“…As can be seen from Figure 1 , there is a large gap in the reflectivity of existing reflectors in the range of VCNs and CNs. A series of papers [ 20 , 64 , 65 , 66 , 67 , 68 , 69 , 70 , 71 , 72 , 73 , 74 , 75 , 76 , 77 , 78 , 79 , 80 , 81 , 82 , 83 , 84 ] explores the possibility of designing effective VCN reflectors in this so-called reflectivity gap in order to increase VCN fluxes extracted from neutron sources and, possibly, to provide the storage of VCNs in closed traps for research. The solution of this problem opens up prospects for the wide use of VCNs in neutron physics.…”