Paper: Overview of the Instrumentation for the Dark Energy Spectroscopic Instrument
Authors: DESI Collaboration, B. Abareshi, J. Aguilar, S. Ahlen, Shadab Alam, David M. Alexander, R. Alfarsy, L. Allen, C. Allende Prieto, O. Alves, J. Ameel, E. Armengaud, J. Asorey, Alejandro Aviles, S. Bailey, A. Balaguera-Antolínez, O. Ballester, C. Baltay, A. Bault, S. F. Beltran, B. Benavides, S. BenZvi, A. Berti, R. Besuner, Florian Beutler, D. Bianchi, C. Blake, P. Blanc, R. Blum, A. Bolton, S. Bose, D. Bramall, S. Brieden, A. Brodzeller, D. Brooks, C. Brownewell, E. Buckley-Geer, R. N. Cahn, Z. Cai, R. Canning, R. Capasso, A. Carnero Rosell, P. Carton, R. Casas, F. J. Castander, J. L. Cervantes-Cota, S. Chabanier, E. Chaussidon, C. Chuang, C. Circosta, S. Cole, A. P. Cooper, L. da Costa, M.-C. Cousinou, A. Cuceu, T. M. Davis, K. Dawson, R. de la Cruz-Noriega, A. de la Macorra, A. de Mattia, J. Della Costa, P. Demmer, M. Derwent, A. Dey, B. Dey, G. Dhungana, Z. Ding, C. Dobson, P. Doel, J. Donald-McCann, J. Donaldson, K. Douglass, Y. Duan, P. Dunlop, J. Edelstein, S. Eftekharzadeh, D. J. Eisenstein, M. Enriquez-Vargas, S. Escoffier, M. Evatt, P. Fagrelius, X. Fan, K. Fanning, V. A. Fawcett, S. Ferraro, J. Ereza, B. Flaugher, A. Font-Ribera, J. E. Forero-Romero, C. S. Frenk, S. Fromenteau, B. T. Gänsicke, C. Garcia-Quintero, L. Garrison, E. Gaztañaga, F. Gerardi, H. Gil-Marín, S. Gontcho A Gontcho, Alma X. Gonzalez-Morales, G. Gonzalez-de-Rivera, V. Gonzalez-Perez, C. Gordon, O. Graur, D. Green, C. Grove, D. Gruen, G. Gutierrez, J. Guy, C. Hahn, S. Harris, D. Herrera, Hiram K. Herrera-Alcantar, K. Honscheid, C. Howlett, D. Huterer, V. Iršič, M. Ishak, P. Jelinsky, L. Jiang, J. Jimenez, Y. P. Jing, R. Joyce, E. Jullo, S. Juneau, N. G. Karaçaylı, M. Karamanis, A. Karcher, T. Karim, R. Kehoe, S. Kent, D. Kirkby, T. Kisner, F. Kitaura, S. E. Koposov, A. Kovács, A. Kremin, Alex Krolewski, B. L'Huillier, O. Lahav, A. Lambert, C. Lamman, Ting-Wen Lan, M. Landriau, S. Lane, D. Lang, J. U. Lange, J. Lasker, L. Le Guillou, A. Leauthaud, A. Le Van Suu, Michael E. Levi, T. S. Li, C. Magneville, M. Manera, Christopher J. Manser, B. Marshall, Paul Martini, W. McCollam, P. McDonald, Aaron M. Meisner, J. Mena-Fernández, J. Meneses-Rizo, M. Mezcua, T. Miller, R. Miquel, P. Montero-Camacho, J. Moon, J. Moustakas, E. Mueller, Andrea Muñoz-Gutiérrez, Adam D. Myers, S. Nadathur, J. Najita, L. Napolitano, E. Neilsen, Jeffrey A. Newman, J. D. Nie, Y. Ning, G. Niz, P. Norberg, Hernán E. Noriega, T. O'Brien, A. Obuljen, N. Palanque-Delabrouille, A. Palmese, P. Zhiwei, D. Pappalardo, X. PENG, W. J. Percival, S. Perruchot, R. Pogge, C. Poppett, A. Porredon, F. Prada, J. Prochaska, R. Pucha, A. Pérez-Fernández, I. Pérez-Ràfols, D. Rabinowitz, A. Raichoor, S. Ramirez-Solano, César Ramírez-Pérez, C. Ravoux, K. Reil, M. Rezaie, A. Rocher, C. Rockosi, N. A. Roe, A. Roodman, A. J. Ross, G. Rossi, R. Ruggeri, V. Ruhlmann-Kleider, C. G. Sabiu, S. Gaines, K. Said, A. Saintonge, Javier Salas Catonga, L. Samushia, E. Sanchez, C. Saulder, E. Schaan, E. Schlafly, D. Schlegel, J. Schmoll, D. Scholte, M. Schubnell, A. Secroun, H. Seo, S. Serrano, Ray M. Sharples, Michael J. Sholl, Joseph Harry Silber, D. R. Silva, M. Sirk, M. Siudek, A. Smith, D. Sprayberry, R. Staten, B. Stupak, T. Tan, Gregory Tarlé, Suk Sien Tie, R. Tojeiro, L. A. Ureña-López, F. Valdes, O. Valenzuela, M. Valluri, M. Vargas-Magaña, L. Verde, M. Walther, B. Wang, M. S. Wang, B. A. Weaver, C. Weaverdyck, R. Wechsler, Michael J. Wilson, J. Yang, Y. Yu, S. Yuan, Christophe Yèche, H. Zhang, K. Zhang, Cheng Zhao, Rongpu Zhou, Zhimin Zhou, H. Zou, J. Zou, S. Zou, Y. Zu
Figure caption: Schematic of one spectrograph that shows the optical design and mechanical structures in each spectrograph. Light enters the spectrograph at the fiber slit array and is directed toward the collimator mirror through a slot in the NIR dichroic, and the collimated light is reflected directly back toward the NIR dichroic. Light in the NIR channel (747–980 nm) passes through the NIR dichroic, is dispersed by the NIR VPH grating, and enters the NIR camera. Shorter wavelength light is reflected off the NIR dichroic and encounters the red dichroic. Blue light (360–593 nm) reflects off the red dichroic, is dispersed by the blue VPH grating, and enters the blue camera. Red light (560–772 nm) passes through the red dichroic, is dispersed by the red VPH grating, and enters the red camera. The exposure shutter is immediately after the fiber slit array in the optical path. There is a second (NIR) shutter before the NIR VPH grating, which is closed when the fiber illumination system is in use. All of the spectrographs are identical.