Transcript SPEC(troscopy)-Trap - uni

End of 2007
• 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
Experimental Plans
1. RF trap ● less complex system to start debugging a new trap
● initial tests with Calcium using existing Laser system
● optimise internal/external optics and loading parameters
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
Progress..
• Complete vacuum system assembled and tested - pressure ~10-9mbar
• Trap with internal optics assembled and aligned - knife edge test
• Calcium oven and filament attached – electron current to all electrodes
detected and glow from oven observed
• RF electronics operational - 500V@1MHz (q=0.7) or 2.6MHz
Progress..
• Complete vacuum system assembled and tested - pressure ~10-9mbar
• Trap with internal optics assembled and aligned - knife edge test
• Calcium oven and filament attached – electron current to all electrodes
detected and glow from oven observed
• RF electronics operational - 500V@1MHz (q=0.7) or 2.6MHz
Spherical mirror =>
enhancement of
light collection
efficiency from
1.3% to 2.5%
Progress..
• Complete vacuum system assembled and tested - pressure ~10-9mbar
• Trap with internal optics assembled and aligned - knife edge test
• Calcium oven and filament attached – electron current to all electrodes
detected and glow from oven observed
• RF electronics operational - 500V@1MHz (q=0.7) or 2.6MHz
Progress..
• Complete vacuum system assembled and tested - pressure ~10-9mbar
• Trap with internal optics assembled and aligned - knife edge test
• Calcium oven and filament attached – electron current to all electrodes
detected and glow from oven observed
• RF electronics operational - 500V@1MHz (q=0.7) or 2.6MHz
Last week..
• First trials in RF operation - Ca+ ions not optically observed
• Possible problems
- wavelengths? verified by PADTRAP
- focal position of laser beams in trap?
- position of detector pinhole?
- Calcium oven not emitting as expected?
- pressure in vacuum system not good enough?
Outlook
• 2-3 weeks optical detection of Ca+ in RF operation
• Setup of external optics for superconducting magnet - fibre optic
bundle, folding mirrors etc.
• 1-2 months begin Penning trap trials.
Ion Trapping @ Imperial College
Ca+ ion in a 0.98 Tesla trapping field
5 reds at present