Niowave 9-2015

Progress Report, September 2015

Simulations were performed to predict the efficiency of producing positrons using a Lead-Bismuth target and a 10 MeV incident electron. MCNPX and GEANT4 were used to predict this efficiency in an effort to benchmark the results. Niowave performed a simulation using MCNPX and ISU used GEANT4. A comparison of the positron production efficiency predictions made by MCNPX and G4beamline (GEANT4) indicates that they were consistent.

PbBi Thickness (mm)	#positrons/million electrons (G4Beamline)	#positrons/million electrons (MCNPX)
1	1138,1154,1097,1159,1125 =1135[math]\pm[/math]25	1091
1.5	1668,1701,1639, 1644, 1628=1656[math]\pm[/math]29	1728
2	1937,1930,1851,1874,1945=1907[math]\pm[/math]42	1984
3	1889,1821,1852,1809,1859=1846[math]\pm[/math]32	1986
4	1726,1696,1673,1693,1681=1694[math]\pm[/math] 20	1858
5	1566,1543,1546,1625,1566=1569[math]\pm[/math]33	1646
6	1549, 1486,1564,1545,1452=1520[math]\pm[/math] 50	1541
7	1462,1327, 1407,1489 ,1477=1432[math]\pm[/math] 67	1541
8	1289, 1335,1280, 1271, 1280 = 1291[math]\pm[/math] 25
10	1141,1241, 1199, 1202, 1148 =1186[math]\pm[/math]42	1216

The spatial distributions observed appear below

Electrons and Positrons after 2mm of LBE:

Electrons:

Positrons: