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SLACspeak Terms

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d
Usually refers to a beam dump. ALSO: D.
D
Dipole magnet.
D Wastes
A federal waste category for those wastes which exceed maximum concentrations of toxic components based on the EP Toxicity test.
D-brane
In string theory, a ten-dimensional membrane that provides an anchoring surface for strings. D-branes can have mass, momentum and charge, and are quantum versions of objects that were first found as solitonic solutions of supergravity.
D-T
Deuterium-Tritium.
DAB
Data Assembly Building. Now called the Main Control Center (MCC).
DAC
Digital to Analog Converter. Usually used to control a power supply.
DAC
Director's Advisory Committee.
DAC
Director's Assurance Council. (SLAC, 2011- )
DAC versus Current Goodness
See DVIG.
DACL
CAMAC DAC location. A magnet database secondary.
DACT
Direct ACTion.
DACV
A magnet database secondary indicating the last DAC value.
Daczero
To run down a magnet to zero current. This is done by putting zero volts on the DAC that controls the magnet's power supply.
Daemon
A server or process running on a server that lies dormant until called upon to perform a service. Most servers are daemons.
DAFNE
phi-meson factory at the Frascati National Laboratories (Italy)
DALEC
Dump All Low Extracted Currents. A system which senses current in the Damping Ring before extraction and stops extracted beam in the Beam Switch Yard if current is below a specified threshold.
DAMA
particle DArk MAtter search. (INFN)
DAMA/LIBRA
particle DArk MAtter search using Large sodium Iodide Bulk for RAr e processes.
DAMIC
DArk Matter In CCDs. (Fermilab)
Damping Ring
A system to reduce the transverse emittance of a beam. In a ring, accelerated particles lose energy due to synchrotron radiation. In a damping ring, the lost energy is partially replaced by an RF source, which boosts the parallel (or longitudinal) energy, but does not correct the damping of the transverse emittance.
Damping Ring Injection Point
See DRIP.
Damping Ring Phase Processor
See DROPP.
Damping Ring RF
See DRRF.
Damping Ring Turns Counter
See DRTC.
DAPHNE
see DAFNE.
DAQ
Data AcQuisition system.
Dark Current
Spurious emission of electrons from a gun cathode or vacuum chamber wall in the presence of high voltage or RF. Dark current can be picked up and accelerated by RF stations out of phase with the main bunch.
DARPA
Defense Advanced Research Projects Agency.
DART
Days Away, Restricted, or Transferred. A subset of the Total Recordable Case (TRC) rate.
DAS
Data Acquisition System (SLD)
DASI
Degree Angular Scale Interferometer.
DASP
DESY double-arm spectrometer.
DAT
An abbreviation for DATA used in VAX file terminology as in `File.Dat.'
Data Compression
A technique used for cutting transmission costs or time, or for saving buffer space. It removes unnecessary gaps, redundancies, and empty fields from data streams.
Database
See DB.
Database Executive
See DBEX.
Database Generation
See DBGEN.
Database Server
A computer running a back-end (or server-based) database management program. The database server performs all database functions (for example, retrieving and sorting data) for clients requesting services.
Database/Database Management System
A collection of information organized in such a way that a computer program can quickly select desired pieces of data; a program specifically designed to manage data.
Dataphones
Service mark of the American Telephone and Telegraph Company for various hardware products.
Dazzler
See AOPDF entry.
DB
Database. A collection of information organized in such a way that a computer program can quickly select desired pieces of data.
dB
Decibel.
DBC
Deuterium bubble chamber.
DBD
Detailed Baseline Design. (ILC)
DBEX
DataBase EXecutive. A VAX process which transfers data between the micros and the host computer.
DBGEN
DataBase GENeration. The process of rebuilding the database on the SLC VAX. It is a process that adds new signals to the database and simultaneously checks that no two signals have the same name.
DBHF
Dirac-Bruckner-Hartreel-Fock
DBI
Dirac-Born-Infeld
DBInstall
Transfer of the complete database from the SLC VAX to the MCC VAX (or vice versa). It involves a brief shut down of operations. (The computer can't use the database while it is being updated.)
DBM
Determined By Management.
DC
Data Challenges (GLAST simulations).
DC
Data Center.
DC
Drift Chamber.
DCAA
Defense Contract Audit Agency.
DCB
Design Cost Board. (ILC)
DCBA
Drift Chamber Beta-Ray Analyzer
DCBD
DC Bending Dipole.
DCC
Disoriented Chiral Condensate
DCC
Directorate Conference Coordinator.
DCCT
Direct Current Current Transformer. A system used in storage rings to measure the stored current. It uses a toroid and an integrator.
DCE
Distributed Computing Environment. An architecture of standard programming interfaces, conventions, and server functionalities for distributing applications transparently across networks of heterogeneous computers. Promoted and controlled by the Open Software Foundation (OSF).
DCH
Drift CHamber. (BaBar)
DCI
Dispositif de Collision dans l'Igloo. The electron - positron storage ring at ORSAY.
DCL
Digital Command Language. The command language used by the VAX.
DCO
Document Change Order
DCR
Detector Concepts Report. (ILC)
DCS
Distributed Control System.
DCVD
Drift Chamber Vertex Detector. It is used for high-precision tracking of charged particles near the interaction point.
DC1
Data Challenge 1. (GLAST)
DC1
DC1 included analysis of data sets representing one day's worth of data. (See Data Challenge 1 Closeout Meeting.)
  Glast Category: operations
  URL: http://www-glast.slac.stanford.edu/software/Workshops/Feb04DC1CloseOut/coverpage.
DC2
Data Challenge 2. (GLAST)
DC2
DC2 included extensive analysis of 55 days of simulated data which, relative to DC1, was more realistic in terms of increased detail and improvements of the detector simulation, event classification, and the sky. (See Data C hallenge II web pages.)
  Glast Category: operations
  URL: http://glast-ground.slac.stanford.edu/workbook/dc2_home.htm
DDAA
Decade of Discovery in Astronomy and Astrophysics.
DDC
Digital Down Converter.
DDCCT
A device which measures and reads out the rate of change of the DCCT. It is used to find the fill/loss rate of current in storage rings.
DDE
Dynamic Data Exchange. A protocol supported by Microsoft Windows that allows cooperating Windows applications (applications that use the DDE specification) to establish both data and command links, which allow these cooperating applications to exchange data in real time, initiate new processes and support compound documents that consist of elements drawn from disparate files that are automatically updated as data changes in the external files.
DDS
Damped Detuned Structure
DE
Dark Energy.
Dead Time
Time during which the LAT does not trigger in response to Gamma-ray events due to physical limitations on the readout rate of the front-end and data acquisition electronics.
  Glast Category: general
DEAR
Department of Energy Acquisition Regulations.
DEAR
Experiment conducted at the Frascati National Laboratories (Italy) phi-meson factory DAFNE
DECam
Dark Energy survey Camera. (Chile-2012)
Dechlorination
Removal of chlorine from a substance by chemically replacing it with hydrogen or hydroxide ions in order to detoxify the substances involved.
Decnet
A VAX communications system protocol between DEC computers. Decnet provides remote file service and remote terminal sessions. It can be used on the Ethernet cable system.
DEEP
Deep Extragalactic Evolutionary Probe.
Deep Well Injection
The disposal of wastes by injecting them into a geological formation deep in the ground, sometimes after pretreatment to avoid solidification.
Degaussing
The process of removing the residual field in the iron of an electromagnet by reversing the polarity of the power supply feeding that magnet, and putting just the right amount of power through the windings in the opposite direction. This type of hysteresis neutralization is used when the operating field of the magnet must be precisely controlled.
Degradation
The process by which a chemical is reduced to a less complex form.
DEIMOS
Deep Imaging Multi-Object Spectrograph.
DEIS
Draft Environmental Impact Statement.
DELCO
Direct ELectron COunter, an experiment at PEP.
Delegated State
A state (or other governmental entity) which has applied for and received authority to administer, within its territory, its state regulatory program as the federal program required under a particular federal statute. As used in connection with NPDES, UIC, and PWS programs, the term does not connote any transfer of federal authority to a state.
Delist
The use of the petition process to have a facility's toxic designation rescinded.
DELPHI
DEtector with Lepton Photon and Hadron Identification. (CERN-LEP)
DEMO
DEMOnstration power plant (ITER).
DEMON
A Monte Carlo program for electron-down quark (e-d) scattering.
DEMTBL
DEMounTaBLe.
DENIS
DEep Near Infrared Survey of the southern sky
Density
Mass per unit of volume, commonly expressed in grams per cubic centimeter (g/cc). The density of water is 1.00 g/cc.
DEO
Director of Emergency Operations.
DEOIC
Deputy Engineering Operator In Charge.
DEPFET
DEpleted P-channelField Effect Transistor detector.
DEPFET
DEpleted P-channel Field Effect Transistor. Pixel detector develop ed at MPI Halbeiterlabor Munchen.
DES
Dark Energy Survey.
Designer Bugs
Popular term for microbes developed through biotechnology that can degrade specific toxic chemicals at their source in toxic waste dumps or in ground water.
DESTINY
Dark Energy Space Telescope
DESY
Deutsches Elektronen-SYnchrotron (Hamburg, Germany)
DESY HERA
DESY Hadron Electron Ring Accelerator
DESY PETRA
DESY Positronen Elektronen Tandem Ring Accelerator (1978- 1986), now PETRA II.
DETF
Dark Energy Task Force. (HEPAP)
DFA
Department of Food and Agriculture. (California)
DFG
Deutsche ForschungsGemeinschaft. (German Research Foundation)
DFI
|Ground software package that provides a user interface to the science data transmitted by the onboard FSW. DFI presents an abstract representation of the datagrams inside the science data stream, allowing user code to access th| |e contents of those datagrams without knowledge of their physical structure. DFI itself uses interfaces provided by the QSEP, QSEC, and other Q-packages in the FSW repository.|
  Glast Category: data processing, package, software
DFR
Doplicher-Fredenhagen-Roberts.
DFS
Distributed File System. A major component of DCE. It is OSF's extended version of the Andrew File System (AFS) from Transarc. DFS is interoperable with other file systems. "cd/:" changes you to the directory at the top of your cell; "cd/..." changes you to the global root.
DFT
Density Functional Theory.
DGLAP
Dokshitser-Gribov-Lipatov-Altarelli-Parisi
DGP
Dvali-Gabadadze-Porrati.
DGRP
Display GRouP. A VAX primary.
DGW
Discharge to Ground Water.
DH
Department Head.
DHCAL
Digital Hadron Calorimeter. (ILC)
DHCP
Dynamic Host Configuration Protocol. An Internet protocol for automating the configuration of computers that use TCP/IP.
DHGHY
Drell-Hearn-Gerasimov-Hosoda-Yamamoto.
DHGI
Drell Hearn Gerasimov Iddings sum rule
DHHS
Department of Health and Human Services. (federal)
DHS
Department of Health Services (California, aka CDHS, SDOHS, DOHS).
DIAMOND
Third-generation synchrotron radiation source under consideration for construction in the UK.
DIANA
DIagram ANAlyser
DIC
Deep Inelastic Collisions
DIDN
Digital Input Device label defiNitions. A VAX primary.
Differential Pumping Station
See DPS.
diffraction
elastic-like scattering
DigiSim
Tool for fast parametric simulations of detector phenomena. (ILC)
Digital
Any system based on discontinuous data or events. Computers are digital machines because at their most basic level they can distinguish between just two values, 0 and 1, or off and on.
Digital Command Language
See DCL.
Digital Input Device Label Definitions
See DIDN.
Digital to Analog Converter
See DAC.
Digitizer
Any analog to digital converter. See also ADC.
Digitizer
A device used to digitize the light intensity created when a profile monitor is inserted in a beam transport line.
DIMAD
A computer program used to study particle behavior in circular machines and in beam lines
Dioxin
Any of a family of compounds known chemically as dibenzo-p- dioxins. Concern about them arises from their potential toxicity and contamination in commercial products. Tests on laboratory animals indicate that it is one of the more toxic manufactured chemicals known.
DIP
Distributed Ion Pump. Pumps that are integrated in the physical structure of dipole magnets, and use the dipole's magnetic field to steer the ions into a 'trap.'
Dipole
A magnet with a North and South pole, typically used to bend or steer a beam.
DIR
Department of Industrial Relations. (California)
DIRC
Detector of Internally Reflected Cherenkov light. DIRC is a device developed for use in the SLAC BaBar Detector. Also: Detection of I nternally Reflected Cerenkov Light. Invented by Blair Ratcliff.
Direct Current Current Transformer
See DCCT.
Directory Services
A network function providing resource (file, user, printer, applications) information to end users.
DIRT
Dust InfraRed Toolbox.
DIS
Deep Inelastic Scattering
Disassembling
Converting a binary program into human-readable machine language code.
Disaster Monitor
Obsolete. See Burn Through Monitor.
Disc Loaded WaveGuide
See DLWG.
Dispersion
The blow up of a beam caused by an energy spread. The dispersion occurs when the beam is bent by a dipole magnet, because charged particles with less energy bend more and particles with more energy bend less. See also ETA function.
Display Group
See DGRP.
Distributed Computing Environment
A comprehensive programming toolkit that includes libraries for remote procedure calls, network communication, and resource- management tools for the network, as well as tools for creating distributed applications.
Distributed File System
A file system in which different pieces of files are contained in multiple file servers in multiple locations throughout a given network. The system maintains all storage information, and ensures that a distributed file appears transparently to the user as one single and whole file.
Distributed Ion Pump
See DIP.
Distributed Processing
An architecture under which different processes of a unique task are performed in multiple locations of a given network. For example, data requested by a client might be retrieved from a database residing on a centralized mainframe, sent to and sorted by a regional minicomputer, and finally returned to the workstation or possibly printed at the workstation's local printer facility.
Dithers
The last x, y correctors in the machine, just before the final triplets. They are air core dipoles which have a fast response time and are used for beam scans and IP wire scans.
DITL
A test designed to demonstrate a fully functional observatory in which the LAT is operated exactly as it will be on orbit. During a DITL, the LAT is under the control of commands stored on the observatory and executed in an ab solute time sequence. DITLs include a number of SAA passes and physics run starts/stops. Tests also exercise the full range of observation modes by including LAT-initiated Autonomous Repoint Requests and Target of Opportunity pointings.
  Glast Category: general, operations
Divergence
The increase in the diameter of a beam as a function of z position.
Divide By Four
Any circuit which divides a frequency (or other parameter) by four.
Divide By Four
A module which divides by four the S-BAND frequency to get the RF subharmonic used in the damping rings.
DKFZ
Deutsches KresForschungsZentrum, a German cancer research center.
DKP
Dispersionless Kadomtsev-Petviashvili.
DL
Dog-Leg beam position monitor. (LCLS)
DLA
Double Logarithmic Approximation
DLA
Direct or Delectric Laser Acceleration.
DLCO
DELCO detector at SLAC-SPEAR or SLAC-PEP.
DLCQ
Discretized Light Cone Quantization
DLDS
Delay Line Distribution System.
DLHC
Double energy Large Hadron Collider.
DLLA
Double Leading Logarithmic Approximation
DLP
Data Loss Prevention. (Symantec)
DLPH
DELPHI detector at LEP.
DLSO
Deputy Laser Saftey Officer.
DLWG
Disc Loaded Wave Guide. The LINAC accelerator pipe is a Disc Loaded Wave Guide.
DM
Deferred Maintenance.
DM.
Disaster Monitor. See Burn Through Monitor.
DMA
Direct Memory Access.
DMP
Data Management Plan.
DMR
Discharge Monitoring Report (from CWA).
DMR
Differential Microwave Radiometers
DMS
see CDMS.
DMSAG
Dark Matter Scientific Assessment Group.
DMUF
Dust Mask User's Form.
DMWG
Data Management Working Group (SD&H).
DM1
Magnetic detector no. 1 at Orsay DCI collider.
DM2
Magnetic detector no. 2 at Orsay DCI collider.
DNF
Disjunctive Normal Form
DNLS
Discrete NonLinear Schrodinger
DNS
Domain Name System. The method used to convert Internet names to their corresponding Internet numbers.
DNSTR
DowN STReam.
DO
Director's Office.
DO
Dissolved Oxygen.
DOD
Department Of Defense. (federal)
Dodecapole
A twelve-pole magnet.
DOE
Department Of Energy. Supercedes ERDA and the AEC. Established 4 August 1977.
DOE ACTS
Department of Energy Academies Creating Teacher Scientists.
DOE ER
Department of Energy, Energy Research. This department supersedes the Energy Research and Development Agency (ERDA), which superseded the Atomic Energy Commission (AEC).
DOE HQ
DOE HeadQuarters (Washington, DC).
DOE OBER
Department of Energy Office of Biological and Environmental Resear ch.
DOE SF
DOE San Francisco Field Office.
DOE/OAK
Department of Energy Oakland Operations Office
DOE/ORO
Department of Energy Oak Ridge Operations office.
DOELAP
DOE Laboratory Accreditation Program.
DOENTS
Department of Energy Nationwide Telecommunication Services.
DOF
Degree-Of-Freedom.
DOHS
Department of Health Services (California, aka CDHS, DHS, SDOHS).
DOI
Digital Object Identifier.
DOM
Digital Optical Modules
Domain
In the Internet, a part of the naming hierarchy. Syntactically, an Internet domain name consists of a sequence of names separated by dots, for example slac.stanford.edu.
Domain Name System
See DNS.
DONUT
Direct Observation of the NU Tau. Experiment (FermiLab) that in 2000 directly observed the tau neutrino for the first time.
DORIS
DOppel RIng Speicher, a storage ring at DESY.
Dose
In radiology, the quantity of energy or radiation absorbed.
Dose-Response Curve
The quantitative relationship between the dose of a toxic agent administered to an organism and the response of the organism.
Dosimeter
An instrument to measure integrated radiation dose. See also TLD.
DOT
United States Department of Transportation.
Dotted Decimal Notation
The syntactic representation for a 32-bit integer that consists of four 8-bit numbers written in base 10 with dots separating them. Used to represent IP addresses in the Internet as in: 192.67.67.20.
Dotted Quad
A set of four numbers connected with periods that make up an Internet address, for example: 147.31.254.130.
DPAC
Deputy Physics Analysis Coordinator (BaBar).
DPB
Division of Particles and Beams (American Physicsl Society).
DPDF
Diffractive Parton Distribution Functions.
DPF
Division of Particles and Fields (American Physical Society)
DPLTA
Data Preservation and Long-Term Analysis. (HEP)
DPS
Differential Pumping Station. A refrigerated section of waveguide which is used to maintain a difference in vacuum pressure between the LINAC and BSY, yet allows beam to pass (also called Refrigerated Baffle).
DPWA
Energy-Dependent Partial-Wave Analysis.
DQC
Dynamic Quantum Clustering.
DR
Damping Ring.
DR
Disaster Recovery.
DRE
Destruction and Removal Efficiency.
DREP
Dosimetry and Radiological Environmental Protection.
DRG
Divisional Response Group.
Drift Chamber
A particle detector that determines the track path of a particle by measuring the drift time for free electrons from ionized gas along the particle's trajectory.
Drift Chamber Vertex Detector
See DCVD.
DRIP
Damping Ring Injection Point. 1. A PPS area between PPS Sector 0 and PPS Sector 2, and the Damping Ring vaults. 2. The point where the beamlines from and to the rings are connected (the Ten Finger Box).
DRIP
Damping Ring Interaction Point.
Driver
A software module that controls an input/output port or external device. PC/TCP uses a device driver to control the network interfaces.
DROPP
See DRPP
Dropp Phase
A Damping ring phase shifter used in phase ramping the damping ring RF to phase the beam with respect to the LINAC S- BAND frequency.
DRPP
Damping Ring Phase Processor. A CAMAC module driving the Damping Ring Phase Shifter. (Sometimes appears as DROPP.)
DRRF
Damping Ring RF. A VAX primary.
DRS
DResS.
DRTC
Damping Ring Turns Counter. A CAMAC module including a 20 bit counter reset by the FIDO missing pulse and incremented by the MTG: used to synchronize extraction from the damping rings with respect to PEP RF when filling the PEP storage ring.
DRV
Damping Ring Vault. (SLC)
DS
Dyson-Schwinger
DS
Direct Supervisor.
DS
Desktop Support.
DSE
Dyson-Schwinger equations
DSES
Dyson-Schwinger Equation Studies.
DSP
Digital Signal Processors
dSph
dwarf Spheroidal (galaxies).
DSR
Data Set Ready.
DSR
Doubly Special Relativity.
DSS
Decision Support Services.
DST
Daylight-Savings Time.
DST
Data Summary Tapes.
DSW
Discharge to Surface Water.
DT
Dynamically Triangulated
DT
Drift Tube.
DTC
Drift-Tube Chambers.
DTD
Document Type Definition (as for SGML)
DTE
Data Terminal Equipment.
DTM
Data Transfer Module.
DTR
Data Terminal Ready.
DTW
Domestic Treatment Works.
DUD
Deep Underground Detector (IMB).
DUMAND
Deep Underwater Muon And Neutrino Detector.
Dump
A device to absorb the full power of a beam, either while tuning or after it has been used by an experiment.
DUPCD
Device Using Pulse Control Devices.
DUSEL
Deep Underground Science and Engineering Laboratory (at Homestake Mine, South Dakota).
Dust
Particles light enough to be suspended in air.
Dustfall Jar
An open container used to collect large particles from the air for measurement and analysis.
DVCS
Deeply Virtual Compton Scattering
DVI
The product of the DAC and power supply transfer functions. For conversion of DAC units to power supply output units. A SLC VAX database secondary.
dvi
A common abbreviation for DeVice Independent. It refers to output produced by TeX, and is often used as the "extension" portion of a computer file specification containing TeX output, as in "myletter.dvi".
DVIG
DAC Versus current Goodness. The root mean square residual error (in DAC bits) from the linear fit as determined from a calibration. A magnet database secondary. Also, a SLC VAX database secondary.
dvips
A commonly-used program that convertls TeX DVI files to PostScript. An important feature is that it can merge other PostScript files into its output, permitting an author to include figures and other graphics with text.
DVM
Digital Volt Meter.
DW
Data Warehouse.
DWA
Dielectric Wakefield Accelerator.
DWBA
Distorted Wave Born Approximation.
DWFA
Dielectric WakeField Accelerator.
DWIA
Distorted Wave Impulse Approximation.
Dynamic Data Exchange
See DDE.
DYWIDAG
DYckerhoff & WIDman AG. Company that manufactures post- tensioning and geotechnical construction systems.
DZM
Darbourx-Zakharov-Manakov.
D0
FNAL-COLLIDER detector (D-Zero).

Send corrections to jmdeken@slac.stanford.edu or propose new terms for SLACspeak.

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