eprintid: 10168654 rev_number: 7 eprint_status: archive userid: 699 dir: disk0/10/16/86/54 datestamp: 2023-04-21 12:44:51 lastmod: 2023-04-21 12:44:51 status_changed: 2023-04-21 12:44:51 type: article metadata_visibility: show sword_depositor: 699 creators_name: Cunningham, MH creators_name: Doel, P creators_name: Brooks, D creators_name: Brynnel, J creators_name: De Jong, RS creators_name: Frey, S creators_name: Schroeck, M creators_name: Gaebler, M creators_name: Sablowski, D creators_name: Barden, SC title: Assembly and alignment of the 4-metre multi-object spectroscopic telescope wide field corrector ispublished: pub divisions: UCL divisions: B04 divisions: C06 divisions: F60 keywords: wide-field multi-object spectrograph facility; visible and infrared survey telescope for astronomy; wide field corrector; 4-metre multi-object spectroscopic telescope note: This version is the version of record. For information on re-use, please refer to the publisher’s terms and conditions. abstract: The 4-metre multi-object spectroscopic telescope (4MOST) is a fiber-fed multi-object spectrograph for the VISTA telescope at the European Southern Observatory (ESO) Paranal Observatory in Chile. The goal of the 4MOST project is to create a general purpose and highly efficient spectroscopic survey facility for astronomers in the 4MOST consortium and the ESO community. The instrument itself will record 2436 simultaneous spectra over a 1/44.2 square deg field of view and consists of an optical wide-field corrector (WFC), a fiber positioner system based on a tilting spine design, and three spectrographs giving both high and low spectral dispersion. The WFC comprises of six lenses grouped into four elements, two of which are cemented doublets that act as an atmospheric dispersion corrector. The first lens element is 0.9 m in diameter while the diameter of the other elements is 0.65 m. For the instrument to meet its science goals, each lens was aligned to be well within 1/4100 μm - a major challenge. This was achieved using contact metrology methods supplemented by pencil beam laser probes. In particular, an off-axis laser beam system has been implemented to test the optics' alignment before and after shipment. This work details the alignment and assembly methods and presents the latest results on the achieved lens positioning and projected performance of the WFC. date: 2023-02-14 date_type: published publisher: SPIE-Intl Soc Optical Eng official_url: https://doi.org/10.1117/1.JATIS.9.1.015002 oa_status: green full_text_type: pub language: eng primo: open primo_central: open_green verified: verified_manual elements_id: 2016946 doi: 10.1117/1.JATIS.9.1.015002 lyricists_name: Doel, Andrew lyricists_name: Brooks, David lyricists_id: APDOE12 lyricists_id: DBROO45 actors_name: Flynn, Bernadette actors_id: BFFLY94 actors_role: owner full_text_status: public publication: Journal of Astronomical Telescopes, Instruments, and Systems volume: 9 number: 1 article_number: 15002 issn: 2329-4124 citation: Cunningham, MH; Doel, P; Brooks, D; Brynnel, J; De Jong, RS; Frey, S; Schroeck, M; ... Barden, SC; + view all <#> Cunningham, MH; Doel, P; Brooks, D; Brynnel, J; De Jong, RS; Frey, S; Schroeck, M; Gaebler, M; Sablowski, D; Barden, SC; - view fewer <#> (2023) Assembly and alignment of the 4-metre multi-object spectroscopic telescope wide field corrector. Journal of Astronomical Telescopes, Instruments, and Systems , 9 (1) , Article 15002. 10.1117/1.JATIS.9.1.015002 <https://doi.org/10.1117/1.JATIS.9.1.015002>. Green open access document_url: https://discovery.ucl.ac.uk/id/eprint/10168654/1/015002_1.pdf