The replacement of the Carbon and Platinum probes with Cernox thermometers (Cernox CX-1050) has allowed us to start using commercial cryogenic temperature controllers. Indeed, only the aging temperature controller developed at ILL in the late 80s (called ILL-SEC) was able to regulate the temperature from two sensors covering overlapping ranges (1-50K with the Carbon and 20-320K with the Pt100).

After testing several products, we have chosen the LakeShore Model 340 shown below that is widely used at research facilities. However, it can only provide 50W of heating power (we use 50Ω heater resistances) and can only store 40 calibration curves. The first problem is fixed by using a Kepco ATE 100-2.5 power amplifier. The second difficulty will be cleared up with a new electronics called Auto-ID and which will be available in 2011. Indeed, the Auto-ID will upload automatically the calibration curves, zone settings and limits.

We show below the recommended zone settings for our cryostats and cryofurnaces. Enter these parameters for each zone and for the control loop #1. When complete, press the Save Screen key to store them in the LakeShore memory and switch on the heater by pressing the Heater Range key. We also invite you to check that the right calibration curves are selected. To determine which calibration curve should be used, please visit the Equipment section and look for your equipment.

ATTENTION: You cannot enter the settings of different cryostats in different zones (e.g. zones 1 and 2 for Ø49 Orange Cryostat and zones 3 and 4 for Ø100 Orange Cryostats). The LakeShore determines the zone to apply from the measured temperature, starting from zone 1.

Zone Settings for Orange Cryostats

These values will allow you to establish initial parameter settings and evaluate closed loop operation with your equipment. You can explore different parameters and you may find better values but that can only be done at your own risk.

Zone Settings for Orange Cryofurnaces

These values will allow you to establish initial parameter settings and evaluate closed loop operation with your equipment. You can explore different parameters and you may find better values but that can only be done at your own risk.

Zone Settings for Cryogen-free Orange Cryostats

These values will allow you to establish initial parameter settings and evaluate closed loop operation with your equipment. You can explore different parameters and you may find better values but that can only be done at your own risk.

Zone Settings for Cryogen-free Joule-Thomson Cryostats on cradles

These values will allow you to establish initial parameter settings and evaluate closed loop operation with your equipment. You can explore different parameters and you may find better values but that can only be done at your own risk.

LKC-340 Converter

The LKC-340 electronics links the LakeShore Model 340 temperature controller to the Kepco ATE 100-2.5 power amplifier. With this electronics, the power amplifier is protected against abnormal LakeShore output voltages and delivers up to 2.5 times the power provided by a LakeShore. The typical use is described by the graph plotted below. When the 6.2mW heater range is selected in the LakeShore, a maximum power of 80W acceptable for a cryostat is delivered. When using a cryofurnace or a cryogen-free cryostat, this power is almost doubled while the heater range is increased by a decade.