S. Stahl: Cryogenic Electronics in Ion Traps Part I

S. Stahl, CEO Stahl-Electronics

Cryogenic Electronics in Ion TrapsCryogenic Electronics in Ion Traps

S. Stahl: Cryogenic Electronics in Ion Traps Part I

OutlineI. Principles of Ion Traps 1. Penning Traps 2. Paul Traps 3. Kingdon Trap 4. Trap Applications in Science and Industry

II. Cryogenic Traps 1. Why Cryogenic ? 2. Precision Measurements in Traps 2.1 Magnetic Moments 2.2 Mass Measurements 2.3 Fundamental Constants

III. Non-destructive Particle Detection 1. Why non-destructive detection? 2. How does it work? 3. Sensitivity improvement 4. Resistive Cooling 5. Detection of cold particles

IV. Design of Cold Amplifiers 1. Which Semiconductors are suitable? 2. Typical Amplifier Design for Ion Traps 3. Anchoring and Cabling 4. Implemention Examples

V. Other Components : Filters, Switches

S. Stahl: Cryogenic Electronics in Ion Traps Part I

Part I

Principles of Ion TrapsPrinciples of Ion Traps

1.1. Penning TrapPenning Trap2.2. Paul TrapPaul Trap3.3. Kingdon TrapKingdon Trap4.4. Trap Applications in Science and IndustryTrap Applications in Science and Industry

S. Stahl: Cryogenic Electronics in Ion Traps Part I

1. Penning Trap

zc Bm

q Lorentz-force: radial confinement

free cyclotron motion:

Electrostatic potential: axial confinement leads to axial oscillation

Charged ParticleMass m, Charge q

S. Stahl: Cryogenic Electronics in Ion Traps Part I

Implementation: Hyperbolical Trap

Magnetic field

=>Advantage: harmonic motion(frequency independent of energy)

S. Stahl: Cryogenic Electronics in Ion Traps Part I

Resulting ion motion

a x ia l m o tio n : o sc illa tio n in E -f ie ld

20

m d

qVz

Axial Motion

242

22zcc

Reduced Cyclotron Motion

242

22zcc

Magnetron Drift

Problem Magnetron-Motion:Inherently unstable

3 degrees of freedom:

Energy: 0 ... eV ... keV~1MHz

~10kHz

~10MHz

S. Stahl: Cryogenic Electronics in Ion Traps Part I

Manipulation of Motions- Excitation: electric dipole ac fields increase amplitude / radii => applying z, +, - radio frequency field => heating until loss of particles-Cooling: Laser cooling, if optical transition exists ( < Millikelvin) Resistive Cooling ( ~ few Kelvin) Sympathetic Cooling (~ few Kelvin to Millikelvin)

-Magnetron Centering Motional Sidebands (+ + -, z + -), or phase-defined - („Magnetron Cooling“) Rotating Wall (large ion numbers)

Lit: Werth, Gheorghe, Major : Charged Particle Traps, published by Springer

S. Stahl: Cryogenic Electronics in Ion Traps Part I

Dipole excitation:

electric dipole field in z or r-direction

S. Stahl: Cryogenic Electronics in Ion Traps Part I

Quadrupole excitation:

electric quadrupole field in r-z direction or radial plane

S. Stahl: Cryogenic Electronics in Ion Traps Part I

Rotating Wall drive:

=> rotating electric wall in radial plane centers particles

A B

CD

90° degrees phase shifted sine signals

Lit.: X.-P. Huang, F. Anderegg, et al., Phys. Rev. Lett. 78, 875 (1997) S. Bharadia, M. Vogel, D.M. Segal, R.C. Thompson, Dynamics of laser-cooled Ca+ ions in a Penning trap with a rotating wall; submitted to Applied Physics B

(applies rather for multiparticle/plasma regime)

S. Stahl: Cryogenic Electronics in Ion Traps Part I

Typical Penning Trap ParametersB0 = 0.1 T .... 6T (typical in science) ... 20T

U0 = 2V .. 200V

Stored particles:from lightest electrons/positrons, to heaviest organic molecules (e.g. m = 10‘000u)

storage times1sec .... 1 year (cryogenic systems)

number of particles:one to several millions

superconductingnormal-conducting (water-cooled)

Magnets

(heavier particles -> high fields required)

(low voltages: patch effect problems)

permanent(up to 2T)

S. Stahl: Cryogenic Electronics in Ion Traps Part I

Penning Trap Variants

- classical hyperpolical electrodes

- cubic type trap (chemistry)A. Marshall et al.Rev. Mass. Spec. 17, 1 (1998).

- 3pole-Brown-Gabrielse-type trap L.S. Brown, G. Gabrielse,Rev. Mod. Phys. 58, 233 (1986).

Laser, Microwaves, Ions,...

B-field

S. Stahl: Cryogenic Electronics in Ion Traps Part I

Penning Trap: Some Real-world designs

Precision trap for single-ion mass analysis(GSI / Univ. Mainz, Triga)

Precision trap for single-ion g-factor determinations (Univ. Mainz)

„Shiptrap“ for mass analysisof short-lived isotopes (GSI)

S. Stahl: Cryogenic Electronics in Ion Traps Part I

Example Open Endcap Structure:

KATRIN-Trap (commissioning 2009..2011)

-Experiment KATRIN, Karlsruhe

-large trap (72mm diam.), open structure-operated at T = 77K-„non-precision“ trap

S. Stahl: Cryogenic Electronics in Ion Traps Part I

Planar Trap

Marzoli et al.Experimental and theoretical challenges for the trapped electron quantum computerJ. Phys. B: At. Mol. Opt. Phys. 42 (2009) 154010 (11pp)

Goldman and Gabrielse: Optimized planar Penning traps for quantum-information studiesPhys. Rev. A 81, 052335 (2010)

S. Stahl: Cryogenic Electronics in Ion Traps Part I

Planar Trap: Easy Access for Photons and Scalability

Open structure allowseasy access with Lasers, Microwaves etc.

Interesting for Quantum Computing, for Mass Analysis, etc.

“100 traps on 1 Euro“

S. Stahl: Cryogenic Electronics in Ion Traps Part I

Planar Traps: Implementation approaches

Schmidt-Kaler et al.• Multiple ring electrode structures• multi-layer PCB• on board filters• easy fabrication• structures > 100..150 µm

QUELE-Project

S. Stahl: Cryogenic Electronics in Ion Traps Part I

2. Paul Traps / Quadrupole Ion Traps

metallic electrodes

- No magnetic field needed- high (1kV) AC fields needed- problem RF-heating => cooling technique needed (like: buffer gas cooling, strong laser cooling)

Resulting macromotionin a pseudo potential ofa few eV=> 3D confinement

S. Stahl: Cryogenic Electronics in Ion Traps Part I

Paul Traps: Many different shapes exist

simple ring(ground around is second electrode)

Paul-Straubel-Type

Trapped particles

Quadrupolar Rodshyperbolic shape

S. Stahl: Cryogenic Electronics in Ion Traps Part I

3. Kingdon Trap

Lit: Blümel, R (1995). "Dynamic Kingdon trap". Physical Review A 51 (1): R30–R33. doi:10.1103/PhysRevA.51.R30

Hu, Noll, Li, Makarov, Hardman, Graham Cooks R (2005):"The Orbitrap: a new mass spectrometer". Journal of mass spectrometry : JMS 40 (4): 430–43. doi:10.1002/jms.856

Pure Electrostatic Trap=> no (expensive) magnet needed

Kingdon Trap

Advantage: very simpleDisadvantage: Short Storage Times

modern variant: Orbitrap

Improved version,Longer Storage timeImportant tool in analytical mass spectrometry

S. Stahl: Cryogenic Electronics in Ion Traps Part I

4. Trap Applications in Science and Industry

Industry: Mass Analysis in Chemistry, Biology, Environmental Analytics-Paul Traps / Mass Filters-Penning Traps (specially FT-ICR-Traps)

Science / Fundamental Research:-Paul Traps Quantum Optics, Frequency Standards, Atomic Physics, ...-Penning Traps Fundamental constants, Laser-spectroscopy, g-factor mass references and.....

Lit: Werth, Gheorghe, Major : Charged Particle Traps, published by Springer

S. Stahl: Cryogenic Electronics in Ion Traps Part I

Mass Measurements in Penning TrapsNuclearNuclearPhysicsPhysics

nuclear binding energies,Q-values

m/m 1·10-7

NuclearNuclearStructureStructure

shell closure, pairing, deformation, halos,

isomers

m/m 1·10-7

m/m 1·10-7

FundamentalFundamentalPropertiesProperties

tests of nuclear modelsand formulae

AtomicAtomicPhysicsPhysics

e- binding energyQED test

m/m 1·10-10

m/m < 3·10-8

WeakWeakInteractionInteractionsymmetry tests,CVC hypothesis

m/m < 1·10-7

AstroAstro--physicsphysics

nuclear synthesis,r- and rp-process

Weighingexotic

systemstrap assisted

decayspectroscopý

trap assistedlaser

spectroscopý

Courtesy Klaus Blaum

S. Stahl: Cryogenic Electronics in Ion Traps Part I

- End of part I -

S. Stahl: Cryogenic Electronics in Ion Traps Part I

Thanks for your attention

S. Stahl: Cryogenic Electronics in Ion Traps Part I

g-factor setup Mainz:vertical 4K-dewar setup(g-factor, Mainz)

g-factor trap

4K-axialamplifier

4K-broadbandFT-ICR amplifier ( Mainz 2004 )

4K-electronics section