- G
- Giga, meaning 10to the 9th power, or billions of . . .(e.g.:
gigabits).
- G & A
- General and Administrative
- G&A
- General and Administrative.
- GA
- GAuge / GAge.
- GAAC
- German American Academic Council
- GAAP
- Generally Accepted Accounting Practices.
- GaAs
- Gallium Arsenide. A compound used in light emitting diodes
and very fast semiconductors. It is used in SLC fast clock chips
for fiducializing and synchonizing the LINAC with PEP, and is
also the basis for cathodes in the polarized guns.
- GAC
- Granular Activated Carbon.
- GAC-SAC
- General Advisory Committee - Science Advisory Committee.
(1960s)
- GADC
- Gated Analog to Digital Converter. A circuit that
selectively converts analog signals to a format readable by the
computer. A SLC database primary.
- GADZOOKS
- Gadolinium Antineutrino Detector Zealously Outperforming Old
Kamio kande Super.
- GAFE
- 12 FREE boards, each mounting 18 GAFE analog ASICs and one
GARC digital ASIC, are required read out the 216 channels of data
from the ACD photomultiplier tubes.__Each GAFE provides for the
charge collection, amplification, shap
ing, and discrimination of the analog input from one PMT.
Glast Category: hardware
- GAINS
- Girls Advancing In STEM
- galaxy
- A massive, gravitationally bound system consisting of stars,
interstellar gas and dust, and dark matter, all typically
orbiting a common center of mass.
Glast Category: ASTRONOMY
- Galaxy Zoo
- A crowd-sourcing project to allow interested members of the
public to classify by type the galaxies imaged by the Hubble
Space Teles cope.
- GALEX
- GALaxy Evolution eXplorer/
- Gallery
- The two-mile-long building where the LINAC klystrons and
LINAC magnet power supplies are housed. The actual LINAC beam
pipe is approximately 25 feet underground below the gallery.
- Gallium Arsenide
- See GaAs.
- GALPROP
- Numerical model of particle propagation in the Galaxy
incorporatin g as much realistic input as possible.
- Gamma
- One of the Twiss parameters, which relates alpha and beta:
beta gamma = 1 + alpha(exp 2). It is also the relativistic factor
used in acceleration calculations.
- Gamma Ray
- A high energy photon.
- Gamma-ray burst
- A short-lived, localized, and intense burst of gamma
radiation that originates outside the solar system from an
unknown source. These bursts last from milliseconds to many
minutes, and are often followed by 'af terglow' emission at
longer wavelengths such as X-ray, UV, optical, IR, and radio.
Glast Category: astronomy
- Gamma, Electron, and Muon Experiment
- See GEM.
- GAM2
- IHEP hodoscope Cherenkov gamma calorimeter GAMS-2000.
- GAM4
- CERN hodoscope Cherenkov gamma calorimeter GAMS-4000.
- GAN
- Global Accelerator Network (proposed).
- GAN
- GAlactic Neighborhood.
- GANIL
- Gran Accélérateur National d'Ions Lourds.
- GAO
- General Accounting Office.
- Gap Monitor
- see GAPM.
- Gap Voltage
- The electrical field between the 2 irises of an RF cavity.
- GAPM
- GAP Monitor. A break in the conductive beam pipe which is
bridged by a ring of ceramic in parallel with a resistance that
provides the proper impedance. The beam induces a voltage drop
across the resistance, which may be measured and displayed on an
oscilloscope. Also called wall current monitor, since it measures
the voltage induced by interrupting the current traveling through
the beampipe due to the passing of the beam.
- GARC
- 12 FREE boards, each mounting 18 GAFE analog ASICs and one
GARC digital ASIC, are required read out the 216 channels of data
from the ACD photomultiplier tubes. The GARC provides the
interface to the 18 GAFEs and contains th e digital logic and
interface circuitry required to prepare event data for transfer
to the ACD Electronics Module (AEM).
Glast Category: hardware
- GARD
- General Accelerator Research and Development.
- Gargamelle
- CERN Bubble Chamber commissioned in 1971.
- GASU
- Global trigger, Acd interface, and Signal distribution Unit.
- GASU
- |The GASU contains the central data acquisition hardware of
the LAT, including circuitry necessary for control of the
detector front-end electronics, including the tower electronics
modules (TEMs), and the anti-coincidence detec|
|tor (ACD) FREE boards. Powered by the PDU and distributing
power to the ACD, the GASU collects instrument data and forwards
it to the event processing unit (EPU) and to the spacecraft
interface unit (SIU).|
Glast Category: hardware
- GATE
- Geant4 Application for Tomographic Emission.
- Gated Analog to Digital Converter
- See GADC.
- Gateway
- A special-purpose dedicated computer that attaches to two or
more networks and routes packets from one network to the other.
In particular, an Internet gateway routes IP diagrams among the
networks it connects. Gateways route packets to other gateways
until they can be delivered to the final destination directly
across one physical network.
- Gateway to Gateway Protocol
- See GGP.
- Gauss
- A unit of magnetic flux density, symbol G. Named after the
mathematician Karl Friedrich Gauss (1777-1855)
- Gaussian
- A statistical distribution of particles or objects which is
`bell shaped' and can be approximated by the Gauss distribution
law. Named after the mathematician Karl Friedrich Gauss (1777-
1855).
- GB
- See Gigabyte.
- GBFEL
- Ground-Based Free Electron Laser.
- GBM
- GLAST Burst Monitor experiment.
- GBM
- See GBM Instrument Description.
Glast Category: hardware
URL: http://www.batse.msfc.nasa.gov/gbm/instrument/description/
- GBT
- Green Bank Telescope (NRAO-West Virginia).
- GC/MS
- Gas Chromatography/Mass Spectroscopy.
- GCEP
- Global Climate and Energy Project. A long-term collaborative
effort to conduct fundamental research on a global energy system
that would significantly reduce greenhouse emissions. (Stanford)
- GCFE
- There are 4 AFEE boards per tower: each board has 48 GCFE
analog ASICs in 4 layers of 12 each: each layer is controlled by
one GCRC ASIC. The GCFE amplifies signals from 2 diodes per
crystal end: a large area diode for the low-energy range, and a
small diode for the high-energy range.
Glast Category: hardware
- GCM
- Generator Coordinate Method
- GCM
- |The GCM is the backup facility for the MOC, located in a
different building at the GSFC. The GCM can command and receive
telemetry from GLAST, but is otherwise very limited. For example,
no Level 0 or other data products are pr|
|ovided to the ISOC while the GCM is active. Instead, the
data is saved and forwarded only after the MOC again becomes
operational.|
Glast Category: operations
- GCN
- See GCN: The Gamma-ray bursts Coordinates Network website.
Glast Category: operations
URL: http://gcn.gsfc.nasa.gov/
- GCP
- General Cascade Program
- GCR
- Galactic Cosmic Rays
- GCRC
- Each tower has 4 GCRC digital ASICs on each of 4 AFEE
boards. Each GCRC processes the high- and low-energy inputs from
each of 12 GCFE ASICs co-located on the same AFEE board. The GCRC
outputs High- and Low-Energy Trigger Requests to the Tower
Electronics Module (TEM).
Glast Category: hardware
- GCT
- Galaxies across Cosmic Time.
- GD
- |Manufacturer of the GLAST spacecraft.|
Glast Category: organization
- GD&T
- Geometric Dimensioning & Tolerancing.
- GD&T
- Geometric Dimensioning and Tolerancing.
- GDE
- Global Design Effort.(ILC)
- GDH
- Gerasimov-Drell-Hearn
- GDP
- General Development Plan.
- GDR
- Giant Dipole Resonance
- GDS
- Global Directory Service. For global namespace, which starts
from a global root and divides into a hierarchical tree at
country, organization, locality, cell, and other points. XDS from
X/Open is the general purpose API for standard applications.
- GEANT
- A pan-European research and education network and the
corresponding four-year project set up by a Consortium of 27
National Research and Education Networks (NRENs) across Europe.
- GEANT2
- Successor to GEANT, see GEANT.
- GEANT3
- A computer program for detector description and simulation.
- Geant3
- Monte Carlo simulation package (CERN).
- Geant3
- Monte Carlo simulation package (CERN).
- GEM
- Gamma, Electron, and Muon experiment. An SSC experiment
which featured the `GEM' detector.
- GEM
- Gas-Electron Multiplier.
- GEM
- Graduate Engineering for Minorities.
- GEM
- Processes inputs from the ACD and all 16 towers to decide
whether or not to trigger a readout of detector data. The sum of
all the information read out of the detector electronics when
triggered is called an event.
Glast Category: hardware
- GEMS
- Graduate degrEes for Minorities in Engineering and Sciences.
(Nati onal consortium)
- GEMS
- Galaxy Evolution from Morphology and Spectral energy
distributions .
- General Purpose Interface Bus
- See GPIB.
- Generator
- The person or facility who, by nature or ownership,
management, or control, is responsible for causing or allowing to
be caused, the creation of hazardous waste.
- GENI
- GENeral Interface.
- GENIUS
- GErmanium in NItrogen Underground Setup. A proposal to use a
ton or more of naked enriched germanium-76 detectors in a
shielding of liquid nitrogen to probe neutrino mass.
- GEONET
- A program for alignment of SLC.
- GERDA
- GERmanium Detector Array. (Italy)
- GERT
- General Employee Radiological Training.
- GES
- Geological and Environmental Sciences.(Stanford)
- GeV
- Giga(billion) electron Volt. An electron volt is the unit of
energy equal to the work done by moving an electron across a
potential difference of one volt.
- GFCI
- Ground Fault Circuit Interrupter.
- GFE
- Government-Funded Equipment.
- GFEP
- GLAST Front-End Processor
Glast Category: data processing
URL:
- GFP
- Government-Furnished Property.
- GGF
- Global Grid Forum. A community-initiated forum of individual
resea rchers and practitioners working on distributed computing,
or "grid" technologies. Particle Physics Data Grid (PPDG) is a
part of this forum.
- GGM
- (CERN) GarGaMelle bubble chamber.
- GGP
- Gateway to Gateway Protocol. The protocol core gateways use
to exchange routing information. GGP implements a distributed
shortest path routing computation. Under normal circumstances,
all GGP participants will reach a steady state in which the
routing information at all gateways agrees.
- GG1
- Global Group 1 (Parameters). (ILC)
- GG2
- Global Group 2 (Instrumentation and Controls). (ILC)
- GG3
- Global Group 3 (Operations and Availability). (ILC)
- GG4
- Global Group 4 (Conventional Facilities and Siting). (ILC)
- GG5
- Global Group 5 (Cost and Engineering) (ILC)
- GG6
- Global Group 6 (Options). (ILC)
- GHG
- GreenHouse Gas.
- GHP
- Geroch-Held-Penrose
- GHS
- Garfinkle-Horowitz-Strominger
- GHZ
- Greenberger-Horne-Zerlinger
- GHZ
- GigaHertZ. (Written GHZ on drawings, or GHz in text.)
- GIAT
- Get-It-All-Together (SLC Group).
- GIC
- Gauge Invariant and Covariant
- gif
- Graphics Interchange Format. Pronounced jiff or giff (hard
g). A bit-mapped graphics file format used by the World Wide Web,
CompuServe and many BBSs. GIF supports color and various
resolutions. It also includes data compression, making it
especially effective for scanned photos.
- GIFT
- Goldstones Instead of Fine Tuning
- Giga
- see G
- Gigabyte
- 2 to the 30th power (1,073,741,824) bytes. One gigabyte is
equal to 1,024 megabytes. Abbreviated G or GB.
- GIM
- Glashow-Iliopoulos-Maiani
- GIMGOM
- |The GIMGOM group meets 4-8 times per year to discuss all
aspects of operations relevant to the mission operations center
and the instrument teams. Topics include observation strategies,
and the operating modes and interactions |
|between the spacecraft, the GBM, and the LAT, as well as
effective coordination between teams during burst alerts. The
GIMGOM also addresses planning of launch and early orbit (LEO)
activities, and the transition from LEO to normal operati|
|ons. Other topics addressed include data flow, file formats,
L0 processing, transfer protocols, and operations data products.|
Glast Category: operations
- GIOC
- |Located at Huntsville, Alabama, the GBM Instrument
Operations Center is responsible for maximizing the GLAST Burst
Monitor's (GBM's) science performance, and for creating and
delivering the GBM science data products to the GSSC|
| on a daily basis. See GBM Data Products.|
Glast Category: operations
URL: http://glast.gsfc.nasa.gov/ssc/data/access/gbm.html
- Girder
- A support structure for the Accelerator. In the LINAC most
girders are 40 feet long. Note that the SLC component numbering
system is referenced to girder numbers.
- GISO
- General Industry Safety Order. (Cal/OSHA)
- GIXS
- Grazing Incidence X-ray Scattering.
- GKS
- Graphic Kernal System. (Obsolete)
- GKZ
- Gelfand-Kapranov-Zelevinski
- GL
- General Ledger.
- GLAD
- Gev Laser Accelerator Developments (Japan).
- GLAM
- Geballe Laboratory for Advanced Materials (Stanford).
- GLARE
- Gemini Lyman-Alpha at Reionization Era.
- GLAST
- Gamma-ray Large Area Space Telescope. A large aperture,
space-based, gamma-ray detector. Also, an international
collaboration involving SLAC, Stanford, NASA, and groups in Japan
Italy, France and Sweden. Renamed Fermi Gamma-ray Space Telescope
(FGST) in August 2008.
- GLAST
- See Goddard Space Flight Center's GLAST Science web page.
Glast Category: organization
URL: http://glast.gsfc.nasa.gov/science/
- GlastRelease
- Primary Science Analysis Systems (SAS) software package
consisting of a toolkit of different application software
packages with a wrapper bundling them into a single package.
Glast Category: software, SAS, package
- GLC
- Global Linear Collider group. (KEK)
- GLC
- Global Linear Collider.
- GLD
- Concept detector for the ILC (Global Large Detector).
- GLEAM
- GLAST Event Analysis Machine.
- GLEAM
- The top-level GlastRelease package whose basic function is
to take the 'raw', Level 0 data delivered to it in LAT Data
Format (LDF data) and convert it to Level 1 data ready for
analysis using Science Tools software.
Glast Category: software, SAS, package, data processing
- GLIF
- Global Lambda Integrated Facility.
- GLIMPSE
- Galactic Legacy Infrared Mid-Plane Survey Extraorinaire.
- Glow discharge
- A luminous electrical discharge without sparks through a
gas.
- GLT
- |The GLT is a function of the Global Trigger Electronics
Module (GEM). In real time, and at the highest level, the GLT
accepts L1 Trigger Request input signals from the TKR, ACD, and
CAL detector modules and decides whether to g|
|enerate a Global L1 Trigger Acknowledge (TACK). __A TACK
response causes information in the detector modules to be
latched. The TACK also includes generation of a Trigger
Acknowledge Message (TAM), which causes a readout of the raw
data.|
| At this point, the raw data for the probable L1 event is
transferred to the Event Builder Module. |
Glast Category: hardware
- Gluino
- In models of supersymmetry, the partner of the gluon.
- GM
- General Motors.
- GMO
- Gell-Mann-Okubo
- GMOR
- Gell-Mann-Oakes-Renner
- GMP
- Ground water Monitoring Plan.
- GMR
- Giant MagnetoResistance.
- GMRES
- Generalized Minimum RESidual.
- GMSB
- Gauge Mediated Supersymmetry Breaking
- GNAT
- Global Network of Astronomical Telescopes.
- Go Around Frequency
- In a storage ring, the number of circumnavigations of the
ring made by any given bunch in one second (expressed in Hertz).
- GOCO
- Government Owned, Contractor Operated (DOE).
- Gold Phase
- The phase of a klystron with maximum efficiency (if the
bunch is riding near the crest of the RF wave). The gold phase is
the phase for the maximum energy transfer.
- GOLI
- CERN GOLIath bubble chamber.
- Gopher
- A menu-based system for exploring Internet resources that
pre-dates the World Wide Web. Requires a gopher server, which
presents its contents as a hierarchically-structured list of
files.
- GOSIP
- Government Open Systems Interconnection Profile. A
government specification (a collection of protocols referred to
as a profile) designed to ensure that communications and
networking software used by the government is indeed OSI-
compliant when OSI compliance is required.
- GOSSIP
- Gas On Slimmed SIlicon Pixel.
- Government Open Systems Interconnection Profile
- See GOSIP.
- GP
- Guiding Principle (ES&H)
- GPCRs
- G Protein-Coupled Receptors.
- GPD
- Generalized Parton Distributions.
- GPDF
- Generalized Parton Distribution Function.
- GPIB
- General Purpose Interface Bus. A communication protocol for
small computers like PCs or MACs to interface with peripherals,
instruments, or other devices. If you want your PC to start your
coffee before you wake up in the morning, you will need a GPIB.
- GPMP
- Ground water Protection Management Program.
- GPMPP
- Ground water Protection Measurement Program Plan.
- GPO
- Group Policy Objects (computing). Policies that are defined
for ea ch computer or user.
- GPP
- General Plant Project.
- GPR
- Gaussian Process Regression.
- GPS
- Global Positioning of Spin
- GPU
- Graphics Processing Unit.
- GR
- General Relativity
- GR
- Gamma Ray.
- GRACE
- An automatic scattering amplitude generator that enables
theoretic al calculations to match the required high-presicion
data analyses required by high-energy physics experiments.
- Gray
- The International System (SI) unit of absorbed dose. One
gray is equal to an absorbed dose of 1 Joule per kilogram (100
RADS).
- Gray Water
- The term given to domestic wastewater composed of washwater
from sinks, kitchen sinks, bathroom sinks and tubs, and laundry
tubs.
- GRB
- Gamma-Ray Burst.
- GRB
- A short-lived, localized, and intense burst of gamma
radiation that originates outside the solar system from an
unknown source. These bursts last from milliseconds to many
minutes, and are often followed by 'afterglow' em ission at
longer wavelengths such as X-ray, UV, optical, IR, and radio.
Glast Category: astronomy
- GREEN-RF
- Generator for REcovering ENergy from RadioFrequency. (A type
of kl ystron)
- Greening
- The action of trimming a phase, a feedback or a BACT to a
nominal value or set-point. The new value as displayed by the VAX
on its color monitors will be green (in tolerance) as opposed to
red or yellow (out of tolerance).
- Grid
- see GGF.
- GRIDCC
- Grid-enabled Remote Instrumentation with Distributed Control
and Computation.
- GridKA
- Grid computing centre KArlsruhe. (Germany)
- Gridpix
- Detector building block combining the timepix chip with
InGrid.
- Grinnel
- A graphic video display system using the PICT imaging
system. Used with the VAX to generate graphics. (The machine is
made by Grinnel Systems Corporation).
- GriPhyN
- Grid Physics Network (pronounced griffin). A system for
handling vast amounts of physics data. Participants include the
Sloan Digital Sky Survey, the Laser Interferometer Gravitational-
Wave Observatory, and two HEP experiments at CERN's LHC.
- GROG
- General Relativistic Overturn of Gravity.
- Gross Alpha Particle Activity
- Total activity due to emission of alpha particles. Used as
the screening measurement for radioactivity generally due to
naturally-occurring radionuclides. Activity is commonly measured
in picocuries.
- Gross Beta Particle Activity
- Total activity due to emission of beta particles. Used as
the screening measurement for radioactivity from manufactured
radionuclides since the decay products of fission are beta
particles and gamma ray emitters. Activity is commonly measured
in picocuries.
- Ground Water
- Water below the land surface in a zone of saturation.
- Growler
- A small damping ring dipole magnet used to generate an
oscillation for tune measurement purposes. When energized, it
will excite the beam to oscillate at its natural resonant
frequencies.
- GRR
- Gravitational Radiation Reactions
- GRS
- Gregory-Rubakov-Sibiryakov
- GRT
- General Relativity Theory.
- GS
- Green-Schwarz
- GSA
- General Services Administration. (US)
- GSB
- General Services Building. (SLAC)
- GSF
- Gross Square Feet.
- GSFC
- Goddard Space Flight Center.
- GSFC
- Established in 1959 as NASA's first space flight center, the
GSFC is located in a Maryland suburb outside of Washington, D.C.
and is home to the nation's largest organization of scientists
and engineers dedicated to learning and sharing knowledge of the
Earth, Sun, Solar System, and Universe.
Glast Category: organization
URL: http://www.nasa.gov/centers/goddard/home/index.html
- GSG
- Graphic Study Group (SCS).
- GSH
- Graduate Student Handbook. (SLAC)
- GSI
- Grid Security Infrastructure.
- GSI
- Gesellschaft für Schwerionenforschung. (Germany)
- GSP
- Greene Scholars Program
- GSS
- Government Scientific Source.
- GSSC
- GLAST Science Support Center.
- GT-MHR
- Gas Turbine -- Modular Helium Reactor.
- GTF
- Gun Test Facility. A research project at SSRL aimed at
developing the high-brightness electron source that will be
needed for future linac-based X-ray free-electron lasers (FELs)
such as SLAC's proposed Linac Coherent Light Source (LCLS). GTF
is a photocathode gun that uses polarized laser light to generate
polarized electrons by means of the photoelectric effect on a
gallium arsenide cathode.
- GTFE
- Each of the 36 Tracker silicon layers consists of 1536
strips managed by 24 GTFE ASICs. These GTFEs are read out by 2
GTRC ASICs. Each GTFE amplifies signals from 64 strips, shapes
the signals, and converts them to digital outp
ut. The final discriminated signals are used to form a
trigger request.
Glast Category: hardware
- GTI
- Good Time Intervals.
- GTL
- Gun-To-Linac. (LCLS)
- GTRC
- Each tower has 72 GTRC ASICs mounted on 36 Multi-Chip
Modules. Two GTRCs read out the signals from 24 GTFEs on each
silicon layer - there is one GTRC for the 'right' end of the
layer and one for the 'left' end of the la yer. Each GTRC forms a
trigger primitive signal, which it sends to the TEM.
Glast Category: hardware
- GUC
- German University in Cairo.
- GUG
- |The GUG represents the interests of the scientific
community that will use GLAST. To view their charter, membership
list, and presentations made at GUG meetings, see the GSSCs GLAST
Users Group web page.|
Glast Category: organization
URL: http://glast.gsfc.nasa.gov/ssc/resources/gug/
- GUI
- Graphical User Interface. Sometimes called windowing
systems, GUIs are software interfaces which allow mouse and icon
actions in place of typed commands.
- GUST
- Grand Unified Superstring Theories
- GUT
- Grand Unified Theories
- GVDM
- Generalized Vector Dominance Model
- GVMD
- Generalized Vector Meson Dominance Model.
- GW
- Ginsparg-Wilson
- GWL
- Ginsparg-Wilson-Luscher
- GWP
- Ground Warfare Panel.
- GWT
- Google Web Toolkit.
- GZK
- Greisen-Zatsepin-Kuzmin.
- G4
- GEANT4.
Send corrections to jmdeken@slac.stanford.edu
or propose new terms for SLACspeak.