Spares / Limited Life / Consumables List

Replacement Difficulty Key:

VERY DIFFICULT	Instrument will be off-line while this replacement happens.
MEDIUM DIFFICULTY	Some care required, or extended time required for replacement
EASY	Component easily accessible with minimal time required for replacement. Partial or no instrument down-time required for change.
OPTICAL REALIGNMENT	Note indicating an optical realignment or verification is required after the component is replaced.

Subsystem	Item Description	Manufacturer & Part Number	QTY in System	Cost / Lead Time*	Replacement Difficulty	Replacement Notes	General Notes	Spares in Hand?	Impact of Failure
FIU	ADC Prism Rotators	Micronix PR-50-C0017	2x	$5,500 ea / 10-12 weeks	VERY DIFFICULTOPTICAL REALIGNMENT	Requires: removing FIU from AO Bench, opening FIU, removing rotator(s) from FIU, removing prism cell from rotator.		None	MAJOR IMPACT ADC correction would be impossible, leading to loss of blue and red flux within science spectra. Radial velocity precision would be impacted.
FIU	H&K Fiber Stage	Micronix PPX-32CR-C0002	1x	$4,500 ea / 10-12 weeks	VERY DIFFICULTOPTICAL REALIGNMENT	Requires: removing FIU from AO Bench, opening FIU, removing Ca HK fibers from stage, removing stage from FIU.		None	MEDIUM IMPACT Throughput of Ca HK spectrometer would diminish, likely to a point were spectra do not have enough flux to be useful. Main spectrometer and rest of system would be unaffected.
FIU	Calibration Fold Mirror Stage	Micronix PPS-20-C0035	1x	$4,400 ea / 10-12 weeks	VERY DIFFICULT OPTICAL REALIGNMENT	Requires: removing FIU from AO Bench, opening FIU, removing stage from FIU ensuring mirror is located properly after new stage is installed.		None	MAJOR IMPACT If it failed out-of-beam: We would not be able to calibrate the main spectrometer and monitor instrument drift. If it failed in-beam: Light from the telescope would be blocked.
FIU	Guide Detector	First Light Advanced Imagery C-RED 2	1x	$39k / 6 weeks	VERY DIFFICULT	Requires removing the FIU from the AO Bench to gain access to detector.		None	MAJOR IMPACT Would not be able to guide on a star with the accuracy required for radial velocity measurements.
Ca HK	Ca HK Detector	Andor Newton 920 (with UV-optimized CCD)	1x	$37k / 12 weeks	MEDIUM DIFFICULTY	Requires opening Ca HK Spectrometer (after swinging it to a horizontal state).		None	MEDIUM IMPACT Ca HK Spectrometer would not be usable if detector failed. Main spectrometer and rest of system would be unaffected.
Cal Unit	Octagon Stepper Motor	Thorlabs NR360S	1x	$2,700	VERY DIFFICULT OPTICAL REALIGNMENT	The rotation stage is accessible on the outside of the Calibration Bench, and mechanically this is a straightforward change. The difficulty lies in re-aligning the fold mirror mounted on the rotation stage, so that is directs the light from all sources onto the various fibers.		None	MAJOR IMPACT At best this would allow use of only one calibration source. However, it would likely take the entire Calibration Unit off-line We would not be able to calibrate the main spectrometer and monitor instrument drift.
Cal Unit	ThAr Lamp	Green Scientific G858A	2x (1x Daily, 1x 'Gold')	$405	EASY	The lamps are easily accessible on the exterior of the Calibration Unit.	Consumable item.	1 spare	If one lamp fails: MINOR IMPACT we can rely on the other lamp of the same type until replacement arrives. If both lamps of the same type fail: MEDIUM IMPACT we lose ability to wavelength-calibrate daily, and will have to rely on past calibrations. Radial velocity precision might be impacted.
Cal Unit	UNe Lamp	Photron P863	2x (1x Daily, 1x 'Gold')	$825	EASY	The lamps are easily accessible on the exterior of the Calibration Unit.	Consumable item.	4 spares
Cal Unit	HCL Power Supply	Photron P209 Hollow Cathode Lamp Power Supply and Green Scientific G200	4x (1x Th-Ar Daily, 1x Th-Ar Gold, 1x U-Ne Daily, 1x Un-Ne Gold)	Green Scientific Supply: $730	EASY	The HCL power supplies are easily accessible within the Calibration Rack.		1x Green Scientific Power Supply	If one supply fails: MINOR IMPACT we can rely on the other lamp of the same type until replacement arrives. If two supplies of the same type fail: MINOR IMPACT we could swap supplies around to have one lamp of each type operational until replacement arrives. If three supplies fail: MEDIUM IMPACT we lose ability to wavelength-calibrate daily, and will have to rely on past calibrations. Radial velocity precision might be impacted.
Cal Unit	Broadband Source	Thorlabs SLS201L	2x (1x Octagon, 1x Flat Field)	$1,200 No lead (June 2023)	EASY	The broadband sources are easily accessible under the Calibration Bench.	Consumable item.	None	MEDIUM IMPACT Would lose some calibration ability but could rely on past calibrations until replacement available. (True?)
Cal Unit	Intensity Monitor Stage	Newmark MSL-50-21	1x	$1,100	MEDIUM DIFFICULTY	Mechanically the stage is easy to remove, and the intensity monitor detector is simply mounted (on a post with no careful alignment requirements). Marked as medium difficulty given the care required to avoid damaging the bare optical fibers within the Calibration Unit enclosure.		None	MINOR IMPACT If stage failed out-of-beam, it could stay there until replaced. If stage failed in-beam, it could be removed from system until replacement is available.
Cal Unit	Filter Wheel	Thorlabs FW102C	3x (1x Octagon, 1x Flat Field)	$1,300 No lead (June 2023)	MEDIUM DIFFICULTY	Mechanically the filter wheels are easy to remove with no careful alignment requirements. Marked as medium difficulty given the care required to avoid damaging the bare optical fibers within the Calibration Unit enclosure.		None	MEDIUM IMPACT Would require a change in calibration strategy (and scripts) but could likely carry on until replacement filter wheel arrived.
Cal Unit	Compensator Motor	Newport TRA12PPD	4x (2x BS, 2x Fold)		Need TBD
Cal Unit	Shutters	Uniblitz DSS25B	6x (2x Cal Bench, 1x Flat Field, 2x SoCal, 1x HK)	$540 ea / 4-5 weeks	MEDIUM DIFFICULTY	The various shutters are designed to be easily removable from their mounts. Marked as medium difficulty given time required to open the enclosure to access shutter, and care required while working around exposed optics and fibers.	Consumable item.	3 spares	If the Calibration shutters fail: MAJOR IMPACT We would no longer be able to calibrate the main spectrometer or track instrument drift. If the SoCal, HK Spectrometer, or Flat Field Fiber shutters fail: MEDIUM IMPACT The main spectrometer would be unaffected.
Cal Unit	Etalon Super Continuum	NKT SuperK EVO	1x	$33.5k for new device, $8.5k to refurbish existing device. Lead time: 4-6 weeks.	EASY	The SuperK is easily accessible within Etalon Rack.	Consumable item.	None	MEDIUM IMPACT If etalon not available, calibrations will have to lean more heavily on the LFC and the HCL lamps. Using the LFC instead of the etalon is more expensive, as it leads to more frequent PCF fiber replacements in the LFC.
Exposure Meter	Exposure Meter Detector	SBIG Aluma 47-10	1x	$15k / 6-8 weeks	MEDIUM DIFFICULTY	Requires opening the Exposure Meter enclosure. Detector is on mounting that is designed to be removable.		None	MEDIUM IMPACT Main spectrometer would remain operational, however, ability to monitor flux within science exposures would be lost. RV quality would suffer because precise exposure midtimes could not be computed.
LFC	PCF Fiber	Menlo Systems	1		MEDIUM DIFFICULTY	Brett Smith (WMKO) installed the replacement when the PCF fiber failed. He said it took about an hour, but one needs to be slow and methodical. Covers, module, output fibers are removed one of which, the IR, is in a tight space. PCF module location is set by pins.	Consumable item.	None	MEDIUM IMPACT LFC cannot be used until replaced. Calibrations will have to lean more heavily on the etalon and the HCL lamps while LFC down; could compromise tracking of instrument stability
Fiber System	Scrambler Timed Shutter	Uniblitz NS65B	1x	$1,280 / 4-5 weeks	MEDIUM DIFFICULTY	This shutter is designed to be easily removable from the scrambler. Marked as medium difficulty given time required to open the enclosure to access the shutter, and care required while working around exposed optics and fibers.	Consumable item.	1 spare	MAJOR IMPACT This shutter controls the exposure time of the main spectrometer. Would not be able to take spectra until shutter is replaced.
Fiber System	Scrambler Source Select Shutter	Uniblitz RS20B	2x	$550 each (minimum quantity was 10 last time we ordered). Lead time: 5-6 weeks	MEDIUM DIFFICULTY	These shutters are designed to be easily removable from the scrambler. Marked as medium difficulty given time required to open the enclosure to access the shutters, and care required while working around exposed optics and fibers.	Consumable item.	10 spares	MEDIUM IMPACT If one of these shutters fails in a closed state, that light path (Science or Sky) cannot be used until the shutter is replaced.
Fiber System	Agitator Motor	Galil BLM-N23-50-1000-B	1x	$500 / 1-2 weeks (in 2018)	MEDIUM DIFFICULTY	Motor is accessible on the outside of the agitator. A flex coupling is used between the motor and the agitator mechanism, so no careful alignment required. Marked as medium difficulty given the agitator is located within the crypt (not easily accessible and potential permits required).		None	MEDIUM IMPACT Observations could continue however the radial velocity precision will be impacted.
Vac Cart	Turbo Pump	Leybold TurboVac 450iX	1x	$7,700	VERY DIFFICULT	Vacuum chamber gate valve must be closed, and Vac Cart enclosure opened to replace pump. Vacuum pressure within chamber will be rising during this time (affecting instrumental stability), making this replacement time-sensitive. A WMKO turbo cart could be connected to the chamber during the replacement to help minimize the vacuum pressure change.		None	MAJOR IMPACT Chamber would start to lose vacuum pressure During time required to obtain replacement pump, vacuum pressure would rise significantly and reset the instrumental stability time series.
Vac Cart	Roots Pump	Leybold EcoDry 65 Plus	1x	$9,600	VERY DIFFICULT	Vacuum chamber gate valve must be closed, and Vac Cart enclosure opened to replace pump. Vacuum pressure within chamber will be rising during this time (affecting instrumental stability), making this replacement time-sensitive. A WMKO turbo cart could be connected to the chamber during the replacement to help minimize the vacuum pressure change.		None	MAJOR IMPACT Chamber would start to lose vacuum pressure During time required to obtain replacement pump, vacuum pressure would rise significantly and reset the instrumental stability time series.
Vac Cart	Isolator Stepper Motors	Lin Engineering 4118M-06S-22RO	5x		VERY DIFFICULT	Requires warming up CCDs, venting main spectrometer vacuum chamber, and opening chamber door(s) to gain access to the motors under the optical bench. Depending on the motor’s location, the Vac Cart, Aux Rack and LN2 Autofill system might need to be disconnected and moved out of the way so the chamber door can open.	Used very infrequently (mainly for initial alignment of bench or realigning after a significant earthquake). Powered off when not in use.	None	SMALL IMPACT Loss of one motor could likely be compensated for through adjustment of the other four. It is very unlikely we would vent the chamber only to replace one of these motors.
Aux Rack	Cryostat Ion Pumps	Gamma 3SDI1V5KNN (3S TiTan)	4x	$770 / 6-7 weeks	VERY DIFFICULT	Requires warming up CCDs, venting main spectrometer vacuum chamber, and removing the large camera-access flange on the side of the vacuum chamber. The ion pumps can be “re-conditioned” at WMKO and re-used.	500 hours at 1e-4mbar 5,000 hours at 1e-5mbar 50,000 hours at 1e-6mbar 500,000 hours at 1e-7mbar	None	Each cryostat has two ion pumps. If one fails: SMALL IMPACT If both fail: MAJOR IMPACT CCD thermal control will be lost
Aux Rack	LN2 Pumps	Instec LN2-SYS	2x		MEDIUM DIFFICULTY	The pumps are easily accessible on the LN2 cart in the basement. Marked as medium difficulty given the steps involved: power down the appropriate Instec controller; connect the new pump and power it on; turn the Instec controller back on; ensure Instec set point is correct and temperature control enabled. There is also some risk involved, as care must be taken to avoid water vapor getting into the lines (leading to ice blocking the lines). If ice blocks the lines then the CCD must be warmed up and the lines purged (with a major disruption to the instrument stability timeline).		1 brand-new spare; 1 used spare	MAJOR IMPACT CCD thermal control cannot be maintained with the LN2 pump running. The CCD will start to warm up.
Aux Rack	Instec Controller	Instec mK2000B	2	$5000 / 4-6 weeks	MEDIUM DIFFICULTY	The pumps are easily accessible on the LN2 cart in the basement. Marked as medium difficulty given the software steps involved: power down the appropriate Instec controller and disconnect cables; connect the new controller and power it on; ensure Instec set point is correct and temperature control enabled.		1 spare has been ordered	MAJOR IMPACT CCD thermal control cannot be maintained without the Instec system running. The CCD will start to warm up.
LN2 Cart	Autofill Solenoids		2x		Have asked John Valiant for details