&DRIFT: TRACK: HEED
Some common particles can be described by name:
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Name Particle Mass [MeV] Charge
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ELECTRON electron (e-) 0.51099907 -1
POSITRON positron (e+) 0.51099907 +1
MU-MINUS negative muon (mu-) 105.658389 -1
MU-PLUS positive muon (mu+) 105.658389 +1
TAU-MINUS negative tau (tau-) 1777.00 -1
TAU-PLUS positive tau (tau+) 1777.00 +1
GAMMA photon 0 0
PION-MINUS negative pion (pi-) 139.56995 -1
PION-0 neutral pion (pi0) 134.9764 0
PION-PLUS positive pion (pi+) 139.56995 +1
KAON-MINUS negative kaon (K-) 493.677 -1
KAON-0 neutral K or anti-K 497.672 0
KAON-PLUS positive kaon (K+) 493.677 +1
PROTON proton (p) 938.27231 +1
ANTI-PROTON antiproton (p-bar) 938.27231 -1
NEUTRON neutron (n) 939.56563 0
ANTI-NEUTRON antineutron (n-bar) 939.56563 0
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If the particle is not known by its name, then one can describe
it with its mass and charge.
The mass can either be a number, in which case it is assumed
to be in MeV, or a number followed by a unit (eV, keV, MeV or
GeV).
[Default: muon mass]
If the particle is not known by its name, then one can describe
it with its mass and charge.
The charge of the particle should be in proton charges, i.e. an
electron would have charge -1, a K+ would have +1.
The energy of the particle traversing the chamber.
The energy can either be a number, in which case it is assumed
to be in MeV, or a number followed by a unit (eV, keV, MeV or
GeV).
[Default: 1 GeV]
Heed will optionally make the incoming particle undergo
multiple scattering.
Keep in mind that multiple scattering will slow Heed down.
Track preparation is compatible with multiple scattering
but such a combination is not meaningful since the drift
path of electrons produced far from the prepared track has
to be computed without interpolation.
[Multiple scattering is on by default.]
Heed generates its electrons through delta electrons. If
you are not interested in the spatial extent of delta
electrons, you may opt to have all electrons moved to the
location of the interaction that created the delta electron.
The DELTA-ELECTRONS option is compatible with track
preparation, e.g. in the context of signal calcultions,
but the drift path of electrons produced far from the
prepared track will be computed rather than interpolated.
Apart from this, there is no substantial gain in time
by switching delta electrons off.
[Delta electrons are by default kept as they come out of Heed]
Delta electrons usually have a sufficiently low energy to be
affected by the E and B fields present in the chamber.
When this option is switched on, they are traced from one
collision to the next following the E and B field. Since this
is a time consuming operation, you may wish to switch tracing
off when studying only the cluster statistics.
Delta electrons are not traced either when the NODELTA-ELECTRON
option is specified.
[Tracing is on by default.]
Keyword index.
Formatted on 10/11/98.