Photon flux proportionality

If we compare the photon flux from the two runs with DU target

run 2467 (7770 positrons total)

and

run 2506 (30312 positrons total)

The average photon flux increased from 90 [math]e^+/min[/math] to 350 [math]e^+/min[/math] and the ratio is 350/90 = 3.9 .

In other way if we look at the integral number of positrons produced during the runs 30312/7770 = 3.9

The number of neutrons used to do narmalization, i.e. the sum of the number of neutrons in three detectors placed at 0 deg left, 90 deg bottom and 0 deg right changed as follows:

run 2467: SUM(0-90-0) = 518 neutrons

run 2506: SUM(0-90-0) = 2195 neutrons

The neutron number ratio is 2195/518 = 4.2 .

run 2522 (19571 positrons total)

That means that photon flux monitor can be used for the purpose of relative normalization.