Method and an apparatus for examining an object by using ionizing radiation

An apparatus for examining an object comprising:

• a source for producing ionizing radiation photons;
• means for providing other particles or photons, said other particles or photons having participated in the production of said ionizing radiation photons, being produced through interaction of said ionizing radiation photons with matter, or being produced simultaneously with the production of said ionizing radiation photons;
• wherein each of said other particles or photons carries information regarding position at a given point of time, time of arrival at a given position, movement direction, and/or energy of a respective one of said ionizing radiation photons before having interacted with said object to be examined;
• a first detector for detecting each of said other particles or photons to retrieve said information of a respective one of said ionizing radiation photons;
• an object area for housing an object to be examined, the object area being arranged so that said ionizing radiation photons are directed to and interact with said object;
• a second detector for detecting at least some of said ionizing radiation photons after having interacted with said object to be examined to retrieve information regarding position at a given point of time, time of arrival at a given position, movement direction, and/or energy of each of said detected ionizing radiation photons;
• and
• a signal-processing device connected to said first and second detectors for correlating each of said detected ionizing radiation photons with a respective one of said other particles or photons, and for deducing information of said examined object by means of said information as retrieved by said first and second detectors.

A method for examining an object comprising the steps of:

• producing ionizing radiation photons;
• providing other particles or photons, said other particles or photons having participated in the production of said ionizing radiation photons, being produced through interaction by said ionizing radiation photons with matter, or being produced simultaneously with the production of said ionizing radiation photons, wherein a ratio of a number of said other particles or photons and a number of ionizing radiation photons is known;
• detecting each of said other particles or photons;
• having said ionizing radiation photons to interact with said object to be examined;
• detecting at least some of said ionizing radiation photons after having interacted with said object to be examined;
• subtracting the number of said detected ionizing radiation photons from the product of the number of said detected other particles or photons and the ratio of the number of said other particles or photons and the number of ionizing radiation photons;
• and
• deducing information of said examined object by means of said difference.

An apparatus for examining an object comprising:

• a source for producing ionizing radiation photons;
• means for providing other particles or photons, said other particles or photons having participated in the production of said ionizing radiation photons, being produced through interaction by said ionizing radiation photons with matter, or being produced simultaneously with the production of said ionizing radiation photons, wherein a ratio of a number of said other particles or photons and a number of ionizing radiation photons is known;
• a first detector detecting each of said other particles or photons;
• an object area for housing an object to be examined, the object area being arranged so that said ionizing radiation photons are directed to and interacting with said object;
• a second detector for detecting at least some of said ionizing radiation photons after having interacted with said object to be examined;
• a signal-processing device connected to said first and second detectors for subtracting the number of said detected ionizing radiation photons from the product of the number of said detected other particles or photons and the ratio of the number of said other particles or photons and the number of ionizing radiation photons, and for deducing information of said examined object by means of said difference.