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

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Presentation on theme: "Studying a strontium MOT – group meeting 01-12-08 Studying a strontium MOT James Millen."— Presentation transcript:

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

2 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

3 Using the photodiode One nW of light corresponds to (27.8±0.2)mV of signal The photodiode “sees” a solid angle Ω of the emitted light Each atom scatters R photons Each atom emits a power Hence there are N A atoms

4 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

5 MOT atom number Rydberg & plasma physics using ultra-cold strontium Strontium MOT I sat corresponds to 19mW of MOT beam power

6 MOT atom number Rydberg & plasma physics using ultra-cold strontium Strontium MOT

7 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 = αI peak

8 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 8μs Each pixel is 6.45μm 2, and we use a 1:1 magnification Calculated counts per pixel per photon μ = 0.132 Allows us to calculate atom number, but also MOT size

9 Studying a strontium MOT – group meeting 01-12-08 Example ∑C = μ ∑ Nγ

10 Studying a strontium MOT – group meeting 01-12-08 Number and density measurements

11 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 = 5.9±0.5mK (Doppler limit 4.8mK)

12 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

13 Release and recapture Studying a strontium MOT – group meeting 01-12-08

14 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


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