1. New, „Flexible“ Plasma Devices for Complex Plasma Experiments
Max-Planck-Institute for Extraterrestrial Physics
New, „Flexible“ Plasma Devices for
Complex Plasma Experiments
U. Konopka
Max-Planck-Institut für Extraterrestrische Physik, Giessenbachstrasse, Garching, Germany

2. Why do we design new plasma chambers for complex plasma experiments ?
With the new setups we would like to reach experimental conditions that go
far beyond what can be established with former designs as i.e.:
PKE-Nefedov: Single parallel plate discharge
PK3-Plus: Single parallel plate discharge
(much more flexible and quality optimized)
PK4: DC-Discharge tube
(addresses different complex plasmas physics (i.e. flows))
IMPF-Predevelopment chambers:
Cylindrical Chamber (capacitive)
Spherical Chamber (inductive)
Spherical Chamber (capacitive)

3. Spherical Chamber (inductive) Spherical Chamber (capacitive)
Experiences from the IMPF (Pre-)Developments
Spherical Chamber (inductive)
Spherical Chamber (capacitive) B
RF-1

4. Spherical Chamber (inductive) Spherical Chamber (capacitive)
Experiences from the IMPF (Pre-)Developments
Spherical Chamber (inductive)
Spherical Chamber (capacitive)
RF-2
RF-3
Random switched RF parallel plate discharge
RF-1

5. Spherical Chamber (inductive) Spherical Chamber (capacitive)
Experiences from the IMPF (Pre-)Developments
Spherical Chamber (inductive)
Spherical Chamber (capacitive)

6. Labor experiences using the IMPF RF chamber
Experimental setup

7. Labor experiences using the IMPF RF chamber
A Transparent Top Electrode
A transparent (ITO-covered) conducting (RF) top electrode was introduced.
camera
a single
particle
camera
New single electrode (Ø ≈ 80mm, groove Ø ≈ 40 mm, 1 mm depth)
used for potential measurements, single particle manipulation

8. Labor experiences using the IMPF RF chamber
The Electrode System α y x
Fc(x)=
mg·sin(α) mg

9. Goals for removing former constrains and their implications?
Limited plasma parameter range:
Range
Main range implications
Electron temperature (Te)
2-3 eV (non-adjustable) eV (adjustable)
× 40
Q × 40
Γ × 1600
Plasma density (ni, ne)
m m-3
× 100
Δ × 10
nd × 1000
Neutral pressure (p)
Pa Pa
× 500
γ × 500
× 2×106
Limited system geometries: Void, Ellipsoids Adaptive, Multi-Clouds
Limited manipulation devices: Function generator Adaptive Elec., Laser Twizers,..
Limited interaction variation: Debye-Hückel Designer-Potential (attractive)

10. Two new design approaches will be studied
Zyflex - Chamber
Zyflex - Chamber
Dodecahedron - Chamber
Flexible plasma chamber with quasi spherical geometry and timeaveraged isotropic plasma structure
Flexible, parallel plate discharge chamber with improved electrode setups

11. The Zyflex-Chamber - Concept
Variable shower head/electrode holder combination
Modular parallel plate electrode system

12. The Zyflex-Chamber – Gasflow and Plasmastructure
for pumping and
dust removal

13. The Zyflex-Chamber – Elektrode modules
Single RF-Electrode (maybe transparent)
Double RF-Electrode (maybe transparent)
Adaptive RF-Electrode
Double DC-RF Combi Electrode
Adaptive DC-RF Combi Electrode
(maybe with second grid for active electron temperature control)

14. The Zyflex-Chamber - Implications
Extended plasma parameter range (√)
Extended system geometries √
Extended manipulation devices √
Extended interaction variation (√)

15. Two new design approaches will be studied
Zyflex - Chamber
Zyflex - Chamber
Dodecahedron - Chamber
Flexible plasma chamber with quasi spherical geometry and timeaveraged isotropic plasma structure
Flexible, parallel plate discharge chamber with improved electrode setups

16. The Dodecahedron-Chamber – Background The attractive potential
Ion flow and ion-wake-potential in 2D
In the limit of smooth angular
Variation of the ion flow the
timeaveraged potential will be
quasi spherical.
With increasing pressure the
crytical angle for a smooth
potential is increasing.
With a smooth controllable ion flow direction, even dedicated non spherical
Potentials might be established. – Disadvantage: Orientation is globally fixed.

17. The Dodecahedron-Chamber - Concept
The plasma generation (Example 2D) DC RF
The real chamber should be driven by 12 independend rf-generators that
can be individually shifted in phase, have different, programmable output
power as well as an arbitrary DC-offset – everthing software controlled (>10kHz).

18. The Dodecahedron-Chamber - Concept
The plasma generation DC RF
Timeaveraged quasi isotropic plasma in 2D/3D – Dodecahedron geometry
But, why a dodecahedron?

19. The Dodecahedron-Chamber - Concept
The plasma generation DC RF
By continuous dc-voltage
control the Ion-drag should
be smoothed directionable
Time averaged 3D

20. The Dodecahedron-Chamber
Extended plasma parameter range √!
Extended system geometries (√)
Extended manipulation devices √
Extended interaction variation √!

21. The Dodecahedron-Chamber
Thank‘s for your attention.