X-Y-Z

X     cross.

X Corrector     See XCOR.

X Recommendations     The CCITT documents that describe data communication network standards. Well-known ones include: X.25 Packet Switching standard, X.400 Message Handling System, and X.500 Directory Services.

X Window System (TM)     A popular window system developed by MIT and implemented on a number of workstations.

X/Open     A group of computer manufacturers that promotes the development of portable applications based on UNIX. They publish a document called the X/Open Portability Guide.

XAFS     X-ray Absorption Fine Structure.

XANES     X-ray Absorption Near Edge Structures.

XAS     X-Ray Absorption Spectroscopy.

XBBM     X Length Bunch Monitor.

XCOR     X CORrector. A small dipole magnet acting in the horizontal plane. Sometimes anXCOR is a trim winding on a larger bend magnet.

X-COW     Two work stations used as a COW. One of the stations is used for display only, the other for a cursor selectable menu (uses DECXWINDOW).

XCS     X-ray Correlation Spectroscopy (LCLS).

XENIX     A version of UNIX originally from Microsoft, now from SCO (Santa Cruz Organization).

XENON     Experiment proposed in 2002 using the dual phase type projection chamber approach to detect WIMP dark matter directly.

XES     eXperimental End Stations. (LCLS)

XES     X-ray Experimental Systems. (LCLS)

XFD     eXperimental Facilities Division (LCLS).

XFDSO     eXperimental Facilities Division Safety Office (LCLS).

XFEL     X-ray Free Electron Laser.

XFELO     XFEL Oscillator

XFO     X-ray Facilities Operations. (SLAC)

XIP     X-ray Improvement Project. (LCLS)

XKMS     XML Key Management System.

XLAM     X-ray Laboratory for Advanced Materials. Name changed to SIMES in 2008.

XLDB     eXtremely Large Databases (workshop).

XLEAP     X-ray Laser-Enhanced Attosecond Pulse

XM-2     SoftX-ray microscopy facility (ALS).

XMASS     Cold dark matter search using liquid Xenon (Kamioko Observatory)

XMC     X-ray Monte Carlo.

XML     eXtensible Markup Language. A pared-down version of SGML, designed especially for Web documents. It enables designers to create their own customized tags to provide functionality not available with HTML. For example,XML supports links that point to multiple documents, as opposed to HTML links, which can reference just one destination each.

XMM-N     X-ray Multi-Mirror Mission - Newton. Launched by an Ariane 504 on December 10, 1999. (ESA)

Xmosaic     AnX11/Motif WWW browser developed by National Center for Supercomputing Applications (NCSA).

XPCS     X-ray Photon Correlation Spectroscopy

XPD     X-ray Powder Diffraction.

XPEEM     X-ray PhotoEmission Electron Microscopy.

XPP     X-ray Pump Probe (LCLS).

XPS     X-ray Photoelectron Spectroscopy

XPSCL     X-ray Phase Safety Checklist. (LCLS)

XPUS     Interchangeable Processing Units.

XRAFEL     X-ray Regenerative Amplifier Free Electron Laser

XRB     X-Ray Background

XRD     X-Ray Diffraction.

XRD-F     X-Ray Diffraction and Fluorescence facility. (SSRL)

XRF     X-Ray Fluorescence. Biological rapid scanning imaging technique.

XROOTD     A highly scalable architecture for data access.

XRT     X-Ray Telescope.

XRT     X-Ray Tunnel (LCLS)

XSPRT     cross SuPpoRT.

XSS     cross-Site Scripting. (Computing)

XT     X Toolkit Intrinsics. A C library to create and use interface components called widgets to build GUIs. Pre-built collections of widgets are available like the Motif widget set.XT provides a higher level of screen and input manipulation than theXlib C library.

XTC     eXtended Tag Container.

XTCAV     X-band radio frequency deflector.

XTES     X-ray Transport and Experimental Systems, also known as FEE (Front -End Enclosure)

XTH     X-ray Transport Hall. (LCLS)

XTOD     X-ray beam Transport, Optics and Diagnostics.

XUV     eXtreme-UltraViolet

X-Windows     A standard protocol for computer display windows and graphics developed by MIT and available for most computers. DECWINDOW is the version for VAXes and microvaxes, MACX is the version for MACs.

Y Corrector     See YCOR.

YAG laser     neodymium-doped Yttrium Aluminum Garnet Nd:Y3Al5O12.

YBCO     Yttrium Barium Copper Oxide

YCOR     Y CORrector. A dipole magnet acting on the vertical position and angle of a particle.

YFS     Yennie-Frautschi-Suura

YITP     C N Yang Institute for Theoretical Physics (Stony Brook University )

YM     Yang-Mills

YN     hYperon-Nucleon

YOP     Youth Opportunity Program.

YP     Yellow Pages. See NIS.

Z     A fundamental particle with the same quantum numbers as the photon, but with a mass of 91.16 GeV. Like the W- and W+ particles, the Z is a carrier of the electroweak force. Discovered at CERN in 1983, the production and study of this neutral intermediate boson is the object of the SLC.

ZDR     Zeroth-Order Design Report (NLC).

ZEPLIN     ZonEd Proportional scintillation in Liquid Noble gases. (UK)

Zeta     The Greek letter (Z) used for the chromatic aberration function.

Zevatron     Hypothetical, highly exotic source capable of accelerating particles to 1 ZeV.

ZTA     Zero Trust Architecture

ZWP     Zero Waste Program.