4. CONCEPTUAL DESIGN REVIEW  (Rev. July 21, 1998)

A conceptual design defines the functional requirements of the beamlines in a sector. All members of a Collaborative Access Team (CAT) should be involved in the development of the conceptual design because the primary scientific objectives and programs are defined during this process. In addition, all CAT members should be in concurrence about the functional requirements of the beamlines. The conceptual design report (about 10-20 pages of text) should include the following:

A Brief Statement of the Scientific Objective of the CAT (1 page)

Rationale for the Choice of Insertion Device

State the short- and long-term goals for the device.

Spectral Requirements

State the spectral requirements of the beamline and describe how these requirements will be met. Examples of spectral requirements are monochromaticity, tunability, polarization, etc.

Optical Design

State the optical objectives of the beamline, and describe how these requirements will be realized. Examples of optical requirements are

- horizontal and vertical size and divergence of the beam at the experiment

- adjustability of optical parameters to meet various requirements

- range of variability of optical parameters

State the rationale for the chosen optical design. Include alternative designs considered, if any, and the reasons for choosing the current design.

Define the optical elements and their performance requirements. Examples of optical element design are

- surface finish and surface figure

- positional and angular stability and reproducibility

- thermal stability

Include any known information indicating that such performance criteria have been met.

Success of Overall Beamline Design

Discuss the elements essential for the success of the beamline design, and describe the impact of any marginal failure in the design performance on the scientific objectives of the proposed program.

R&D Requirements

Describe any R&D needed to meet the specifications of the design, and explain how this R&D will be conducted. If R&D is required to complete the final design, outline the schedule of R&D activities. State the backup plan to be followed if R&D does not produce the anticipated results. Is it expected that any portion of the R&D be carried out by the APS staff?

Drawings and Ray Diagrams

Provide a plan view and elevation view of the beamlines with sketches of supports, experiment station, optics enclosure, location of instruments and electronics, etc.

A ray diagram with extremal rays should be shown on a separate drawing (using a 10-fold compressed scale along the beamline length) to assure that the apertures, slits, masks, optics, etc. have been adequately considered.

The purpose of these drawings is to test the proof-of-principle and the feasibility of the optical designs. It should be understood that these designs will change with a better definition of parameters.