Low efficiency for neutron detector

Hi there,

I am simulating the neutron detector with the C6D6 and nitrogen as a scintillating material. I modeled my energy deposition as shown in example B1, using fScoringVolume. I also calculated the energy deposition by neutrons only and the secondaries. I am using the following physics lists:

QGSP_INCLXX_HP (in my main)
RegisterPhysics (new G4EmStandardPhysics());
RegisterPhysics (new HadronElasticPhysicsHP(1));

But there are two issues that arise:

1.) total deposited energy doesn’t match with neutron deposited only+ secondary

2.) The efficiency is too low, less than 1%, for example with 100000 events, only 315 neutrons deposited the energy

Could anyone help me out here? Am I missing any physics which I should have included?
Could you also tell me something about the mismatch of the energy deposited?

Check energy of neutrons you are using.