Advanced Photon Source

The Advanced Photon Source (APS) at Argonne National Laboratory is a national synchrotron-radiation light source research facility funded by the United States Department of Energy, Office of Science, Office of Basic Energy Sciences. Argonne National Laboratory is managed by UChicago Argonne, LLC, which is composed of the University of Chicago, Jacobs Engineering Group Inc. and BWX Technologies, Inc. (BWXT).

Using high-brilliance X-ray beams from the APS, members of the international synchrotron-radiation research community conduct forefront basic and applied research in the fields of materials science, biological science, physics, chemistry, environmental, geophysical, planetary science, and innovative X-ray instrumentation.

How APS works

Electrons are produced by a cathode that is heated to about 1,100°C (2,000°F). The electrons are accelerated to 99.999% of the speed of light in a linear accelerator. [cite web | title=Linear Accelerator | work=Argonne National Laboratory | url=http://www.aps.anl.gov/About/APS_Overview/linac.html | accessmonthday=9 January | accessyear=2008] From the linear accelerator, the electrons are injected into the booster synchrotron. Here, the electrons are sent around an oval racetrack of electromagnets, providing further acceleration. Within one-half second, the electrons reach 99.999999% of the speed of light. [cite web | title=The Booster Synchrotron | work=Argonne National Laboratory | url=http://www.aps.anl.gov/About/APS_Overview/booster.html | accessmonthday=9 January | accessyear=2008] Upon reaching this speed, the electrons are injected into the storage ring, a 1,104 meter (3 622 ft) circumference ring of more than 1,000 electromagnets. [cite web | title=The Electron Storage Ring | work=Argonne National Laboratory | url=http://www.aps.anl.gov/About/APS_Overview/storage_ring.html | accessmonthday=9 January | accessyear=2008]

Once in the storage ring, the electrons produce x-ray beams that are available for use in experimentation. Around the ring are 40 straight sections. One of these sections is used to inject electrons into the ring, and four are dedicated to replenishing the electron energy lost though x-ray emission by using 16 radio-frequency accelerating cavities. The remaining 35 straight sections can be equipped with insertion devices. [cite web | title=Insertion Devices | work=Argonne National Laboratory | url=http://www.aps.anl.gov/About/APS_Overview/insertion_devices.html | accessmonthday=9 January | accessyear=2008] Insertion devices, arrays of north-south permanent magnets usually called "undulators," cause the electrons to oscillate and emit light in the invisible part of the electromagnetic spectrum. Due to the relativistic velocities of the electrons, that light is Lorentz contracted into the x-ray band of the electromagnetic spectrum. ["Ibid."]

The Experiment Hall surrounds the storage ring and is divided into 35 sectors, each of which has access to x-ray beamlines, one at an insertion device, and the other at a bending magnet. [cite web | title=Experiment Hall & Beamlines | work=Argonne National Laboratory | url=http://www.aps.anl.gov/About/APS_Overview/experiment_hall.html | accessmonthday=9 January | accessyear=2008] Each sector also corresponds to a lab/office module offering immediate access to the beamline. [cite web | title=LOMs & Beamlines | work=Argonne National Laboratory | url=http://www.aps.anl.gov/About/APS_Overview/loms_beamlines.html | accessmonthday=9 January | accessyear=2008]

ee also

References

External links

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* [http://www.lightsources.org Lightsources.org]