An ion filter is used for a gas detector including a gas electron multiplier. The ion filter includes: an insulating substrate; a first patterned conductive layer on one main surface of the insulating substrate; and a second patterned conductive layer on another main surface of the insulating substrate. The ion filter has a plurality of through-holes formed along a thickness direction of the insulating substrate on which the first patterned conductive layer and the second patterned conductive layer are formed. The one main surface of the insulating substrate is disposed on an upstream side in a movement direction of electrons in the gas detector. The other main surface of the insulating substrate is disposed on a downstream side in the movement direction of the electrons in the gas detector. The first patterned conductive layer has a line width thicker than a line width of the second patterned conductive layer.

An ion filter is used for a gas detector including a gas electron multiplier. The ion filter includes: an insulating substrate; a first patterned conductive layer on one main surface of the insulating substrate; and a second patterned conductive layer on another main surface of the insulating substrate. The ion filter has a plurality of through-holes formed along a thickness direction of the insulating substrate on which the first patterned conductive layer and the second patterned conductive layer are formed. The one main surface of the insulating substrate is disposed on an upstream side in a movement direction of electrons in the gas detector. The other main surface of the insulating substrate is disposed on a downstream side in the movement direction of the electrons in the gas detector. The first patterned conductive layer has a line width thicker than a line width of the second patterned conductive layer.

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 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 detection element includes a plurality of pixel electrodes, each pixel electrodes including a first electrode placed on the first surface of an insulating member and having an opening portion and a second electrode placed at the opening portion of the first electrode. The plurality of pixel electrodes is arrayed in the row direction and the column direction. The pitch of the pixel electrodes in the row direction and the column direction is 380 ?m or less. An area ratio between the first electrode and the second electrode falls within the range of 14.5:1 to 154.6:1.

A radiation detection element includes a plurality of pixel electrodes, each pixel electrodes including a first electrode placed on the first surface of an insulating member and having an opening portion and a second electrode placed at the opening portion of the first electrode. The plurality of pixel electrodes is arrayed in the row direction and the column direction. The pitch of the pixel electrodes in the row direction and the column direction is 380 ?m or less. An area ratio between the first electrode and the second electrode falls within the range of 14.5:1 to 154.6:1.

An ion filter is used for a gas detector including a gas electron multiplier. The ion filter includes: an insulating substrate; a first patterned conductive layer on one main surface of the insulating substrate; and a second patterned conductive layer on another main surface of the insulating substrate. The ion filter has a plurality of through-holes formed along a thickness direction of the insulating substrate on which the first patterned conductive layer and the second patterned conductive layer are formed. The one main surface of the insulating substrate is disposed on an upstream side in a movement direction of electrons in the gas detector. The other main surface of the insulating substrate is disposed on a downstream side in the movement direction of the electrons in the gas detector. The first patterned conductive layer has a line width thicker than a line width of the second patterned conductive layer.

A radiation detection element includes a plurality of pixel electrodes, each pixel electrodes including a first electrode placed on the first surface of an insulating member and having an opening portion and a second electrode placed at the opening portion of the first electrode. The plurality of pixel electrodes is arrayed in the row direction and the column direction. The pitch of the pixel electrodes in the row direction and the column direction is 380 ?m or less. An area ratio between the first electrode and the second electrode falls within the range of 14.5:1 to 154.6:1.

A radiation detection element includes a plurality of pixel electrodes, each pixel electrodes including a first electrode placed on the first surface of an insulating member and having an opening portion and a second electrode placed at the opening portion of the first electrode. The plurality of pixel electrodes is arrayed in the row direction and the column direction. The pitch of the pixel electrodes in the row direction and the column direction is 380 ?m or less. An area ratio between the first electrode and the second electrode falls within the range of 14.5:1 to 154.6:1.

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.