KILLVX_NEUTRON

The command is:

• $killvx_neutron 1 (or some other value, 0-9)

The KILLVX_NEUTRON flag is independent of the KILLVX flag. This allows the user to discard a selection of neutron vertices of increasing importance without jeopardising the transport of other particles (photons, electron/positrons, and gammas). The allowed values and what they discard are;

0 : 		 		 No vertices are discarded. 


1 : 		 		 Neutron boundary vertices are discarded. 


2 : 		 		 Neutron elastic scattering vertices are discarded. 


3 : 		 		 T(n,n$^{\prime}$)T$^{\prime}$ vertices are discarded. 


4 : 		 		 (n,2n), (n,3n), (n,np) and (n,$\alpha$) vertices are discarded. 


5 : 		 		 All neutron capture vertices are discarded.

Note that, as is usual with KILLVX flags, all higher values are lower value inclusive, so KILLVX_NEUTRON $= 2$ discards boundary vertices as well as elastic scattering vertices.

KILLVX_NEUTRON $= 2$ is the maximum value recommended. All higher values results in the discard of events that either produce neutrons or light, and in any case such events are rare in a neutron's history. KILLVX_NEUTRON $= 2$ cuts out all the elastic scattering, which is the dominant event in a neutron's history, and should be sufficient to greatly reduce the memory requirements for a history.