We had many iterations. At first we had no reflective material, a big copper puck, short stubby legs. We couldn't get below 20K without the attocube and not below 35K with.
We improved our vacuum and vented with only N2 while warming up.
We tried stopping the freezing on the outside with plastic bags and heaters.
We had kapton windows fail and tried many different iterations and now we have a fairly confident mechanical solution.
We tried different sized pedal stools and wrapping of cables and shields of the cold finger.
Now we are at ~9 on the copper plate and 4-5K on the cold finger.
