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SLACspeak Terms

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H
Horizontal.
H II region
A cloud of glowing gas and plasma in which star formation is taking place. Named for the large amount of ionized atomic hydrogen it contains.
H&C
Hoist and Crane.
H&R
Hoisting and Rigging.
HA
Hazard Assessment.
Hacking
The activity of computer enthusiasts who are challenged by the practice of breaking security measures designed to prevent unauthorized access to one or more computer systems. (Hacking which involves criminal activity is called cracking.)
HAD
Hazardous Atmosphere Detector.
HADES
High Acceptance Di-Electron Spectrometer
Hadron
Generic name for members of the largest family of elementary particles. Hadrons interact strongly with one another, usually produce additional hadrons in collisions at high energy, and are roughly spherical.
HAGGLeS
HST Archive Galaxy-scale Gravitational Lens Survey.
Half Duplex
Data transmission in either direction, but only one direction at a time.
Half-Life
The time required for the elimination of one half a total dose of radiation from the body.
Half-Life
The time required for a pollutant to lose half its effect on the environment. For example, the half-life of DDT in the environment is 15 years, of radium, 1,580 years.
Half-Life
The time required for half of the atoms of a radioactive element to undergo decay.
Halogen
Any of a group of five chemically-related nonmetallic elements that includes bromine, fluorine, chlorine, iodine, and astatine.
Halogenated Hydrocarbons
A group of organic compounds which include one or more atoms of a halogen, e.g., chlorine or bromine, in their molecular structures.
Halon
Bromine-containing compounds with long atmospheric lifetimes whose breakdown in the stratosphere cause depletion of ozone. Halons are used in fire-fighting.
Handshaking
The procedures and standards (protocol) used by two computers or a computer and a peripheral device to establish communication.
Handypak
Histogram and display package program. Computer graphics software used at SLAC.
HAP
Hazardous Air Pollutant.
HAPD
Hybrid Avalanche Photo Detector.
HAPPEX
Hall A Proton Parity EXperiment, at the US DOE's Jefferson Lab.
HAPS
Hazardous Air PollutantS.
HAPS
High-Availibility Power Supplies.
HAR
Hydrogeological Assessment Report. (TPCA)
Hardware Address
The low level address used by a physical network. Each type of network hardware has its own addressing scheme. For example, Ethernet uses 48-bit hardware addresses assigned by the vendor, while proNET-10 uses small integer hardware addresses assigned when a connection to the network is installed.
Hardware Status
See HSTA.
HASC
House Armed Services Committee. (US)
HASYLAB
The synchrotron radiation laboratory at DESY (Germany)
HAWG
Hazard Analysis Working Group.
Hazard
A threat to workers, public, environment, or property.
Hazard Evaluation System and Information Service
See HESIS.
Hazardous Air Pollutants
Air pollutants which are not covered by ambient air quality standards but which, as defined in the Clean Air Act, may reasonably be expected to cause or contribute to irreversible illness or death. Such pollutants include asbestos, beryllium, mercury, benzene, coke oven emissions, radionuclides, and vinyl chloride.
Hazardous and Solid Waste Amendments
See HSWA.
Hazardous Experimental Equipment Committee
See HEEC.
Hazardous Ranking System
The principal screening tool used by EPA to evaluate risks to public health and the environment associated with abandoned or uncontrolled hazardous waste sites. The HRS calculates a score based on the potential of hazardous substances spreading from the site through the air, surface water, or ground water and on other factors such as nearby population. This score is the primary factor in deciding if the site should be on the National Priorities List, and, if so, what ranking it should have compared to other sites on the list.
Hazardous Substance
Any substance named by EPA to be reported if a designated quantity of the substance is spilled in the waters of the United States or if otherwise emitted into the environment.
Hazardous Substance
Any material that poses a threat to human health and/or the environment. Typical hazardous substances are toxic, corrosive, ignitable, explosive, or chemically reactive.
Hazardous Substance Account
See HSA.
Hazardous Waste
By-product of society that can pose a substantial or potential hazard to human health or the environment when improperly managed. Possesses at least one of four characteristics (ignitability, corrosivity, reactivity, or toxicity), or appears on special EPA lists.
Hazardous Waste Control Account
State fund derived from fees paid by operators of onsite and offsite disposal facilities and used to support the hazardous waste management program of the Department of Health Services.
Hazards Analysis
The procedures involved in (a) identifying potential sources of release of hazardous materials from fixed facilities or transportation accidents, (b) determining the vulnerability of a geographical area to a release of hazardous materials, and (c) comparing hazards to determine which present greater or lesser risks to a community.
Hazards Identification
Providing information on which facilities have extremely hazardous substances, what those chemicals are, and how much there is at each facility. The process also provides information on how the chemicals are stored and whether they are used at high temperatures.
HAZCOM
HAZard COMmunication. An Occupational Safety and Health Administra tion (OSHA) standard that requires all employers to instruct their workers on the hazards associated with the chemicals they use.
HAZOP
HAZard and OPerability study.
HAZWOPER
HAZardous Waste OPerations and Emergency Response standard. (OSHA)
HB-0
The bend in the DRIP where the beams returning from the rings get injected back into the LINAC.
HBC
Hydrogen bubble chamber.
HBCPT
Heavy Baryon Chiral Perturbation Theory
HBCU
Historically Black Colleges and Universities (US).
HBL
High-energy cut-off BL Lac object.
HBT
Hanbury-Brown-Twiss
HBV
Hepatitis B Virus.
HCAL
Hadron barrel CALorimeter.
HCP
Hazard Communication Program. (SLAC)
HCPBM
Heavily Charged Particles in Biology and Medicine.
HCS
Hazardous Communications Standard. (OSHA)
HCV
Hepatitis C Virus.
HD
Higher Deriviative.
HDBC
Hydrogen and deuterium bubble chambers.
HDF
Hubble deep field.
HDF5
Hierarchical Data Format 5.
HDM
Higgs Doublet Model.
HDMS
Heidelberg Dark Matter Search (Gran Sasso)
HDPE
High Density PolyEthylene.
HDSC
Hardware DeSCripter.
HDSCP
HoDoSCoPe.
HDSPC
High Density Spiral Projection Chamber.
HDU
|Basic unit of a FITS file consisting of an ASCII header and a data table.|
  Glast Category: SAS, software
HDX
Hybrid Damped structure.
HEACC
High Energy Accelerator Conference.
HEAD
High-Energy Astrophysics Division (American Astronomical Society).
Header
The portion of a packet, preceding the actual data, containing source and destination addresses and error-checking fields.
HEALPix
|This pixelization produces a subdivision of a spherical surface in which each pixel covers the same surface area as every other pixel. The pixel centers occur on a discrete number of rings of constant latitude, and the number o| |f constant-latitude rings depends on the resolution of the HEALPix grid.|
  Glast Category: SAS, software
  URL: http://healpix.jpl.nasa.gov/
HEASARC
High Energy AStrophysics Science ARChive (Goddard).
HEASARC
| HEASARC archives data from Gamma-ray, X-ray, and extreme ultraviolet observations of cosmic (non-solar) sources. The HEASARC group provides access to analysis software, data, and documentation. See NASA's HEASARC website.|
  Glast Category: astronomy, organization
  URL: http://heasarc.gsfc.nasa.gov/
Heat Exchanger
A locked radiation area where radioactive cooling water coming back from the slits, collimators and beam dumps is cooled and demineralized. (The heat exchange is with the cooling tower water.) The radiation levels in the heat exchangers are monitored by OHP.
Heavy Metals
Certain metallic elements having a high density and which are generally toxic, e.g., lead, silver, mercury, and arsenic.
HEB
High-Energy Beam.
HEBC
HElium Bubble Chamber.
HED
High-Energy Density Science (LCLS).
HEDS
High-Energy Density Science. (LCLS)
HEE
High-Energy Extraction.
HEEC
Hazardous Experimental Equipment Committee. An ad hoc committee which reviews and approves certain hazardous systems such as pressure vessels or large volumes of hazardous gases or cryogenic liquids for use by experimenters.
HEEP
High Energy Equipment Pool. A SLAC organizational group. Also High Energy Electronics Pool.
HEFT
High Energy Focusing Telescope.
HEGRA
High Energy Gamma Ray Astronomy telescope. Five-telescope array built in La Palma by a German-Spanish-Armenian collaboration.
HELEN
High Energy physics Latin-american-European Network.
HELEN
High-Energy Laser Embodying Neodymium. British laser brought to LC LS in 2011.
HELIOS
CERN Super Proton Synchroton detector
Helmholtz Coil
A coil in which the first and last winding are separated by 2r where r is the radius of the winding. Used to produce a uniform solenoid field. Designed by Hermann Helmholtz.
Helmholz Alliance
Network of German laboratories and universities involved in the LH C and the ILC.
HENIT
High-Energy North Injection Transport.
HENP
High Energy and Nuclear Physics.
HEP
High Energy Physics.
HEP
High Energy Physics. A major SPIRES database maintained jointly by the SLAC and DESY libraries which in 1999 contained > 390,000 references to preprints, journal articles, reports, theses, and conference papers. Used worldwide.
HeP E-tool
Hazard Evaluation and Planning Electronic tool. (SLAC ES&H) This tool is an activity-based questionnaire intended for use by n on-ESH staff, in particular supervisors, activity planners and UTR s. The tool identifies SLAC required permits and plans based on re sponses t the questions. May be accessed from the WPC website.
HEPA
High Efficiency Particulate Air.
HEPAP
High Energy Physics Advisory Panel.
HEPC
High Energy Photon Conference.
HEPDATA
Physics databases maintained at Durham/Raleigh.
HEPL
W. W. Hansen Experimental Physics Laboratory, Stanford University. (Formerly, High Energy Physics Laboratory.)
Hepnet
High Energy Physics Network. An international network linking computers of High Energy Physics laboratories.
HEPP
High Energy and Particle Physics, a division of the EPS.
HEPT
HElium Proportional Tubes.
HER
High Energy Ring for PEP-II, a 9 GeV storage ring for electrons.
HERA
See DESY HERA
HERMES
an experiment at DESY.
Hertz
See Hz.
HERWIG
Hadron Emission Reactions With Interfering Gluons.
HESIS
Hazard Evaluation System and Information Service. Sponsored by SDOHS and Cal OSHA. Provides information on chemicals to employers and employees.
HESS
High Energy Stereoscopic System. A next generation system of imaging atmospheric Cherenkov telescopes aimed at the study of cosmic gamma rays. (Namibia) Name honors Viktor Hess, who received the 1936 Nobel prize for his discovery of cosmic rays.
HESYRL
Hefei SYnchrotron Radiation Laboratory.
HET
Hobby-Eberly Telescope.(McDonald Observatory)
HETC
High Energy Transport Code
HETC
High Energy Transport Code
HETDEX
Hobby-Eberly Telescope Dark Energy Experiment.
Heuristics
In computing and artificial intelligence, common sense rules drawn from experience and used to solve problems.
HF
High Frequency. Allocated band of radio frequencies from 3MHz to 30 MHz.
HFAG
Heavy Flavor Averaging Group.
HFB
Hartree-Fock-Bogoliubov
HFBR
High-Flux Beam Reactor (Brookhaven)
HFF
Heavy Fermion Formalism
HFS
HyperFine Structure constant
HGO
Haleakala Gamma Ray Observatory.
HGRF
High-Gradient Radio-Frequency.
HHCPT
Heavy Hadron Chiral Perturbation Theory
HHMI
Howard Hughes Medical Institute.
HHW
Household Hazardous Waste.
HHWR
Heating Hot Water Return.
HHWS
Heating Hot Water Supply.
Hi-Potting
A troubleshooting technique. The process of increasing a voltage potential to a specified high level, with respect to ground, in order to check for failure or ground fault in a magnet. Used to measure very high resistances, or the voltage at which an insulator will break down.
HIC
Heavy Ions Collision
Hierarchical Routing
Routing that is based on a hierarchical addressing scheme. Most Internet routing is based on a two-level hierarchy in which an Internet address is divided into a network portion and a host portion. Gateways use only the network portion until the datagram reaches a gateway that can deliver it directly. Subnetting introduces additional levels of hierarchical routing.
HIF
Heavy Ion induced Fusion. Also, Heavy Ion Fusion.
Higgs Boson
the last undiscovered particle of the Standard Model, predicted by Peter Higgs, a Scottish theorist. The Higgs Boson is thought to be heavier than any particle as yet observed.
Higgsino
SUSY partner of the elusive Higgs boson.
High Energy Equipment Pool
See HEEP.
High Energy Physics
See HEP.
High Energy Physics Network
See Hepnet.
High Frequency
See HF.
High Voltage Ready
See HVR.
High-Level Radioactive Waste
See HLW.
HILAC
Heavy Ion Linear Accelerator.
HIMAC
Heavy-Ion Medical Accelerator in Chiba, Japan. Began operating in 1994.
HIP
A program for symbolic calculation of Feynman diagrams.
HIP
Holding Ion Pump.
HIPPI
High Intensity Pulsed Proton Injector (CERN).
HippoDraw
A data visualization program for displaying histograms developed by Paul Kunz (SLAC) and Jeff Gould (Gould Software).
HiRes
High Resolution Fly's Eye, an experiment.
HIS
HIT
Heidelberg Ion Therapy centre.
HIV
Human Immunodeficiency Virus.
HJ
Hamilton-Jacobi
HKT
HyperKahler with Torsion
HLA
High-Level (physics) Applications. (LCLS)
HLAM
Horizontal LAMbertson. A septum magnet used to extract the scavenger beam from the LINAC to the positron target. Designed by Glen Lambertson. See Septum.
HLBC
Heavy-Liquid Bubble Chamber.
HLS
Haag-Lopuszanski-Sohnius
HLS
Hydrostatic Leveling System.
HLT
High-Level Trigger.
HLW
High-Level Radioactive Waste. Waste generated in the fuel of a nuclear reactor and found at nuclear reactors or nuclear fuel reprocessing plants. It is a serious threat to anyone who comes near the wastes without shielding.
HM
Hazardous Materials. (DOE)
HMBP
Hazardous Material Business Plan.
HMC
Hybrid Monte Carlo
HMP
Hazardous Materials Program. (DOE)
HMPID
High Momentum Particle Identification Detector (ALICE).
HMSF
Hazardous Materials Storage Facility.
HMTA
Hazardous Materials Transportation Act. (49 U.S.C. Sec. 1801 et seq)
HOA
Hand-Off-Automatic.
HOC
Halogenated Organic Compound.
Hodoscope
A detector, usually used for triggering and based on scintillation counters with very short output pulses, which records the paths of ionizing particles by means of ion counters in close array. (From the Greek "pathviewer")
hohlraum
In inertial confinement fusion reaction experiments, a gold- lined, pencil-eraser-sized chamber that contains the nuclear energy. Fr om the German for 'small hollow.'
HOM
Higher Order Modes.
HOME
HOMEstake underground scintillation detector (South Dakota)
Hood Capture Efficiency
The emissions from a process which are captured by hood and directed into the control device, expressed as a percent of all emissions.
Horizontal Lambertson
See HLAM.
Host
The current computer being used in a network. Also called a server.
Host Name Resolution
A mechanism with static and dynamic elements for resolving host names into numeric addresses. The Internet Name Server Protocol accesses an Internet Name Server which provides dynamic name-to-number translation (this process is specified in IEN 116). The Domain Name Protocol accesses a Domain name Server which provides dynamic name-to-number translation (this process is specified in RFCs 1033 and 1034). A static local host table can also be accessed for name-to-number translation.
Host Table
An ASCII text file where each line is an entry consisting of one numeric address and one or more names associated with that address. Host tables are used to resolve host names into numeric addresses.
Hostname
The name given to a machine. See also FQDN.
HOT
Sponsored by SLAC Computing Services, this meeting includes a review of scheduled power outages, a discussion of identified problems and outstanding issues, along with a brief recap of the Accelerator Operations daily meeting. The meeting is open to all laboratory staff.
HP
Health Physics.
HP
Health Physicist.
hPa
Hectopascal. 100 Pascals.
HPC
High Performance Computing.
HPD
Hybrid PhotoDiode
HPF
High Performance FORTRAN. An evolving industry standard based on FORTRAN 90 + a FORALL statement + data partition directives that will be available on IBM's POWERparallel Systems like the 9076 SP1.
HPI
Human Performance Improvement.
HPRF
High-Power RF.
HPS
Hutch Protection System.
HPSB
High-Performing Sustainable Building.
HPSS
High-Performance Storage Systems.
HPT
Health Physics Technician.
HPTM
High Power Target Module.
HPW
Harvard-Pennsylvania-Wisconsin detector.
HPWR
High PoWeR.
HQ
High-field Quadrupole.
HQ
DOE HeadQuarters (Washington, DC).
HQEFT
Heavy Quark Effective Theory.
HQET
Heavy Quark Effective Theory
HQH
Hybrid Quark Hadron.
HR
Human Resources Department (SLAC).
HRA
High Radiation Area.
HRIS
Human Resources Information Systems.
HRMS
Human Resources Management System.
HRS
PEP High-Resolution Spectrometer (SLAC).
HRS
Hazard Ranking System. (CERCLA)
HRSC
Hoisting and Rigging Saftey Committee.
HSA
Hazardous Substance Account. A California state fund derived from fees paid by persons who deposit more than 500 pounds per year of hazardous or extremely hazardous waste to onsite or offsite hazardous waste disposal facilities. This is the primary funding source for the State Superfund program. (CH&SC Sec. 25300 et seq)
HSD
Health and Safety Directive.
HSS
Health, Safety and Security office. (DOE)
HST
Hubble Space Telescope.
HSTA
Hardware STAtus. A VAX database status bit indicating if a device is on-line or off-line.
HSWA
Hazardous and Solid Waste Amendments. The 1984 law which amended RCRA and created a federal program for underground tanks.
HTL
Hard Thermal Loop
HTM
Hierarchical Triangular Mesh.
HTML
HyperText Markup Language. The standard language used for creating hypermedia documents within the World Wide Web. It specifies the layout and linking commands present in the hypertext documents themselves.
HTS
High Temperature Superconductivity
HTSC
Hartle-Thorne-Sedrakian-Chubarian
HTTP
Hypertext Transfer Protocol. The standard application-level protocol for distributed, collaborative, hypermedia information systems. It describes the way that hypertext documents are fetched over the Internet and is most commonly associated with the World Wide Web.
HUP
Hutch User's Panel. (LCLS)
HV
't Hooft-Veltman
HV
High Voltage.
HV
Heating and Ventilating unit.
HVAC
Heating, Ventilation and Air Conditioning.
HVR
High Voltage Ready. A klystron SDS message indicating that a given klystron is ready for use.
HVTC
High Voltage Terminal Cabinet.
HWA
Health and Welfare Agency (California).
HWCL
Hazardous Waste Control Law. (CH&SC Sec. 25100 et seq)
HWMC
Hazardous Waste and Material Coordinator.
HWSA
Hazardous Waste Storage Area.
HWSY
Hazardous Waste Storage Yard.
HXC
Hard X Corrector.
HXRSS
Hard X-Ray Self-Seeding.
HYBR
HYBRid: bubble chamber + electronics.
HYC
Hard Y Corrector.
Hydrocarbons
A large group of organic compounds composed largely of carbon and hydrogen.
Hydrogeology
The geology of ground water, with particular emphasis on the chemistry and movement of water.
Hydrology
The science dealing with the properties, distribution, and circulation of water.
HYP
HYPercubic.
Hypercard
A kind of programming environment that organizes all forms of information into what appear as stacks of index cards. The user then manipulates those stacks to create applications.
Hyperlink
An element in an electronic document that links to another place in the same document, or to an entirely different document. Typically, you click on the hyperlink to follow the link. Hyperlinks are the most essential ingredient of all hypertext systems, including the World Wide Web.
hyperon
A heavy version of a neutron. Hyperons can be made artificially in accelerators, where they are unstable and decay quickly.
Hz
Hertz. The basic unit of frequency measurement that replaced the former unit of cycles per second (cps). One hertz is equal to one cycle per second.
H1
DESY-HERA detector

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

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