A radiation imaging system includes a radiation imaging apparatus and an imaging control apparatus, the radiation imaging apparatus includes a dose detection pixel that detects a dose of radiation irradiated from a radiation source, and the imaging control apparatus controls the radiation imaging apparatus. Before radiation imaging, the imaging control apparatus specifies a position of the dose detection pixel in a region of interest for calculating a dose indicator value of a radiation image, determines a threshold according to the position of the dose detection pixel, and transmits the position of the dose detection pixel and the threshold to the radiation imaging apparatus. The radiation imaging apparatus makes a setting of the position of the dose detection pixel in the region of interest and the threshold transmitted from the imaging control apparatus, and performs imaging based on the setting.

A gas ionization chamber, includes a first electrode, a fence electrode disposed below the first electrode, a second electrode disposed below the fence electrode, a first dielectric layer disposed between the first electrode and the fence electrode, and a second dielectric layer disposed between the fence electrode and the second electrode. The first and second electrodes, and the first and second dielectric layers include a plurality of aligned holes forming channels configured to permit gas flow between the first electrode to the second electrode through an opening in the fence electrode, the plurality of aligned holes being arranged in a pattern having a central region with a first set of aligned holes and a peripheral region having a second set of aligned holes, and wherein a diameter of at least one hole of the first set of aligned holes is less than or equal to about 0.5 millimeters.

Device and method for measuring in-situ time-resolved X-ray absorption spectrum. The device comprises an X-ray source, a first slit, an acousto-optic tunable X-ray filter, a radio frequency transmitter, a second slit, a front ionization chamber, a front ionization chamber signal amplifier, a sample to be tested, a rear ionization chamber, a rear ionization chamber signal amplifier, a data collector, and a computer. The X-ray source, the acousto-optic tunable X-ray filter, and the radio frequency transmitter are used to generate a monochromatic X-ray beam; the front ionization chamber is used to measure the intensity of the X-ray beam before passing through the sample; the rear ionization chamber is used to measure the intensity of the X-ray beam after passing through the sample; the front ionization chamber signal amplifier, the rear ionization chamber signal amplifier, the data collector, and the computer are used for data acquisition and data processing.

Device and method for measuring in-situ time-resolved X-ray absorption spectrum. The device comprises an X-ray source, a first slit, an acousto-optic tunable X-ray filter, a radio frequency transmitter, a second slit, a front ionization chamber, a front ionization chamber signal amplifier, a sample to be tested, a rear ionization chamber, a rear ionization chamber signal amplifier, a data collector, and a computer. The X-ray source, the acousto-optic tunable X-ray filter, and the radio frequency transmitter are used to generate a monochromatic X-ray beam; the front ionization chamber is used to measure the intensity of the X-ray beam before passing through the sample; the rear ionization chamber is used to measure the intensity of the X-ray beam after passing through the sample; the front ionization chamber signal amplifier, the rear ionization chamber signal amplifier, the data collector, and the computer are used for data acquisition and data processing.

According to one embodiment, a radiation-measurement-instrument support device comprising: a cylindrical casing configured to house at least one phantom and a radiation measurement instrument and formed in a cylindrical shape; a base configured to rotatably support the cylindrical casing in a circumferential direction in a state where a cylindrical axis of the cylindrical casing is directed in a horizontal direction and fix the cylindrical casing at an arbitrary rotation angle in the circumferential direction; and an angle display configured to display the rotation angle.