%A"Kobayashi, M [ed.]" %D1991 %I; National Lab. for High Energy Physics, Tsukuba, Ibaraki (Japan) %2 %J[] %K43 PARTICLE ACCELERATORS, TRISTAN STORAGE RINGS, SYNCHROTRON RADIATION SOURCES, FEASIBILITY STUDIES, BEAM OPTICS, BEAM EMITTANCE, BEAM INJECTION, RF SYSTEMS, WIGGLER MAGNETS, 430400, STORAGE RINGS %PMedium: X; Size: 133 p. %TReport from `Orbit sub-group` of task force for MR synchrotron radiation project %XThis report includes feasibility studies for a new synchrotron radiation source using TRISTAN Main Ring (MR) of KEK now being used as an electron and positron collider. A task force for the feasibility study started in the spring of 1990, and a sub-group was organized to study and discuss the problems related to the lattice of MR. The main subject in this report is how to realize both very small emittance and large dynamic aperture in a new lattice. Two long straight sections in the present lattice called `Nikko` and `Oho` must be modified like a gable roof, 1) to get free space for insertion devices, 2) to extract their synchrotron radiation to the experimental hutches which will be set in the ring tunnel in those sections and 3) to add a radiation shielding wall between the ring and the beam channel for the synchrotron radiation. The other two long straight sections called `Fuji` and `Tsukuba` will be used for injection, RF cavities and damping wigglers necessary for the very low emittance. The ultimate emittance will be 1.6 nm rad with the horizontal dynamic aperture of 36 x 10{sup -6} m rad that is about half the aperture experienced at the present MR. (author). %0Technical Report %NKEK-91-5;Other: ON: DE92751024; TRN: JP9111215 %1 %CJapan %Rhttps://doi.org/ Other: ON: DE92751024; TRN: JP9111215 JPN %GJapanese