the pitz plasma sourcepitz.desy.de/.../infoboxcontent201847/wismar_june2015_wg1_mgross.pdfthe pitz...
Post on 14-Apr-2018
223 Views
Preview:
TRANSCRIPT
The PITZ Plasma Source
Matthias Gross
LAOLA Workshop
Wismar, 24. June 2015
WG1 – Plasma targets, diagnostics and plasma beam transport
Matthias Gross | LAOLA workshop | 24. June 2015 | Page 2
Beam Line Remodeling
Electron
Beam
Plasma cell
Ionization laser
Dipole
Quad 1…4
Quad 5…6
Quad 7…8
Matthias Gross | LAOLA workshop | 24. June 2015 | Page 3
Plasma Cell Design
Thermal
Insulation Cooling
Sleeve
Electron
Window
Helium
Distribution
Heating Coils
e-
Ionization
Laser Path Laser
Window
Design:
Gerald Koss
Matthias Gross | LAOLA workshop | 24. June 2015 | Page 4
> ASTRA simulations: electron beam scattering impedes focusing into the
plasma
> Maximal agreeable scattering angle: 0.2 mrad
> 8m Kapton foil for first experiments expect 1 mrad
Scattering at Electron Window
Strongly defocused
0.4 mrad
Window position Middle of plasma cell
Focus still ok –
can be optimized
0.2 mrad
Matthias Gross | LAOLA workshop | 24. June 2015 | Page 5
Pre-experiment #1: Screen station
> Purpose: Find quadrupole settings for best focusing
> Best result: <100m spot size (100 pC bunch charge; 22 MeV; no
scattering foil)
e-
Screen
Station
Camera
Matthias Gross | LAOLA workshop | 24. June 2015 | Page 6
> Purpose: test of interaction electron beam electron window foils
Pre-experiment #2: Dummy Plasma Cell
e-
Electron
windows:
8m Kapton
Gas inlet
(1mbar Ar)
Matthias Gross | LAOLA workshop | 24. June 2015 | Page 7
> Purpose: test of interaction electron beam electron window foils
> Capturing of tightly focused beam behind plasma cell (at that time only
2 Quads available for beam capturing)
Pre-experiment #2: Dummy Plasma Cell
Matthias Gross | LAOLA workshop | 24. June 2015 | Page 8
Summary
> PITZ beamline was remodeled for plasma experiments
> Several preparatory experiments have been performed
1) Beam dynamics: <100m focusing into plasma cell was achieved
2) Electron beam – plasma cell interaction: 8m Kapton foil could be used for first
experiments
> Simulation shows strong scattering, but beam passed plasma cell intact
Matthias Gross | LAOLA workshop | 24. June 2015 | Page 9
Backup
Matthias Gross | LAOLA workshop | 24. June 2015 | Page 10
> Purpose: Find maximal allowable window foil thickness
> Result: 3m (to be checked: gas diffusion)
Pre-experiment #3: Electron Beam Scattering
0.1 1 10
0.01
0.1
1
10
Simulation (FLUKA)
Equation (Multiple Coulomb scattering)
Experiment in PITZ beam line
Div
erg
en
ce
(m
rad
)
Foil thickness (µm)
Goal: 0.2 mrad
top related