Question #1: The wrong course (easy).

Given that a machine operating at Luminosity 8334x1030/cm2s aborts. After 4 minutes injection begins under "filling" conditions where Rf is 695x1030/cm2s per minute (corresponding to ~12 minutes to fill all the way back). Given also that a trickle condition exists in which Rtrickle is 174x1030/cm2s per minute for a fill to trickle ratio of 4:1.

Consider the two following courses for filling:

Can you show that the total (integrated) delivered luminosity lost in the second course is 10% greater than the total (integrated) delivered luminosity lost in the first course?

Solution to Question #1

For both courses, the solution comes from substituting in Eq V the appropriate value for LDelivered.

In the first course LDelivered is the optimal value LPeak(1-Rtrickle/Rfill). The reader should confirm that this substitution yields an expression for the luminosity lost as:

Luminosity Lost (first course) = Lpeak(t1-t0) + L2peak(1-Rtrickle/2Rfill) /Rfill

In the second course, substituting into Eq V a value of LDeliver the value LPeak yields (again with some algebra which you can do):

Luminosity Lost (second course) = Lpeak(t1-t0) + L2peak /Rfill

I've tailored the numbers in the problem to be consistent with typical operation while making the arithmetic easy for you. When you punch in all the numbers, the luminosity lost in the second course is 10% greater than the luminosity lost in the first course. (The first course lose 7.25 pb-1 while the second course loses 8.00 pb-1).