Stage B: 50 ns

Potential Performance

Month	Comment	Turn around time	Availability	Max number bunches	Protons/Bunch	% nom. intensity	Min beta*	Peak Luminosity cm^-2s^-1	Integrated Luminosity
1	Beam commissioning								First collisions
2	Pilot physics, partial squeeze, gentle increase in bunch intensity, 40%	Long	Low	43	3 x 10¹⁰		4 m	1.2 x 10³⁰	100 - 200 nb^-1
3		5	40%	43	5 x 10¹⁰		4 m	3.4 x 10³⁰	~ 2 pb^-1
4		5	40%	156	5 x 10¹⁰	2.5	2 m	2.5 x 10³¹	~13 pb^-1
5	No crossing angle; could squeeze further	5	40%	156	7 x 10¹⁰	3.3	2 m	4.9 x 10³¹	~25 pb^-1
6	50 ns	5	40%	144	7 x 10¹⁰	6.7	2 m	4.3 x 10³¹	~23 pb^-1
7	50 ns	5	40%	288	7 x 10¹⁰	4.5	2 m	8.6 x 10³¹	~45 pb^-1
8	50 ns*	5	40%	432	7 x 10¹⁰	9.3	2 m	1.3 x 10³²	~68 pb^-1
9	50 ns*	5	40%	432	9 x 10¹⁰	11.5*	2 m	2.1 x 10³²	~110 pb^-1
10		5	40%	432	9 x 10¹⁰	11.5*	2 m	2.1 x 10³²	~110 pb^-1
								TOTAL	~ 300 pb^-1

LHCb equivalent

Assuming:

8 hour fill length throughout - it could be longer, but given the possibility of lost fills, system un-reliability etc. 8 hours is probably optimistic.
20 hours luminosity lifetime - with the intensities above it should be longer but given vacuum, the learning process etc. it won't be optimum.
30 day months. Availability gives time available for physics including normal turn arounds. Rest of time in machine development, access, recovery etc.
Constant availability assumed throughout, thus the total can be scaled as needed.
Nominal crossing angle assumed for 75 (and 50 ns - see below).
Total intensity limited to around 10% of nominal (see * below).
No squeeze beyond 2 m.- conservative - to avoid the operational difficulties which start to come in with squeezing beyond 2 m. We could play the squeeze to 1 m off against the bunch intensity if required (ß* from 2 to 1 m buys a 30% reduction in intensity (or a doubling of the luminosity) ).

* Working with these intensities implies impeccable performance of the machine protection system, and a fully commissioned collimation system capable of highly efficient beam cleaning,. This is going to take time and must not be rushed.

For beam losses, it would be reasonable to take around 10% of the first year figures quoted in "Estimates of Annual Protons Doses in the LHC" where 25 ns running and a peak luminosity of 10³³ cm^-2s^-1 is assumed.

ML Feb 08