Introduction

Over the last fifteen years, the techniques of cooling and trapping of atoms with use of laser light have developed rapidly. In the experimental setup I used, the goal was to create an intense parallel beam of He* atoms with an adjustable mean velocity. The cooling devices used to create this He* beam are the collimator, the Zeeman slower and the Magneto-Optical Compressor (MOC). Most of the time was spent working on the collimator [1][2], a cooling device used to decrease the perpendicular velocity of the He* beam, making the beam more parallel.

In this thesis I will first give a short introduction to the general principles of laser cooling, and the theory of the collimator (chapter 1). In chapter 2 I will give a description of the setup used for the experiments. Chapter 3 deals with the various experiments done with this setup. Finally in chapter 4 I will summarize the results obtained with the performed experiments, and give some further suggestions of what can be measured using this setup.