Difference between revisions of "Niowave 10-2015"

Revision as of 14:50, 13 April 2016

Niowave Positron Project Progress for October 2015

A comparison was made between MCNPX and GEANT4 using a cylindrical electron beam with a radius of 1 cm. The 10 MeV incident electrons impinged a 2 mm thick PbBi target. Positrons escape the surface of the PbBi target with a mean momentum of 2.3 MeV. The positron production efficiency predictions from MCNPX and GEANT4 are within uncertainties.

Incident Electron spatial distribution and energy

Positron and Electron Momentum after the converter

Text files were delivered to Niowave so Niowave could begin designing a beamline to transport the positrons using a solenoid immediately downstream of the PbBi target. Dmitry, from Niowave, used the test files to calculate the beam transport properties of the positrons escaping the PbBi target.

Dmitry's processing of Tony's GEANT simulations showing transverse phase space portrait (left) and longitudinal phase space portrait (right). Phase space portraits show coordinate x or y vs diveregense=px/pz or py/pz (or time vs kinetic energy ). Captions show:

1. geometric (not normalized) emittance for transverse and emittance for longitudinal phase space portraits (ellipse areas divided by "pi")

2. Twiss parameters

3. Ellipse centroid for longitudinal phase portrait

4. sqrt(beta*emittance) and sqrt(gamma*emittance) - half sizes of the projections of the ellipses on the coordinate and divergence axes respectively.

Positrons - RMS

Positrons - 68.2% core

@@ Line 16: / Line 16: @@
-Text files were delivered to Niowave so Niowave could begin designing a beamline to transport the positrons using a solenoid immediately downstream of the PbBi target.
+Text files were delivered to Niowave so Niowave could begin designing a beamline to transport the positrons using a solenoid immediately downstream of the PbBi target.  Dmitry, from Niowave, used the test files to calculate the beam transport properties of the positrons escaping the PbBi target.
 Dmitry's processing of Tony's GEANT simulations showing transverse phase space portrait (left) and longitudinal phase space portrait (right). Phase space portraits show coordinate x or y vs
@@ Line 28: / Line 28: @@
 . sqrt(beta*emittance) and sqrt(gamma*emittance) - half sizes of the projections of the ellipses on the coordinate and divergence axes respectively.
-Electrons - RMS
-[[File:Ed1.png| 400 px]]
-Electrons - 68.2% core
-[[File:Ed2.png| 400 px]]
 Positrons - RMS
@@ Line 44: / Line 36: @@
 [[File:Pd2.png| 400 px]]
-Dmitry's processing of Tony's GEANT simulations showing transverse phase space portrait (left) and longitudinal phase space portrait (right). Phase space portraits show coordinate x or y vs
-diveregense=px/pz or py/pz (or time vs kinetic energy ). Captions show:
-. geometric (not normalized) emittance for transverse and emittance for longitudinal phase space portraits (ellipse areas divided by "pi")
-. Twiss parameters
-. Ellipse centroid for longitudinal phase portrait
-. sqrt(beta*emittance) and sqrt(gamma*emittance) - half sizes of the projections of the ellipses on the coordinate and divergence axes respectively.
-Electrons - RMS
-[[File:E1.png| 400 px]]
-Electrons - 68.2% core
-[[File:E2.png| 400 px]]
-Positrons - RMS
-[[File:P1.png| 400 px]]
-Positrons - 68.2% core
-[[File:P2.png| 400 px]]
-The plot below shows the energy deposited in MeV along the pipe.  The Z axis is along the beam direction.  The distance around the beam pipe is determine by taking the pipe radius (34.8 mm) and multiplying it by the Phi angle around the pipe.  The bins are 1cm x 1cm.
-{| border="1"
-| [[File:BeamPipeDepEPhi_34.8_082815.png |200px]] ||[[File:BeamPipeDepE_34.8_082815.png| 200 px]]
-|+ A maximum of 450,000 MeV is deposited in a 1 cm<math>^2</math> bin when 20 Million , 10 MeV electrons are incident on a 2 mm thick PbBi target located at Z=-902 mm.
-|}
-Below is energy deposited contributions from from photons(AVSzWg), positrons (AVSzWpos), and electrons.
-[[File:BeamPipeDepE_34.8_082815_parttype.png | 200 px]]
-Why is the positron hotspot upstream of the target?  Because beam was going from right to left.
-root commands used
- TH2D *AVSz=new TH2D("AVSz","AVSz",100,-1000,0,12,-60,60)
- BeamPipeE->Draw("35.*atan(PosYmm/PosXmm):PosZmm>>AVSz","DepEmeV");
- AVSz->Draw("colz");

Difference between revisions of "Niowave 10-2015"

Revision as of 14:50, 13 April 2016

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