- Private (computer drive designation).
- P Wastes
- A federal waste list comprised of substances categorized as
- synchrotron light monitor.
- Parking and Transportation or Packaging and Transportation.
- P-Gun or PGUN
- Polarized gun. See also PLS.
- Public Affairs.
- Preliminary Assessment.
- Pascal. A unit of pressure.
- Project & Activity code. (SLAC)
- Price-Anderson Amendments Act.
- Physics & Astrophysics Building (Stanford).
- Physics / Project Advisory Committee.
- Perturbed Angular Correlation
- Physics Analysis Coordinator (BaBar).
- Particle Accelerator Conference.
- Phase and Amplitude Controller.
- The unit of data sent across a packet switching network. The
term is used loosely defined. While some Internet literature uses
it to refer specifically to data sent across a physical network,
other literature views the Internet as a packet switching network
and describes IP datagrams as packets.
- Packet Internet Groper
- See PING.
- Potential Asbestos Containing Material.
- A concrete shielding structure at each end of the SLD
detector between the endcaps and the pit walls. The two huge
overlapping sections of each PacMan can be opened for access to
the beam pipe.
- Phase and Amplitude Detector. An RF measurement module which
has been designed to measure the phase difference between two RF
inputs: the signal source and the reference source. The PAD data
is fed into the database after several adjustments (linearization
of pad error, MDL length, upstream sources). The reference signal
is usually derived from the MDL on a local reference line called
- Phase and Amplitude Detector Offset. The time at which the
- Pakistan's Atomic Energy Commision.
- Presidential Award for Excellence in Science, Mathematics
and Engi neering Mentoring.
- Palo Alto Fire Department.
- Polycyclic Aromatic Hydrocarbons.
- Pair Production
- The creation of an electron and a positron from a high
energy photon in a strong electric field such as that surrounding
a nucleus. This process is used to create positrons at the
- Pohang Accelerator Laboratory.(Korea)
- A member of a small family of large, herbivorous marine
mammals that inhabited the northern Pacific coastal region during
the Miocene epoch (20 to 10 million years ago). A fossil skeleton
of paleo was unearthed at SLAC in October 1964, during the
excavation for the linear accelerator beam switchyard.
- Payload for Antimatter Matter Exploration and Light-nuclei
- Planned Accessible Machine Maintenance. (LCLS)
- Proton ANtiproton annihilation DArmstadt.
- Particles And Nuclei International Conference.
- Panic Circuit
- Part of the linac PPS system that consists of EMERGENCY OFF
buttons that will trip off all the VVSs in the LINAC when
- Panofsky Long Ion Chamber
- See PLIC.
- Public Affairs Office
- Performance Assurance Plan (GLAST).
- Personnel Access Platform (GLAST).
- Powered Air-Purifying Respirator.
- A VAX process that handles error messages from micros or
from a SCP process that are destined either for a user or a SCP
terminal. All error messages are written to the ERRLOG list which
can be retrieved at any later time when investigating a fault or
- Xerox Corporation's Palo Alto Research Center
- Phase And Radial Motion in Electron LinAcs. An accelerator
simulation program for electron linacs. (CERN) See also PARMILA.
- Phase And Radial Motion in ELectron Linear Accelerators. A
modeling and design program for transport line optics that
incorporates beam bunching.
- Phase And Radial Motion In LinAcs. An accelerator simulation
program for linacs. (CERN) See also PARMELA.
- Project Assessment and Reporting System. (DOE)
- Project assessment and Reporting System.
- Particle Astrophysics Scientific Assessment Group.
- PArticles, Strings and COSmology (Symposium).
- Package for Automated Snoop Hardware Analysis.
- Precision with which one measures the projected angle in two
adjacent planes of a single TKR tray.
Glast Category: hardware
- Pattern Receiver Interrupt Multiplexer
- See PRIM.
- Pulsed Amplitude Unit. A CAMAC module used to control
devices such as pulsed magnets and phase shifters which must
change state at the accelerator pulse rate (up to 120 PPS).
- Physics Analysis Workstation. A computer program available
from CERN, PAW is an interactive utility for visualizing
experimental data in a computer graphical display.
- Producer-Archive Workflow Network (NARA)
- Parallel Assessment Window System.
- Polarized Antiproton eXperiment.
- Performance Baseline
- Pep Beamline. (SSRL)
- Propane Bubble Chamber.
- Package that controls the initial stage of the CPU boot
process. At the end of primary boot, operators have a basic
interface, which they can use to upload files, read memory, and
Glast Category: FSW, package
- Partial Breaking of Global Supersymmetry
- Pulsed Bend Horizontal. Refers to the dipole magnet used to
switch electron bunches to the North Ring and positrons to the
South Ring. Note that this magnet is no longer pulsed.
- Primordial Black Holes
- Proton Beam Radio-Therapy.
- Plasma Beat Wave (laser) Acceleration
- Private Branch eXchange. A private telephone network used
within an enterprise. PBX users share a certain number of outside
lines for making telephone calls external to the private network.
- Personal Computer.
- Protection Collimator.
- Parsec. An astronomical unit of measurement equivalent to
3.26 li ght years' distance, calculated using the PARallax of 1
arc SECond .
- Partially Conserved Axial vector Current
- President's Council of Advisers on Science and Technology.
- PolyChlorinated Biphenyl. A group of toxic, persistent
chemicals used in transformers and capacitators for insulating
purposes and in gas pipeline systems as a lubricant. Further sale
or new use was banned by law in 1979.
- Printed Circuit Board.
- Power Conversion Department. Engineers, maintains and
installs cables for modulators, sub-boosters and all power
supplies from the injector through the Research Area.
- Photon Controls and Data Systems.
- PerChloroEthylene. (aka tetrachloroethylene, or `perc'.)
- Peripheral Component Interconnect
- Phase Contrast Imaging.
- Programmable Control Module.
- Personal Computer Memory Card International Association.
This group of manufacturers created the new PCMCIA industry
standard adapter. It looks like a credit card and is mounted by
pushing it into an external computer slot, similar to an ATM.
- Project Controls Management System. (FGST)
- President's Council on the National Laboratories.
- Phase CONfiguration. The phase of a klystron taken from a
model or a saved configuration.
- PEP Control Room.
- Polymerase Chain Reaction.
- Parity Charge conjugation and Time reversal.
- Process Cooling Water.
- Program Deputy. (MCC)
- Physics Discussion.
- Project Director.
- Protein Data Bank.
- Partial Differential Equations.
- Phase DESired for a klystron.
- Portable Document Format.
- Parton Distribution Function or Pair-Distribution Function.
- Powder Diffraction File.
- Particle Data Group. The PDG
is an international international collaboration with affiliations
at LBNL, CERN, KEK, INFN, IHEP, SLAC and elsewhere. The PDG
reviews the field of particle physics and compiles and analyzes
data on particle properties.
- Project or Product Data Management.
- Programmed Data Processor. A Digital Equipment Corporation
- Preliminary Design Review.
- Pole Divergent Subtraction
- Power Density Spectrum.
- Programmable Delay Unit. A CAMAC module that contains in
memory a beam matrix of 256 beam code possibilities contained in
16 channels and a desired time of output pulses for each of these
channels. The PDU receives the beam code from the micro and the
fiducial signal from the FIDO. In this way the two data paths
(timing and beam codes) meet.
- PDU Channel
- One of the 16 channels of a PDU.
- Plant Engineering. A SLAC organizational group merged under
Facilities and renamed the Site Engineering and Maintenance
- Plant Engineering and Design.
- Plans Examiner/Building Inspector.
- Personnel Exclusion Area.
- Plant Engineering Department.
- Project Engineering and Design.
- PhotoElEctron Microscopy.
- Polarized Electron Gun. A CID injector gun used to generate
a polarized electron beam.
- Physical Electronics Group.
- PEp Gas tArget Spectrometer sYStem.
- Polarized Electron Gun (with additional gy to make it
- Permissible Exposure Limit. Maximum exposure levels for
workplace chemicals as determined by OSHA.
- Physical ELectronics. Renamed "Surface and Materials
Science" in 2005.
- Performance Evaluation and Measurement Plan. (DOE)
- Pencil Beam
- A beam with low energy spread and low emittance: usually
tightly collimated by one or more adjustable collimators.
- The flow of a hazardous chemical through zippers, stitched
seams, pinholes, or other imperfections in protective clothing
- A type of Feynman diagram describing the weak decay of a
quark through an intermediate quark - weak boson loop, in which a
gluon (or Z or photon) couples to the quarks in the loop, and
then decays to a quark - anti-quark pair.
- Plant Engineering Operations. (SLAC)
- Positron Electron Project (originally the Positron Electron-
Proton Project). A 2.2km circumference storage ring at SLAC with
six interaction points, two SSRL beam lines, electron-positron
storage and collision capability, 4 - 18 GeV energy range, and 50
mA currents. PEP has been upgraded to be the site of the SLAC B
Factory. See also PEP-II.
- Project Execution Plan.
- PEP II
- See PEP-II.
- PEP OIC
- Operator-in-charge of PEP.
- Upgraded SLAC PEP electron-positron collider. Its
transformation into an asymmetric B Factory included addition of
a second storage ring, as well as new beam power and control
- PEP-II Database
- The PEP-II Project-wide Oracle-based database. It is
envisioned to encompass off-line data for machine configuration
and administration, as well as much of the detector counterpart
- Upgrade to PEP-II (proposed).
- Synchrotron storage ring project at SLAC utilizing PEP-II.
- PEP UPgrade.
- PEP-II (Use for Spires).
- PERsonnel Department.
- PERioDic Permanent Magnet.
- Periodic Permanent Magnet Klystron
- An advanced generation klystron developed at SLAC, and
planned to provide microwave power for the NLC.
- Practical Extraction and Report Language. An interpretive
programming language developed by Larry Wall. Because of its
strong text-processing abilities, Perl has become one of the most
popular languages for writing CGI scripts.
- An invisible process by which a hazardous chemical moves
through a protective clothing material.
- Permissible Exposure Limit
- See PEL.
- A pattern gate used to allow the gun to pulse when a set of
interlocks is complete. The BCS and some MPS systems remove the
permissive in response to interlock trips. Operators also have
control of the permissive. This is a `fail-safe' method of
killing the beam, in that the gun can only pulse when the
permissive gate is present.
- An authorization, license, or equivalent control document
issued by EPA or an approved state agency to implement the
requirements of an environmental regulation, e.g., a permit to
operate a wastewater treatment plant or to operate a facility
that may generate harmful emissions.
- The property of a chemical whereby it tends to remain in the
environment in its original molecular form.
- Personnel Protection System
- See PPS.
- Program/project Evaluation and Review Technique.
- Positron Emission Tomography.
- Photon-Enhanced Thermionic Emission.
- See DESY PETRA
- Power Extraction and Transfer Structure. (CLIC)
- Accelerator of cosmic rays with energies of several PeV.
- Protection Factor. That number which when multiplied by the
TLV of a substance yields the maximum permissible concentration
in which the respirator in question may be used. Protection
factors are assigned to classes of respirators.
- Photon Factory
- Particle Flow Algorithms.
- President's Foreign Intelligence Advisory Board.
- ProFile MONitor.
- Pulse Forming Network.
- Pseudo-Goldstone Boson
- Plane Grating Monochromator.
- A measure of corrosivity on a scale from O to 14, with 7
being neutral, acidity increasing toward O and alkalinity
increasing toward 14.
- Phase Acceptance
- See Acceptance.
- Phase Advance
- The phase change of a betatron oscillation over a certain
distance (s) which can be a lattice cell.
- Phase and Amplitude Detector
- See PAD.
- Phase and Amplitude Detector Offset
- See PADO.
- Phase and Radial Motion in ELectron Linear Accelerators
- See PARMELLA.
- Phase Bump
- The `Phase Bump' is used to change the phase of the RF fill
of an accelerator section. The general intent is to change the
average phase of the RF seen by one beam, independent of that
seen by the other beam. This is achieved by tweaking the phase
(plus or minus) 90 degrees in the first or last 60 ns of the fill
time. Currently, this method is used to adjust the energy spread
of the scavenger beam.
- Phase Configuration
- See PCON.
- Phase Decker
- See Phase Bump.
- Phase Jump
- A Phase Shifter to compensate for the beam loading effect of
the Damping ring RF cavities.
- Phase Ramp
- Damping Ring RF Facility for varying the phase so that the
time of arrival of the extracted beam at the compressor and LI02
will be changed. Phase Ramp is moved in units of S-BAND degrees
or 0.973 picosecond. Operators tweak Phase Ramp to adjust the
beam spectrum and energy at the end of the LINAC, using X-ray
screens in the BSY area.
- Phase Raw
- See PRAW.
- Phase Shift Keying
- See PSK.
- Phase Space
- A plot of the beam position versus its phase angle.
- A system for measuring and correcting the tune of the SLC
- To adjust the timing of any periodic device less than 360
- To change the timing of a klystron's RF output with respect
to the bunch. This will add or subtract energy from the bunch by
causing the bunch to see a greater or smaller accelerating
- the Pioneering High Energy Nuclear Interation eXperiment is
located at BNL and is investigating high energy collisions
between heavy ions and protons.
- The practice of sending false email in an effort to trick
the receiver into revealing information that can be used to
perpetrate identity theft. Phishers direct the unwary to sites
that look legitimate, but are not.
- Klystron summary display indicating that the station mean
phase is out of tolerance.
- PHase Mean.
- Polynomial Hybrid Monte Carlo
- a detector at RHIC.
- wave-like vibration of an atom in a solid.
- A photon to current transducer amplifier which uses the
photoelectric effect and secondary emissions in cascaded diode
cells to produce a measurable electric current from a relatively
weak light source.
- A particle of light. In 1889, Max Planck postulated that
light is not continuous, but comes in bunches, or "quanta." Each
of these granular quanta of light is made up of photon particles.
- The technology of using particles of light as carriers of
- Personal Home Page (original meaning). General purpose
scripting l anguage developed by Rasmus Lerdorf.
- Physical Address
- A grouping of numbers that identifies a particular piece of
computer hardware connected to a local area network or other data
communications system. Contrast with logical address.
- Physical ELectronics
- See PEL.
- International Conference on Statistical Problems in Particle
Physi cs, Astrophysics and Cosmology.
- |The LAT Principal Investigator is the lead scientist
directly responsible for completion of the project and reports
directly to the funding agencies. See Dr. Peter Michelson - GLAST
LAT Principal Investigator.|
Glast Category: management
- PI Mode
- One of the two modes of bunch oscillation caused by the RF
in the Damping Rings (the other one is called O MODE). In Pi mode
the two bunches in a ring are opposite and oscillate toward each
other (they are Pi radians, or 360 degrees out of phase with each
- Product of Incomplete Combustion.
- Person In Charge. The person in charge of laboratory
response to emergencies.
- Pocket Ion Chamber.
- Protection Ion Chamber.
- Port d'Informació Científica. (Scientific
- A unit of area equal to 10 to the minus 12 barns. Used to
measure cross-sections in nuclear and particle physics.
- Measurement of radioactivity. A picocurie is one million
millionth, or a trillionth, of a curie, and represents about 2.2
radioactive particle disintegrations per minute.
- Picocuries Per Liter
- A unit of measure used for expressing levels of radon gas.
See also Picocurie.
- Physics with Integrated Cmos Sensors and ELectron machines.
- Picture Element
- See Pixel.
- Photo-Ionization Detector.
- Particle IDentification.
- Precourt Institute for Energy. (Stanford)
- A container, usually lead, used to ship or store radioactive
- Package providing low-level routines for controlling the LAT
power-up and LAT network configuration sequence.
Glast Category: FSW, package
- Personally Identifiable Information.
- See Parameter Interface Library Users Manual.
Glast Category: software
- PIxel ApparaTUs for the Sls project.
- The fuel element in a nuclear reactor.
- Profile Intensity Monitor.
- Path Integral Monte Carlo
- Proton and Ion Medical Machine Study.
- Packet INternet Groper. A program which is useful for
testing and debugging networks. It sends an ICMP Echo packet to
the specified host, and waits for a response. It reports success
or failure and statistics about its operation. The term is used
as a verb: "Ping host X to see if it is up!"
- Ping End-to-end Reporting.
- Public Information Officer.
- Programmable Input/Output Processor. A CAMAC module used for
- Project Implementation Plan. (ILC)
- Pipeline Mode
- A PAU mode of operation in which a beam code signals the PAU
to act on the following beam code. This mode of operation is
often used in dealing with time slot separation problems.
- Unauthorized copying of software.
- Primary Instrument Scientist.
- Pi-mode stabilizing loops
- PhotoInjector Test Facility, Zeuthen. (DESY)
- Personal Identification Verification.
- Picture element. A dot of video graphics that can be in
either an on or off state. The number of pixels determines the
resolution. Resolution is the number of pixels on the monitor and
is determined by multiplying the number of horizontal pixels by
the number of vertical pixels. For example, VGA is 640 x 480 or
307,200 pixels on the monitor.
- Peking University 3rd. A 1.3 gigahertz TESLA-type nine-cell
niobiu m superconducting cavity.
- Pulsed Linac (FEL).
- Programming Language 1. General-purpose language used for
both scientific and business applications.
- Plant Engineering
- See PE.
- Plastic detector.
- Programmable Logic Controller.
- Pulsed Laser Deposition.
- PoLicy Enforcement in Data Grid Environments. (NARA)
- A pulsar wind nebula powered by the relativistic wind of an
energetic pulsar. Often found inside the shells of supernova
remnants, magnetic fields accelerate the particles, forming jets
near the poles of the collapsed sta r and a ring flowing away
from the equatorial region.
Glast Category: astronomy
- Panofsky Long Ion Chamber. A gas filled cable running along
the linac housing or primary beam transport line used to detect a
mis-steered beam. The point where the beam is lost can be
determined from the time of arrival of the ion shower that the
lost beam sprays into the cable-chamber. Conceived by Wolfgang K.
H. Panofsky, SLAC Director Emeritus.
- PLant Office.
- Polarized Light Source. The SLC laser Gun.
- Pohang Light Source. (Korea)
- Plug Compatibility
- Manufactured hardware that is designed to be interchangeable
with another vendor's product, even though internal details may
- Pixelated Ladder with Ultra-Low Material Embedding. (ILC)
- DESY PLUTO detector.
- Detector at the DORIS electron-positron collider (DESY).
- Preventive Maintenance.
- Pulsed Magnet.
- Performance Measures.
- Peripheral Monitors.
- Project Management.
- Protection colliMator.
- Pulse-bending Magnet.
- Pulsed MAGnets. A VAX database primary.
- Project Management Assurance Group.
- Performance Measurement Baseline.
- PCI Mezzanine Card. (GLAST)
- Project Management Control System
- Photon Multiplicity Detector.
- Plant Maintenance Electrical.
- Plant Maintenance Instrumentation.
- Plant Maintenance Mechanics.
- Pre-Manufacture Notification.
- Project Management Office. (SLAC)
- Project Management Oversight Group. (Obsolete--See PMAG)
- Plant Maintenance Services.
- Program Management System.
- Peripheral Monitoring Stations.
- PhotoMultiplier Tube. See also Photomultiplier.
- |A vacuum tube that emits a large electron current
proportional to the small number of photons that enter the tube.|
Glast Category: hardware
- Plant Maintenance and Utilities Building.
- Pulse-bending Magnet Vertical.
- Parity NonConservation, or Parity NonConserving.
- Pattern Network Module.
- Pseudo-Nambu-Goldstone Boson.
- An abbreviation for `Panel.'
- Pacific Northwest National Laboratory.
- Particle-Nuclear Physics Pool.
- Position, Navigation and Time.
- Purchase Order.
- Pump Out.
- Plan Of Action and Milestones.
- Point Of Contact or Point of Connection.
- Publications Oversight Committee (American Physical
- Pockels Cell
- A crystal which changes its angle of light polarization when
submitted to a high voltage. A Pockels cell is used in the PLS to
chop the laser beam and also for polarization and intensity
control. It is useful for fast switching and control of polarized
- Principal Organic Hazardous Constituent.
- Person Of Interest.
- A modeling program used for calculating magnetic fields.
- A type of statistical distribution (see also Gaussian) named
after the mathematician Simeon Denis Poisson.
- Polarized Electron Gun
- See PEG.
- Polarized Light Source
- See PLS.
- Poll 0
- A VAX process which checks all SLCNET micros for database
status changes and errors. If a micro is not talking anymore, it
is removed from the poll list and its poll becomes `0.'
- Connecting to another system to check for things like mail
- Polychlorinated Biphenyl
- See PCB.
- A color-neutral collective partonic excitation; the
aggregate mechanism responsible for elastic scattering.
- Planned Operational Machine Maintenance. (LCLS)
- Principles Of OPeration. An SLC control system document.
- Post Office Protocol. A protocol used to retrieve e-mail
from a mail server. Most e-mail applications (sometimes called an
e-mail client) use the POP protocol, although some can use the
newer IMAP (Internet Message Access Protocol).
- Panel on Public Affairs (APS).
- POst Processor for Beam Coupling Interfaces.
- Polarized positrons.
- A particle with a mass equal to an electron but with
opposite charge. First postulated by P.A.M. Dirac in 1929, and
experimentally discovered by C.D. Anderson in 1931.
- Positron Electron Project
- See PEP.
- Palomar Observatory Sky Survey (1950-1955).
- Post Telephone and Telegraph Administration
- See PTT.
- The person responsible for taking care of mail problems,
answering queries about users, and other related work at a site.
- A commonly-used graphics description language designed for
use with computer printers. Most modern computer word processors
and graphics programs can produce PostScript output.
- Publicly-Owned Treatment Works.
- Plan Of the Week. (SLAC)
- Power Conversion Department
- See PCD.
- Power Supply Controller
- See PSC.
- Power Supply Operations Group
- See AME.
- Power Teks.
- See AME.
- Pp Beam #
- The higher byte of the PPYY is the PP beam code number used
by the T-Matrix to define a certain beam. This number is
generated by MP00 and broadcast to all micros.
- Particle Physics and Astrophysics (Directorate-SLAC).
Changed in August 2007. Was Particle and Particle Astrophysics
- Particle Physics and Astronomy Research Council (UK).
- Parts per billion.
- Planning and Policy Board. (Stanford University)
- Parallel Plate Chamber
- PEP Policy Committee. (Obsolete)
- Particle Physics Data Grid. Collaboration formed in 1999 to
develop a world-wide distributed computing model.
- Personal Protective Equipment.
- Preprints in Particles and Fields. A weekly list of new
preprints received in the SLAC Library and entered in the HEP
database. Available on the web at
- Pervasive Parallelism Laboratory. (Stanford - Computing)
- Pole PLate.
- Parts per million.
- Piecewise Parabolic Method.
- Periodic Permanent Magnet.
- PPM Focusing
- Periodic permanent magnet focusing. Uses an array of closely
spaced magnetic lenses of alternating polarity, driven by ring-
shaped, high-energy, rare earth magnets (which provide stable
fields and require no input current).
- Parametrized PostNewtonian
- Program Planning Office, an ES&H Division Department
- Pulsed Power Output Module. A CAMAC module.
- Point to Point Protocol. A protocol that allows a computer
to use the TCP/IP protocols and become a full Internet member
with a standard phone line and a hi-speed modem. Replaces SLIP.
- Preferred Procurement Products. (DOE)
- Poison Prevention Packaging Act. (Federal)
- Princeton Plasma Physics Laboratory.
- Polarized Photocathode Research Collaboration.
- Pulses Per Second.
- Personnel Protection System. A safety system designed to
protect people from radiation hazards. It includes the access
control system of radiation areas and the radiation detection
systems (BSOIC and BCS).
- Public Packet Switched Network, e.g., Telnet, Tymnet, Uninet
in the U.S., Datapac in Canada, Datexp in Germany.
- A 16 bit word used by timing software and hardware to select
times at which devices should be triggered on an upcoming machine
pulse. It is generated at MP00 and broadcast at 360hz on the
SLCNET to the various devices. It is received by the CAR in Crate
1 of a typical sector micro. PP is the high order eight bits or
`beam code' used to select the time delays for devices such as
klystrons and kicker magnets. YY is the low order eight bits,
used to synchronize additional devices such as BPMs.
- Perturbative QCD
- Perturbative Quantum Field Theory.
- beam position monitor, cherenkov cell, phosphor screen.
- Paperwork Reduction Act. (1995)
- Phase RAW. A database secondary. It is the raw phase
measured by the PAD.
- Premeable Reactive Barriers.
- PRoperty Control.
- People's Republic of China.
- Permit Required Confined Spaces.
- Physics Requirements Document.
- Pressure Relief Damper.
- A small pulsed magnet used on SLC to cancel the kick
received by the second bunch on the previous turn of the NDR.
- Physical Requirements and Exposures Checklist.
- A manuscript intended for publication but circulated among
peers for comment prior to being submitted for publication.
- Preprints in Particles and Fields
- See PPF.
- Preset Buttons
- PPS search devices which need to be activated by an operator
when searching an accelerator area. These buttons are placed
strategically in the beam housing to ensure that the search team
does a complete job of searching all the nooks and crannies in
- Pattern Receiver Interrupt Multiplexer. A multibus module
which receives PPYYs from the CAR and interrupts the micro CPU.
- Interactive computer graphics program for Picturing,
Rotation, Isolation, and Masking in up to 9 dimensions. Developed
at SLAC in the 1970's.
- A class of signal names in the VAX SLC database.
- Primary Waste Treatment
- The first steps in wastewater treatment. Screens and
sedimentation tanks are used to remove most materials that float
or will settle. Primary treatment results in the removal of about
30 percent of carbonaceous biochemical oxygen demand from
- Post-RefInement and MErging. Software program for analyzing
data f rom X-ray laser experiments.
- Princeton-Stanford Storage Rings
- See Stanford-Princeton Storage Rings.
- Principles of Operation
- See POOP.
- Print Server
- A network server assigned to manage local or remote printers
and printer queues. The print server keeps track of print jobs,
allows manipulation of print queues, and sends print jobs to
- Priority Pollutants
- A list of chemicals selected from the list of toxic
pollutants by the EPA as priority toxic pollutants for regulation
under the Clean Water Act.
- Phase-Rotated Intense Slow Muon Source (Osaka).
- Private Branch Extension
- See PBX.
- Phase Reference Line (For PAD).
- Positron Return Line.
- Physics Review Letters.
- A number between zero and one that represents the chance of
occurrence of a given event, wherein a probability of zero means
there is no chance of the event occurring, and a probability of
one means the event must happen. (A fifty percent chance of
occurrence is a probability of one half).
- Any autonomous program executed by a computer's CPU is a
process. Sometimes called a job.
- Photon Research and Operations Division.
- Production SLAC Web space
- Holds all the SLAC Web pages and associated files connected
to the SLAC Core Pages except Individual Home Pages. Files in the
Production Space are made available to the Web by authorized SLAC
WWW server that use the standard port (now 80), for example,
files in /afs/slac/www served by the www host.
- Production Web Pages
- Pages and directories that are linked directly or indirectly
from the SLAC Home Page. Production pages are meant to be viewed
(i.e., they are "in production") by any intended audiences,
including people outside of SLAC. See also: Non-Production Web
- PROFile Monitor. A VAX primary.
- Profile Monitor
- A screen inserted in a beam transport line to view the beam
cross section. The visible emission created by the beam exiting
the screen's phosphor coating (usually zinc sulfide) is viewed by
a video camera and the picture transmitted to the Control Room.
Profile monitor screens can usually be inserted and removed
remotely by the machine operators.
- Program Deputy
- The physicist temporarily in charge of the current program.
Program deputies usually have the `duty' for a period of one or
- Programmable Delay Unit
- See PDU.
- Programmable Input/Output Processor
- See PIOP.
- Programmable Synchronization Unit
- See PSU.
- Programmable Width Unit
- See PWU.
- Programmed Data Processor
- See PDP-11.
- Programming Language 1
- See PL/1.
- Project M
- The Stanford University project, developed by interested
parties in the Hansen Laboratories and Physics Department, for
the construction of a 2-mile, multi-BeV linear electron
accelerator. Called Project M from 1956 - 1960, the project was
renamed "Stanford Linear Accelerator Center" in 1960. The "M"
stood for "Multi-Gev" and/or for "Monster."
- Prop. 65
- Safe Drinking Water and Toxic Enforcement Act of 1986,
citizen's referendum in California.
- Proton therapy project at the Paul Scherrer Institute (PSI).
- Protection Factor
- See PF.
- Protection System
- See PTS.
- A formal description of message formats and the rules two
computers must follow to exchange those messages. A Protocol can
describe low-level details of machine-to-machine interfaces
(e.g., the order in which bits and bytes are sent across a wire)
or high-level exchanges between allocation programs (e.g., the
way in which two programs transfer a file across the Internet).
- Proton-Electron Project
- See PEP.
- The mechanism whereby one system "fronts" for another system
in responding to protocol requests. Proxy systems are used in
network management to avoid having to implement full protocol
stacks in simple devices, such as modems.
- Potentially Responsible Party.
- Proposal or Program Review Panel.
- Physical Review Special Topics - Accelerators and Beams.
- Participating Research Team (SSRL)
- Power Supply.
- A commonly used abbreviation for PostScript. Often used as
the "extension" portion of a computer file specification
containing PostScript language commands, as in "myletter.ps".
- Photon Science (Directorate-SLAC).
- Program Support. (DOE)
- vacuum Pumping (above housing)
- Pressure Switch.
- PCB waste Storage Area.
- Presidential Science Advisory Committee (US)
- Preliminary Safety Analysis Document.
- Power Supply Board.
- Planar Spark Counter.
- Power Supply Controller. A single width CAMAC module used to
control large power supplies. The PSC contains both a DAC and/or
an ADC plus control and status bits.
- Prevention of Significant Deterioration. (from CAA)
- Pulse Shape Discrimination.
- Power Systems Engineering group (SLAC).
- Pretreatment Standards for Existing Sources. (from CWA)
- Describes the response of an imaging system to a point
source or point object. The degree of spreading (blurring) of the
point object is a measure for the quality of an imaging system.
See LAT Performance.
Glast Category: astronomy
- Point Spread Function.
- Planetary Systems and Star Formation.
- A revolutionary long-lived meson discovered simultaneously
at SLAC and MIT in 1974. Burton Richter (SLAC) and Sam Ting (MIT)
shared the 1976 Nobel Prize in Physics for the discovery of this
particle, called J by the MIT team.
- The Greek letter `y.' See also Phase Advance.
- Pounds per Square Inch (unit of pressure).
- Protein Structure Initiative (NIH/NIGMS).
- Paul Scherrer Institute.(Switzerland)
- Photon Science Integration Study. (SLAC)
- Phase Shift Keying. Used in the SLED system to add the
energy stored in the sled cavity to that being produced by the
klystron. The PSK knob moves the envelope of the RF for sector 2-
30 with respect to the beam. It affects both beams, unlike the
phase ramp knob which is used to adjust the e+ and e- beam
- Photon Science Laboratory Building. (Proposed)
- vacuum Pumping (Mech.) (above housing)
- Proper Shipping Name. (from 49 CFR)
- Power Supply NaMe or serial number.
- Pretreatment Standards for New Sources. (from CWA)
- Power Supply Operations Group. Obsolete: was part of EFD.
- A rotating neutron star with jets of particles streaming out
from its magnetic poles. Thus, its radiation intensity varies
over a regular period corresponding to the star's rotation.
Radiation from some pulsars is seen only at specific intervals
and not all of the time. This is known as the 'lighthouse'
Glast Category: astronomy
- Programmable Synchronization Unit. Provides timing for
delays longer than the fiducial period, which is about 2.8
milliseconds, or provides multiple pulses per fiducial. Used to
synchronize devices to the damping ring beams. The PSU delay,
period and pulse width are programmable.
- high-energy Photon Science.
- Transverse momentum.
- Projects-Tasks-Awards. (Stanford)
- Potential To Emit.
- Physics Teacher Education Coalition.
- Pulse To Pulse Stabilizer.
- ProTection System. The SLAC operational group charged with
designing and troubleshooting electronics systems used in Beam
Containment and PPS.
- Post Telephone and Telegraph Administration. A generic term
for government-operated common carriers in countries other than
the U.S.A. and Canada. Examples of the PTT are British Telecom in
the United Kingdom, the Bundespost in Germany, and the Nippon
Telephone and Telegraph Public Corporation in Japan.
- Public Disk
- A Macintosh in the computer center used as a file server for
the MAC network.
- Public Packet Switched Network
- See PPSN.
- Power Usage Effectiveness.
- Photon Ultrafast Laser Science and Engineering center
- Pulsed Amplitude Unit
- See PAU.
- Pulsed Bend Horizontal
- See PBH.
- Pulsed Power Output Module
- See PPOM.
- Pump down
- Pump Probe
- A technique developed for the observation of ultrafast
events. A sample of material is 'pumped' at regular intervals to
create discrete events, and as the sample is changing, the
experimenters 'probe' the response of the system to the created
- PolyVinyl Alcohol.
- Parallel Virtual Machine. A message-passing library and
processor daemon for coordinating tasks across processors. Public
domain from Oak Ridge National Lab. Like Express and Linda, usage
has been growing explosively. Used in conjunction with batch
programs like Condor on MPPs or clusters to take better advantage
of multiple processors. PVM node programs aren't currently under
- Pressure Vessel Safety Officer. (SLAC)
- ProzeßVisualisierungs und SteuerungsSystem, an LHC
- Partial-Wave Analysis.
- Proportional Wire Chamber
- Plasma-based WakeField Acceleration.
- Pre-Work Hazard Assessment.
- |(Also known as a plerion.) A synchrotron nebula powered by
the relativistic wind of an energetic pulsar. Pulsar wind nebulae
(PWNe) are believed to be powered by active rotation-powered
pulsars, through a relativistic wind of p|
|articles and magnetic fields and, at an early stage of
evolution, are often found inside the shells of supernova
remnants. The pulsar's wind is decelerated to a_sub-relativistic
speed across a strong standing shock.|
Glast Category: astronomy
- Pressurized Water Reactor.
- Ports and Waterways Safety Act. (Federal)
- Plane Wave Transformer.
- Programmable Width Unit. A CAMAC module used for gated
pulses such as gun triggers. Triggers are received from the
backplane and outputs are pulsed with programmed duration.
- Capable of igniting spontaneously when exposed to dry or
moist air at or below 130 degrees F (54.44 C).
- The destruction of molecular composition through heating,
resulting in smaller, simpler, and generally less toxic
- P2/E2 Plan
- Pollution Prevention and Energy Efficiency Plan.
- Particle Physics Project Prioritization Panel.
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or propose new terms for SLACspeak.