Ph.D. Thesis - Physics

Figure 7-19: The plastic socket that holds the cpga mounted above the 4 K baseplate (at
center of photograph). Electrical connections are made to each pin receptacle from below.
probably switching to a fully-copper 40 K shield would help, as copper is a much better
thermal conductor than the stainless steel that the octagon is made of.
Some supplementary information concerning practical aspects of operating the cryogenic
experiment may be found in Appendix C.
7.5 Experimental study of the elliptical trap
In this section we present an experimental investigation of the elliptical traps discussed in
Sec. 7.1, focusing on verifying the secular frequency and ion crystal structure calculations.
We begin by discussing the experimental setup, then report verification of our theoretical
calculations.
7.5.1 Experimental setup
Trap mounting, oven, connections
The trap is held above the 4 K copper baseplate by copper standoffs, onto which screws
a copper plate which holds a plastic socket into which the cpga is inserted. The electrical
connections are plugged into the bottom side of this socket, making reconfiguration of the
pinout relatively simple.
The socket mounted above the 4 K baseplate, surrounded by the 40 K shield, is depicted
in Fig. 7-19. Fig. 7-20 contains two photographs: first, a labeled photograph of Uraniborg
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