Simulating Beam Distributions for NLC and TESLA machines

NLC-500 Results for e+e- collisions
TESLA-500 Results
NLC-500 and TESLA-500 luminosity spectrum studies

    Andrei Seryi uses the MATLIAR package to simulate transport of the beams from the Damping Ring to the IP, giving the beam distributions at the IP.  This includes typical alignment errors and beam parameter correlations.
He generated the files "electron.ini" and "positron.ini," which are subsequently used by Daniel Schulte's GUINEA-PIG
simulation package to generate:
    i) the outgoing beam distribution files "beam1_IP.dat" (for outgoing electrons) and "beam2_IP.dat" (for outgoing positrons) at
            the IP. 
    ii) the luminosity file "lumi.dat" to describe distributions of the colliding particles that make luminosity (ie. luminosity-weighted
            distributions of colliding beam energies, and collision co-ordinates).  Beamstrahlung and ISR can be separately turned
            on or off for these studies.
    iii) the file "pair.dat" to describe distributions of low energy e+e- pairs generated by two-photon processes.

Takashi Maruyama's GEANT-3 simulation was then run by Ken Moffeit to transport the "beam1_IP.dat" file to the mid-chicane, generating the file "beam1_chicane.dat".  Additionally, a DIMAD tracking simulation of the extraction line has been done by Yuri Nosochkov, using the same "beam1_IP.dat" input file at the IP to generate the file "beam1_chicane_dimad.dat".  We use a common extraction line (NLC design) for both NLC and TESLA beam parameters.  The current results ignore the crossing angle and the detector solenoid field.

The TRANSPORT R-matrix from the IP to mid-chicane has been calculated by Yuri Nosochkov to be:

-1.68 0 0.012 0 0 0.
0.0056 -0.595 0 0.004 0 0
-0.016 0 -2.26 0 0 0.02
0 -0.003 -0.099 -0.443 0 0
0 0 -0.002 -0.009 1 0
0 0 0 0 0 1

     The beam vector is (x, x', y, y', z, dE/E) with units (m, rad, m, rad, m, dimensionless).  xchicane = R xIP.

Recent talks on Extraction Line Studies:
     1.  "Disrupted Beam to Mid-Chicane using GEANT", updated version of K. Moffeit's March 5 talk
     2.  "GEANT 3 Simulation Package", T. Maruyama 05-Mar-2003.

Recent talks on Luminosity Spectrum Studies:
    1.  "Effect of Beam Energy Spread on Precision Measurments of m_top and m_Higgs", M. Woods July, 2003.

Recent talks on other IP BI topics:
    1.  "Luminosity, Energy and Polarization Studies:  Comparison of e+e- and e-e- for NLC and TESLA", M. Woods
                December, 2003.


Last Updated:  January 28, 2004