Abstract: The use of an externally located dipole array mounted upon a high dielectric material for heating biological tissues is disclosed. This dipole array provides improved flexibility and adaptability to varying tissue surface contours. The adjustable dipole antenna array or other type of electromagnetic antenna applicators provides an ability to adapt the heating pattern to meet the needs of the different tissue zones, applicator positions, and applicator mechanical scanning by adjusting individual power amplitude and phase to the various elements of the applicator array for controlling the heat distribution of heat in target tissue having areas of varying power absorption and cooling effect (blood flow). The array design may also include capacitively coupled metal elements in the form of strips, patches or tubes.

Abstract: A direct contact microwave hyperthermia applicator includes a plurality of rectangular waveguide sections each having a radiating aperture. The waveguide sections are mounted with their long sides abutting. A pair of shutter elements for individually varying the radiating aperture is associated with each of the waveguide sections. The shutters can be adjusted to form a desired composite aperture which produces a radiation pattern adapted for efficient hyperthermia treatment of a tumor having a prescribed size, shape and location. Microwave power supplied to the radiating elements can be varied in phase and power level to further control the radiation pattern.

Abstract: A direct contact hyperthermia applicator includes an ultrasonic lens with an array of ultrasonic transducers and an array of microwave antenna elements mounted behind the lens and positioned for transmission of ultrasonic wave energy and microwave energy therethrough. The antenna elements can be waveguide sections having radiating apertures or microstrip antenna elements. A fluid enclosure is defined between the front surface of the lens and a thin rubber sheet sealed around the periphery of the lens. During hyperthermia treatment, the rubber sheet conforms to the contours of the patient's body. The fluid, which is typically cooled distilled water, improves coupling of microwave energy and ultrasonic wave energy into the patient's body and cools the surface region.

Abstract: An improved microwave applicator includes a frequency tuner discoupled from an input power coupling tuner. The frequency tuner includes parallel elongated dielectric bars axially adjustable in a dielectric-filled waveguide. A central passageway space is provided between the dielectric bars for incorporation of an input coupling tuner in the form of a magnetic loop assembly. The magnetic loop assembly includes a metal loop connected to a metal block and means for axially adjusting the position of the loop assembly within the central passageway space between the elongated dielectric members. Frequency and input coupling tuning controls, as well as the microwave input connector, are located behind the closed end of the waveguide applicator to facilitate optimization of mutual positioning of multiple applicators.

Abstract: Multiple microwave applicators are configured to optimize the treatment in a hyperthermia system. Individual applicators are positioned for incrementally varying the treatment field size by the addition or subtraction of individual applicators. A fan beam geometric configuration may be utilized with individual applicators for producing a concave electric field for focusing the electromagnetic energy at a particular region of the body. The microwave applicator system may be positioned either in direct or indirect contact with a treatment area by positioning individual applicators to conform to the contours of the surface treatment area. The applicators may be combined to provide a continuing electromagnetic field pattern.

Abstract: A hyperthermia treatment system has multiple applicators and multiple temperature sensors for controlling the operation of the hyperthermia system. A temperature sensor probe implanted within a tumor provides a temperature signal for controlling and optimizing the power input to multiple applicators to maintain the system output during the treatment period at a predetermined control temperature. Temperature sensors implanted in the region of the healthy tissue provide temperature signals to override the controls providing power input to the applicators to prevent injury to healthy tissues. Individual microwave applicators are evaluated during the hyperthermia treatment to determine their effect on the overall heating pattern for optimizing the heating pattern.

Abstract: In a resonant chain of coupled cavities such as used in a standing-wave linear particle accelerator it is often desirable to change the field strength in some cavities relative to some others. For example, if the output particle energy of an accelerator is changed by varying the fields of all cavities, the distribution of energies of output particles is disturbed. This distribution is largely controlled by the fields in the first group of cavities traversed by the particle beam. According to the invention, the fields can remain constant in the first group and be varied in following cavities. This is done by varying the distribution of electromagnetic field in one cavity asymmetrically with respect to the preceding and the following cavity. The asymmetric coupling produces different acceleration fields in one part of acceleration structure relative to another part.

Abstract: Variable energy selection is accomplished in a side cavity coupled standing wave linear accelerator by shifting the phase of the field in a selected side coupling cavity by .pi. radians where such side coupling cavity is disposed intermediate groups of accelerating cavities. For an average acceleration energy of E.sub.1 (MeV) per interaction cavity, and a total number of N interaction cavities, the total energy gain is E.sub.1 (N-2N.sub.1) where N.sub.1 is the number of interaction cavities traversed beyond the incidence of the phase shift. The phase shift is most simply accomplished by changing the selected side cavity configuration mechanically in repeatable manner so that its resonant excitation is switched from TM.sub.010 mode to either TM.sub.011 or TEM modes. Thus, the total energy gain can be varied without changing the RF input power. In addition, the beam energy spread is unaffected.

Abstract: A standing-wave linear charged particle accelerator is disclosed which comprises a plurality of interlaced substructures, with each substructure having a plurality of accelerating cavities disposed along the particle beam path and having side cavities disposed away from the beam path for electromagnetically coupling the accelerating cavities. A radio-frequency electromagnetic standing wave is supported in each substructure, with the wave in each substructure being phased with respect to the wave in every other substructure so that the particle beam will experience a maximum energy gain throughout its path through the accelerator. A slotted input coupler is connected to the accelerator to individually drive each of the substructures.

Abstract: A standing-wave linear charged particle accelerator is disclosed which comprises a plurality of interlaced substructures, with each substructure having a plurality of accelerating cavities disposed along the particle beam path and having side cavities disposed away from the beam path for electromagnetically coupling the accelerating cavities. A standing radio-frequency electromagnetic wave is supported in each substructure, with the wave in each substructure being phased with respect to the wave in every other substructure so that the particle beam will experience a maximum energy gain throughout its path through the accelerator. A single input waveguide is divided into plural branches to individually drive each of the substructures.

Abstract: In the field of side-cavity coupled accelerators the accelerating cavity to which the accelerating power input is connected has preferably a smaller diameter than the other accelerating cavities. A side cavity is connected by a separate passage to the accelerating cavities of different diameter it couples together, whereby the areas of the coupling irises formed where said passages enter said accelerating cavities can be independently controlled by selecting the length of the respective passage. This separate passage arrangement is particularly described in an accelerator which comprises a plurality of interlaced substructures, with each substructure having a plurality of accelerating cavities disposed along the particle beam path and having side cavities disposed away from the beam path for electromagnetically coupling the accelerating cavities. A standing radio-frequency electromagnetic wave is fed to an accelerating cavity in each substructure so there are plural driven cavities in a single accelerator.

Abstract: A standing-wave linear charged particle accelerator is disclosed which comprises a plurality of interlaced substructures, with each substructure having a plurality of accelerating cavities disposed along the particle beam path and having side cavities disposed away from the beam path for electromagnetically coupling the accelerating cavities. A standing radio-frequency electromagnetic wave is supported in each substructure, with the wave in each substructure being phase with respect to the wave in every other substructure so that the particle beam will experience a maximum energy gain throughout its path through the accelerator. This interlaced substructure configuration minimizes the transit time of the particles across the gap of each accelerating cavity and makes it possible to operate the accelerator without radio-frequency breakdown at a power level that provides a substantially higher average value of the accelerating electric field along the beam path than has heretofore been obtainable.

Abstract: A ferrite-to-metal bond suitable for the environment of a high-power microwave circulator is disclosed. The bonding surface of a gyromagnetic ferrite or garnet button is metallized by a sputtering process that deposits successive layers of nichrome, copper and gold thereon. During the sputtering process, a flexible stainless steel band surrounds the button to prevent sputtered material from being deposited on other than the bonding surface of the button. The metallized bonding surface is then soldered to a metal wall of the circulator. The bond so formed is capable of withstanding a peak power level in the circulator of 2.0 megawatts and an average power level of 3.5 kilowatts under standing-wave conditions.

Abstract: A ferrite-to-metal bond suitable for the environment of a high-power microwave circulator is disclosed. The bonding surface of a gyromagnetic ferrite or garnet button is metallized by a sputtering process that deposits successive layers of nichrome, copper and gold thereon. During the sputtering process, a flexible stainless steel band surrounds the button to prevent sputtered material from being deposited on other than the bonding surface of the button. The metallized bonding surface is then soldered to a metal wall of the circulator. The bond so formed is capable of withstanding a peak power level in the circulator of 2.0 megawatts and an average power level of 3.5 kilowatts under standing-wave conditions.

Abstract: A ferrite-to-metal bond suitable for the environment of a high-power microwave circulator is disclosed. The bonding surface of a gyromagnetic ferrite or garnet button is metallized by a sputtering process that deposits successive layers of nichrome, copper and gold thereon. During the sputtering process, a flexible stainless steel band surrounds the button to prevent sputtered material from being deposited on other than the bonding surface of the button. The metallized bonding surface is then soldered to a metal wall of the circulator. The bond so formed is capable of withstanding a peak power level in the circulator of 2.0 megawatts and an average power level of 3.5 kilowatts under standing-wave conditions.