[en] Earley at al, suggested that ferrite tune RF cavities have lower ferrite power dissipation if the ferrite bias field is perpendicular rather than parallel to the RF magnetic field. A 50-84 MHz cavity has been constructed in which ferrite can be biased either way. Low power measurements of six microwave ferrites show that the magnetic Q's of these ferrites under perpendicular bias are much higher than under parallel bias, and that the high Q region extends over a much wider range of RF permeability. TDK Y-5 ferrite was found to have a magnetic Q of 10,800, 4800, 1200 and 129 at RF permeabilities of 1.2, 2.4, 3.7 and 4.5, respectively. Measurements of perpendicularly biased ferrite at various power levels were made in coaxial line cavity. The Q of Y-5 ferrite was found to decrease by less than a factor of 2 as the power density in the ferrite was increased to 1.3 W/cm³. A cavity design for a 6 GeV, high current, rapid cycling synchrotron using transversely biased ferrite tuning is described

[en] A compact, small diameter, standing-wave linear accelerator structure suitable for industrial and medical applications is presented. The novel structure utilizes a new type of coaxial cavity as the coupling cavity for π/2 mode, standing-wave operation. This structure offers a significant reduction in overall diameter over the side-coupled, annular ring, and existing coaxial coupled structures, while maintaining a high shunt impedance and large nearest neighbor coupling (high group velocity). A prototype 4 MeV, 36 cm long, S-band accelerator incorporating the new structure has been built and tested. Theoretical accelerator design parameters, as well as experimental results, are presented

[en] Recently, the authors have reliable cw operation of the Fusion Materials Irradiation Test (FMIT) radiofrequency quadrupole (RFQ) accelerator. In addition to the operational experiences in achieving this status, some of the modifications of the vacuum system, cooling system, and RF structure are discussed. Preliminary beam-characterization results are presented

[en] An Alvarez linac is being built to increase the injection energy of the booster synchrotron from 20 MeV to 40 MeV. Its drift tubes are equipped with quadrupole permanent magnets. It has post couplers and still inherits the two feed system. Two TH 516 RF high power amplifiers, which have excited the 20 MeV linac, are modified so that one excites the old linac and the other the new one. 40 MeV H^- beams will be supplied to the booster in November of 1985

[en] High yields of separated, radioactive isotopic ions (up to 10¹¹ atoms/sec per μA of incident protons) at on-line mass separators, e.g. ISOLDE at CERN (SC), make it feasible to consider using such secondary ions as projectiles for nuclear reactions. A pressing need for reaction data involving radioactive species exists in nuclear astrophysics. This requires having available projectiles (A ≤ 60) in the energy range from about 200 keV/amu to 1.5 MeV/amu. At TRIUMF, an ISOL devise is proposed using the available high proton current (≤100 μA). A beam of radioactive species, extracted with about E = 60 keV from the target/ion source, would be mass analyzed and transported vertically to experimental areas for use there or to be injected into a post-accelerator. Although other possibilities are being considered, most attention so far has been devoted to a RFQ/drift tube linac combination. Parameters for one possible system are presented

[en] The authors study a new RF-source, LASERTRON, aiming to apply it for future very-high-energy e⁺e^- linear colliders. They started a research and development program to construct a LASERTRON with a peak RF-power of 50 MW by using GaAs or GaAsP photocathode as a first step to achieve GW. Design studies and preliminary experiments are described

[en] The Los Alamos Accelerator Theory and Simulation Group (AT-6) maintains and distributes a standard version of the Poisson-Group codes (LATTICE, AUTOMESH, TEKPLOT, POISSON, PANDIRA, MIRT, FORCE, SUPERFISH, and SF01). These codes are the product of man-decades of development under the guidance of R.F. Holsinger and K. Halbach. The main applications are in the design of electromagnets (POISSON and PANDIRA) and RF cavities (SUPERFISH). Other applications include electrostatics, heat transport, and finding mathematical surfaces of minimum area. With special financial support from DOE-HEP, the authors have revised and corrected the standard version and are writing a comprehensive manual containing many examples and a summary of the theory behind the codes. This paper will illustrate some of the capabilities of the codes and will summarize the manual. The revised codes are available upon request

[en] This paper is a status report on an on-going program at SLAC to study accelerator structures under high-gradient electric field conditions. The study is a part of a much broader program dealing with future linear colliders. The experiments done so far at SLAC deal with a conventional disk-loaded accelerator section of the constant-gradient type running at 2856 MHz. The original objective was to reach an accelerating gradient of at least 100 MV/m. The accelerating gradient at which the SLAC disk-loaded waveguide operates routinely is ∼ 9 MV/m (with 36 MW klystrons feeding four 3 m sections without SLED) and ∼ 12 MV/m with SLED I (2.5 μsec pulse). With 50 MW tubes and SLED II (5 μsec pulse) the gradient is presently being increased to over 20 MV/m. To reach 100 MV/m in a conventional 3 m constant-gradient section without SLED, one would need a klystron with a peak power output of 900 MW. Since such a tube is not available, the authors decided to use a short standing-wave section in which the resonant fields can build up. The design criteria for this section, the fabrication, matching and tuning, the experimental set-up and the results are described below

[en] The Argonne National Laboratory Synchrotron Light Source Storage Ring is designed to have a natural emittance of 6.5 x 10^-9 m for circulating 6-GeV positrons. Thirty of the 32 long straight sections, each 6.5-m long, will be available for synchrotron light insertion devices. A circulating positron current of 300 mA can be injected in about 8 min. from a booster synchrotron operating with a repetition time of 1.2 sec. The booster synchrotron will contain two different RF systems. The lower frequency system (38.97 MHz) will accept positrons from a 360-MeV linac and will accelerate them to 2.25 GeV. The higher frequency system (350.76 MHz) will accelerate the positrons to 6 GeV. The positrons will be produced from a 300-MeV electron beam on a tungsten target. A conceptual layout is shown

[en] A coaxial pulse line accelerating structure, conceived as a candidate for the linear collider application, where the goal is the acceleration of single micropulses of relativistic particles to very high energies at very high acceleration rates with minimal investment in stored energy, will be described. The structure consists of a coaxial transmission line surrounding a sequence of pillbox accelerating cells. Pulses of electromagnetic energy propagate along the transmission line, at the speed of light, feeding the accelerating cells where the energy converges to the axis producing very high gradient electric fields suitable for acceleration of short bursts of relativistic charged particles. The energy efficiency of the structure could be very high and the fill-time of the structure is essentially zero. One or more schemes for generating the intense electromagnetic pulses required by the system will be described. An example design of a 1-TeV Linear Lepton Collider (LLC) will be presented