The TOTEM experiment
Kenneth Osterberg
Department of Physical Sciences, University of Helsinki 
and Helsinki Institute of Physics, Finland

on behalf of the TOTEM collaboration

TOTEM will measure the total pp cross section at LHC with an accuracy 
of 1 % or better using the luminosity independent method based on 
simultaneous measurement of the elastic event rate down to very small 
-t and the total event rate. These measurements will be done in runs 
with a special LHC beam optics("high beta*"), optimized for the purpose. 

The total inelastic and diffractive event rate will be measured by two
forward tracking telescopes, covering together an eta interval between
3.1 and 6.7, on each side of the interaction point. The elastically and 
diffractively scattered protons will be measured by a set of special 
detector systems, either Roman pots or Microstations, which will be 
moved very close to the outgoing proton beams.  

An intensive R&D program is currently being pursued to find the most
suitable sensor technology fulfilling the proton detection requirements 
as defined by the physics aims in terms of detector performance and 
mechanical and electrical integration. A Roman Pot design especially 
developed for TOTEM have been made and a first prototype will be ready
by the end of the year for extensive testing. As an option to the Roman 
Pots, a new type of device, the Microstation, that is lighter and more 
compact, has also been developed. 
 
In the case of elastic scattering, the TOTEM measurements will cover 
the full -t range between 10^-3 and 10 GeV^2. Moreover, TOTEM will study 
diffraction and the physics of minimum bias events in runs with high 
beta* optics and luminosities up to 10^29 cm^-2 s^-1. In addition, TOTEM
intends to study diffraction together with CMS in runs with the standard 
LHC optics and luminosities up to 10^33 cm^-2 s^-1.