HARPS at La Silla

team The HARPS Integration Team was very busy at La Silla!
HARPS at La Silla, still without cables and fibres

HARPS at Geneva

closed HARPS closed
open HARPS open
another HARPS at Preliminary Acceptance Europe

Individual HARPS components

Cassegrain Fibre Adapter

HCFA The HARPS Cassegrain Fibre Adapter
1 The HARPS Cassegrain Fibre Adapter as seen from above (telescope side)
The variable neutral density filter in the Cassegrain fibre adapter. It is used to balance the flux between the star (fibre A) and the ThAr lamp (fibre B) independent of the exposure time

Fibre link, image scrambler

A view of the fibre end in the Cassegrain fibre adapter. The long protective tube at the lower end of the HCFA has been removed to show the fibre head.
fibre link The fibre link entering the HARPS room. The ``shower tubes'' protect the sensible fibres against mechanical damage. One tube (the one bending downward) contains the two science fibres, the other two contain one calibration fibre each which send the light from the calibration unit (next to the instrument) up to the Cassegrain fibre adapter on the telescope.
scrambler The double image scrambler, for both the star and reference light fibres (green)
A direct vacuum feed-through with two fibres, so far used for test purposes

Vacuum vessel with spectrograph

bench The plain spectrograph bench, still at the factory
Inside the spectrograph bench, below the echelle grating (visible at the top): the fibre entrance for the spectrograph. The fibre bundle (containing both the star and the reference fibre) with black protective sleev, coming from upper right.
Above the fibre head one can see the plane folding mirror re-directing the light from the upper part of the collimator back to the lower part of the collimator (see the optical scheme)
Looking towards the fibre head from the position of the collimator mirror. On top, the echelle, between the echelle and the fibre head, the plane folding mirror.
optics partly installed The spectrograph before the installation of the echelle grating. The small mirror of the exposure meter and the large collimator are visible on the left side.
HARPS optics The spectrograph optics fully installed. From left to right: echelle grating (back view), mirror for the exposure meter, collimator.
spectrograph View towards the detector side of HARPS with the grating side of the echelle well visib.le
echelle The HARPS echelle grating during the tests performed in the ESO Garching optical laboratory.
echelle The echelle now installed in the spectrograph.
collimator The HARPS collimator mirror
collimator The HARPS collimator mirror, ready to be installed in the instrument
The collimator mirror installed at the end of the spectrograph bench. The small mirror in front of it (with a part cut off) is the mirror focusing light on the exposure meter.
The HARPS cross disperser grism before mounting
cross disperser The HARPS cross disperser grism already installed under/inside the spectrograph bench
camera The HARPS camera
camera focusing The focusing mechanism of the camera. It is fixed before the vacuum vessel is closed. The spectrograph cannot be focused during operations.
2 The HARPS vacuum vessel

Detector system

cryostat The complete HARPS detector cryostat before installation in the instrument. The bellows connecting the continuous flow cryostat (right) with the actual detector head (left; it will be in the spectrograph vacuum when finally installed) is still stabilised by some stiffening bars. The vacuum flange (bottom) is a mock-up which will later be replaced by a flange on the vacuum vessel.
mosaic The detector mosaic during the mounting and alignment procedure in the Garching ODT laboratory
mosaic The detector mosaic mounted and ready inside the cryostat, well visible behind the entrance window of the cryostat which also serves as the field lens.
The inside of the continuous flow cryostat, during final integration at La Silla. Liquid nitrogen cools the detector mosaic to about 148K.
The detector system during final integration at La Silla. The continuous flow cryostat is being attached to the bellows which connects it to the detector head containing the CCD mosaic (bottom, on the table).
A view of the detector system mounted on the optical bench of the spectrograph, prior to the addition of the vacuum vessel. The black cylinder is the camera.
cryostat on bench The detector system mounted on the spectrograph bench just before the front end of the vacuum vessel is closed.
The detector system installed in the vacuum vessel. The HARPS system is special in that the detector head (the shiny cylinder left of the centre) is inside the vacuum of the spectrograph and all cables have to be fed through the vessel wall. In front of the field lens one can see the three bars of the focusing mechanism. They determine the distance and tilt of the CCD mosaic with respect to the camera (right). They are set once during the integration and test phase to the correct focus and are then locked. No focusing during operations is possible - or necessary!
The electronics rack containing the CCD controller (FIERA) and the controls for the detector temperature, cryostat and vessel vacuum. In the foreground is the pump stand for the detector and spectrograph vacuum.

Miscellaneous items

calibration unit The calibration unit: the calibration lamps with fibre selection slide (upper left)
calibration unit The calibration unit (external view)
2 The Iodine absorption cell to be mounted inside the Cassegrain Fibre Adapter. A second one will be mounted in the calibration unit.
The complete assembly of the iodine cell in the HCFA
The iodine cell partly moved outside of its protective housing, into the telescope beam.
The iodine cell itself
Another view of the iodine cell
The iodine cell assembly built into the HCFA
exposure meter The exposure meter consisting of two photomultipliers.
The exposure meter uses the light picked up by the long thin mirror in front of the gap separating the two parts of the echelle mosaic. No light is lost by this design
enclosure The climatized enclosure which houses the spectrograph.
The turbo-molecular and rotary pumps used to keep a good vacuum in the spectrograph vacuum vessel and in the detector head. In the background is the liquid nitrogen dewar for the cooling of the detector.
2 A new high performance cable, patent pending! HARPS will be able to measure if a star moves at a speed of one of the black cable parts per second!