The BPM-bellows front-end photon block with ellipse
cross-sections has been designed for Hefei Advanced Light Facility
(HALF). Such structure has lower longitudinal coupling impedances
than the photon block with commonly-used circle cross-sections. In
addition, two types of cooling structures have been designed, which
are shared water-cooling pipe (cooling structure 1, CS1) and
independent water-cooling tank (cooling structure 1, CS2),
respectively. The CS1 is simple and space-saving, while the CS2 has
better heat dissipation capability. In order to calculate power
density on complex light-receiving surfaces, the Monte Carlo
simulation tool, Synrad, was applied. By building finite element
models and importing power density data from Syrand, the temperature
and thermal stress distributions of photon blocks with two different
cooling structures were calculated. The thermal analysis indicates
that the maximum temperature (37.73°C) is located at CS1, but
the maximum stress (16.28 MPa) is on CS2 due to the difference in
structure and heat dissipation capability. Moreover, the maximum
temperature and thermal stress values are far below the material
criteria of CuCrZr. Therefore, the simple and space-saving CS1 is
more suitable for HALF, which can reduce manufacturing costs and
better satisfy the compact layout in the storage ring.