Prof.dr Ing. J.F.J van den Brand, Sep. 2006 – 25
| Four years later
the positron was discovered by the American Carl Anderson in one of his
pictures of the tracks of particles in a detector known as a cloud chamber. |
|
| This device was
in a magnetic field produced by the coils of cable you see in the photograph.
The magnetic field has the effect of bending charged particles. From the
direction of bend it is deduced that the particle has positive charge. From
the amount of energy it loses as it passes through the plate in the middle of
the chamber it is possible to deduce its mass. |
|
| Note the size of
his detector. Later we will see others, somewhat larger, but with similar
features. |
|
| We now know that
all particles have antiparticles and I will now take a minute or two to
discuss antimatter since it is not just the stuff of Star Trek science
fiction, it is also science fact. |
|