For reaching a small emittance in a modern light source, triple bend achromats （TBA）, theoretical minimum emittance （TME） and even multiple bend achromats （MBA） have been considered. This paper derived the neces...For reaching a small emittance in a modern light source, triple bend achromats （TBA）, theoretical minimum emittance （TME） and even multiple bend achromats （MBA） have been considered. This paper derived the necessary condition for achieving minimum emittance in TBA and MBA theoretically, where the bending angle of inner dipoles has a factor of 31/3 bigger than that of the outer dipoles. Here, we also calculated the conditions attaining the minimum emittance of TBA related to phase advance in some special cases with a pure mathematics method. These results may give some directions on lattice design.展开更多
文摘For reaching a small emittance in a modern light source, triple bend achromats （TBA）, theoretical minimum emittance （TME） and even multiple bend achromats （MBA） have been considered. This paper derived the necessary condition for achieving minimum emittance in TBA and MBA theoretically, where the bending angle of inner dipoles has a factor of 31/3 bigger than that of the outer dipoles. Here, we also calculated the conditions attaining the minimum emittance of TBA related to phase advance in some special cases with a pure mathematics method. These results may give some directions on lattice design.
