L
L Large, Long (abbreviation used in SLAC drawings)
L2SI LCLS-2 Strategic Initiative or LCLS-II Instruments
L3 Detector at LEP (CERN).
LA License Application.
LA Liquid Argon.
LAA Local Administering Agency. (CH&SC Sec. 25500 et seq)
LAA Lepton Asymmetry Analyzer.
LABELIT-CCI Data characterization software for macromolecular crystallography.
LABL Serial number or other label for a magnet.
LABRADOR Large Analog Bandwidth Recorder And Digitizer with Ordered Readout .
LAD License Application Design.
LAER Lowest Achievable Emission Rate. (from CAA)
LAF Linac Accelerator Facility. Includes LCLS-SC, FACET, LCLS-Cu linac areas
LAL Laboratoire de l'Accélérateur Linéaire. (Orsay)
LAM Look At Me! A Handshaking protocol between digital electronic systems.
LAMA Library Administration and Management Association.
Lambda CDM Lambda Cold Dark Matter. The leading modern cosmological model.
Lambertson A type of septum magnet named after Glen Lambertson of LBNL. It is used to extract the beam from the LINAC to the positron target. See also HLAM.
LAMP LCLS-ASG-Michigan Project for novel science with the LCLS FEL.
LAMPF Los Alamos Meson/Proton Factory (1460 MeV/c Plab).
LAN Local Area Network. Any physical network technology that operates at high speed over short distances (up to a few thousand meters).
Land Ban Informal name for Land Disposal Restricted (LDR).
Landfarming A treatment technique which involves spreading waste on land and utilizing evaporation and microbial action to degrade the wastes. Used primarily for crude oil wastes. It is not the same as landfilling.
LANL Los Alamos National Laboratory
LAPP Laboratoire d'Annency-L GOV
LAR Large Adaptive Reflectors.
LAr TPC Liquid Argonne Time Projection Chamber.
Large Power Supply See LGPS.
Large Scale Collaboration Center facility for lab-wide support of science and computing staff with completion planned in FY2024 (SLAC)
LARP LHC Accelerator Research Program. (US)
Larse A brand name for a general purpose alarm system chassis used at SLAC for monitoring fire alarms.
Laser Light Amplification by Stimulated Emission of radiation. A device that uses the principle of amplification of electromagnetic waves by stimulated emission of radiation and operates in the infrared, visible, or ultraviolet region.
Laser Cavity Shutter See LCS.
Laser Feedback Intensity Control See LFIC.
Laser Safety Officer See LSO.
Laser Safety Stopper See LSS.
LASS LASer analyzing Station. A B-line apparatus.
LAST Life, Art, Science, Tech festival
LAT Large Array Telescope (GLAST --FERMI).
LAT Local Area Transport.
LATOR Laser Astrometric Test of Relativity.
Lattice A repeating pattern of magnets.
Launch Knob A multiknob using a set of correctors to launch beam in the LTRs, the Rings or other sections of the machine. The knobs are orthogonalized to give independent control of position and angle at a given reference point.
LBL Low-energy cut-off BL Lac object.
LBL see LBNL
LBNE Long-Baseline Neutrino Experiment. (FermiLab)
LBNF Long-Baseline Neutrino Facility.
LBNL Lawrence Berkeley National Laboratory, CA. Full name of lab is Ernest Orlando Lawrence Berkeley National Laboratory.
LC Liquid Crystal.
LC Linear Collider.
LCA Labor Condition Application.
LCA Laser Controlled Area.
LCB Lat Communications Board.
LCC Linear Collider Collaboration. A collaboration between SLAC and KEK to define common parameters for a TeV center-of-mass energy linear collider.
LCCA Life Cycle Cost Analysis.
LCD Liquid Crystal Display.
LCD Linear Collider Detector.
LCDG4 GEANT4-based flexible full-detector simulation program.
LCFI Linear Collider Flavour Identification Project (ILC).
LCFOA Linear Collider Forum Of America (ILC).
LCFT Logarithmic Conformal Field Theory.
LCG LHC Computing Grid.
LCHb An experiment at the Large Hadron Collider (LHC) to study in detail the physics of the 'b' or 'beauty' quark.
LCID Linac CID.
LCIO Linear Collider Input/Output.
LClo Lethal concentration low. The lowest concentration of a substance in air which has been reported to have caused death in humans or animals.
LCLS Linac Coherent Light Source. A linac-based X-ray free-electron laser at SLAC.
LCLS-II Linac Coherent Light Source II. next-generation X-ray laser
LCLS-II HE LCLS-II High Energy upgrade
LCPC Laboratory Computer Policy Committee
LCS Laser Compton Scattering.
LCS Laser Cavity Shutter. A PPS device used to stop the PLS laser whenever the laser room door is opened.
LCSGA Linear Collider Steering Group of the Americas.
LCSR Light Cone Sum Rules.
LCTPC Linear Collider Time Projection Chamber collaboration.
LCUK Linear Collider collaboration - United Kingdom (ILC).
LCW Low Conductivity Water. Used for cooling magnets, electrical cables and other devices where normal water could cause a short under high voltage. LCW is manufactured by deionizing 'house' water at a plant on the SLAC site.
LCWS Linear Collider WorkShop.
LD50 Lethal Dose Fifty. A calculated dose of a substance which is expected to cause the death of 50 percent of an entire defined experimental animal population.
LDA Local Density Approximation.
LDA Large Aperture Dipoles.
LDAP Lightweight Directory Access Protocol.
LDC Large Detector Concept for the ILC.
LDlo Lethal dose low. The lowest dose of a substance introduced by any route other than inhalation which has been reported to have caused death in humans or animals.
LDIP Laboratory Diversity & Inclusion Plan (SLAC)
LDMX Light Dark Matter eXperiment (LCLS-II)
LDR Land Disposal Restricted (Land Ban).
LDRD Laboratory Directed Research and Development. A program to direct the Laboratory's scientific research capabilities toward vital and emerging scientific challenges that align with the Laboratory's current mission.
LEA Local Enforcement Agency (for solid waste in California).
Leachate A solution of contaminants produced by water flowing through materials such as organic matter, soil, or landfills.
Lead (Pb) Used extensively at accelerator facilities to shield equipment and personnel from electromagnetic radiation. A heavy metal that is hazardous to health if breathed or swallowed. Its use in gasoline, paints, and plumbing compounds has been sharply restricted or eliminated by federal laws and regulations. See also Heavy Metals.
LEAP Low Energy Antiproton Physics, a biennial international conference .
LEAPS League of European Accelerator-based Photon Sources.
LEAR Low Energy Antiproton Ring (CERN)
LEARN Listen, Engage, Assess, Respond, Notice (SLAC)
LEB Low Energy Beam.
LEBT Low-Energy Beam Transport
LeCosPA Leung center for Cosmology and Particle Astrophysics.(Taiwan)
LECT Liquid Effluent Cooling Tank.
LED Light Emitting Diode.
LEE Low Energy Extraction.
LEED Low Energy Electron Diffraction, a popular surface-imaging technique.
LEED Leadership in Energy and Environmental Design (certification from USGBC).
Leed-NC Leed - New construction.
LEEM Low-Energy Electron Microscope.
LEET Large Energy Effective Theory.
LEFF The effective length of a magnet in meters.
LEI Low Emittance Injector
LEIR Low-Energy Ion Ring (CERN), formerly LEAR.
LEL Lower Explosive Limit or Lower Flammable Limit (LFL). By percentage, the lowest concentration of a substance in air which will ignite. Compare UEL and flammability range.
Lemming An operator action which consists of adjusting the LINAC quads to the actual energy of the beam using the LEM procedure. The computer ascertains the beam energy at each quadrupole from the phases of the klystrons to that point, and then adjusts the current in each quadrupole for that calculated energy.
LENA Nonmagnetic lead-glass NaI detector at DORIS.
LENS A solenoidal focusing magnet.
Lens Any focusing element.
LEP Large Electron Positron collider (CERN).
LEPC Local Emergency Planning Committee. (from EPCRA)
LER Low Energy Ring in PEP-II, a 3.1 Gev storage ring for positrons.
LESIT LEistungselektronic, Systemtechnik und Informations Technologie.
LESIT Low Energy South Injection Transport.
LESR Laser-Electron Storage Ring
LET Low Energy Theorem
Lethal Concentration Low See LClo.
Lethal Dose Fifty See LD50.
Lethal Dose Low See LDlo.
LEUTL Low Energy Undulator Test Line (APS-Argonne).
LFD Light Front Dynamics
LFD Linac & FEL Division (within the Accelerator Directorate)
LFIC Laser Feedback Intensity Control. A feedback system designed to compensate for the loss in laser light intensity of the PLS. SLAC
LFL See LEL.
LFO Laboratory Financial Operations.
LFTD Light Front Tamm-Dancoff
LFV Lepton-Flavor-Violating/Violation.
LGO Lunar Geoscience Orbiter.
LGT Lattice Gauge Theories
LH2 Liquid Hydrogen.
LHC Large Hadron Collider (CERN).
LHCb Large Hadron Collider beauty experiment. (CERN)
LHT Liquid Hydrogen Targets.
LHW Liquid Hazardous Waste.
LI Abbreviations for Linac.
LIAR LInear Accelerator Research code. Accelerator structure design software.
LIARP LInear Accelerator Research code Parallel. Accelerator structure design software.
LIC Line Item Construction.
Lichtenberg tree Or Lichtenberg Diagram. See Beam Tree.
LIDAR LIght Detection And Ranging
LIGO Laser Interferometer Gravitational-wave Observatory
LIL Linac Injecteur de LEP.
LINAC LINear ACcelerator. A type of particle accelerator in which charged particles are accelerated in a straight line, either by a steady electrical field or by means of radio frequency electric fields. In the latter variety, the passage of the particle is synchronized with the phase of the accelerating field. The SLAC LINAC was built as a two-mile long accelerator, consisting of cylindrical, disc loaded, copper wave-guides placed on concrete girders in a tunnel about 25 feet underground. Rebuilt to power the LCLS-II, in 2023 the linac became a superconducting accelerator.
LINAC Energy Management See LEM.
Linear Accelerator See LINAC.
Linear Charge Detector See LINQ.
Linear Variable Differential Transformer See LVDT
LINKS LCLS Information Network for Knowledge Sharing
LINQ Linear Charge Detector, usually a toroid. `Q' is the physical symbol for electrical charge.
Linux A freely-distributable implementation of UNIX that runs on a number of hardware platforms. It was originally developed by Linus Torvalds.
LION Long IONization Chamber
Liouville's Theorem The mathematical support to the notion that the area in phase space (emittance) occupied by accelerated particles is constant.
Liquid Argon Calorimeter See LAC.
LISA Laser Interferometer Space Antenna
LISP LISt Processor. A high-level programming language popular for artificial intelligence applications. LISP was developed in the early 1960's by John McCarthy at MIT.
List Shorthand term for EPA list of violating facilities or list of firms debarred from obtaining government contracts because they violated certain sections of the Clean Air or Clean Water Acts. The list is maintained by the Office of Enforcement and Compliance Monitoring.
Listed Waste Wastes listed as hazardous under RCRA but which have not been subjected to the Toxic Characteristics Listing Process because the dangers they present are considered self-evident.
Little-endian A format for storage or transmission of binary data in which the least significant byte or bit comes first. See big-endian.
LJE Liquid Jet End station (LCLS)
LLD Lower Limit of Detection.
LLL See LLNL.
LLM Large Language Model
LLMW Low Level Mixed Waste.
LLNL Lawrence Livermore National Laboratory.
LLO LIGO Livingston Observatory.
LLP Long-Lead Procurement.
LLR Lunar Laser Ranging.
LLRF Low-Level Radio Frequency. Also called low level RF. Pertains to controlling the phase and amplitude of RF signals at low power levels, before they are amplified to high power levels.
LLRW Low-Level Radioactive Waste (ESH)
LLS Synchrotron Light Laboratory (Spain).
LLW Low-Level Waste (ESH)
LMA Large Mixing Angle.
LMC Large Magellanic Cloud.
LMP Lightest Messenger Particle.
LMS Learning Management System. (SLAC)
LN Liquid Nitrogen (tank).
LN2 Liquid Nitrogen
LNF Laboratori Nazionali di Frascati. (INFN)
LNLS Laboratorio Nacional de Luz Sincrotron (Brazil).
LNS INFN Laboratori Nazionali del Sud, Italian laboratory located in Catania.
LNTF Liquid Noble Test Facility
LNW Lehmann-Newton-Wu
LO Leading Order.
LOB Laboratory Operations Board.
LOC Level of Concern. (related to EPCRA)
Local Area Network See LAN.
LODCM Large Offset Double Crystal Monochrometer. Also referred to as LOM (Large Offset Monochrometer).
LOF LAT Operations Facility. (GLAST- FERMI)
LOFAR Low Frequency ARray.
LOI Letters of Intent. (ILC)
LOIS Loss Of Interim Status.
LOLA S-band transverse deflecting structures. Named for creators Greg Loew, Rudy Larsen and Otto Altenmueller.
LOM Large Offset Monochrometer.
Long Ion Chamber A BCS type beam line device in use in the FFTB tunnel at SLAC. They are gas filled tubes running parallel to the beam line which are able to detect stray beams using the ionization effect.
Look At Me! See LAM.
LOPA Layer Of Protection Analysis.
LOREA angle-resolved photoemission beamline at ALBA.
LOS Level Of Service.
LOS LockOut Stop.
LOS Laboratory, Office and Shops building (SSRL).
LOSB Laboratory, Office and Shops Building (SSRL).
Lost Phase See LST.
LOTO Lock Out / Tag Out.
Low Conductivity Water See LCW.
Low RF See LRF.
Lower Explosive Limit See LEL.
Lower Flammable Limit See LEL.
LP Laboratory Protection, department.
LPA Large Piwinski Angle.
LPC Laboratory Policy Council.
LPC LHC Physics Center.(Fermilab)
LPC Laser Pulse Chopper.
LPG Liquified Petroleum Gas.
LPHD Local Parton Hadron Duality
LPL Lunar and Planetary Laboratory (University of Arizona).
LPM Landau-Pomeranchuk-Migdal
LPR License Plate Reader.
LPS Leading Proton Spectrometer
LPS Lab Partnering Service (DOE)
LPSPL Low-Power Superconducting Proton Linac.
LQ Long Quadrupole.
LQCD Lattice Quantum ChromoDynamics
LR Long Racetrack.
LRCA Limited Radiological Control Assistant.
LRDP Long-Range Development Plan.
LRF Low RF, A klystron summary display message indicating that the RF power is lower than its normal tolerance setting.
LRIS Low Resolution Imaging Spectrograph.
LRS Local Rotational Symmetry
LRSM Left-Right Symmetric Model.
LS Level Switch.
LSA Low Specific Activity.
LSBK L-Band Sheet Beam Klystron.
LSC Laser Safety Committee.
LSCC Large Scale Collaboration Center.
LSD Lenses Structure and Dynamics.
LSE Laser Stabilization Experiment.
LSF Load-Sharing Facility. (Computing)
LSH Level Switch High.
LSI Large-Scale Integration.
LSL Level Switch Low.
LSND Liquid Scintillator Neutrino Detector (Los Alamos).
LSO Laser Safety Officer. A person who has authority to monitor and enforce the control of laser hazards.
LSP Lightest Supersymmetric Particle.
LSR Local Standard of Rest. (Astronomy)
LSRA Life Science Research Associate.
LSS Lean Six Sigma (process improvement method).
LSS Laser Safety System. A system of interlocks around a secured enclosure to protect personnel from laser light.
LSS Large Scale Structure
LSST Legacy Survey of Space and Time (formerly Large Synoptic Survey Telescope).
LSSTC Legacy Survey of Space and Time Corporation (formerly Large Synoptic Survey Telescope Corporation).
LST LoST Phase. A klystron summary status indicating that the PAD is not able to measure the klystron phase.
LST Laser Science and Technology division (LCLS)
LSZ Little String theory.
LTB Lemaitre-Tolman-Bondy
LTB Linac-To-Booster
LTD Low-Temperature Detectors.
LTE Long-Term Exposure (photography)
LTMR Low Temperature Materials Research Group (SLAC)
LTR Low Temperature Materials Research.
LTR Low Temperature Reservoir.
LTU Linac-To-Undulator.
Lucretia A physics toolbox for the simulation of high-performance single-pass electron beam transport systems.
LUFT Leaking Underground Fuel Tank.
Luminosity A measure of the number of events per second and per unit cross section at the IP.
LUSI LCLS Ultrafast Science Instrument Project.
LUST Leaking Underground Storage Tank.
LUX Large Underground Xenon dark matter experiment.
LVD Large Volume Detector (Gran Sasso)
LVDT Linear Variable Differential Transformer. A device for measuring positions relative to a fixed reference, (e.g., for measuring slit positions).
LVV Limited Visibility Vehicle.
LWBM Lab-Wide Budget Model
LWC Lost Work Cases.
LWFA Laser WakeField Acceleration
LZ LUX-ZEPLIN detector. (South Dakota)
