An adjustable slit mechanism for a fiber-fed multi-object spectrograph

摘要

Fiber-fed multi-object spectrographs have greatly enhanced the spectroscopic capabilities of the world's premieretelescopes, but their flexibility has typically been limited by a fixed effective slit size that constrains the availableresolving power. We present a novel mechanism that, for the first time, equips a fiber-fed spectrograph withmultiple discreet slits of different widths. In this paper, we detail the mechanical design of our variable slitmechanism, which is capable of positioning any one of six slits in front of the fibers immediately prior toinjection into the spectrograph's optical train. Further, we present the details of related systems necessary toachieve closed loop positioning of the slit mechanism given that no encoder is used. We also briefly discuss ouruse of open source and open hardware projects in the design. Finally, we describe the control system we haveimplemented for this subsystem.© (2012) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.