SPEC(troscopy) -Trap Outline of talk Introduction – motivation for two cross continent traps Imperial College Group – areas of interest and expertise SPECTRAP/SPECTRAP’ – a comparison of the different requirements of the traps – a L00K at SPECTRAP’ SPECTRAP’ Experimental plans – Layout of the Laboratory – initial trials in RF operation – Penning mode configuration – simulations in SIMION Conclusion and Outlook

Introduction It was decided that a clone of SPECTRAP, SPECTRAP’, would be built in London for the main purpose of gaining experience early that can be bought to GSI. We have a compatible superconducting magnet in London. Hence we can be the first to test SPECTRAP in a Penning configuration. SPECTRAP has a split-ring electrode structure, hence a broad usability for other experiments in the group e.g. Axialisation fixed ω c /2 If delays occur at GSI, they will have less of an impact on us. We can employ real time ion imaging to investigate the rotating wall technique – Low charge states have a much faster optical transition.

Ion Imperial College Laser cooling and Spectroscopy of single charged ions e.g. Ca+, Be+ and Mg+. Cooling to sub-Kelvin temperatures? Applications in Quantum Information Processing with electronic energy levels representing the qubits. We can use existing optical setup for Ca + and transport laser light through optical fibre to the trap.

Ion Imperial College Ca + ion in a 0.98 Tesla trapping field 3 reds? Old diagram

Ion Imperial College

SPECTRAP/SPECTRAP’ OHFC copper construction Singly charged ions created inside the trap – electron impact ionisation Room temperature Pressure ~ Solid split ring with through holes for real 2D optical imaging on CCD camera Gold coated OHFC copper construction. Highly charged ions from HITRAP with in-flight ion capture. Cryogenic Pressure ~ LIF capture through wire mesh covered ring electrode – detection with PMT/APD Ion Source Internal Environment Light Collection Construction

SPECTRAP/SPECTRAP’ SPECTRAP’ optics internal – collimating lens inside vacuum chamber – spherical mirror doubling amount of light collected external – image relay by high resolution fibre optic bundle ~10µm cores – CCD camera AR coatings throughout. SPECTRAP ? Edmund Optics Image Conduit

SPECTRAP/SPECTRAP’

Ion Imperial College

Experimental Plans 1. RF trap – less complex system to start debugging a new trap – optimise internal optics 2. Penning trap – investigate cloud compression using the rotating wall technique for which we already have the electronic driver in London – look for fluorescence from Pb + weak infrared transition at 710 nm to gain experience of low LIF levels

SIMION Simulations We have models of both traps in SIMION: -SPECTRAP simulation has showed us that we need a capture voltage of 6 kV and magnetic field > 4 tesla to trap all ions from the Cooler Trap, assuming ions delivered at 5 keV/q with emittance of 10 mm mrad and diameter of 5mm. -SPECTRAP’ RF stability region mapped.

SPECTRAP’ RF operation in SIMION azaz qzqz From Axial Fit C 2 ~0.6 Mathieu stability region

Conclusion SPECTRAP’ is being built in London to trap Ca+ ions with real imaging capabilities Early RF operation expected Jan 2008 Penning operation Feb/Mar 2008