Estimated ‘In-Kind Income’ for REF Analysis

After consultations with STFC, the UK Node has received guidelines for the calculation of REF 'in-kind income' for use of ALMA by UK PIs. These number refer to 'in-kind income' with respect to access payments as made to ALMA from the UK via ESO.

ALMA operates for ~80% of the calendar year with a shutdown period due to adverse weather conditions. In Cycle 7 (the latest cycle), the 12m array (50 antennas) has 4300 hours of astronomical observations available. The ACA and total power (TP) arrays (16 antennas) have 3000 hours of dedicated time for astronomy. Earlier cycles had slightly smaller numbers of hours available for the 12m array.

The UK pays on average (for the last 3 years) £26.3M per annum for its ESO subscription (including the ELT). We should distinguish between ALMA and ESO (VLT, VLTI, APEX, and the La Silla facilities), with a suggested ratio from the STFC of 2/3 ESO and 1/3 ALMA, which gives ~8.75M /per year (per cycle) from the UK to ALMA.

For Cycle 7:
12m operations: £8.75M*(50/66)/4300 = £1.54k/hr (Total = £6.62M)
ACA and TP operations: £8.75M*(16/66)/3000 = £0.71k/hr (Total = £2.13M)

These are in line with rough estimates from STFC of £30k per 'day' where an operational day is ~(18 - 20) hrs.

Estimates can be made for Cycles 5 and 6 by inserting 4000 hrs offered by the 12M array and 3000 hrs by the ACA.