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--- wiki:design_construction [2022/02/02 17:31]
henri.godfrin@neel.cnrs.fr
+++ wiki:design_construction [2022/12/15 17:46] (current)
henri.godfrin@neel.cnrs.fr
@@ Line 9: / Line 9: @@
    * Small dilution refrigerators ("la Jolla" style) have diameters of a few cm, their 3He flow rate is ~10 to 50 µmol/sec. They are often used as "inserts" in a liquid helium dewar . Due to their small size, the heat exchangers have a small total area, and heat leaks make it difficult to reach temperatures below 10 mK.
-   * Larger refrigerators with heat exchangers of typical diameters larger than 10 cm ("Grenoble design") can reach temperatures on the order of 2 mK, with flow rates of 100 *mol/s. They can also provide large cooling power, with flow rates up to 10 mmol/s, obviously at higher working temperatures.
+   * Larger refrigerators with heat exchangers of typical diameters larger than 10 cm ("Grenoble design") can reach temperatures on the order of 2 mK, with flow rates of 100 µmol/s. They can also provide large cooling power, with flow rates up to 10 mmol/s, obviously at higher working temperatures.
    * Cooling power at the MC is given by the simple expression
@@ 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 73: / Line 77: @@
-===== Troubleshooting =====
+===== 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...

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