Alignment and Testing of a Telecentric Zoom Lens Used for the Cygnus X-ray Source

Conference · Sun Sep 01 00:00:00 EDT 2013 · Proc. SPIE 8844, Optical System Alignment, Tolerancing, and Verification VII

DOI:https://doi.org/10.1117/12.2022768· OSTI ID:1136418

Malone, R. M. ^[1]; Baker, S. A. ^[1]; Brown, K. K. ^[1]; Castaneda, J. J. ^[1]; Curtis, A. H. ^[1]; Danielson, J. ^[1]; Droemer, D. W. ^[1]; Esquibel, D. L. ^[1]; Haines, T. J. ^[2]; Hollabaugh, J. S. ^[1]; Howe, R. A. ^[1]; Huerta, J. A. ^[1]; King, N. S. P. ^[2]; Lutz, S. S. ^[1]; Kaufman, M. I. ^[1]; McGillivray, K. D. ^[1]; Smith, A. D. ^[1]; Stokes, B. M. ^[1]; Tibbitts, A. ^[1]

---

1. NSTec
2. LANL

Cygnus is a high-energy radiographic x-ray source. Three large zoom lenses have been assembled to collect images from large scintillators. A large elliptical pellicle (394 × 280 mm) deflects the scintillator light out of the x-ray path into an eleven-element zoom lens coupled to a CCD camera. The zoom lens and CCD must be as close as possible to the scintillator to maximize light collection. A telecentric lens design minimizes image blur from a volume source. To maximize the resolution of objects of different sizes, the scintillator and zoom lens are translated along the x-ray axis, and the zoom lens magnification changes. Zoom magnification is also changed when different-sized recording cameras are used (50 or 62 mm square format). The LYSO scintillator measures 200 × 200 mm and is 5 mm thick. The scintillator produces blue light peaking at 435 nm, so special lens materials are required. By swapping out one doublet and allowing all other lenses to be repositioned, the zoom lens can also use a CsI(Tl) scintillator that produces green light centered at 540 nm (for future operations). All lenses have an anti-reflective coating for both wavelength bands. Two sets of doublets, the stop, the scintillator, and the CCD camera move during zoom operations. One doublet has x-y compensation. Alignment of the optical elements was accomplished using counter propagating laser beams and monitoring the retro-reflections and steering collections of laser spots. Each zoom lens uses 60 lb of glass inside the 425 lb mechanical structure, and can be used in either vertical or horizontal orientation.

• Research Organization: Nevada Test Site (NTS), Mercury, NV (United States)
• Sponsoring Organization: USDOE National Nuclear Security Administration (NNSA)
• DOE Contract Number: DE-AC52-06NA25946
• OSTI ID: 1136418
• Report Number(s): DOE/NV/25946-1845
• Journal Information: Proc. SPIE 8844, Optical System Alignment, Tolerancing, and Verification VII, Vol. 8844; Conference: SPIE Conference on Penetrating Systems and Applications XIV, San Diego, CA; August 25-29, 2013
• Country of Publication: United States
• Language: English

Related Subjects

zoom lens
telecentric lens design
optical metrology
optical alignment