivity than the first material.

An emitter according to the present disclosure includes: first and second heaters generating heat by energization; an electron source comprising a first material emitting an electron by being heated by the first and second heaters; and an intermediate member interposed between the electron source, and the first and second heaters, the intermediate member comprising a second material lower in thermal conductivity than the first material.

A charged particle beam system includes a charged particle source that generates a first charged particle beam and a multi beam generator that generates a plurality of charged particle beamlets from an incoming first charged particle beam. Each individual beamlet is spatially separated from other beamlets. The charged particle beam system also includes an objective lens that focuses incoming charged particle beamlets in a first plane so that a first region in which a first individual beamlet impinges in the first plane is spatially separated from a second region in which a second individual beamlet impinges in the first plane. The charged particle beam system also includes a projection system and a detector system including a plurality of individual detectors. The projection system images interaction products leaving the first region within the first plane due to impinging charged particles onto a first detector and images interaction products leaving the second region in the first plane onto a second detector.

A charged particle beam system includes a charged particle source that generates a first charged particle beam and a multi beam generator that generates a plurality of charged particle beamlets from an incoming first charged particle beam. Each individual beamlet is spatially separated from other beamlets. The charged particle beam system also includes an objective lens that focuses incoming charged particle beamlets in a first plane so that a first region in which a first individual beamlet impinges in the first plane is spatially separated from a second region in which a second individual beamlet impinges in the first plane. The charged particle beam system also includes a projection system and a detector system including a plurality of individual detectors. The projection system images interaction products leaving the first region within the first plane due to impinging charged particles onto a first detector and images interaction products leaving the second region in the first plane onto a second detector.

An activation mechanism is provided in an activation region of an electron gun, and includes a light source device 3 configured to irradiate a photocathode with excitation light, a heat generating element, an oxygen generation unit configured to generate oxygen by heating the heat generating element, and an emission current meter configured to monitor an emission current generated by electron emission when the photocathode 1 is irradiated with the excitation light from the light source device. In a surface activation process, the photocathode is irradiated with the excitation light from the light source device, an emission current amount of the photocathode is monitored by the emission current meter, the heat generating element is heated to generate oxygen by the oxygen generation unit, and the heating of the heat generating element is stopped when the emission current amount of the photocathode satisfies a predetermined stop criterion.

An activation mechanism is provided in an activation region of an electron gun, and includes a light source device 3 configured to irradiate a photocathode with excitation light, a heat generating element, an oxygen generation unit configured to generate oxygen by heating the heat generating element, and an emission current meter configured to monitor an emission current generated by electron emission when the photocathode 1 is irradiated with the excitation light from the light source device. In a surface activation process, the photocathode is irradiated with the excitation light from the light source device, an emission current amount of the photocathode is monitored by the emission current meter, the heat generating element is heated to generate oxygen by the oxygen generation unit, and the heating of the heat generating element is stopped when the emission current amount of the photocathode satisfies a predetermined stop criterion.

A method for manufacturing an electron source according to the present disclosure includes steps of: (A) preparing a first member provided with a columnar portion made of a first material having an electron emission characteristic, (B) preparing a second member which has a higher work function and a lower strength than the first material, and in which a hole is formed extending in a direction from one end surface toward the other end surface, and (C) pushing the columnar portion into the hole in the second member, wherein the first member has a cross-sectional shape that is dissimilar to the cross-sectional shape of the hole; and in the step (C), by pressing the columnar portion into the hole, a portion of a side surface of the columnar portion scrapes the inner surface of the hole and bites into the second member, thereby fixing the columnar portion to the second member.

A method for manufacturing an electron source according to the present disclosure includes steps of: (A) preparing a first member provided with a columnar portion made of a first material having an electron emission characteristic, (B) preparing a second member which has a higher work function and a lower strength than the first material, and in which a hole is formed extending in a direction from one end surface toward the other end surface, and (C) pushing the columnar portion into the hole in the second member, wherein the first member has a cross-sectional shape that is dissimilar to the cross-sectional shape of the hole; and in the step (C), by pressing the columnar portion into the hole, a portion of a side surface of the columnar portion scrapes the inner surface of the hole and bites into the second member, thereby fixing the columnar portion to the second member.

In a cylindrical guard electrode (5) provided on the outer peripheral side of an electron generation part (31) of an emitter (3), a distal end section (5A) 5 positioned in the emission direction of an electron beam (L1) from the electron generation part (31) includes: a distal end inner-peripheral-side part (A1) having an inner-peripheral-side curved surface portion (a1) convex in the emission direction; a distal end outer-peripheral-side part (A2) having an outer-peripheral-side curved portion (a2) convex in the emission direction; and a 10 distal end middle part (A3) positioned between the distal end inner-peripheral-side (A1) and the distal end outer-peripheral-side part (A2). The distal end middle part (A3) has a flat surface portion (a3) between the inner-peripheral-surface portion (a1) and the outer-peripheral-side curved surface portion (a2) so as to extend in the direction therebetween.

A photoelectric surface electron source includes a glass substrate configured to receive laser light incident from a substrate back surface to emit the laser light from a substrate main surface, a photoelectric surface provided on the substrate main surface and configured to receive the laser light and emit a photoelectron, a lens array disposed on the substrate back surface and including a plurality of microlenses for condensing the laser light toward the photoelectric surface, and a light shielding portion provided on the glass substrate. The light shielding portion has a back surface-side light shielding layer provided on a back surface-side light shielding surface interposed between the plurality of microlenses on the substrate back surface, and a main surface-side light shielding layer provided on a main surface-side light shielding surface.