Appendix A
Glossary of Terms
The physics part of this chapter
derives mainly from "The ATLAS-Experiment Glossary" [60].absorption
lossThat part of the transmission loss due
to the dissipation or conversation into other forms of energy.
acceleratorA
machine used to accelerate particles to high speeds and thus high energy
compared to their rest mass-energy.
ALEPHA
particle detector of the LEP accelerator.
ALICEA
future particle detector for the LHC accelerator.
ASDBLRThe
analogue chip of the front-end electronics of the ATLAS TRT.
ASICA
custom microchip designed for a specific application.
ASTRALName
of the combined ASDBLR and DTMROC chip.
ATLASA
future particle detector for the LHC accelerator.
back-end electronicsThe
electronics outside the detector.
baryonA
hadron made from three quarks. The proton (uud) and the neutron (udd) are
both baryons. They may also contain additional quark-antiquark pairs.beamThe
particle stream produced by an accelerator usually clustered in bunches.bosonA
particle that has integer intrinsic angular momentum (spin) measured in
units of (spin = 0, 1, 2,...). All particles are either fermions or bosons.
The particles associated with all the fundamental interactions (forces)
are bosons. Composite particles with even numbers of fermion constituents
(quarks) are also bosons.bottom quarkThe
fifth flavor of quark (in order of increasing mass), with electric charge
-1/3.bremsstrahlungRadiation
emitted by a charged particle under acceleration.
calorimeterA
device that can measure the energy deposited in it.
characteristic impedanceThe
impedance of a circuit that, when connected to the output terminals of
a uniform transmission line of arbitrary length, causes the line to appear
infinitely long.charm quarkThe
fourth flavor of quark (in order of increasing mass), with electric charge
+2/3.
CMSA
future particle detector for the LHC accelerator.
colliderAn
accelerator in which two beams travelling in opposite directions are steered
together to provide high-energy collisions between the particles in one
beam and those in the other.CP-violationCP-violation
is one of three conditions outlined in 1964 by Russian physicist Andrei
Sakharov to account for the observed imbalance of matter and antimatter
in the universe.cross talkAn
undesired signal disturbance introduced in a transmission circuit by mutual
coupling with other transmission circuits.
daughter board (also stamp board)The
PCB with bonded die(s). This PCB does the actual signal read out.
DELPHIA
particle detector of the LEP accelerator.
detectorAny
device used to sense the passage of a particle. Also a collection of such
devices designed so that each serves a particular purpose in allowing physicists
to reconstruct particle events.
DMILLMixed
analog-digital BiCMOS technology.
doseThe
term dose (absorbed dose) refers to the mean energy imparted by ionizing
radiation to the matter in a volume divided by the mass contained in the
respective volume.down quarkThe
second flavor of quark (in order of increasing mass), with electric charge
-1/3.DTMROCThe
digital chip of the TRT-front-end electronics.
electromagnetic compatibilityThe
condition or situation whereby a device or system is capable of functioning
satisfactorily in the electromagnetic environment without introducing intolerable
disturbance to that environment
electromagnetic interactionThe
interaction due to electric charge; this includes magnetic effects which
have to do with moving electric charges.electronThe
least massive electrically charged particle, hence absolutely stable. It
is the most common lepton, with electric charge -1.electronvoltThe
energy of radiation is usually measured in units of electronvolt (eV).
This unit is defined as the energy gained by an electron when it is accelerated
through a potential difference of one volt. The relation between the SI
unit and the electron volt is:
electroweak interactionIn the Standard
Model, electromagnetic and weak interactions are related (unified), physicists
use the term electroweak to encompass both of them.event:What
occurs when two particles collide or a single particle decays. Particle
theories predict the probabilities of various possible events occurring
when many similar collisions or decays are studied. They cannot predict
the outcome for any single event.far-field
regionThe region of the field of an antenna
where the angular field distribution is essentially independent of the
distance from the antenna
fermionAny
particle that has odd-half-integer (1/2, 3/2, ...) intrinsic angular momentum
(spin). As a consequence of this peculiar angular momentum, fermions obey
a rule called the Pauli-Exclusion Principle, which states that no two fermions
can exist in the same state at the same place and time. Many of the properties
of ordinary matter arise because of this rule. Electrons, protons and neutrons
are all fermions, as are all the fundamental matter particles, both quarks
and leptons.flavorThe
name used for the different quark types (up, down, strange, charm, bottom,
top) and for the different lepton types (electron, muon, tau). For each
charged lepton flavor there is a corresponding neutrino flavor. In other
words, flavor is the quantum number that distinguishes the different quark/lepton
types. Each flavor of quark and charged lepton has a different mass. For
neutrinos we do not yet know if they have a mass or what the masses are.
front-end electronicsThe
electronics detached on the detector.
ghostA
secondary image or signal resulting from echo, envelope delay distortion,
or multipath reception.
gluonThe
carrier particle of strong interactions.ground
loopA condition where the local grounds
at each end of a length of cable or of two distant points in system are
at a different potential. This sometimes causes
hadronA
particle made of strongly-interacting constituents. These include the mesons
and baryons. Such particles participate in residual strong interactions.Higgs
bosonThe carrier particle or quantum excitation
of the additional force needed to introduce particle masses in the Standard
Model. Not yet observed.interactionA
process in which a particle decays or it responds to a force due to the
presence of another particle (as in a collision). Also used to mean the
underlying property of the theory that causes such effects.kaonA
meson containing a strange quark and an anti-up (or an anti-down) quark,
or an anti-strange quark and an up (or down) quark.L3A
particle detector of the LEP accelerator.
LEPThe
LEP is the largest particle collider in the world. In a ring 27 km in circumference,
buried about 100 m underground, bunches of electrons and positrons race
round in opposite directions as they are accelerated to almost the speed
of light.leptonA
fundamental fermion that does not participate in strong interactions. The
electrically-charged leptons are the electron, the muon, the tau, and their
antiparticles. Electrically-neutral leptons are called neutrinos.LHCThe
Large Hadron Collider at the CERN laboratory in Geneva, Switzerland. LHC
will collide protons into protons at a center-of-mass energy of about 14
TeV. When completed in the year 2005, it will be the most powerful particle
accelerator in the world. It is hoped that it will unlock many of the remaining
secrets of particle physics.LHCbA
future particle detector for the LHC accelerator.
LVDSLow-Voltage
Differential Signaling is a data interface standard which is defined in
the TIA/EIA-644 and the IEEE 1596.3 standards.
masssee
rest mass.mesonA
hadron made from an even number of quark constituents. The basic structure
of most mesons is one quark and one antiquark.
microstripA
transmission line consisting of a metallized strip and a solid ground plane
metallization separated by a thin, solid dielectric.muonThe
second flavor of charged lepton (in order of increasing mass), with electric
charge -1.neutrinoA
lepton with no electric charge. Neutrinos participate only in weak and
gravitational interactions and therefore are very difficult to detect.
There are three known types of neutrino all of which are very light and
could possibly even have zero mass.neutronA
baryon with electric charge zero; it is a fermion with a basic structure
of two down quarks and one up quark (held together by gluons). The neutral
component of an atomic nucleus is made from neutrons. Different isotopes
of the same element are distinguished by having different numbers of neutrons
in their nucleus.neutron fluenceParticle
fluence is defined as the number of particles traversing a unit area in
a certain point in space in a unit period of time.
OPALA
particle detector of the LEP accelerator.
particleA
subatomic object with a definite mass and charge.
photonThe
carrier particle of electromagnetic interactions.pionThe
least massive type of meson, pions can have electric charges 1 or 0.pixel
detectorA semiconductor detector made of
wafers with very small rectangular two- dimensional detector elements.
positronThe
antiparticle of the electron.
protonThe
most common hadron, a baryon with electric charge (+1) equal and opposite
to that of the electron (-1). Protons have a basic structure of two up
quarks and one down quark (bound together by gluons). The nucleus of a
hydrogen atom is a proton. A nucleus with electric charge Z contains Z
protons; therefore the number of protons is what distinguishes the different
chemical elements.quark (Austrian: Topfen
- Farmer's Cheese)A fundamental fermion
that has strong interactions. Quarks have electric charge of either 2/3
(up, charm, top) or -1/3 (down, strange, bottom) in units where the proton
charge is 1.
reflectionThe
abrupt change in direction of a wave front at an interface between two
dissimilar media so that the wave front returns into the medium from which
it originated.
rest massThe
rest mass of a particle is the mass defined by the energy of the isolated
(free) particle at rest, divided by the square of the velocity of the speed
of light.
roof boardThe
PCB designed to cover one half of the tension plate with mounted daughter
boards.
slew rateTime
dervative of output voltage in response to a sudden change in input voltage.
SPSThe
Super-Proton Synchrotron is a circular accelerator, 6 km in circumference,
buried underground. It was built originally to accelerate protons but it
has since operated as a proton-antiproton collider, a heavy-ion accelerator,
and an electron/positron injector for LEP. As a proton-antiproton collider
in the 1980s, it provided the first observations of the W and Z particles,
the carriers of the weak force.
Standard ModelPhysicists'
name for the theory of fundamental particles and their interactions. It
is widely tested and is accepted as correct by particle physicists.
strange quarkThe
third flavor of quark (in order of increasing mass), with electric charge
-1/3.strawThe
detecting element of the TRT.
striplineA
transmission line consisting of a conductor above or between extended conducting
surfaces.
tau leptonThe
third flavor of charged lepton (in order of increasing mass), with electric
charge -1.tension plateThe
PCB of the barrel placed on the end of the straws. This PCB supplies the
mechanical fastening for the read-out wires and connects the input-signal
to the read-out daughter boards.
termination:The
load connected to a transmission line, circuit, or device. For a uniform
transmission line, if the termination impedance is equal to the characteristic
impedance of the line, wave reflections from the end of the line will be
avoided.
top quarkThe
sixth flavor of quark (in order of increasing mass), with electric charge
2/3. Its mass is much greater than any other quark or lepton.trackThe
record of the path of a particle traversing a detector.
transition radiationTransistion
radiation is produced when a relativistic particle traverses an inhomogeneous
medium.
transmission lineThe
conductive connections between circuit elements that carry signal power.TRTTransition
Radiation Tracker, the central vertex detector for the ATLAS detector.
up quarkThe
least massive flavor of quark, with electric charge 2/3.
vertex detectorA
detector in collider experiments positioned as close as possible to the
collision point. The goal of a vertex detector is to measure particle tracks
very close to the interaction point.
waveguide below cutoffA
waveguide operated in a frequency range such that there is no real propagation
of energy and incident fields are attenuated exponentially with length.
