Supercycle proposal for 2014+

1. Lau Gatignon, TDAQ meeting, 18 December 2013 Supercycle proposal for 2014+

2. Introduction • CNGS has been completed. • CNGS required to add many 6 seconds cycles to the supercycle, thus increasing the overall length. Without change of flat top the duty cycle would thus decrease from 33 to about 10%. • As the CNGS cycles consume very little RMS power, it was decided that we would double the flat top from 4.8 to 9.6 seconds, to reach a duty cycle of 21%. • Now that CNGS is completed it is of general interest to find back the highest duty cycle.

3. The proposal • Go back to a 4.8 seconds flat topWith the same instantaneous intensity this needs fewer protons in the machine per cycle. Hence smaller losses (non-linear). This also avoids a conflict in proton sharing with COMPASS. (Also faster for setting up the beam). • Combine two flat tops in a longer super-cycleThis leaves more freedom for the other users of the PS complex • Still respect the RMS power limit in the SPSThis imposes a minimum time between two flat tops • Note that LHC filling is not required in 2014, but maybe MD’sBut the proposed scheme should be the same for 2014 and 2015+

4. The proposal in detail

6. Implications for NA62 (and NA) 14.4 s 6 s I.e. less time between cycle 1 and 2 than between cycle 2 and next cycle 1. Each cycle comes with the usual timing events (WWE, WE, EE)There is no event distributed for the super-cycle For the cycle without LHC filling the time between flat tops in 9.6 seconds