I have been reading papers related to the theoretical computation of a neutron monitor count rate, which is defined as the integral of the "yield function" of the specific neutron monitor times the energy spectrum of CR in the insterstellar medium. I know that the "yield function" is related to the response of the the neutron monitor, but I still don´t understand what information do you get when you plot or analyse this function, does it have any physical meaning itself?
It's just how much signal the monitor "yields" for a given energy. You'd like that function to be 100% everywhere, but typically there is some efficiency which drops that maximum efficiency to, well, whatever, 17.3%, and then in addition, there will be a energy dependence for example due to neutron cross sections being energy dependent and due to a trigger roll-off, etc.
Hence, yes, there is a physical meaning: This yield function by itself is the response of a monitor to a hypothetical neutron spectrum that is flat in energy.
$\begingroup$ Nice, I also found a paper which explains the necessity of the response functions after the invention of the neutron monitor. It is "NEUTRON MONITOR RESPONSE FUNCTIONS" by JOHN M. CLEM and LEV I. DORMAN, very helpful to understand. $\endgroup$ Aug 17, 2022 at 21:16