Content Comparison

• 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

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

• 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

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

• 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)

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

• Observations could continue however the radial velocity precision will be impacted.

Vac Cart

Turbo Pump

Leybold TurboVac 450iX

1x

$7,700

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

• 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

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

• 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

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

• 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

Gamma 3SDI1V5KNN (3S TiTan)

4x

$770 /
6-7 weeks

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:

  Status
  colour Green title minor impact

• If both fail:

  Status
  colour Red title major impact

  • CCD thermal control will be lost

Aux Rack

LN2 Pumps

Instec LN2-SYS

2x

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

Each cryostat has two ion pumps.

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

• 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

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

• CCD thermal control

Aux Rack

LN2 Pumps

Instec LN2-SYS

• cannot be maintained without the Instec system running. The CCD will start to warm up.

LN2 Cart

*updated*

Autofill System

2x solenoids

The

solenoids and other components are

accessible on the LN2

• 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.

cart in the basement. Marked as medium difficulty given there is 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).

3x Solenoids

Also shared spares available for:

• Maple PLC (and HMI and I/O modules

• temperature sensors

• pressure transducers

• CCD thermal control cannot be maintained with the LN2 pump runningwithout LN2 in the KPF dewars. The CCD will start to warm up.

Aux Rack

Instec Controller

Instec mK2000B

2

Computer

*updated*

kpfserver

ASL Lancelot
2884-SRT

1

$10k /
1 week (in 2021)

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.

Backup computer already installed within KPF Calibration Rack. When switching to the backup computer, the USB cable for the Exposure Meter detector needs to be moved from kpfserver to the backup computer.

However the WMKO-standard OS and files need to be installed.

1 spare

• CCD thermal control cannot be maintained without the Instec system running. The CCD will start to warm up.

LN2 Cart

Autofill Solenoids

2x

• If kpfserver goes down, we lose remote control of the instrument (and all telemetry)