[Kimura and M. Takahashi]
To search for the cause of the anomalous behavior of the BS-side duct shield cryo-cooler called Xfs in IXC, we took temperature measurements of various parts inside the compressors for the cryo-coolers in operation at the center and Y-end.
The following table shows the results.
| Xfs | Xfa | X-P53 | X-P55 | Yfs | Yfa | Y-P53 | Y-P55 | Yea | Yer | |
| Helium gas supply (°C) | 22.5 | 21.4 | 21.5 | 22.1 | 20.6 | 21.1 | 21.1 | 20.6 | 15.7 | 15.6 |
| Helium gas return (°C) | 24.6 | 24.2 | 23.7 | 24.0 | 23.3 | 23.8 | 23.4 | 23.3 | 20.2 | 20.3 |
| Adsober OUT (°C) | 22.6 | 21.6 | 21.8 | 22.2 | 21.3 | 21.4 | 21.9 | 21.3 | 16.7 | 16.5 |
| Adsober IN (°C) | 22.3 | 21.8 | 21.9 | 21.0 | 20.5 | 21.0 | 21.7 | 20.8 | 15.4 | 15.4 |
| Oil separator IN (°C) | 20.5 | 20.8 | 20.8 | 20.1 | 20.7 | 19.6 | 19.7 | 20.8 | 15.3 | 15.5 |
| Oil separator OUT (°C) | 21.8 | 21.7 | 20.8 | 21.0 | 20.4 | 19.9 | 20.7 | 20.8 | 15.2 | 15.0 |
| Heat exchanger IN-1 (°C) | 89.7 | 59.0 | 64.7 | 65.3 | 59.4 | 65.8 | 64.0 | 64.1 | 61.0 | 60.9 |
| Heat exchanger IN-2 (°C) | 85.0 | 65.3 | 61.3 | 64.0 | 64.0 | 65.7 | 66.0 | 64.1 | 57.1 | 60.1 |
| Surface temp. of the main unit (°C) | 55 | 50 | 60 | 60 | 50 | 55 | 65 | 65 | 55 | 60 |
| Water inlet temp. (°C) | 19.0 | 19.1 | 19.3 | 19.4 | 19.5 | 19.3 | 19.2 | 19.2 | 13.7 | 14.1 |
| Water outlet temp. (°C) | 26.9 | 25.9 | 25.7 | 25.8 | 28.1 | 27.7 | 28.1 | 28.5 | 20.0 | 20.9 |
| Psupply (MPa) | 2.28~2.30 | 2.32~2.36 | 2.35~2.40 | 2.30~2.35 | 2.35~2.40 | 2.29~2.32 | 2.33~2.38 | 2.31~2.36 | 2.31~2.34 | 2.36~2.40 |
| Preturn (MPa) | 0.655~0.696 | 0.683~0.710 | 0.628~0.683 | 0.641~0.697 | 0.640~0.687 | 0.655~0.697 | 0.690~0.717 | 0.662~0.717 | 0.632~0.685 | 0.662~0.679 |
| Pdeff (MPa) | 1.625~1.604 | 1.637~1.65 | 1.722~1.717 | 1.659~1.653 | 1.71~1.713 | 1.635~1.623 | 1.64~1.663 | 1.648~1.643 | 1.68~1.655 | 1.698~1.721 |
As a result of the temperature measurements, it was confirmed that the gas temperature of the compressor in the BS-side duct shield cryo-cooler was more than 20°C higher than the others.
We are currently inquiring with the manufacturer whether this situation is normal.