EBIT – Electron Beam Ion Trap

O. Antonov

Physics Department, Technion, 32000 Haifa, Israel

Selected Topics in Astrophysics - 118111

EBIT – Electron Beam Ion Trap

Outline

•Motivation

•History

•EBIS/EBIT – operation principles

•Operating parameters

•EBIT facilities around the world

•Summary

•Bibliography

EBIT – motivation

Highly-charged ions

•In a plasma of fusion facilities

•Corona of the sun

•Boundary of black holes

EBIT can be used as a source of highly-charged ions for

•Studying the ions by themselves inside a trap (small kinetic energy)

•Injecting the ions to larger facilities in order to study interactions with the ions

•Lithography/Medicine/Industrial applications, etc.

History

1965/67 – Proposal of the idea of Electron

Beam Ion Source1

1969 – First Electron Beam Ion Source

facility and report on generation of Au19+(1)

1988 – Invention of first Electron Beam Ion

Trap facility by Morton Levine and Ross

Marrs in Lawrence Livermore National

Laboratory2

1994 – Bare Uranium (U92+) produced in

Super-EBIT facility3

1. E.D.Donets, USSR Inventor’s Certificate No. 248860 16.03. (1967); Bull. OIPOTZ 24 (1969) 652 .Morton A. Levine et al. “The Electron Beam Ion Trap: A New Instrument for Atomic Physics Measurements” Physica Scripta. T22, 157-163, 19883. R. E. Marrs et al. “Production and Trapping of Hydrogenlike and Bare Uranium Ions in and Electron Beam Ion Trap” Phys. Rev. Lett. 72, 4082, 1994

EBIS/EBIT – operation principles

• High density electron beam was used to trap, ionize and excite the ions• Magnetic field provided by superconducting Helmholtz-pair magnet• Axial trapping voltage provided by cylindrical cathodes• EBIT facility produce highly-charged ions which stay in the trap for surprisingly long times

EBIS/EBIT – operation principles

Operating parameters

Typical operating parameters

•Electron Beam Energy: 0.7-33 [keV] (up to 200 [keV] for Super-EBIT in

Lawrence Livermore National Laboratory)

•Initial Electron Beam Radius: about 1 [mm]

•DC Magnetic Field: 3 [Tesla]

•Focused Electron Beam Radius: 30 [µm]

•Trap Length: 3 [cm] (only 2 [cm] visible)

•Ion Density: 3*109 [1/cm3]

•Electron Density: 4*1012 [1/cm3]

•Vacuum: 1*10-8 [Pa]

EBIT Facilities Around the Globe

1. The limit of 1012 charges for the trap capacity has been overcome in design only in the last decade

2. Even today projects are started with water and LN2 cooled solenoids as well as with permanent magnets

3. There is a need for highly charged ions in the full range of 105–1012 charges/pulse

4. An EBIT for spectroscopy and atomic physics needs only a low capacity, an EBIS for charge breeding and synchrotron injection a high one

5. For SC solenoids and Helmholtz coils cryogen-free cooling by refrigerators has become the standard

Summary

• EBIT facility generate and excite ions of high ionization levels, when the kinetic energy of the ions is comparable to the potential energy (cold ions)

• Spectroscopic measurements taken using EBIT facility were useful in many fields of physics (like: Plasma physics, Atomic physics, X-Ray astrophysics)

• EBIT is relatively small and can be easily combined with large facility as an ion source (DC or pulsed)

• Physical principles in EBIT and EBIS are the same• The current (main) problem in EBIT and EBIS facilities

is the cooling problem• TESIS may have promising parameters, that have to be

proved experimentally

Bibliography

Publications:1.Morton A. Levine et al. “The Electron Beam Ion Trap: A New Instrument for Atomic Physics Measurements” Physica Scripta. T22, 157-163, 19882.O. Heber et al. “Electrostatic ion beam trap for electron collision studies” Review of Scientific Instruments 76, 013104, 20053.Reinard Becker and Oliver Kester “Electron beam ion source and electron beam ion trap” Review of Scientific Instruments 81, 02A513, 2010

Other sources of information:Günter Zschornack et al. “Electron Beam Ion Sources”http://www.nist.gov/https://www-pls.llnl.gov/http://www.nscl.msu.edu/

Thank you

for atte

ntion

.