I've had this problem with the four circle goniometers. I imagine your setup looks similar to https://www.med.upenn.edu/biocbiop/jf/bsbcore/images/X-ray_Rigaku_MicroMax-007.jpg ?
At high chi values, I would also observe a 'tail' of ice off my pins. As you mentioned in the manual, it's because at high angles, the cryo stream hits the pin first and *then* hits your crystal. This disrupts laminar flow, introduces turbulence, and then that turbulence is mixing humid air from the environment and depositing it on your crystal. Reposition the cryostream so the laminar flow hits your crystal first. Very surprised that its enough to blow your crystal off the pin! Best, F On Sep 13, 2017, at 3:54 PM, Annette Herta Erbse <annette.er...@colorado.edu> wrote: > > Dear All, > > We have a Rigaku XtalLab with a MM003 generator, a 4 axis goniometer and an > Oxford 700 cryostream. I have been running into the problem that if I make > full use of the 4 axis goniometer in the collection strategy I run into > geometries where the angles between the pin/Xtal and the Oxford cryo head > nozzle are smaller than 90 0 and in these positions I start collecting a lot > of ice to a point were it get's blown off by the cold stream and I have lost > Xtals. I was wondering if others have experienced the same and if there is a > good way to avoid it. At the moment I feel like I simply have to avoid these > ranges which is a shame since it restricts the data collection strategy. > > I appreciate any advice - Annette
