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--- wiki:design_construction [2022/02/02 17:14]
henri.godfrin@neel.cnrs.fr
+++ wiki:design_construction [2022/02/03 14:02]
henri.godfrin@neel.cnrs.fr
@@ Line 49: / Line 49: @@
   * The still plays an important role: the **3He flow rate** of the dilution refrigerator, and hence the cooling power available at the level of the mixing chamber, **is mainly determined by the power applied to the still**.
+===== The Continuous heat exchanger  =====
+===== The Step ("discrete") heat exchangers =====
 ===== The Mixing Chamber  =====
@@ Line 71: / Line 75: @@
   * Pumped 3He refrigerators have larger cooling powers that dilution refrigerators for T>0.35 K. The are also significantly more user friendly...
+===== Troubleshooting Dilution Refrigerators =====
+  * 1 K pot hot, pressure is low. Filling capillary blocked. Remove LHe so that the bath level is below the intake, keep 4He pressure in Pot above bath pressure. Having a heater on the 1K pot capillary can help, applying heat pulses...
+  * High inlet pressure. Air? Hydrogen? Water?
+  * Low still pressure. Still empty? Check T_still vs. P_still ! If there is no liquid, the pressure j
+  * is low, but the temperature is high.
+  * No cooling power. Interface level in MC? Heat leak to MC? Apply heat and check cooling power at higher temperatures. 3He/4He ratio OK?
+  * Heating spikes, temperature oscillations. Superfluid leak to Vacuum can? Check for spikes in the vaucum can pressure.

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