2. BEAMLINE DEFINITIONS AND RESPONSIBILITIES (Rev. July 21, 1998)

2.1 Definitions

Beamline: In a general sense, a beamline is the transport through which x-rays are propagated from the source to the experimental station. It includes the enclosure shielding, as well as the optics that define the beam characteristics. At the APS, the user's portion of the beamline starts at a window or differential pump, which isolates the downstream beamline from the front end, the radiation source and the accelerator systems. This pump or window is located in the experiment hall immediately outside the storage-ring shielding.

Beam Transport: The chambers, typically vacuum chambers, through which the x-ray beam is propagated and which provide shielding from scattered radiation, as needed.

Equipment Protection System: The equipment protection system (EPS) consists of the instrumentation, including interlocks, designed to prevent equipment on the beamline from being damaged from thermal loads, radiation, etc.

Experiment Stations: At the APS, experiment stations are shielded enclosures that contain the experimenter's equipment. When beamline shutters have been closed and the personnel safety system (PSS) interlocks have been satisfied, personnel can enter the enclosure. The experiment stations are constructed of panels of lead and steel. Typically, as described above, they can contain the experiment-specific optics, samples stages and environments, analyzing optics, and photon detectors.

First Optics Enclosure: The first optics enclosure (FOE) is a shielded experiment station containing the beamline optics that accept the full spectrum of the x-rays from either an insertion device or bending magnet and the optics that select the portion of the spectrum to be transmitted down the beamline.

Front End: The front end (FE) is an ultrahigh-vacuum transition that provides for the extraction of radiation from the storage ring. The front end contains radiation collimators, masks, shutters, photon beam position monitors, and vacuum isolation valves. (The APS is responsible for the design, construction, and operation and maintenance of all APS front ends.)

Personnel Safety System: The Personnel Safety System (PSS) consists of the instrumentation controls that are configured to provide for the safety of personnel using the radiation beam.

White Beam: The spectrally unmodified radiation beam from the insertion device or bend magnet.

2.2 Responsibilities

The responsibility for the design, construction, installation, operation, and maintenance of the beamline components will be the responsibility of the CAT as described in The Advanced Photon Source User Policies and Procedures. However, the beamline components and any other equipment that is installed at the APS must be designed so that it conforms to all applicable safety regulations and incorporates acceptable measures for the protection of personnel, equipment, and the storage-ring vacuum. In general, responsibility is assigned as follows:

2.2.1 APS Responsibilities

  • Design, construction, installation, operation, and maintenance of all bending magnet and insertion device sources.
  • Design, construction, installation, operation, and maintenance of all front-end components.
  • Design, construction, installation, and maintenance of all beamline personnel safety system interlocks.

2.2.2 CAT Responsibilities

  • Design, construction, and installation of all beamline components (including first optics, beam transport, additional optics, and experiment stations and any other equipment at the APS). (Note: As described above, interlocks and controls related to personnel safety will be installed and maintained by the APS.)
  • Design, construction, and installation of all the equipment inside the experiment stations, excluding the personnel safety system equipment.