U. Konopka

Max-Planck-Institut für Extraterrestrische Physik, Giessenbachstrasse, 85741 Garching, Germany

email: konopka@mpe.mpg.de

New, „Flexible“ Plasma Devices forComplex Plasma Experiments

New, „Flexible“ Plasma Devices forComplex Plasma Experiments

Max-Planck-Institute for Extraterrestrial PhysicsMax-Planck-Institute for Extraterrestrial Physics

Why do we design new plasma chambers forcomplex plasma experiments ?

Why do we design new plasma chambers forcomplex plasma experiments ?

With the new setups we would like to reach experimental conditions that gofar beyond what can be established with former designs as i.e.:

PK3-Plus: Single parallel plate discharge (much more flexible and quality optimized)

PK4: DC-Discharge tube (addresses different complex plasmas physics (i.e. flows))

PKE-Nefedov: Single parallel plate discharge

IMPF-Predevelopment chambers:

Spherical Chamber (capacitive)Spherical Chamber (inductive)Cylindrical Chamber (capacitive)

Spherical Chamber (capacitive)

Spherical Chamber (inductive)

RF-1

B

Experiences from the IMPF (Pre-)DevelopmentsExperiences from the IMPF (Pre-)Developments

Spherical Chamber (capacitive)

Spherical Chamber (inductive)

RF-1

RF-2

RF-3Random switched RF parallel plate discharge

Experiences from the IMPF (Pre-)DevelopmentsExperiences from the IMPF (Pre-)Developments

Experiences from the IMPF (Pre-)DevelopmentsExperiences from the IMPF (Pre-)Developments

Spherical Chamber (capacitive)

Spherical Chamber (inductive)

Labor experiences using the IMPF RF chamberExperimental setup

Labor experiences using the IMPF RF chamberExperimental setup

Labor experiences using the IMPF RF chamberA Transparent Top Electrode

Labor experiences using the IMPF RF chamberA Transparent Top Electrode

A transparent (ITO-covered) conducting (RF) top electrode was introduced.

camera

camera

New single electrode (Ø ≈ 80mm, groove Ø ≈ 40 mm, 1 mm depth)used for potential measurements, single particle manipulation

a singleparticle

mg

mg·sin(α)

α

Fc(x)=

y

x

Labor experiences using the IMPF RF chamberThe Electrode System

Labor experiences using the IMPF RF chamberThe Electrode System

Goals for removing former constrains and their implications?Goals for removing former constrains and their implications?

Limited plasma parameter range:

Range Main range implications

Electron temperature (Te)

2-3 eV (non-adjustable) 0.1 - 6 eV (adjustable)

× 40 Q × 40

Γ × 1600

Plasma density (ni, ne) 1014 - 1016 m-3 1013 - 1017 m-3

× 100 Δ × 10

nd × 1000

Neutral pressure (p) 10 - 200 Pa 0.1 - 1000 Pa

× 500 γ × 500

× 2×106

Limited manipulation devices: Function generator Adaptive Elec., Laser Twizers,..

Limited system geometries: Void, Ellipsoids Adaptive, Multi-Clouds

Limited interaction variation: Debye-Hückel Designer-Potential (attractive)

Two new design approaches will be studiedTwo new design approaches will be studied

Flexible, parallel plate discharge chamber with improved electrode setups

Flexible plasma chamber with quasi spherical geometry and timeaveraged isotropic plasma structure

Zyflex - ChamberZyflex - Chamber Dodecahedron - ChamberDodecahedron - Chamber

The Zyflex-Chamber - ConceptThe Zyflex-Chamber - Concept

Variable shower head/electrode holder combinationModular parallel plate electrode system

for pumping and dust removal

The Zyflex-Chamber – Gasflow and PlasmastructureThe Zyflex-Chamber – Gasflow and Plasmastructure

Double RF-Electrode (maybe transparent)

Single 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)

The Zyflex-Chamber – Elektrode modulesThe Zyflex-Chamber – Elektrode modules

The Zyflex-Chamber - ImplicationsThe Zyflex-Chamber - Implications

Extended plasma parameter range (√)

Extended manipulation devices √

Extended system geometries √

Extended interaction variation (√)

Two new design approaches will be studiedTwo new design approaches will be studied

Flexible, parallel plate discharge chamber with improved electrode setups

Flexible plasma chamber with quasi spherical geometry and timeaveraged isotropic plasma structure

Zyflex - ChamberZyflex - Chamber Dodecahedron - ChamberDodecahedron - Chamber

The Dodecahedron-Chamber – BackgroundThe attractive potential

The Dodecahedron-Chamber – BackgroundThe attractive potential

Ion flow and ion-wake-potential in 2D

In the limit of smooth angularVariation of the ion flow thetimeaveraged potential will bequasi spherical.

With increasing pressure thecrytical angle for a smoothpotential is increasing.

With a smooth controllable ion flow direction, even dedicated non sphericalPotentials might be established. – Disadvantage: Orientation is globally fixed.

The Dodecahedron-Chamber - ConceptThe Dodecahedron-Chamber - Concept

The real chamber should be driven by 12 independend rf-generators thatcan be individually shifted in phase, have different, programmable outputpower as well as an arbitrary DC-offset – everthing software controlled (>10kHz).

DC RF

The plasma generation (Example 2D)

The Dodecahedron-Chamber - ConceptThe Dodecahedron-Chamber - ConceptThe plasma generation

Timeaveraged quasi isotropic plasma in 2D/3D – Dodecahedron geometry

But, why a dodecahedron?

DC RF

The Dodecahedron-Chamber - ConceptThe Dodecahedron-Chamber - ConceptThe plasma generation

DC RF

By continuous dc-voltagecontrol the Ion-drag shouldbe smoothed directionable

3D

Time averaged

The Dodecahedron-ChamberThe Dodecahedron-Chamber

Extended plasma parameter range √!

Extended manipulation devices √

Extended system geometries (√)

Extended interaction variation √!

Thank‘s for your attention.

The Dodecahedron-ChamberThe Dodecahedron-Chamber