Over the past years, problems have been reported by our customers that they have problems reaching temperatures below 4.2 K when using liquid helium in combination with a capillary to cool down to around 1.8 K. Prof. Rillo from the University of Zaragoza has finally identified these problems to originate from hydrogen contamination inside the liquid helium. A new article from Will and Haberstroh from the Technical University in Dresden summarizes this phenomenon and gives an insight into how the capillary blockage forms .
Do you use an ATP30 gas purifier? Then one possible solution is to equip your helium gas purifier with a catalyst that either burns or binds hydrogen. This option is called Hydrogen Removal Cartridge.
Source:  doi:10.1088/1757899X/755/1/012117