[en] The axial electric field in the KEK linac cavity is measured by a bead perturbation method. The beat signal of around 1 kHz is generated with the rf signals from the cavity in self-excitation and from a signal generator whose output frequency is fixed. The period of the beat signal is measured by a counter in order to detect the small change in the resonant frequency of the cavity due to a bead perturbation. The counting data are transferred to a mini-computer after each period of the beat signal. The average fields of each gap are calculated in the computer and they are displayed on a storage oscilloscope. It takes about 50 seconds to complete the whole process of the measurement. The measuring system and the results obtained are described in this paper. (auth.)

[en] A possibility for acceleration of deuterons in the KEK accelerator is presented with some modifications required to the present machine. Deuteron beam of an intensity as high as 350 mA was obtained in the present duoplasmatron ion source. The emittance and acceptane of the 20-MeV proton linac are calculated for deuterons. A modification in the field distribution by means of tuners is considered to save the rf power and to improve the longitudinal emittance. Acceleration in the booster and main synchrotrons as well as in the 180-GeV intersecting storage ring proposed for a KEK future project are discussed. Intensity of the obtainable neutron beam is also estimated. (auth.)

[en] In the KEK 20 MeV linac, the electric field anti E increases linearly along the cavity from the injection end but the synchronous phase is supposed to be constant throughout the acceleration. While BNL group reported that the method of ''synchronous phase law'' reduced the energy spread and the variation in mean energy. The KEK linac consists of only single cavity, and the field distribution can be changed by fourteen tuners to some extent. So we tried the experiment of tilting the field distribution and varying the overall field level to find a better operating condition. However we could not find out any reason to operate at any other condition than our designed value in the aspect of the mean energy, the energy spread and the capture efficiency. (auth.)

[en] We revise Garnier-Okamoto's coalescent diagram of isomonodromic deformations and give a possible coalescent diagram from the viewpoint of isomonodromic deformations. We have ten types of isomonodromic deformations and two of them give the same type of Painleve equation. We can naturally put the 34th Painleve equation in our diagram, which corresponds to the Flaschka-Newell form of the second Painleve equation