Studying a strontium MOT – group meeting 01-12-08 Studying a strontium MOT James Millen

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  • Slide 1
  • Studying a strontium MOT group meeting 01-12-08 Studying a strontium MOT James Millen
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  • Theory 689nm 7.6kHz Up to 13mins* *Yasuda, Katori Phys. Rev. Lett. 92, 153004 (2004) (5s 2 ) 1 S 0 461nm 32MHz (5s5p) 1 P 1 620Hz (5s4d) 1 D 2 0.33 (105Hz) (5s5p) 3 P 2 0.67 (213Hz) 3P13P1 679nm (1.4MHz) 707nm (6.4MHz) (5s6s) 3 S 0 3P03P0 7.6kHz Studying a strontium MOT group meeting 01-12-08
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  • Using the photodiode One nW of light corresponds to (27.80.2)mV of signal The photodiode sees a solid angle of the emitted light Each atom scatters R photons Each atom emits a power Hence there are N A atoms
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  • Atom number experimental sequence Controlled by LabView via FPGA card MOT beams always on A)B-field & slowing light off B) Slowing light on C) B-field and slowing light on D) B-field on, slowing light off E) B-field & slowing light off Studying a strontium MOT group meeting 01-12-08
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  • MOT atom number Rydberg & plasma physics using ultra-cold strontium Strontium MOT I sat corresponds to 19mW of MOT beam power
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  • MOT atom number Rydberg & plasma physics using ultra-cold strontium Strontium MOT
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  • Some preliminary results MOT lifetime Rydberg & plasma physics using ultra-cold strontium Strontium MOT Black line I = I peak Blue line I = I average Green line I = I peak
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  • Studying a strontium MOT group meeting 01-12-08 Using the camera We use a pco. pixelfly qe CCD camera, with 1392x1024 pixels It has an internal shutter that shutters in about 8s Each pixel is 6.45m 2, and we use a 1:1 magnification Calculated counts per pixel per photon = 0.132 Allows us to calculate atom number, but also MOT size
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  • Studying a strontium MOT group meeting 01-12-08 Example C = N
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  • Studying a strontium MOT group meeting 01-12-08 Number and density measurements
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  • Time of flight measurement Studying a strontium MOT group meeting 01-12-08 Create a MOT, let it go, and after some variable time image it and record its width. Assume Gaussian cloud shape and velocity distribution T = 5.90.5mK (Doppler limit 4.8mK)
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  • Release and recapture A)MOT and slower light on (molasses) B) MOT coils on (MOT fills) C) Slower light off (8ms) D) MOT light off E) MOT light back on Studying a strontium MOT group meeting 01-12-08
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  • Release and recapture Studying a strontium MOT group meeting 01-12-08
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  • To do Studying a strontium MOT group meeting 01-12-08 Analyze more temperature data Investigate effect of intensity / detuning on temperature Get some decent density data Next: Turn on MCP Make some ions Make some Rydbergs