Status of the GRANIT Facility

Table 3

Comparison of previous and recent measurements with simulations. The number of extractible UCNs correponds to the number of UCNs available in the source after the UCN density has been saturated according to the simulation. The number of extracted UCNs corresponds to the number of UCNs detected during the experiments. The measured (resp., simulated) extraction efficiency is the ratio of the number of UCNs detected during the measurement (resp., the simulation) to the simulated number of extractible UCNs. The missing factor is calculated according to the discrepancy between these two efficiencies.

Configuration	2010 [12, 13]	2013
Storage time (meas.)	67 s	30 s
Extractible UCNs (sim.)
Extracted UCNs (meas.)	274000
Extraction efficiency (meas.)	%	%
Extraction efficiency (sim.)	65–50%	15–5%
Missing factor	4-5	2.5–7