1. Modification to Various Projects in Raithel’s Lab Louise Niu, University of Michigan REU 2008 Advisor: Georg Raithel http://cold-atoms.physics.lsa.umich.edu

2. Outline 2 Magneto-Optical Trap Laser Cooling & MOT Building Compensating Magnetic Coils Bose-Einstein Condensation How to make a BEC Building High Voltage Power Supply

3. Laser Cooling 3 Atom  Rb Atoms absorb photons in the laser beam  Conservation of Momentum  Atom slows down  Atom spits photons in a random direction  Continuous photon stream from one direction One dimensional laser cooling Animation

4. Magneto-Optical Trap (MOT) 4  3 orthogonal pairs of counter- propagating laser beams.  Quadruple magnetic field trap atoms in the center.  Cool Rb Atoms to 1mK. (MOT)

5. Building Compensating Magnetic Coils 5  Motivation:  Create bias magnetic field to adjust MOT postion for Cryo-MOT  Design & Setup:  3-dimentional Anti-Helmholtz magnetic field  Each pair coils generates 2 gauss magnetic field in its center  Vertical direction: wrap coils on the chamber  Horizontal plane: coil form+cardboard Made by Louise !! lol

6. Building Compensating Magnetic Coils 6  MATLAB Simulation: 

7. Building Compensating Magnetic Coils 7 1. Coil Wrapping2. Mount Coils 3.Connect to Power Supply

8. Testing 8

9. 9 Building Compensating Magnetic Coils

10. Bose-Einstein Condensation (BEC) 10  Bosonic Atoms: having integer spin  Low temperature: very close to absolute zero (10s of nK)  Atoms are in the same lowest energy level  Atoms are absolutely identical  Act as one giant wave

11. How to make a BEC 11 1. Laser cooling and trapping 2. Turn laser light off and turn 3-D magnetic trap on 3. Evaporative cooling: 11

12. Building High Voltage Power Supply 12  Motivation:  To supply high voltage for MCP  Micro-Channel Plate:  A component to detect Ions  Phosphor screen Ions Phosphor screen

13. Building High Voltage Power Supply 13 Current meter Power supply Power plug Aluminum Box Power switch High V-source

14. Building High Voltage Power Supply 14

15. In addition… 15  Other projects:  Laser Amplifier  Pulsed Coil  Atom Laser  Software Applied: MATLAB Mathematica Photoshop Adobe Illustrator AutoCAD

16. Acknowledgements 16  Prof. Georg Raithel  Graduate Students:  Aaron Reinhard  Brenton Knuffman  Eric Paradis  Kelly Younge  Mallory Traxler  Melinda Morang  Rachel Sapiro  Rahul Mhaskar  Rui Zhang  Undergraduate Students:  Jordan Montgomery  Varun Vaidya

17. Thanks for your attention !