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This page illustrates the target operator's role and responsibilities. It first explains how a new Target Operator can access NM4, what training is required, and what monitoring they must do. 

The following link directs to a General Training page that helps the Target Operator access the NM4 Experimental Hall. 

General Training to Get Access at NM4 

Please see the NM4 Control Room Layout:

See the close picture of the Target-Related screens on the desk's Right half. 

Image RemovedImage Removed

The following sections will introduce the strip charts relevant to monitoring and helping to track the cryogenics. You can see the following strip charts on Target TV. 

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provides all the information that you need to be a SpinQuest Target Operator.  The section below provides the link to the training required to complete before you can take shifts as a Target Operator.  You need both FNAL training to be able to access NM4/NM3 and you need Target Operator Training and Target Operator Practical to be able to know what to do on your shift.  Also listed below is a list of qualified Target Experts and Target Operators.  Make sure your name is on the list of Target Operators before you show up for a shift.

TO Required Training

General NM4 Access Requirement

Target Operator Training

Target Operator Practical

Qualified Target Personnel

Qualified Target Operators

Qualifier Target Experts

Target operator Role

The target operator's job is to monitor and maintain the cryogenic system of the polarized target while continuously maximizing polarization of the target whenever possible while beam is on. 
The Target Operator should be constantly checking the status of these following five critical components of the system:

Shift Duties (Draft)

  • Beginning of shift
    • Arrive at NM4 at least five minutes before the start time of your shift.  Take over the status and the plan of the target system from the outgoing shifter.
    • If the Shift Leader is absent, call MCR (x3721) and say something like "This is <YOUR NAME> at SpinQuest (NM4), and we are starting a new shift."  The MCR person will thank you.
    • If the Shift Leader is absent, complete the "Beginning of Shift" form in the ECL elog.
    • Complete the Target Operator Shift Report : ← copy this table to your ECL elog entry and fill it out.
      Note: Submit this ECL elog entry at the end of your shift, as you cannot edit an ECL entry after posting/submitting.
    • Confirm that the "Active Alarm for Target Operator" page is functioning on "uva-nuc-02", as instructed in this page.
    • Power Outages can be very hard for the cryogenic system to recover from.  If you are aware about an upcoming power outage, or having an outage or even a power flicker, then let the Target Expert know immediately.
  • Frequent checks: 
    •  IMPORTANT!!!  Is the Internal Vacuum Chamber (IVC) good and at pressure below 10-6 Torr (spikes above 10-5 Torr for a few seconds during filling are OK, but if it takes longer than a few minutes to come back down, then check the controller's front panel from the cameras (on CCP machine): the following image shows when the turbo-pump is working normally.
      Image Added

      and see whether you are seeing a blinking green light or any error message with the RED light       (see the following images), then mention it in the discord and immediately follow the steps on this page IVC and also call the Target Expert on Shift.
      IVCError.jpgImage Added

    • Is the Liquefier producing normally without any alarms (RED lights indicating alarms on the QT screen) and are the cold head compressors all running (green light)? If there is an alarm or the coldhead indicators are RED, then call the Target Expert.
    • Check whether the magnet is ramped up.  Is there any sign of a target magnet quench? If it is and at some point you see the magnet pressure shoot up to 9 psi in a few seconds, call the Target Expert immediately. The magnet control VI will also indicate a quench.
    • What are the LCW temperatures?  If

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  • Every hour
    • Confirm that all computers/programs are running (not got stuck), including the QT HMI screen, the PDP screen, the target computer, the microwave+lifter computer, "uva-nuc-01" and "uva-nuc-02".
    • Check all strip charts and communicate with the Target Expert immediately if you notice anything unusual: especially IVC, LCW flow, LCW pressure, LCW temperature, LCW temperatures on QT compressors
  • On-demand
    • Manipulate the Microwave Control system in case of the "Production" mode.
    • Respond to all target-related alarms, as instructed in this page.
  • End of shift
    • Hand over details to the incoming shifter.
    • Ensure to submit your completed Target Operator Shift Report
    • If the Shift Leader is absent, complete the "End of Shift" form in the ECL.

Strip charts: https://e906-gat1.fnal.gov/data-summary/e1039 (click on "All Parameters" under the "Target Control Data")


In addition to the tasks mentioned (above), perform the following Routine Maintenance Tasks for Owl/Day/Swing shifts

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Owl-Shift

      Once every hour

  • Check whether both LHe liquefiers are producing with a rate of ~4 L/hr.
  • Check when the Liquefiers are going to be FULL (use

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  • level.php), and notify the Target Expert with the time estimate (communicate this information to the Target Expert).
  • Check the total consumption rate (Magnet return flow + Separator return flow + Main return flow), and estimate how long the magnet LHe will take to get to 0%
    (communicate this information to the Target Expert) 
    You can use this page:

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Day-Shift

     Once per shift

Swing-Shift

      Once every hour



The Target Operator must know how to monitor the system, move the target position, control and optimize the microwaves, Take an NMR Thermal Equilibrium Measurement (TE), perform the necessary cryogenic fills, respond to any system alarms, and log everything.

System Monitoring

Target Position

Microwaves

NMR TE Measurements

Cryogenic Fills

Cryo Control Panel

System Alarms

FNAL Target Elog

Polarization Optimization


Additionally, there are three main modes that the target system can be in.  Idle mode is without any liquid helium in the nose and the only goal is to conserve liquid over some time period. Hold Cold Mode also has the goal of reducing liquid helium consumption as much as possible but to also keep the target material in the fridge below 100K.  Production Mode is the normal mode we want to be in when the beam is on and we are taking data.  You should know how to switch between these modes and how to sustain them.

Idle Mode

Hold Mode

Production Mode

Target Preserve Mode


Basic Operations' Direct links

Sub-System
QT
(Helium Liquefier)
  1. Helium Liquefier (QT) System Summary
  2. How to fill LN2 to the Purifier and Magnet LN2 spaces
  3. How to fix the QT-HMI if its screen got frozen
  4. Fixing dewar level indicator
  5. Resolving Liquefier Blocking Alarm when Liquefier is on Liquefy Mode
  6. Resolving Liquefier Blocking Alarm when Liquefier is on Idle Mode
  7. How to restart the QT PLC
  8. How to fix if the outlet flows of Liquefiers are showing strange values
Magnet
  1. How to control the Magnet Return flow
  2. How to fill LN2 to the Purifier and Magnet LN2 spaces
  3. How to move the magnet current
  4. Magnet Power Supply Ramping Up - Down Procedure
Separator
  1. How to control the Separator Return flow
NMR
  1. How to take a baseline and then take data on UVA-NMR system
Microwave
  1. Microwave Operation
Fridge, Gate Valve
Gate-Valve Bypass
  1. Fridge Fill Procedure
  2. How to control the Fridge Return flow (GV and GV Bypass)
  3. How to Open or Close Fridge Valves
  4. Fridge Filling Procedure (Warm Filling) Using Bypass Valve
  5. Fridge Filling Procedure (Cold Filling) Using Run Valve from any level of Liquid Helium in the Fridge
  6. How to identify the fridge LHe level
Roots-pumps
  1. Roots pumps PLC interface
Kmag, Fmag
  1. How to power ON Fmag or/and Kmag


Switching Between Modes

1. Transitioning from the Hold mode to the Production Mode
2. Transitioning from the Production Mode to the Hold Mode
3. Transitioning from the Production Mode to the Idle Mode


Note: Please coordinate with the Target Expert on shift if there is a transition from one mode to another.

Useful information for troubleshooting







Older information


  • Frequent checks: 
    •  IMPORTANT!!!  Is the Internal Vacuum Chamber (IVC) good and at pressure below 10-6 Torr (spikes above 10-5 Torr for a few seconds during filling are OK, but if it takes longer than a few minutes to come back down, then check the controller's front panel from the cameras (on CCP machine): the following image shows when both turbo-pump and HiCube are working normally.
      Image Added

      and see whether you are seeing a blinking green light or any error message with the RED light       (see the following images), then mention it in the discord and immediately follow the steps on this page IVC and also call the Target Expert on Shift.
      IVCError.jpgImage Added
      On the high-cube pump was installed at NM3 and a camera was also arranged. So, check that camera and follow the instructions on How to restart the high-cube pump
      if you see the red light with an error message (see the sample image below), also notify the target team via discord.
      Image Added

The following sections will introduce the strip charts relevant to monitoring and helping to track the fridge level. You can see the following strip charts on Fridge 2x3.

The Fridge 2x3 provides information about the liquid level in the fridge Fridge 2x3 (fnal.gov) and its related target parameters. 

Image Removed 

Each Target Parameter of Fridge 2x3 is explained below:

  1. In the 1st row and 1st column, the strip chart is related to the chip resistor, which we installed in different locations on the fridge. The purpose of these chip resistors is to track the level of liquid helium in the fridge. When the liquid is at a certain level, say Heat-Ex Bottom (Ohm), it should show 1400 or 1450 Ohm resistance. Usually, we fill the fridge to the Heat-Ex Top (Ohm) and leave it there. But, during a regular, sustainable polarization study, we must keep the Heat-Ex Bottom (Ohm) level. 
  2.  The strip chart in the first row and the second column relate to the fridge nose level (in percentage) and the two valves, the Run and Bypass valves, which we usually use to fill the fridge. We can use a Bypass valve when we have to fill the fridge quite quickly. But during sustainable polarization, to replenish the liquid level in the fridge, we have to use a Run valve to keep the level at Heat-Ex Bottom (Ohm). 
  3. The strip chart in the first row and the third column is related to the total consumption or the boil-off at the cryostat. The Main (SLM) target parameter shows the evaporation from the fridge while filling it by opening the Run or Bypass valve. The Separator (SLM) target parameter shows the separator flow we are getting from the magnet reservoir via a U-tube to fill the fridge. The MagRetBypass (SLM) target parameter shows the boil-off from the magnet reservoir. The Total (SLM) shows the sum of the three target parameters. 
  4. The strip chart in the second row and the first column are related to fridge pressure. The Fridge/1000 (Torr) target parameter shows the fridge pressure more accurately when it is above 100 torr. Still, the Fridge/100 (Torr) target parameter shows the fridge pressure more accurately when it is under 100 torr. Suppose the fridge pressure is above 100 torr. In that case, the Fridge/1000 (Torr) target parameter is reliable, and the fridge temperature to the Fridge/1000 (K) target parameter is in the second row and second column. Suppose the fridge pressure is under 100 torr. In that case, the Fridge/100 (Torr) target parameter is reliable, and the fridge temperature to the Fridge/100 (K) target parameter is in the second row and second column. 
  5. The second row and third column show the CAD model of the fridge.    

The following procedure is used to fill the fridge from empty to full and keep the fridge level at the Heat-Ex bottom during sustainable polarization with annotated pictures. 

Fridge Filling Procedure (Annotated Procedure)

QT-Terminal

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