Radiation generating apparatus and radiation imaging apparatus

An X-ray radiation imaging apparatus comprising:

• an X-ray radiation generating apparatus which comprises:
• an envelope which has a first window through which radiation is transmitted;
• a radiation tube which is held in said envelope, and has, at a position facing said first window, a second window through which the X-ray radiation is transmitted;
• a shielding member which has a radiation passing hole which is in communication with said second window;
• an insulating liquid which is filled between said envelope and said radiation tube;
• and
• a solid insulating member which is arranged between said shielding member and an inner wall of said envelope, and is apart from said shielding member, and has an opening at a position corresponding to said first window,
• wherein a shortest length of a supposed straight line stretching from said shielding member to said first window through said opening of said insulating member without intersecting said insulating member or stretching from said shielding member to said inner wall of said envelope through said opening of said insulating member without intersecting said insulating member is longer than a shortest length of a supposed straight line stretching from said shielding member to said first window and intersecting said insulating member or stretching from said shielding member to said inner wall of said envelope and intersecting said insulating member;
• a radiation detector configured to detect the radiation emitted from said radiation generating apparatus and transmitted through an object;
• and
• a controlling unit configured to control said radiation generating apparatus and said radiation detector.