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 layout of the target screens (left side) and the pictures of the Target-Related screens (right side).
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
Qualified Target Personnel
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)
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- 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.
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.
- 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
- 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.
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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.
Each Target Parameter of Fridge 2x3 is explained below:
- 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.
- 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).
- 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.
- 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.
- 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
This section contains the QT-Terminal, liquefier level, LN2 (Liquid Nitrogen) level in the Purifier, and Magnet Shield. Make sure you are on this System Overview screen.
If you are lost in the QT-HMI and not able to go back to the main screen, please follow the following annotated pictures:
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How do we check the production rate of the Liquid A/B? Please follow the following steps. Make sure to be on the System Overview screen.
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How do you check the production rate for Liquefier A/B? Please use the following link to do calculations. Combined Calculators (fnal.gov)
Please see the picture of the calculator:
NMR Terminal:
The following section explains the NMR terminal, polarization, NMR Signal, and how to take a new baseline and data.
How do we create a New Baseline?
Click on the Baseline in the above Green circled area, and it will pop up a new window like the one below:
Click on Create a new Baseline. It will close this window and come to the Main Display. After that, follow the picture below to set the sweeps:
Insert 5000 at point 1 (Sweeps) and click at point 2 on 'One Point.' The baseline will be completed in around 324 seconds. You will see a new baseline at the bottom left of the above picture.
Microwave Terminal:
Please follow this page for the Microwave Terminal Microwave System Manual - Wiki Post Portal - Confluence (virginia.edu).
Target Lifter Terminal:
Please follow this page for the Target Lifter Terminal Target Lifter Manual - Wiki Post Portal - Confluence (virginia.edu).
Procedures:
This section will explain how to do an LN2 (Liquid Nitrogen) filling to purifier and magnet shield. Please see the following links to do both fillings:
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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
| Owl-Shift | Once every hour
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| Day-Shift | Once per shift
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| Swing-Shift | Once every hour
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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.
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.
Basic Operations' Direct links
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.
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.
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.
- 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.
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