The Stave Thermo-Conductivity QC Procedure Idea

1
The Stave Thermo-Conductivity QC Procedure Idea
P.Netchaeva, A.Pozzo INFN Genova

• The piece (half) of the ex-baseline stave 8 has
  been used.

2
The Idea

• The baseline stave (with Al tube inside)
  transverse thermoconductivity must be estimated
  before attaching modules.
• This can be done
• Using heaters.
• The temperature is being measured on the surface
  of the heater (not C-C).
• The procedure of applying heaters is rather
  complicated itself (reproducibility?).
• The stave after QC procedure should be cleaned.
• Joule effect. We can use the resistance of the
  stave itself to simulate working modules.
• R stave 5 Ohm
• (due to the glue between 2 tmt!)
• R half-stave 0.2 0.3 Ohm

3
The Setup with Heaters
4 heaters I 1.07 A , U 24.0 V, W1 6.42 W

• Cooling
• water 17.6 oC
• ( air -gt turbulent flow)

4
The Joule Effect

• R half-stave8 0.24 Ohm
• I 12.5 A Cooling
• U 3.0 V water 17.6 oC
• W1 6.25 W ( air)
• Electrical contacts Indium

water
5
The Joule Effect Thermocamera images
Water direction
Water direction
6
The Joule Effect vs. Heaters
The temperature has been measured on the surface
of the heaters
7
Temperature vs. Cross-Section
The temperature has been measured on the 4
central shingles of the half-stave
8
The Joule Effect vs. Heaters16W / module
9
Conclusions

• The ideal stave (without Al tube inside) has
  been used.
• The Joule effect heating method gives the
  temperature distributions along the ideal stave
  corresponding to those we get from the method
  with heaters simulating real modules.
• Using the Joule effect we measure the temperature
  directly on the carbon-carbon, while using the
  heaters we can measure the temperature only on
  the heaters surface.
• Applying the heaters we introduce a systematic
  error due to non perfect uniformity of the
  thermal grease between carbon-carbon and heaters.
• Further tests on the baseline staves (with Al
  tube) are needed.