FourStar and MMIRS are large infrared instruments that should be opened only in clean environments free of dirt, dust, and condensable volatiles. Their detectors are sensitive to electrostatic discharges so an ESD-safe area is also needed. They will not fit in the existing clean flow bench at the astronomer support building (ASB).
The Magellan Council approved building a cleanroom laboratory facility at Las Campanas to support large infrared instruments. The cleanliness requirement is class 10,000 (a few dozen air changes per hour with fewer than 10,000 particles larger than 0.5 microns per cubic foot). Besides the large infrared instruments, the cleanroom will also be used for smaller instruments such as FIRE and Megacam that might require on-site maintenance.
The clean laboratory will be located next to the existing astronomer support building (ASB) in the gravel area to the right of the low stone wall in the photo below. Its size and expected level of activity prevents it being located at the summit where it would disturb airflow and produce too much warm exhaust air.
Rencoret, who designed and built the astronomer support building, submitted a preliminary plan and cost estimate on 28 March 2006. The original Renecort design enclosed 10 by 18 meters with a clean bay area of 10 x 12 meters and a dirty prep area of 10 x 8 meters.
Photo above: Door and dock lift installed (January 2010)
The LCO laboratory will be modeled after the SAO clean area at Discovery Park in Cambridge, MA. That facility is a windowless high bay within which is a split soft wall class 10,000 cleanroom on wheels. The split allows overhead crane access for instrument assembly.
The floor at SAO is rough concrete painted with a static-dissipative polyurethane paint, although their preference was for a conductive epoxy paint, which is more durable. Around the edge of the room is an exhaust plenum to clear fumes from work areas.
Outside the high bay is an anteroom for indoor unpacking and storage. Two large roll up doors (photo below) lead to the high bay and the loading dock. (There's a third door at SAO that doesn't apply at LCO.) We do not need the vinyl strips seen in the SAO version.
Three distinct areas of the clean lab are described below.
Drawing files for this figure [ DWG | PDF ]
This is the instrument work area. It was designed specifically to support FourStar assembly and MMIRS maintenance.
[Sep 2009 inspection: The above photo was taken from the unpacking area looking into the clean bay. The roll-up doors have not been installed. You can see the crane rail on the ceiling and the cable tray for power, telephone, and data cables.]
Photo above: We erected the clean tent structure, installed the fans and lights, and tested the electrical operation.
Clean tent construction crew (L-R Emilio Cerda, Andy Monson, Miguel Mendez, Nelson Ibacache; Nov 2009)
Photo above: We finished the clean tent assembly and installed electrical service (Jan 2010)
It should be possible to make the clean bay dark. Doors should have light control and it should be possible to switch off lighted signs, etc.
The clean bay minimum floor area is set by FourStar, the near-IR imager. This instrument fits in a rectangular space 10 feet by 6 feet when assembled ("FourStar workspace" in the drawing above).
At a July 12, 2007, phone conference, we determined that a clean space 18 feet by 18 feet enclosed by a splittable soft wall clean room is needed to service FourStar and MMIRS. The cleanroom placement is 3 feet off the back wall of the clean bay (left wall in the drawing above) with 5 to 6 feet on either side (up and down in the figure), but it could be located anywhere in the space. This placement allows a large clear area on one side (to the right in the drawing) that can be used for assembly and maneuvering.
In September 2009, the as-built clean bay area was measured to be 35'-7" by 30'-2".
MMIRS desired a crane hook-height of 14 feet above the floor for assembly. The as-built rail height is 14 feet, placing the hook height somewhat lower (about 27 inches).
MMIRS needs a minimum 3750 lb lift capacity and 14 feet hook height. FourStar requires 2500 lbs lift and 10 feet hook-height but will not need a crane in the clean bay.
A 3-ton crane that traverses the building centerline as shown ("Crane rail") is needed.
We installed a Yale Hoist Y80M03-030S09-V 3-ton hoist with a maximum 9 fpm hook speed, with a motorized 50 fpm trolley (Carnegie PO 32833, purchased from Craneveyor Corp., 1524 N. Potrero Ave, S. El Monte, CA 91733, 626-580-3253). [ Spec sheet and instruction manual ]. In retrospect, we probably would have wanted a slower trolley speed (less than 50 fpm).
The floor is concrete painted with static-dissipative epoxy paint. A base coat in a contrasting color to flag damage was used at SAO. As-built: we did not use a red undercoat.
The walls are drywall with glossy white or near-white paint, insulated to the outside. There are no exterior windows in the clean bay area.
There is a hole in this wall connecting the clean bay with the unpacking room to allow cooling hoses from the FIRE water chiller in the unpacking area to enter the clean bay. A minium 3-inch diameter hole, about 6-inches above floor level, is needed.
The ceiling should be insulated against weather. The downward exposed surfaces should not generate particles. There are no ceiling windows in the clean bay area.
There are three doors. A large roll-up door 12 feet by 12 feet is centered on the wall leading into the unpacking area. This door should be light-tight, or nearly light-tight. A person-door next to the roll-up door connects the clean bay to the unpacking area. This door has a window with a view into the clean bay for collision avoidance. A blackout shade is on the clean bay side of this door window and light seals are installed all around the door.
[Sep 2009 inspection note: The roll-up door is 10 feet by 10 feet, not 12 x 12. We originally anticipated that instruments would get larger as they were assembled in the unpacking area but we decided during a management meeting that a 10x10 door would be adequate. A second person-door planned for location C, an entry into the machine shop, was removed from the plan.]
Overhead lighting should provide 45-50 foot-candles at floor level in all areas. The clean tent will include brighter lighting inside. All overhead lighting is explosion protected. On/off switches near every door. [January 2010: The overhead lights are not protected, but since they are standard fluorescent tubes, we don't expect breakage problems. The on/off switch in the clean bay is inconveniently located a few feet from the person-door.
The most important clean bay environment item is relative humidity to control static charge. A value of about 50% RH should be possible at all times with control resolution of +/-5% in RH within the temperature range 65 F to 75 F. When the clean bay is not in use, humidity control may be turned off.
When in use, the temperature should be about 68 F, adjustable with +/-2 F resolution between 65 F and 75 F. The allowable temperature range when the clean bay is in use is 65 F to 75 F. When the clean bay is not in use, temperature control can be turned off.
Suggestion from Brad Young of Witter Young (Brad@wyhvac.com):
Questions: Is propane available for heating? Is chilled water available for cooling?
[Sep 2009 inspection: HVAC system has not yet been installed.] [Jan 2010: HVAC installed, but we want a new power transformer for the ASB to use it.]
A dry type extinguisher system as used elsewhere on the Magellan site will be installed. We are planning also to install a fire alarm extension to the existing ASB setup.
[Sep 2009 inspection note: The room is equipped with handheld fire extinguishers.]
Clean dry compressed air at 125 psi similar to that at the telescope should be available near locations B and D.
[Sep 2009 inspection note: no air lines were run, but they can be pulled from the adjoining machine shop area. The ASB has its own compressor system.]
Plumbing to supply and return a loop of the usual glycol/water cooling fluid should be available near location B as seen in the drawing above. The cooling fluid will be the same as at the Magellan telescopes, Dow Therm SR-1 glycol, 10%, ambient temperature. Flow rate required is 3 gallons per minute, minimum.
Plumbing to supply MIRAC refrigerator at location B (water?).
[Sep 2009 inspection note: no refrigerant or coolant lines were run, but these can be installed later, as needed.]
A fan-driven exhaust plenum should run along the wall near location D at 8-foot height to exhaust fumes from work benches. A reasonable number of self-closing ports are brought to bench-level. The photo shows the SAO system.
[Sep 2009 inspection note: We did not install an exhaust system; this might limit the kind of work that can be done in the clean area, but we don't expect it to be a problem.]
Here's a summary of special electric power requirements (see also the table below):
At location A, 9 feet above the floor: Three circuits of 20-amp 117 VAC 60 Hz power outlets to power the fans and lights on top of the clean room and to supply instrument dirty power. Two of these circuits power the fans and lights; the third is for instrument use.
At location A, 9 feet above the floor: One 20-amp 117 VAC 60 Hz UPS circuit for instrument power.
At location B, near the floor: One 30-amp 117 VAC 60 Hz single-phase circuit for MMIRS and FourStar power. One 208 VAC, 3-phase, 60 Hz, 30 A circuit for FIRE compressor (same branch as at location G). One 208 VAC, single-phase, 60Hz, 20 A circuit with 6-20 R receptacles for FIRE chiller (may be same branch as at locations G & H).
At location C, 9 feet above the floor: Two circuits of 20-amp 117 VAC 60 Hz power outlets for circulating fans, ionizer bars, and lights in the cleanroom.
At location D, bench height: One strip of 20-amp 117 VAC 60 Hz outlets should be at bench height (about 45 inches above the floor).
At location G, near the floor: One 208 VAC, 3-phase, 60 Hz, 30 A circuit for FIRE compressor (same branch as at location B). One 208 VAC, single-phase, 60Hz, 20 A circuit with L6-20 receptacles for FIRE chiller (may be same branch as at location B & H).
This table summarizes the type and location of unusual power connectors:
| Purpose | Volts | Amps | Phases | Circuit | Location (height), see drawing | Receptacle & McMaster # | Looks like this |
| Softwall cleanroom section 1 | 117 | 20 | 1 | C-11 | C (high) | L5-20 Turn-lock 9081T52 |  |
| Softwall cleanroom section 2 | 117 | 20 | 1 | C-5 | A (high) | L5-20 Turn-lock 9081T52 | |
| Instrument power (use adapter cables if necessary) | 117 | 30 | 1 | C-10 | B (low) | L5-30 Turn-lock 9081T53 |  |
| Vacuum pumps | 117 | 20 | 1 | C-4 | B (low; a near-floor position was added) | 5-20 duplex straight-blade 9096T322 |  |
| FIRE Compressor | 208 | 30 | 3 | C-9 | B (low) and G (low), same circuit, two locations | L21-30 Turn-lock 5-blade 7184K36 or direct wire to FIRE UPS |  |
| FIRE chiller | 208 | 20 | 1 | C-17 | B (mid), G (mid), H (mid; in unpacking area) all same circuit | L6-20 Turn-lock 3-blade 7162K52 |  |
| Computer UPS | 117 | 20 | 1 | C-7 | A (low; a near-floor position was added) | 5-20 duplex straight-blade 9096T322 | |
Crane: Power for the crane, as necessary.
Lighting: Power for lighting, as necessary.
Multiple switched outlets of Cat-5 100 Base-T Ethernet should be available at location A at 9 feet above the floor. The incoming building connection may be different, but Cat-5 should be available to run into the clean room. A row of connections should also be placed at bench height on the wall indicated by location D.
Wireless networking should also cover the entire space.
Two separate telephone circuits should be available in the clean bay. One at location A 9 feet above the floor for hookup inside the clean tent and one at location E near the entrance.
The soft wall cleanroom splits along a centerline to allow crane access. Specifications are in this drawing (PDF version):
The clean tents were manufactured by Pacific Environmental Technologies (http://www.peticleanair.com). The construction is as if there are two independent softwall cleanrooms, each missing a wall. Links to drawings and the packing list for the two softwall cleanrooms are shown below. We moved the gowning area from the position shown above to the location shown in the as-built drawing to accomodate MMIRS movement into and out of the area.
1. F-01.1_(INSTALL-PLN1).pdf (small section)
2. F-01.2_(INSTALL-PLN2).pdf (large section)
3. F-02.0_(DETAILS).pdf (details for both)
4. F-03.0_(DETAILS).pdf (more details for both)
A description of the clean bay furniture and accessories will appear later. We plan to ship the flow bench and some contents from the Pasadena FourStar cleanroom for use in this facility.
Photo above: A lab table, medium-sized cart, shelving, and chair are in the clean area. A laminar flow bench is being shipped. (Jan 2010)
This room isolates gross dirt and packing materials from the clean bay. Some instrument assembly will happen here, too. It is well-lit and has a fixed hoist at the center. We anticipate this area will be used for temporary storage and unpacking work. No workbenches or office space is needed here.
[Sep 2009 inspection note: The photo above shows Francisco Figueroa in the unpacking area with the exterior roll-up door to the left, the clean bay to the right.]
The unpacking room is 15 feet wide and 30 feet long. We need enough floor space for empty shipping containers plus their contents.
[Sep 2009 inspection note: The room is 15' by 32'.]
MMIRS requires room for a hoist with 14-foot hook height here.
[Sep 2009 inspection note: The crane rail is 14 feet above the floor, making the hook height less than 12 feet (the hook is 27 inches below the rail).]
MMIRS needs a minimum 3750 lb lift capacity and 14 feet hook height. FourStar requires 2500 lbs lift capacity, fixed, with a hook height of 10 feet in this area. We suggest a 3-ton lift capacity, minimum.
A 3-ton crane, minimum, with a 16 foot hook height, minimum, that traverses the building centerline as shown ("Crane rail," but see the note above). We will install a Yale Hoist Y80P03-030S09-V 3-ton hoist with a maximum 9 fpm hook speed (Carnegie PO 32833, purchased from Craneveyor Corp., 1524 N. Potrero Ave, S. El Monte, CA 91733, 626-580-3253). This is almost the same as the hoist in the clean bay (the trolley is not motorized and runs on a different sized track). [ Spec sheet and instruction manual ]
Smooth concrete, bare. [Sep 2009 inspection note: The floor in this area is painted with a continuation of the paint in the clean bay.]
Finish is the same as for the clean bay. There are no windows on this wall.
There is a pass-through (hole) in this wall that connects the clean bay with the unpacking room. This hole allows cooling hoses from the FIRE water chiller in the unpacking area to enter the clean bay. A minium 3-inch diameter hole, about 6-inches above floor level.
Insulated; otherwise no special requirements.
Doors to the clean bay are described above in the clean bay description. There is a 10-foot by 10-foot roll-up door facing the loading dock and a person-door adjacent to it. The person-door has a large landing outside so we can easily carry boxes and equipment into the unpacking room through the person-door.
[Sep 2009 inspection note: The person-door was moved to the wall on the parking lot and the stairs were not installed. The ground level of the lab is near the ground level of the exterior pavement so stairs were not necessary.]
Two levels of lighting should be available: 25 foot-candles for safety, 75 foot-candles for work. All lighting is explosion proof.
Same as the clean bay except RH control is not necessary.
Same as the clean bay. [Sep 2009 inspection note: There are hand operated portable fire extinguishers installed; no sprinker system.]
Compressed air at 125 psi should be available near location F. [Sep 2009 inspection note: compressed air will need to be installed later.]
A stainless steel sink with hot and cold water should be installed at location F. This location should be suitable for small parts cleaning. [Sep 2009 inspection note: Only cold water.]
Multiple circuits of 117 VAC (US) and 220 VAC (Chilean standard) wall outlets around the perimeter.
At location H, near the floor: One 208 VAC, single-phase, 60Hz, 20 A circuit with 6-20 R receptacles for FIRE chiller (may be same branch as at locations B & G). [Jan 2010: All circuits are 60 Hz, including Chilean standard voltages.]
Hardwired telephone and Ethernet connections should be available at a convenient locations inside the unpacking room. Wireless networking should also be installed.
A 12-foot wide by 13-foot deep loading dock is shown. Most of this space is occupied by a 12 foot by 8 foot dock lift. Minimum requirement is 3 ton capacity; suggest 5 tons. It is possible that with a lift this large we might not need a loading dock; just the roll-up door and the steps and landing to a person-door.
The loading dock is covered for protection from direct sunlight from late morning to mid-afternoon at least six feet from the building wall.
The dock lift is a Pentalift model HED 81212 (click the image for PDF versions):
The dock lift was ocean-shipped from a US distributor and arrived in Chile on September 22, 2009 by ocean. It was trucked to La Serena on September 23, 2009.
Instrument movement will be on wheeled carts or crates throughout the building. The three sections should all be at the same level with no steps required to go from one area to the next. Floor seams should be covered with thresholds that do not impede rolling heavy instrumentation.
| Revision | Date | Changes | Authors |
| 100128 | 2010.01.27 | Updated the softwall cleanroom drawing for mods made in January 2010 | Uomoto |
| 091211 | 2009.12.11 | Added anchor to electric outlet table | Uomoto |
| 091202 | 2009.12.02 | Added electric receptacle details | Uomoto |
| 091008 | 2009.10.08 | Added as-built clean tent drawings & packing list, crane specifications | Uomoto |
| 090924 | 2009.09.24 | Minor edits; added arrival date of dock lift, photos | Uomoto |
| 090911 | 2009.09.11 | Added PETI cleanroom drawings (F-01.1.pdf and F-01.2.pdf) | Uomoto |
| 090723 | 2009.07.23 | Increased cleanroom ceiling height to 8.5 feet to accommodate FIRE | Uomoto |
| 090506 | 2009.05.06 | Added truck dock (Pentalift) drawings | Uomoto, Perez |
| 090429 | 2009.04.29 | Modified softwall cleanroom drawing details | Uomoto |
| 090421 | 2009.04.21 | Modified interior door size to reflect earlier decision, added Simcoe requirements for power and coolant | Uomoto, Simcoe |
| 080813 | 2008.08.13 | Small edits; emphasize ESD safety | Persson |
| 071004 | 2007.10.04 | Added notes in "Environment" section | Uomoto |
| 070816 | 2007.08.16 | Removed option for windows on the separating wall | Uomoto |
| 070719 | 2007.07.19 | FourStar flow bench, coolant update, environmental update | Perez, Persson |
| 070717 | 2007.07.17 | Added clean bay dark requirements, door descriptions, FIRE and MIRAC | McLeod, Uomoto |
| 070716 | 2007.07.16 | Wider dock lift (MMIRS needs 8 feet wide), added cleanroom description, wireless networking, back door | Osip, Persson, Uomoto |
| 070713 | 2007.07.13 | Modified crane requirements, re-sized clean tent, rearranged power distribution | McLeod, Murphy, Nystrom, Osip, Perez, Persson, Smee, Uomoto |
| 070711 | 2007.07.11 | Added links to AutoCad files | Uomoto |
| 070710 | 2007.07.10 | First draft | Uomoto |