these stages and are controlled by a simple heater. · pdf filethese stages and are controlled...
TRANSCRIPT
Lab of Alliances in Nanosciences & Energies for the FutureLab of Alliances in Nanosciences & Energies for the FutureEq
uip
mEn
ts 2
01
1-2
01
2Easycool
Principal investigatorsJean-Marc Duval (INaC, Philippe CaMus (NEEl), Thomas Prouvé (INaC), olivier Exshaw (NEEl), Jean-louis DuraND (INaC), Florian BaNCEl (INaC), Daniel lEPoITTEvIN (NEEl), Joël Balay (NEEl)
Laboratories: NEEl, INaC
Easycool has been proposed as a demonstrator of continuous magnetic cooling at a temperature below 100 mK. It is focused at providing a cryogen-free and autonomous operation for the user. The challenge in the realization of Easycool is the design and operation of 5 stages of adiabatic demagnetization refrigerator (aDr) which will provide two levels of continuous cooling. Designed for scientific research and high sensitivity cryogenic detectors, this system is compatible with the most demanding applications. This compatibility will be validated in the last step of this project by testing a Kinetic Inductance Detector (KID) array in the magnetically shielded experimental area.
DescriptionEasycool is based on a series of 5 adiabatic demagnetization stages. Each stage operates in a defined temperature range with a limited temperature gradient to optimize the efficiency and low mass of the cryocooler. Heat switches based on the gas-gap principle are used between each of these stages and are controlled by a simple heater. The colder heat switch is based on superconducting switches which turns on or off with applied magnetic field. The main components of this demonstrator (ADR stages and heat switches) benefit from the high maturity and reliability of our developments for space applications.
The control of the cooler is fully automated by software controlling the power supply for the magnetic stages, the heat switches. In order to improve the robustness of the system, a dedicated quench detection system to protect the superconducting coils has been designed as part as this project.
Easycool is operating at 1 K and 100 mK continuously as shown in the figure. A magnetically shielded box has been designed to provide an experimental area for sensitive experiments. A demonstration will be done with kinetic inductance detectors (KID) from Institut Néel.
Coupled to a pulse-tube cooler, this continuous ADR is the first demonstration of a fully cryogen-free refrigerator below 100 mK.
We plan to push further its maturity to be proposed to scientific with demanding cryogenics need and who would benefit for this autonomous cryocooler.
Operation with a 1 K and 100 mK continuous stage
Outcomes: Easycool an autonomous sub 100 mK refrigerator, will be presented at the 16th International Workshop on Low Temperature Detector, Grenoble 20-24 June 2015.
CONTACT
[email protected] [email protected]
4
3
2.5
3.5
0:00 2:00 4:00 6:00 10:008:00 12:00
T0
T1
T2
T3
T4
T continous1.5
0.5
2
1
0
Tem
per
atu
re (
K)