Abstract: The chamber contains a first and a second measuring electrode and a third electrode. The first measuring electrode is essentially a first flat ring portion. The second measuring electrode comprises an inner circular area to the periphery of which a second flat ring portion adjoins in an electrically conducting manner. The first and the second measuring electrodes are arranged in a first plane. The first and the second ring portion are combined approximately 360.degree.. The third electrode is arranged in a second plane parallel to and spaced from the first plane. When ionizing radiation (X-rays, electrons) enters the space between the first and second measuring electrodes on the one side and the third electrode on the other side, electrical signals will be derived from said respective first and second electrode.

Abstract: The collimator assembly comprises a collimator shielding block for blocking undesired X-rays and an insert piece inserted into the shielding block. The insert piece which is made of a material of high atomic number, has an inner conical surface which defines the X-ray cone transmitting the insert piece and therefore the maximum field size which can be obtained for medical treatment. In order to supply different maximum field sizes, there are provided means for easily interchanging the insert in the collimator shielding block with another insert having a different interior conical dimension. By using inserts of different cone angles, which can easily be inserted into the shielding block, for instance by means of a screw thread from below the shielding block, morbid tissues of different sizes can be treated while the surrounding healthy tissue is fully protected.

Abstract: The filter arrangement for an X-ray apparatus contains an X-ray source for emitting a diverging beam of X-rays and a filter plate positioned in the beam of X-rays. The beam is symmetrical with respect to a center beam axis. The filter plate which serves for attenuation of the X-rays before they impinge on a target is mounted on a pivoting axis. The pivoting axis is preferably arranged remote from and transverse to the center beam axis. By pivoting the filter plate about the pivoting axis into a selected position, a selected radiation profile can be obtained on the target. The rotatable filter plate can thus replace a plurality of wedge filters.

Abstract: The energy interlock system is designed for a linear accelerator having no electron beam bending system. The accelerator emits electron pulses which are directed to a target for generation of X-ray pulses. The interlock system contains an ionization chamber, a discriminator and a switch. The ionization chamber is exposed to the X-ray pulses for measuring their intensity distribution. It comprises a control electrode and a plurality of electrode segments. The discriminator is connected for detecting energy inhomogeneities in the X-ray pulses. The switch is operated by the discriminator and connected to switch the accelerator on and off.

Abstract: The collimator assembly comprises a collimator shielding block for blocking undesired X-rays and an insert piece inserted into the shielding block. The insert piece, which is made of a material of high atomic number, has an inner conical surface which defines the X-ray cone transmitting the insert piece and therefore the maximum field size which can be obtained for medical treatment. In order to supply different maximum field sizes, there are provided means for easily interchanging the insert in the collimator shielding block with another insert having a different interior conical dimension. By using inserts of different cone angles, which can easily be inserted into the shielding block, for instance by means of a screw thread from below the shielding block, morbid tissues of different sizes can be treated while the surrounding healthy tissue is fully protected.

Abstract: The energy interlock system contains a measuring device, a discriminator and a switch. The measuring device determines the level of the particle beam pulses which are emitted by the accelerator. For this purpose it contains a target which is exposed to the particle beam pulses. The discriminator determines whether the level of the particle pulses has crossed a predetermined value. The switch is operated by the discriminator. It is connected for supervision of the accelerator.

Abstract: The particle accelerator contains an accelerator guide for accelerating particles, an injector for injecting particles into the accelerator guide, a pulsed source of high frequency power which has power adjusting means, a device for introducing the high frequency power from the source into the accelerator guide, a measuring device for measuring particle pulses emitted from the accelerator guide, and a power control circuit connected to the power adjusting means. The power control circuit includes a circuit for supplying an adjusting signal in dependence on the deviation of each particle pulse from an optimum pulse form and a connecting circuitry for connecting the adjusting signal to the power adjusting means. By changing the high frequency power of the source, the form of the measured particle pulses is adjusted towards the optimum pulse form.

Abstract: The invention relates to a radio therapy apparatus comprising an electron accelerator having a target and a collimator for limiting the X-ray cone. In the use of such electron accelerators, the radiation load of the patient is increased in an undesirable manner by neutrons in addition to the therapeutically desired roentgen quanta. To reduce the neutron level the invention provides that the edge zone of the collimator facing the target is made of a material of low effective cross-section for (gamma, n) processes. The dimension of this edge zone material approximately corresponds to the half-value depth of the X radiation in this material.

Abstract: The electron exit window assembly contains a metal cover plate, a titanium insert piece and a titanium exit window. The cover plate covers the interior of the last cavity of the accelerator. It contains an insert opening into which is inserted the insert piece in a vacuum tight manner. The insert piece in turn contains a hole which is covered by the exit window. The cover plate preferably is made of stainless steel, and the insert piece is preferably brazed into the insert opening of the cover plate.

Abstract: The target assembly contains a metal plate which has two end faces, a recess in one of these end faces, a target for generating X-rays when hit by high-energy electrons, and a cooling channel in the metal plate for directing a cooling medium therethrough. The target is arranged in the recess of the metal plate such that the recess is divided into two chambers. The cooling channel passes through these two chambers thereby exposing the target directly to the cooling medium when the latter flows through the cooling channel.

Abstract: The electron applicator incorporates a stationary support tube and an insert tube. The support tube and the insert tube each have a first end portion and a second end portion. The first end portion of the insert tube slideably extends into the second end portion of the support tube. Electrons of high energy are transmitted through the assembly of both tubes. The surface of the insert tube is tapered inwardly toward the end thereof in the travelling direction of the high energy electrons. A device is provided for preventing the insert tube from sliding out of the support tube. A first engaging device engages the insert tube in a first working position. This device is such that upon a predetermined axial force which may inadvertently be exercised by a patient under treatment, the insert tube will slide into the support tube.An adapter for small field or cavetory treatment may be connected to the output end of the insert tube.

Abstract: The invention relates to an electron accelerator including an evacuated acceleration tube, a target exposed to the electron beam, an electron absorber following the target in beam direction, a collimator and a compensation body arranged therein centered on the axis of symmetry thereof. In such electron accelerators, used in radiotherapy, the soft radiation component is to be suppressed as much as possible. To this end the invention provides a filter plate made of heavy metal beyond the electron absorber, while the compensation body is made of a material of comparatively low atomic number. The filter plate may be inserted between the electron absorber and the compensation body. The target may be provided on the side of the electron absorber facing the acceleration tube.

Abstract: A charged particle accelerator has an accelerator chamber in the interior of which a narrow beam of charged particles is accelerated. The particle beam is directed to a discharge window for discharging the particles therethrough. A device is provided for wobbling the beam of particles before the particles strike the discharge window, thereby enlarging the area where the particles strike the window. Preferably a magnetic wobbling device may be used. Such a device may have one or more magnetic coils which is/are arranged near the discharge window and which receive(s) a varying electric current. The accelerator may be a linear accelerator generating high energy electrons or X-rays for medical treatment.

Abstract: The radiation emitting apparatus contains a radiation source which projects a beam of radiation along a central axis onto a surface to be irradiated. There are provided a first and a second light-beam localizer for emitting a first and a second plane light fan, respectively, towards the surface to be irradiated. The second light fan intersects the first light fan in an intersecting line which coincides with the central axis of the emitted radiation. A scale may be projected towards the surface along with one of the light fans. In a preferred embodiment the radiation source is an electron accelerator and the surface is the skin of a patient to be treated.