Towards experiments on a superconducting atom chip.
Date of Issue2009
School of Physical and Mathematical Sciences
Ultra Cold Atom Laboratory, NTU
This thesis widely reviews the literatures on laser cooling and trapping, magnetic trapping and atom chip. Temperatures and atom number densities of 87-Rubidium cloud in our magneto-optical trap, compressed magneto-optical trap and molasses experiments are reported. For `Z' traps with wires of width-to-thickness ratio = 500, discrepancy in the magnetic field distribution from those of `Z' wires at much more moderate widthto-thickness ratio during the compressing stage is discovered through simulations with Finite Element Method. Offset magnetic field has to be reduced in order to recover the normal feature of a `Z' trap during the compressing stage. The thermally induced atom spin flip lifetime in our `Z' trap is also approximated. The design of a cold finger structure which can enhance the cooling of a YBCO superconducting atom chip inside a liquid nitrogen cryostat to below critical temperature is summarized. The distortion to the magnetic quadrupole trap due to the eddy current inside a nearby chip holder at liquid nitrogen temperature during the fast switching of the trap is investigated.
Final Year Project (FYP)