17 juil 09 Hybrid source @ 8GeV: particles distributions after the crystal and after the amorphous
A 8 GeV electrons beam (composed by 1.1e+4 particles) impinge on a <111> oriented tungsten crystal of 1mm thickness.
Particles at the exit of the crystal
For display reason a cut is apply on px and py value (abs(px&&py)<20 MeV/c).
First case a transverse distribution of sigma=1mm is added to the particles transverse distribution
Electrons phase space at the exit of the crystal
Photons phase space at the exit of the crystal
Positrons phase space at the exit of the crystal
Second case a transverse distribution of sigma=2.5mm is added to the particles transverse distribution
Electrons phase space at the exit of the crystal
Photons phase space at the exit of the crystal
Positrons phase space at the exit of the crystal
Particles at the exit of the amorphous
The photons at the exit of the crystal is use to impinge on 8mm amorphous tungsten
(for 2.5mm rms value)
After the amorphous px,py and pz are defined by the following
Photons phase space at the exit of the amorphous
Electrons phase space at the exit of the amorphous
Positrons phase space at the exit of the amorphous
Tags: channeling, hybrid source, positron source
01 avr 09 Hybrid source: positrons distribution
(Robert Chehab’s graphic and summary)
In the following we took:
For both case (10 GeV and 5 GeV) the inital x and y electron distribution follow (ROOT syntax)
x=gRandom->Gaus(0,2.5e-3)/sqrt(2.); // gaussian centered x=0 with rms_x=2.5mm y=gRandom->Gaus(0,2.5e-3)/sqrt(2.); // gaussian centered y=0 whith rms_y=2.5mm
Electron beam energy : 10 GeV
- Crystal thickness : 0.1 cm
- Distance between amorphous and amorphous : 2m
- Amorphous thickness : 0.8 cm
(initial particles impinging on the crystal = 5000 macro e-)
Photons energy spectrum
Positrons phase space after the amorphous target
Energy (no energy cut)
Energy (below 400 MeV):
X:
Y:
Px:
Py:
Positrons spatial distribution after capture section (AMD)
AMD caracteristics
Transverse phase space of the positrons from the target.
We apply a cut in the radius, r<20mm corresponding to the aperture of the
pre-accelerating cavities.
In blue after the amorphous and in red after the AMD
Angle distribution
Electron beam energy : 5GeV
- Crystal thickness : 0.14 cm
- Distance between amorphous and amorphous : 2m
- Amorphous thickness : 1 cm
(initial particles impinging on the crystal = 6000 macro e-)
Photons energy spectrum
Positrons phase space after the amorphous target
Energy (no energy cut):
Energy (below 200 MeV):
X:
Y:
Px:
Py:
Positrons spatial distribution after capture section (AMD)
AMD caracteristics
Transverse phase space of the positrons from the target.
We apply a cut in the radius, r<20mm corresponding to the aperture of the
pre-accelerating cavities.
In blue after the amorphous and in red after the AMD
Angle distribution
EXTRA …
(thanks to Laurent Garnier Qt implementation see http://users.lal.in2p3.fr/garnier/G4QtTutorial.html#interface)
Tags: AMD, channeling, hybrid source, positron
