1. Magnetic Injection Scheme for The Atom Laser Karl Lundquist REU Summer 2010 Raithel Lab August 17 2010

2. Outline Overview of current generation atom laser setup Theory/Simulation of magnetic injection Experimental setup of magnetic injection o In the vacuum o Electronics o Enclosure o Software

3. Overview of current setup Zeeman slower Primary MOT Pusher Beam Secondary MOT Magnetic Injection Magnetic Compression Surface Adsorption evaporative cooling Continuous BEC!

4. Basic idea behind magnetic injection Transferring atom into evaporative cooling region with light would cause atoms to gain heat. Instead, if we transfer atoms with magnetic field only, the process can be slow enough to be adiabatic. From secondary MOT, we can transfer atoms along the guide using a moving magnetic field minimum.

5. Magnetic field sources in the injection region Guiding wires produce transverse trapping potential (~250 amps) Injection coils produce moving magnetic field minimum (2-3 amps each) Racetrack coils produce quadrupole magnetic field for secondary MOT

6. Coil current profiles Period ~ 1second

7. Injection Simulation

8. High Current Power Supply HP6651A 0-8 Volts 0-50 Amps Low gauge wire and aluminum rods for high current transport

9. Circuit setup Need easy way to control current in each coil with low voltage signal from computer Traditional differential amplifier setup Must drop signal over R test in order to maintain equilibrium op-amp pushes transistor base until allowed current causes required voltage drop R=.5 Ohms I=V/R => I = 2V*(1/Ohm) Directly proportional

10. Testing Measuring voltage across load resistor will indicate the amount of current flowing through coils A circuit can be tested by checking that the signal in is identical to the signal out

11. Cooling 2-3 Amps through transistors makes them very hot use heat sinks and high powered fans too keep them cool

12. Circuit Control United Electronics Industries PowerDNA Cube Allows for DAQ communication via Ethernet port LabVIEW user interface

14. Acknowledgments Georg Raithel Andrew Schwarzkopf Andrew Cadotte David Anderson Eric Paradis Mallory Traxler Sarah Anderson Erik Power Betty Slama Stefan Zigo Kareem Hegazy Kevin Smith Much thanks to everyone in Raithel Lab for a great summer!