In-Pile ⁴He Source for UCN Production at the ESS

Table 1

Heat-load on cryogenic ⁴He and integrated cold/intermediate/thermal flux for the ESS implementation of Golub’s UCN design discussed in the text and shown in Figure 4. The relative statistical uncertainties are ∼0.1%.

Heat-load	Flux [0–5] meV	Flux [5–20] meV	Flux [20–100] meV
[mW/cm^3]	[n/cm^2/s]	[n/cm^2/s]	[n/cm^2/s]
2.5	3.8 · 10^12	9.0 · 10^12	1.8 · 10^12