Abstract: A dual polarity transmission line structure that can provide high-voltage pulses of very short duration, such as can be incorporated in a compact accelerator of charged particles as well as other applications, is presented. The exemplary structure has a transmission line, formed a pair of conducting strip with dielectric between them, and a pair of switches. Each of the switches is connected between one of the conducting strips and a charging section, so that when the switches are off, the capacitor plates that are respectively connected to a first and a second of the switches are charged to voltage levels above and below the level at which the first and second conductive strips are set. A pulse is then generated by turning on the switches. Multiple such structures can be stacked to provide a pulse generating system.
Abstract: A loaded blumlein structure is described. At one end, the blumlein can be used to generate an electromagnetic pulse. At the other end, the top and bottom conductive connected by a resistive (or more generally a lossy) connection. This allows for subsequent pulses after the initial pulse to be dampened, maintaining the amplitude of the primary pulse, while reducing the stress on the system from the later ringing of the pulse. A number of geometries are described. In other examples, a pulse dampening section connected between the top and bottom conductive strips to provide the dampening effect.
Abstract: A blumlein assembly incorporating a solid-state switch is presented. In the exemplary embodiment, a semiconductor switch is placed between first and second conducting strips, with dielectric material filling in the space between the strips on either side of the switch. A third conductive strip, parallel to the other two strips, is separated from the middle one of the strips by another dielectric layer. Rather than having the switch attach directly to the dielectric material on either side, a holder or carrier structure is used, which may be formed of several pieces or of a monolithic structure. The holder is formed of a material whose dielectric constant is closer to that of the switch than the dielectric material on either side, but whose boundary with the dielectric on either side has at least a portion that extends in a non-orthogonal direction with respect to the conducting strips. The arrangement allows the structure to withstand higher electric field levels without breakdown.
Abstract: Circuitry is presented that can provide high-voltage radio-frequency pulses in the range of from a few volts to megavolts for charged particle accelerators. Individual pulse forming sections, such as transmission line transformers (TLTs) or blumleins, are formed in clusters. The pulse forming sections of each cluster are connected in series and have transmission lines ending in a ring structure. Multiple clusters can then be arranged with their rings aligned along the axis of the accelerator.
Abstract: Circuitry is presented for use in the pulse-forming lines of compact linear accelerators of charged particles. This presents devices that can provide high-voltage radio-frequency pulses in the range of from a few volts to megavolts for charged particle accelerators. The devices can use as input an external charge voltage and an optical pulse to create output RF pulses with a peak voltage that is increased over the input voltage. The exemplary embodiment presents a circuit of pulse forming lines for compact linear accelerator that includes an opto-switch and RF transmission lines that form a pulse shaper and a ladder-like pulse multiplier unit, with or without an output shaper.