THOUGHTS on BUBBLE CHAMBER PICTURE POSSIBILITIES for HST2003

   Introduction

   The HST website (http://teachers.web.cern.ch/teachers/)
   is an archive of work carried out at HST Summer Schools
   over the past few years.

   The bubble chambers pages
   (http://teachers.web.cern.ch/teachers/materials/bubblechambers.htm
   contain

   (a) some  bubble chamber images, specially  selected
   for their potential for use in teaching: they demonstrate
   the reality of particles and how we study their properties;
   they also illustrate many general physics concepts in
   particularly intuitive ways (eg. conservation of energy,
   momentum, charge; motion of charged particles in magnetic fields ...)

   (b) teaching materials and explanatory notes produced by teachers;
   many of these are very well thought out, but, due to the pressure
   of time, they are not yet in the polished form that CERN would be
   happy with if it were to launch an `official' site for teachers.

   (This comment applies to many other pages on the HST site.)

   This year, we feel that it would be good to focus on the material
   we have already and to try to think about how we can make the best
   use of it.



   Possibilities

   *  If one regards the current bubble chamber site as `draft 0'. what
    needs to be done to turn it into a much better `draft 1'.

     Detailed thought needs to be given to

      (a) its overall presentation;

      (b) the details of individual parts;


           eg. What is a bubble chamber?
     How does it work? How do we `read' the tracks?  How can we
     recognise particles from the characteristic tracks they make?
     ...


     (c) Can we develop `model' interactive exercises?

     For example: with a suitable picture one might be able to
     ask a set of questions that would lead the student through
     a qualitative analysis:

         Can you find any electrons?
         Which way are they curving?
         (Why do they curve much more than the nuclear particles
         that are being studies?)
         Which way is the magnetic field pointing?
         How many beam tracks are there?
         (Are there any spurious background tracks? What might they be?)
         How many beam tracks make collisions?
         How many particles are there in the final state of
         the interaction?
         How many are positive and how many are negative; and  how
         can you tell?
         Are there any neutral particles?
          . . . . and many more such questions?

      (d) Maybe it would be a good idea to develop packages that
      cut across the working group boundaries?

      For example:
      the force on a current in a magnetic field is fundamental
      to `ordinary' electromagnetism. In particle physics in is
      crucial because accelerators use it to keep the beam going
      round and detectors use it to measure momentum. The
      same force protects us from charged particle radiation from
      the sun.



    (e) What do teachers really need/want (these words mean
    different things)? Here we might wish to think about teachers
    who have never been to CERN, and maybe never will.

    (f) CERN HST2003 is still only a 3-week programme? If funding
    were to become available, how should it be used?