Executive Summary

• Respond to Alarms (& Alerts)
  • Compressor calls First-Responder for help (email, txt)
    • Wake up
• Determine Mimir Status and Electrical Power Status
  • Did compressor recover on its own? (~minutes)
  • How long has compressor been stopped?
    • Short time (< 1 hr)
    • Long time (> 1 hr)
  • Vacuum status?
    • Less than 10^-4 torr = OK
    • Between 10^-4 and 10^-3 torrIf compressor < 1 hr off, OK
      • If compressor > 1 hr off, Call Second-Responder
    • Higher than 10^-3 torr = Call Second-Responder
  • Electrical Power Status – All 3-phases present?
• Re-Evaluate and Intervene or Call Second-Responder
  • Get to Mesa
  • Re-Evaluate Mimir Vacuum Status & Electrical Power Status
    • If both OK, turn compressor on
    • If Vacuum NOT OK, call Second-Responder
    • If 3-Phase power not OK, wait…
• Report Actions
  • Email to Dan Clemens about Status, Intervention
  • Txt to Dan Clemens if Second-Responder called
• Problems beyond routine, CALL Dan Clemens (781-492-2726)

Key Web Pages and Links:

• Mimir Status – LUX (within Lowell firewall) = http://lux.lowell.edu/mimir/mimir_status.html
• Mimir Status – IAR (outside Lowell firewall) = http://iar.lowell.edu/mimir/
• Compressor Status (w/i Lowell only) = http://compressor.lowell.edu/current-values-control.htm
• Compressor Shed WebCam = https://www.samsungsmartcam.com/web/ (must create your account)
  • Cam Name = 'Compressor Shed' (no quotes)
  • Cam S/N = KHNL6V2G7002CBM
  • Cam Password = 'mimir123' (no quotes)

Dan Clemens Contact Info:

• Email -> clemens_dp@comcast.net, clemens@bu.edu
• Phone, Txt, FaceTime: 781-492-2726
• Home: 781-444-6478
• Skype -> dan.clemens

Intervention Principles

1. 1. Don't panic! Mimir will survive moderate power failures or other problems.
   2. Don't panic! Key time-scales are hours, not minutes or seconds.
      1. Some email alarms don't turn out to be real problems (APS corrects itself, as does the compressor)
      2. Check Mimir status before heading out the Mesa to intervene
   3. 4:1 rule of thumb. For every 1 hour that the compressor is not supplying helium to Mimir, it will take about 4 hours to cool back to operating temperatures.
      1. If a Mimir observer is asleep (daytime), it is best to respond within an hour, so as to not lose the upcoming observing night.
      2. If Mimir is not on the telescope, then response within 2-3 hours is probably OK.
   4. Check the vacuum (remotely or in person); Check the 3-Phase electrical power
      1. Vacuum: Via Mimir Web Page, or at the Varian vacuum unit (in person, or call observer)
         1. If pressure < 1.0x10^-4 torr, then turning on the compressor is fine.
         2. If the time the compressor has been off is < 1 hour, turning on the compressor is fine.
         3. If the time is > 1 hour and the pressure > 1.0x10^-4 torr, then vacuum pumping (Second-Responder Action) is likely indicated.
         4. Any time the pressure goes > 1.0x10^-3 torr, vacuum pumping (Second-Responder Action) is required, and Dan Clemens should be contacted
      2. 3-Phase power – look for GREEN light on left (South) inside of helium compressor
      3. For problems beyond compressor and vacuum, the WebCam has a 2-way audio link. Dan Clemens can either talk you through something or elect to abort intervention.

Example Mimir Status Pages and Compressor Pictures, from the web page and web cam

Mimir operation in a NORMAL operations state:

.

Snapshot from compressor shed WebCam showing front of compressor during NORMAL operations

• Temperature is 60 F
• Input (return) gas pressure is 100 psi
• Output (supply) gas pressure is 320 psi.

Compressor Status Web Page (Logger Webpage) under NORMAL operations

ANOMALY, from Mimir Web Status Page

• This shows the TB – Detector Temperature 7 day summary plot
  • Click on the "(TB) detector" blue TB link on the Mimir Web Status Page
    • Shows detector temperature in black; detector heater power in purple
    • Detector temperature rose to 62 K at day -6, when compressor turned off

Determining Mimir Vacuum Status

• Mimir Web Status Page
  • Three Rectangle Colored Status Lights

• If "Vacuum" is Green, Pressure < 10^-3 torr

Pressure Plot ("Plot 1: Pressure History" on Web Page)

• Thermocouple (TC) gauge is ALWAYS on = black line
  • But, it does not measure BELOW 1x10^-3 torr
  • Useful for revealing gross problems (2^nd Responder Calls)
• Bayard-Alpert (BA) Gauge readings in red
  • Turns on 2x per day for 15 min each, normally
  • Red "Last BA: xxx" gives the last BA Gauge reading
  • Dan Clemens can command BA to turn on/off remotely

Turning on the BA Gauge directly with the Varian Multi-Gauge Controller

• Front Panel of Mimir Electronics small rack

• If the Varian Multi-Gauge display says "OFF" then the BA gauge is not powered
• As long as the Thermocouple gauge remains below 10^-3 torr, BA can be powered up

• If TC below 10^-3 torr, then press the 'EMIS' button to start the BA gauge

• After EMIS button is pressed, BA gauge will start.
• Allow 2 min to settle before reading.

Decide what to do or not do

• Examine the 3-Phase power sensor inside the helium compressor
  • On the left (South-facing) side of the compressor
  • If the LED is GREEN, then 3-phase power is in place and you can proceed
  • If the LED is NOT green, then 3-phase power is not present, and you MUST wait
• If Mimir pressure is in the OK range, then turn on Compressor main power switch
  • Temperatures should begin to drop immediately
  • Pressure might drop in about 10 min
  • Watch for normally decreasing Temperatures and Pressures for 20 min, to be sure all is well
    • If so, press "EMIS" button on Varian Multi-Gauge to turn the BA gauge off
  • Send email status report to Dan Clemens & Bill DeGroff
  • Close compressor shed door, depart site
• If Mimir pressure outside OK range, then call Second-Responder
  • Describe Mimir state to Second-Responder
  • Leave BA gauge ON
  • Send txt and email report to Dan Clemens
  • Depart site, or stay, depending on Second-Responder instructions