Experimental analysis of operation failure for a neon cryogenic loop heat pipe

•A neon CLHP integrated with a G-M cryocooler was developed and investigated.•Three factors were identified to cause supercritical startup failure of the CLHP.•The CLHP can realize supercritical startup with a small amount of impurity air.•Three factors were found to have detrimental effect on CLHP steady-state operation.•The CLHP can reach a heat transport capability of 4.8 W over a distance of 0.6 m.