The TITAN-EBIT

(Electron Beam Ion Trap)

A Status ReportGünther Sikler

g.sikler@mpi-hd.mpg.de

Introduction- Motivation- Principle

Setup- Requirements- Status

Outlook- Schedule- Measurements

NBqTm

mm

RF ⋅⋅⋅≈

δB

mq

c ⋅⋅=π

ν21

• High precision mass measurements

– Higher q (or B) allows for • better accuracy or

• shorter observation times or

• smaller count rate

EBIT meets rare isotope facilityMotivation

mmδ

RFT

N

• “EBIT physics”: Spectroscopy on HCI → Test QED– Calculations for heavier systems limited by

» applicability of perturbation theory» nuclear effects

→ J. Braun (this workshop)

The electron beam is compressed by a magnetic (Helmholtz) field.

Ions are trappedradially by space charge potential, longitudinally by external field.

Creation of highly charged ionsby multiple subsequent electron impact

The principle of an EBIT

Be- beam

B ≈ 6 - 8 T,Ie ≈ 0.1 – 1 Adeb ≈ 100µm,φsc ≈ 0.1 – 1 keVTion ≈ 100 – 500 eVtionize ≈ 1 ms – 10 s

Charge breeding of RadionuclidesCharge breeding of Radionuclides

Charge state (10 Charge state (10 –– 50)50)‘medium’ high voltage;‘medium’ high voltage; design value: design value: E = 20keVE = 20keV

RapidRapid charge breeding (5 charge breeding (5 –– 50 ms)50 ms)High electron current; design value: High electron current; design value: I = 5 AI = 5 A

Injection + ExtractionInjection + Extraction with high efficiencyopen apertures + open apertures + improved ion opticsimproved ion optics

Handling Handling isobaric contaminationsisobaric contaminationslarge trap, deep space charge potentialslarge trap, deep space charge potentials

..

..

..

Further RequirementsFurther RequirementsCapture into a Penning trap

injection into a strong magnetic field(more critical for HCIs)

deceleration to restshort bunches, small emittance, small ∆E

Extraction of ions in well-defined charge statedriving the cyclotron frequency of the desired speciesextraction over an electrostatic barrierradially segmented central trap electrode extraction\ injection path covered with electrodes

pump

pump

pump

manipulator

insulators

shutter valve

magnet

collector

compensator

insulators

trap

electrongun

ElectronGun

Cathode assembly

Collector

21 mm

174 mm

(provisional)Trap

Outlook:

June ’05: first electron beam (I<500mA, E<2keV)first extraction of ions (injected as neutrals)

July ’05: advanced tests of injection/extraction opticsfirst injection of ions (from test ion source)

-Sept. ’05: final trap setup ready for operationlast installations (electric, cooling..) complete

creeping out of the valley of tears

q/m selection, pos. sensitive detector, emittance meter, TOF-detection, etc…

in operation

Measurement Program:

optimize electron beam current, energy spread

optimize injection and stopping

investigate cooling by admixture of ‘light’ gascharge selective extraction

check characteristics: bunch-length

breeding time charge state

Ie Ee

energy spreademittance

J. Crespo, J. Dilling, S. Epp, M. Froese, G. Sikler, J. Ullrichand the HD-EBIT groupC. Osborne, M. Trinczek