2n preliminary data analysis

Data on [math]MT target/D_2O[/math]:

Run with 2 Al sheets (2x0.678 mm) as bremsstrahlung converter w/o hardener. [math]E_e = 10.5 MeV[/math], Detector G(1/left).

Bin-by-bin subtraction of the two timing spectra after normalization:

Data on thick U-target and D2O from 8/13/2012:

Data (detector G(1,2)) were normalized to the gun trigger signal. Runs 3999(D2O) and 4001(no target), and 4011(thick U-target) and 4012(no target).

Data on thick U-target,D2O and H2O from 8/16/2012:

Data (detector F(1)) were normalized to the gun trigger signal. Runs 4097(D2O) and 4098(H2O), and 4011(thick U-target) and 4012(no target). [math]E_e = 10.5 MeV[/math]

Data (detector H(2)) were normalized to the gun trigger signal. Runs 4100(thick U-taget) and 4099(MT target). [math]E_e = 10.5 MeV[/math]

Photon flux study.

The current we were running at (3 sheets of Al):

And when we asked the operator to cut the electron current twice, our photon flux monitor showed:

Data on thick U-target,D2O and H2O from 8/17/2012:

Detector layout:

Geant4 setup:

File:Geant setup.eps

Solid angles subtended by the detectors and defined by point source (second column) and volume source filled with deuterium and 1 MeV neutrons were generated through all the volume isotropically (third column):

Det E		0.106		0106	sr
Det M		0.118		0.119	sr
Det F		0.096		0.094	sr
Det G		0.063		0.061	sr
Det H		0.033		0.031	sr
Det K		0.019		0.018	sr
Det I		0.011		0.011	sr

Calibration of detector array efficiency via D2O photodisintegration (run 4111):

And the rest of the detectors:

Jitter of the PS detector and "Ilyusha" (placed on the beam) w.r.t. the gun trigger signal (run 4112):

H2O calibration run (run 4112):

And the rest of the detectors:

Run with MT target (run 4113):

And the rest of the detectors:

Thick U-target data (run 4118):

And the rest of the detectors:

Neutron data bank (two production runs 4118 and 4119 added together). Coincidences between two PMTs for each detector are shown below.

Some simulation

Neutron energy and neutron polar angular distribution from D2O photodisintegration by unpolarized bremmstrahlung photons with end point energy 10.5 MeV were simulated by G4.

Bremsstrahlung photon spectrum:

Neutron energy spectrum w/o target material effect:

Neutron polar angular distribution. Zero degree is the initial incident photon direction: