A radiation detection element includes a base material, a first electrode, a second electrode, a third electrode, a fourth electrode, a fifth electrode, a first external terminal, a second external terminal, a third external terminal, and a fourth external terminal. Each of the first external terminal, the second external terminal, the third external terminal, and the fourth external terminal is a solder ball, and the first external terminal, the second external terminal, the third external terminal, and the fourth external terminal are insulated from each other. A region provided on the first electrode, the second electrode, the third electrode, the fourth electrode, and the fifth electrode overlaps at least one of the first external terminal, the second external terminal, the third external terminal, and the fourth external terminal in a view vertical to the first surface side of the base material.

A detection element can obtain a high-resolution radiation image having a high signal intensity and a high S/N ratio. A detection element including a substrate having a through hole, an insulating layer arranged inside of the through hole, a through electrode arranged further to the inner side of the through hole than the insulating layer, a resin layer having insulating properties and having an opening portion exposing the through electrode, a first electrode arranged above the through electrode and the resin layer, the first electrode being connected to the through electrode through the opening portion, and a second electrode arranged above the resin layer, the second electrode being separated from the first electrode.

A radiation image forming apparatus includes a detection unit including a plurality of Compton cameras. Each of the plurality of Compton cameras including a radiation detection device that includes a plurality of pixels, each configured to detect an electron generated by the track of a recoil electron generated by Compton scattering, and is configured to output a detection signal configured to specify the position of a pixel that has detected the electron and a time when the pixel has detected the electron, and a detection module configured to detect the incident position of scattered rays generated by the Compton scattering. The plurality of the Compton cameras arranged annularly to surround a region in which a specimen is placed.

A radiation detector using gas amplification, includes: an insulator having a first surface and a second surface positioned at a back surface side of the first surface; a first electrode layer that is provided on the first surface of the insulator and has a circular opening portion; a pixel electrode positioned inside the opening portion; a second electrode layer provided on the second surface of the insulator; and a via hole conductor that has one end surface thereof bonded to the second electrode layer through the interior of the insulator and has the other end surface thereof bonded to the pixel electrode, in which at least a part of the other end surface side of the via hole conductor exhibits a column or truncated cone shape and an outer diameter of the via hole conductor becomes smallest at the one end surface.

An ion filter used for an electron multiplier includes an insulating substrate; a first conductive layer formed on one main surface of the substrate; and a second conductive layer formed on another main surface of the substrate. The ion filter has a plurality of through-holes formed along a thickness direction of the substrate. The one main surface of the substrate is disposed at a downstream side in a moving direction of electrons in a chamber of the electron multiplier and the other main surface of the substrate is disposed at an upstream side in the moving direction of electrons in the chamber of the electron multiplier. A first thickness of the first conductive layer formed on the one main surface of the substrate is thicker than a second thickness of the second conductive layer on the other main surface of the substrate.

An ion filter used for an electron multiplier includes an insulating substrate; a first conductive layer formed on one main surface of the substrate; and a second conductive layer formed on another main surface of the substrate. The ion filter has a plurality of through-holes formed along a thickness direction of the substrate. The one main surface of the substrate is disposed at a downstream side in a moving direction of electrons in a chamber of the electron multiplier and the other main surface of the substrate is disposed at an upstream side in the moving direction of electrons in the chamber of the electron multiplier. A first thickness of the first conductive layer formed on the one main surface of the substrate is thicker than a second thickness of the second conductive layer on the other main surface of the substrate.

A radiation detection element includes a base material, a first electrode, a second electrode, a third electrode, a fourth electrode, a fifth electrode, a first external terminal, a second external terminal, a third external terminal, and a fourth external terminal. Each of the first external terminal, the second external terminal, the third external terminal, and the fourth external terminal is a solder ball, and the first external terminal, the second external terminal, the third external terminal, and the fourth external terminal are insulated from each other. A region provided on the first electrode, the second electrode, the third electrode, the fourth electrode, and the fifth electrode overlaps at least one of the first external terminal, the second external terminal, the third external terminal, and the fourth external terminal in a view vertical to the first surface side of the base material.

A radiation detection element includes a base material, a first electrode, a second electrode, a third electrode, a fourth electrode, a fifth electrode, a first external terminal, a second external terminal, a third external terminal, and a fourth external terminal. Each of the first external terminal, the second external terminal, the third external terminal, and the fourth external terminal is a solder ball, and the first external terminal, the second external terminal, the third external terminal, and the fourth external terminal are insulated from each other. A region provided on the first electrode, the second electrode, the third electrode, the fourth electrode, and the fifth electrode overlaps at least one of the first external terminal, the second external terminal, the third external terminal, and the fourth external terminal in a view vertical to the first surface side of the base material.

A radiation detector using gas amplification, includes: an insulator having a first surface and a second surface positioned at a back surface side of the first surface; a first electrode layer that is provided on the first surface of the insulator and has a circular opening portion; a pixel electrode positioned inside the opening portion; a second electrode layer provided on the second surface of the insulator; and a via hole conductor that has one end surface thereof bonded to the second electrode layer through the interior of the insulator and has the other end surface thereof bonded to the pixel electrode, in which at least a part of the other end surface side of the via hole conductor exhibits a column or truncated cone shape and an outer diameter of the via hole conductor becomes smallest at the one end surface.