D

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&D     Decontamination and Decomissioning

D0     FNAL-COLLIDER detector (D-Zero).

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 Assurance Council. (SLAC, 2011- )

DACT     Direct ACTion.

Daemon     A server or process running on a server that lies dormant until called upon to perform a service. Most servers are daemons.

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.

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.

DASEL     DArk Sector Experiments at LCLS-II     

DASI     Degree Angular Scale Interferometer.

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.

DBA     DataBase Administrator

DBD     Detailed Baseline Design. (ILC)

DBHF     Dirac-Bruckner-Hartreel-Fock

DBI     Dirac-Born-Infeld

DBM     Determined By Management.

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.

DC     Data Challenges (GLAST simulations).

DC     Drift Chamber.

DC     Data Center.

DC1     Data Challenge 1. (GLAST)

DC2     Data Challenge 2. (GLAST)

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).

DCIM     Data Center Information Management.

DCO     Document Change Order

DCR     Detector Concepts Report. (ILC)

DCS     Design and Construction Services. F&O department/group at SLAC.

DCS     Distributed Control System.

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 DC Current Transformer (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.

DDO     Deputy Director for Operations (SLAC)

DDP&I     Deputy Director for Projects and Infrastructure

DDS&T     Deputy Director of Science & Technology (SLAC)

DE     Dark Energy.

DEAR     Department of Energy Acquisition Regulations.

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.

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 pre-treatment 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.

DEI     Diversity, Equity, and Inclusion

DEIA     Diversity, Equity, Inclusion and Accessibility

DEIMOS     Deep Imaging Multi-Object Spectrograph.

DEISD     Draft Environmental Impact Statement.

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.

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-channel Field Effect Transistor detector.

DEPFET     DEpleted P-channel Field Effect Transistor. Pixel detector developed at MPI Halbeiterlabor München.

DES     Dark Energy Survey.

DESC     Dark Energy Science Collaboration.

DESI     Dark Energy Spectroscopic Instrument.

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 PETRA     DESY Positronen Elektronen Tandem Ring Accelerator (1978-1986), now PETRA III.

DETF     Dark Energy Task Force. (HEPAP)

Deuce, The     LCLS II.

DFA     Department of Food and Agriculture. (California)

DFG     Deutsche ForschungsGemeinschaft. (German Research Foundation)

DFMEA     Design Failure Modes and Effects Analysis

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.

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 in the UK.

DIANA     DIagram ANAlyser

DIC     Deep Inelastic Collisions

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.

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)

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.

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.

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.

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.

DKFZ     Deutsches KresForschungsZentrum, a German cancer research center.

DKP     Dispersionless Kadomtsev-Petviashvili.

DL     Dog-Leg beam position monitor. (LCLS)

DLA     Direct or Delectric Laser Acceleration.

DLA     Double Logarithmic Approximation

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)

DLS     Desktops & Labs Services (Computing)

DLSO     Deputy Laser Safety Officer.

DLWG     Disc Loaded Wave Guide. The LINAC accelerator pipe is a Disc Loaded Wave Guide.

DM     Deferred Maintenance.

DMA     Direct Memory Access.

DMAIC     Define, Measure, Analyze, Improve and Control.

DMAT     Disaster Medical Assistance Team.

DMF     Detector Microfabrication Facility. New state-of-the-art cleanroom in ASC for superconducting circuit fabrication (SLAC)

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).

DNA     DeoxyriboNucleic Acid ENVIRO

DNF     Disjunctive Normal Form

DNLS     Discrete NonLinear Schrödinger

DNS     Domain Name System. The method used to convert Internet names to their corresponding Internet numbers.

DNSTR     DowN STReam.

DO     Dissolved Oxygen.

DO     Director's Office.

DOD     Department Of Defense. (Federal)

Dodecapole     A twelve-pole magnet.

DOE     Department Of Energy. Supersedes ERDA and the AEC. Established 4 August 1977.

DOE HQ     DOE HeadQuarters (Washington, DC).

DOE/ORO     Department of Energy Oak Ridge Operations office.

DOELAP     DOE Laboratory Accreditation Program.

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.

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.

DPB     Division of Particles and Beams (American Physicsl Society).

DPDF     Diffractive Parton Distribution Functions.

DPE     Dual-Phase Extraction (ESH)

DPF     Division of Particles and Fields (American Physical Society)

DPHEP     Data Preservation in High Energy Physics. An international collaboration of organizations for data preservation and long term analysis.

DPLTA     Data Preservation and Long-Term Analysis. (HEP)

DPO     Differing Professional Opinions program (DOE)

DPWA     Energy-Dependent Partial-Wave Analysis.

DQC     Dynamic Quantum Clustering.

DR     Damping Ring. 

DR     Disaster Recovery.

DRA     Data Risk Assessment (Stanford)

DRE     Destruction and Removal Efficiency.

DREAM     Dynamic REAction Microscope (or Microscopy)

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.

Driver     A software module that controls an input/output port or external device. PC/TCP uses a device driver to control the network interfaces.

DRP     Data Reduction Pipeline

DS     Direct Supervisor.

DS     Desktop Support.

DS     Dyson-Schwinger

DSE     Dyson-Schwinger equations

DSES     Dyson-Schwinger Equation Studies.

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     Drift Tube.

DT     Dynamically Triangulated

D-T     Deuterium-Tritium.

DTC     Drift-Tube Chambers.

DTD     Document Type Definition (as for SGML)

DTM     Data Transfer Module.

DTN     Data Transfer Node

DTR     Data Terminal Ready.

DTW     Domestic Treatment Works.

Dump     A device to absorb the full power of a beam, either while tuning or after it has been used by an experiment.

DUNE     Deep Underground Neutrino Experiment.

DUPCD     Device Using Pulse Control Devices.

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

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.

DXS     Dynamic X-ray Scattering instrument features two major experimental programs: Inelastic X-ray Scattering and X-ray Photon Correlation Spectroscopy (LCLS-II HE)

Dynamic Data Exchange     See DDE.

DYWIDAG     DYckerhoff & WIDman AG. Company that manufactures post-tensioning and geotechnical construction systems.

DZM     Darbourx-Zakharov-Manakov.