Niowave 3-2016
Niowave Positron Project Progress for March 2016
Event files using different beam energies and devoid of vacuum spaces between the target and its windows were delivered to Niowave. Event files were generated assuming an ideal solenoid having an inner radius of 2.527 cm surrounding a beam pipe with a radius of 1.74 cm. Electrons impinge a 2mm thick PbBi liquid target that has a surface area of 2.54 cm x 2.54 cm. Stainless steel windows 0.25 mm thick sandwhich the PbBi target at locations Z= -10.4875 and Z= -10.7125 cm. The target is located at Z = -10.6 cm and the beam begins upstream at Z = -1.1 m. The incident electron beam is a 0.5 cm radius cylinder.
Positrons exiting the Solenoid
The solenoid design has changed such that the max field is 0.20 Tesla (0.22) and its length is 150 mm.
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| Overall Target layout | Closeup of Target Simulation Geometry. The center of the 0.25mm thick stainless steel windows are a distance of 1.125 mm from the center of the LBE target. 1.125 mm, mm, .25 mm. | An example positron production event. The yellow lines represents a sensitive detector used to record all positron events. The red line represents the incident 10 MeV electron that produces two bremsstrahlung photons shown in green. The first photon has an energy of 2.151 MeV and pair produces in the stainless steel window. The second photon has an energy of 1.393 MeV and exits the system without interacting. The first photon is created at time t= 3.323 ns. The first photon produces a 234.6 keV electron and a 894.2 keV positron at time t=3.336 ns. Only the positron has enough energy to exit the stainless steel window. |
Event files for positrons and electrons are created at two positions, the exit of the downstream SS windows and the exit of the solenoid.
Twenty (20) million incident electrons with an energy of 10 MeV and forming a cylindrical beam with a 0.5 cm radius cylinder impinged a 2mm thick LBE target located at Z = -106 mm. The Z location of positrons exiting the beam pipe at the end of the 15 cm long solenoid is 44 mm. The positrons are 150.00 mm from the middle of the LBE target (Z=44mm).
A space delimited text file with the above events in the format of
PID, x(mm),y,z,Px,Py,Pz(MeV),t(ns)
in units of mm for distance and MeV for momentum is located at
http://www2.cose.isu.edu/~foretony/PosAtExitWindowNoGaps6MeV.dat
for positrons exiting the last SS windows
and
http://www2.cose.isu.edu/~foretony/ElectronsAtExitWindowNoGaps6MeV.dat
for electrons.
Sample Events
The Sensitive detector is located either 1.1 mm (Z=-103.775 mm) away from the last SS window or 15 cm (Z= 46.225 mm )downstream.