ProtoDUNE-SP Purity Monitor Operation Jianming Bian, Isloo Seong - - PowerPoint PPT Presentation

ProtoDUNE-SP Purity Monitor Operation

Jianming Bian, Isloo Seong (UCI) Casandra Morris, Andrew Renshaw (UH) Stephen Pordes (FNAL)

ProtoDUNE-SP Purity Monitors

Top PrM Middle PrM Bottom PrM Individual PrMon:

• Xe flash lamp light source
• Al-Ti-Au photocathode for drift

electron generation

• Cathode/anode gates for charge

screening at readout

• Internal cable shields tied to

PrMon cage and flange

• M. Adamowski et al., JINST 9, P07005 (2014).

ProtoDUNE-SP Purity Monitors

Bottom PrM Middle PrM Top PrM Xenon Light Source Top Flange Fiber Protector PrM Electronics

Purity Monitor Operation

• July 23, purging started
• Turned on purity monitors at ~15:50 pm, July 25, in Ar Gas
• August 7, Start to fill LAr
• August 21, Bottom PrM submerged by LAr
• August 31, PrM anode signals reduced in size considerably due to

filters beginning to saturate, regenerate filter

• September 6, top PrM submerged by LAr
• September 19, start to recirculate LAr

July 25, in Ar Gas, -30V,300V

After cooling down (Aug 3), -30V,300V

August 21, Bottom PrM submerged by LAr,-300V,3000V first LAr signal, lifetime = 45 us

45us,

August 31, PrM anode signals reduced in size considerably due to filters beginning to saturate, regenerate filter

e-lifetime dropped from 45us to ~30us, anode signal significantly reduced

Use cathode signal to estimate lifetime

Use cathode signal to estimate lifetime

September 6-19, before LAr recirculation

In GAr

Summary

• We see cathode and anode signals on the three purity monitors
• All three purity monitors and the xenon light source work properly
• Purity monitor DAQ works well
• Found filter saturation at early stage
• Start to monitor purity during LAr recirculation