Cgr Mev

Duc Tien Tran

Jacques Kervizic

Dominique Tronc

Bernard Hurt

Guy Azam

Andre Bensussan

Claude Perraudin

Jean-Baptiste Gallet

Device for addition of the power from two alternating signals in a

The invention discloses a resonant system for accelerating charged particles of the cyclotron type allowing this cyclotron to operate successively at two resonant frequencies f.sub.1 and f.sub.2 =mf.sub.1 (m=2 for example) without modification of the structure, this resonant system comprising a sealed enclosure connected to ground and in which is disposed at least one hollow electrode or 'Dee' having the shape of a sector, the enclosure and the 'Dee' being associated with a resonant element formed from a tubular external conductor closed at one of its ends by a metal plate and whose other end opens into the enclosure and, placed inside this external conductor, two internal conductors connected together, at one of their ends, by means of a connecting element determining with the external conductor a capacity C variable in value, for adjusting the operating frequencies f.sub.1 and f.sub.2 of the cyclotron and more particularly the ratio f.sub.1 /f.sub.2.

Microwave resonant system with dual resonant frequency and a cyclotron

An irradiation apparatus comprising a fluid-tight enclosure in which are located a linear electron accelerator, a magnetron supplying a high frequency signal, means for injecting this high frequency signal into the accelerating structure, means for supplying voltage to the magnetron and the accelerator. A magnetic deflecting system can be associated with the linear accelerator for deflecting the accelerated electrons towards a target emitting X-rays. Cooling systems are provided inside the enclosure 1, in particular for cooling the magnetron.

Compact irradiation apparatus using a linear charged-particle accelerator

A linear accelerator for generating a beam of charged particles accelerated within a wide energy range without modifying the microwave energy injected into the accelerator structure, this accelerator structure comprising a bunching section and an accelerating section respectively constituted by a plurality of resonant cavities, the cavities of the bunching section being electromagnetically coupled in such a manner that two adjacent cavities are phase-shifted of .pi. one with respect to the other, these bunching and accelerating sections being respectively supplied by a microwave generator delivering a microwave signal w divided, by means of a combined coupler and phase shifter, into two microwave signals w.sub.1, w.sub.2 respectively injected into the accelerating and bunching sections with predetermined amplitudes and phases.

Linear accelerators of charged particles

A compact accelerating structure comprises an accelerating section and a complementary section which may be used as a bunching section and/or a preaccelerating section, this complementary section being constituted by a first cavity and a second cavity joined to one another and electromagnetically coupled with one another in a direct manner, the second cavity, which is adjacent to the accelerating section, having a length L and being electromagnetically coupled to the first cavity and to the accelerating section in such a manner that the electromagnetic accelerating field is zero in this second cavity.

Accelerating structure for a linear charged particle accelerator

An accelerating structure for a linear particle accelerator operating in the progressive wave mode or in the stationary wave mode and comprising at least one accelerating section and a complementary bunching or pre-accelerating section formed by a resonant cavity C of the 'reentrant' type magnetically coupled with the first cavity of the accelerating section by means of a coupling iris, the cavity C having a length L=(2m+1).lambda..sub.o/4 and the distance D separating the interaction spaces of the cavity C and the first cavity of the accelerating section being equal to D=(2k+n/2+.alpha.).pi..beta..lambda..sub.o, with O.ltoreq..alpha..ltoreq.1/4, n and k being integers, .beta. being the reduced velocity v/c of the particles and .lambda..sub.o being the operating wave length of the accelerator.

An extractive electrode allowing to reduce the vertical focusing and defocusing effect of the hyperfrequency electrical field used for accelerating the particles of a beam within an accelerator of cyclotron type. The extractive electrode comprises a metallic block having a substantially prismatic shape and provided in its entry face facing the particle source with at least a window which opens onto a deep notch delimited by two curved lateral walls forming a channel C for the passage of the beam. A median element located within this channel C allows to obtain two separated channels for the passage of the two beams corresponding to two harmonic operating frequencies.

Extractive electrode situated in the vicinity of the particle source of

A controlled-frequency arrangement for feeding a linear charged particle accelerator and enabling the power reflected by the accelerator toward the microwave generator feeding it to be minimized when the accelerator is loaded by the particle beam. The feeding arrangement comprises means for obtaining a continuous signal v of which the amplitude is proportional to the phase shift .DELTA..phi. which may exist between the microwave signal injected into the accelerator and the signal stored in the accelerator, and for comparing this signal v with a variable reference signal v.sub.4 to obtain an error signal v - v.sub.r which, when applied to a frequency controlling system, causes the frequency F of the microwave generator associated with the accelerator to be suitably varied, this variation in frequency .alpha.F enabling the phase shift .alpha..phi. to be eliminated.

Controlled-frequency feeding arrangement for a linear accelerator using

A high-frequency focusing device making it possible to achieve suitable horizontal and vertical focusing of a beam of charged particles issued from a particle source located substantially at the center of a cyclotron, this device comprising pairs of focusing electrodes fixed to the edges of parallel plates forming each sector-shaped Dees of the cyclotron, each pair of electrodes being arranged in such a manner that the particle beam passes between them, these electrodes which project into the acceleration space e of the cyclotron, making it possible to compensate for lack or excessive vertical focusing brought about by the magnetic field developed in the acceleration space e.

High-frequency focusing device for focusing a beam of charged particles

The present invention relates to an hyperfrequency resonant system designed to accelerate a beam of charged particles, and comprising at least a first resonant cavity (or a group of resonant cavities similar to this first cavity) tuned at a fundamental frequency F and excited by means of an external electro-magnetic energy source and a resonant element which is, for example, a second resonant cavity tuned at harmonic frequency 2F and excited by means of the bunched particle beams. The invention is applicable, for example, to particle accelerators of the 'microtron' kind.

Hyperfrequency resonant system for accelerating a charged particle beam

A particle accelerator for obtaining high energy particle beams, comprises an accelerating structure S.sub.A, one mirror or two mirrors constituted with magnetic achromatic and stigmatic deviators and a source K of particles located at the entry of the accelerating structure S.sub.A and having an annular shape allowing the accelerated particles having passed twice through the accelerating structure S.sub.A to cross the source K, the axis of the source K being coincidental with the axis of the accelerating stucture S.sub.A. Magnetic fields are determined in such a manner that the mirrors totally reflect the particles having a predetermined energy level and totally transmit the particles having an energy level higher than this predetermined energy level.

Linear particle accelerator using magnetic mirrors

Multiperiodic linear accelerating structures comprising a succession of cylindrical accelerating cavities C.sub.a having a revolution axis X.sub.1 X.sub.2, and being coupled to each other by cylindrical coupling cavities C.sub.c having the axis X.sub.1 X.sub.2 as revolution axis, which coincides with the mean path of the beam of the particles to be accelerated, the radius R.sub.c of the coupling cavities C.sub.c being substantially equal to the radius R.sub.a of the accelerating cavities C.sub.a. Accelerating and coupling cavities are constituted by a stack of elements easy to machine and braze together.

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Paris, France

Duc Tien Tran