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.
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.
The Target TV page 'https://e906-gat1.fnal.gov/data-summary/e1039/target-par-preset/target-tv.php' gives you an overall idea about the entire system (but not all the parameters).
In addition to the "Target TV," there are two dedicated pages designed for the convenience of the Target Operator / Target Helper.
1. https://e906-gat1.fnal.gov/data-summary/e1039/target-par-preset/target-helper.php
2. https://e906-gat1.fnal.gov/data-summary/e1039/target-par-preset/target-helper-2.php
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: