Visible Integral-Field Replicable Unit Spectrographs (VIRUS) E M I - - PowerPoint PPT Presentation

▶

visible integral field replicable

Visible Integral-Field Replicable Unit Spectrographs (VIRUS) E M I - - PowerPoint PPT Presentation

Jan 28, 2023 161 likes •309 views

Production and Alignment of the Visible Integral-Field Replicable Unit Spectrographs (VIRUS) E M I L Y M A R T I N T H A N K S T O : T E X A S A & M U N I V E R S I T Y D R . J E N N I F E R M A R S H A L L P H Y S I C S , 2 0 1 2

slide-1

SLIDE 1

E M I L Y M A R T I N T E X A S A & M U N I V E R S I T Y P H Y S I C S , 2 0 1 2 9 / 2 3 / 2 0 1 1

Production and Alignment of the Visible Integral-Field Replicable Unit Spectrographs (VIRUS)

T H A N K S T O : D R . J E N N I F E R M A R S H A L L D R . D A R R E N D E P O Y

slide-2

SLIDE 2

 Universe is expanding at

accelerating rate

 ~75% of Universe is made up

f Dark Energy

 Thousands of theories to

explain Dark Energy

 Several projects to

investigate effects of Dark Energy upon the universe

Credit: NASA/CXC/M.Weiss

Dark Energy

slide-3

SLIDE 3

Hobby Eberly Telescope Dark Energy Experiment (HETDEX)

 Improve HET focal plane

to 22 arcmin field of view

 Use of ~192 VIRUS

spectrographs

 Large blind survey for

LAEs 1.9<z<3.5 starting in 2012

 Measurement of

expansion rate of Universe to measure evolution of Dark Energy

Credit: Proc. SPIE, Vol. 7735, 20

slide-4

SLIDE 4

Visible Integral-Field Replicable Unit Spectrographs (VIRUS)

 First large scale

replication of spectrographs

 Simple design  Cost efficient  Interchangeable parts

 Over 33,000 fibers will

be fed into the spectrographs

 2 spectrographs per unit

Credit: Proc. SPIE, Vol. 7735, 20

slide-5

SLIDE 5

 Spherical collimator and fold

flat mirror

 Vacuum housed Schmidt

camera

 2 lenses  Spherical mirror  CCD

 VPH grating with wavelength

range of 350-550 nm

 Resolving Power, R~700

Credit: Proc. SPIE, Vol. 7735, 20

slide-6

SLIDE 6

Integral Field Units (IFUs)

 Developed by Astrophysical Institute Potsdam  ~450 fibers per unit head, split between

spectrograph pair

Credit: Proc. SPIE, Vol. 7735, 20

slide-7

SLIDE 7

Production Status

 3 VIRUS structures have been made  Various parts ordered in quantities of 200  Most optical components ordered, including 200

CCDs

 9 IFUs have been made and are being tested

Texas A&M VIRUS team

slide-8

SLIDE 8

VIRUS 3D Layout

slide-9

SLIDE 9

Collimator Alignment

The process:

1.

Auto-Collimation using a 6” round flat mirror in the grating housing

2. Final Adjustment using a large spherical lens to

focus the collimated light on a CCD

slide-10

SLIDE 10

Auto-Collimation

Collimator Fold Mirror Fibers Fold Mirror Grating Housing

slide-11

SLIDE 11

Final Adjustment

Collimator Achromatic Spherical Lens Grating Housing Fibers, Fold Mirror CCD

slide-12

SLIDE 12

Spot Diagrams

Perfectly Aligned Spot Diagram Collimator displaced by 0.1° on Y axis Collimator displaced by 0.1° on X and Y axes 1000 μm 1000 μm 1000 μm

slide-13

SLIDE 13

What’s Next?

 Parts arriving from Oxford  Epoxy/RTV testing on collimator and fold mirror  Alignment of optical components in coming months  Mass assembly of VIRUS collimator units

slide-14

SLIDE 14

Thank You!