Thermometers selection: temperature range and magnetic field. Phys 590B Fall 2018 Mingyu Xu

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1 Thermometers selection: temperature range and magnetic field Phys 590B Fall 2018 Mingyu Xu

2 Primary Thermometers Can be used without calibration 1. Helium Vapor Pressure Thermometer 2. Helium melting curve thermometer 3. Nuclear orientation thermometry 4. Coulomb blockade thermometer 5. Magnetic susceptibility 6. NMR thermometer 7. Noise thermometer

3 Helium Vapor Pressure Thermometer Temperature range: 0.45K- 5K. usual measure at 1K-4.2K. accuracy <1%. poor resolution, poor response time, require long tubes from the cryostats to the measuring equipment, correction for gravity etc. 9 T = A 0 + i=1 A i [ Inp B C ] i M J Mehta and B K Basu 1982 J. Phys. E: Sci. Instrum

4 Helium melting curve thermometer Temperature range: 0.9 mk - 1K. 0.1% uncertainty in the absolute melting pressure at T = 10 mk will cause a 9% uncertainty in the absolute temperature. 3He melting curve thermometer (MCT) is both costly and time-consuming. Insensitive to magnetic field below about 0.5T. Meas. Sci. Technol. 15 (2004)

5 Nuclear orientation thermometer Temperature range: 1-40 mk. Some rare earth up to 100mK. Sensitive to magnetic field. JOURNAL OF RESEARCH of the National Bureau of Standard Js Vol. 88, No. 3, May-June 1983

6 Coulomb blockade thermometer Temperature range: 20mK- 30K. Insensitive to magnetic fields (27 T) J.P. Pekola, K.P. Hirvi, J.P. Kauppinen, and M. A. Paalanen, Phys. Rev. Lett. 73 (1994) 2903 J.P. Pekola, T. Holmqvist, and M. Meschke,, Phys. Rev. Lett. 101 (2008)

7 Magnetic susceptibility Temperature range: 2mK -1K (the salt cerium magnesium nitrate(cmn)). Hard to measure accurately and incentive to magnetic field. A. C. ANDERSON, R. E. PETERSON, AND J. E. ROBICHAUX THE REVIEW OF SCIENTIFIC INSTRUMENTS V 41, 4

8 NMR thermometer Pt thermometer has been used to measure temperatures as low as 7.9 mk for a dilute 3He-4He solution in an 8 T field. High magnetic field difficult: the nuclear heat capacity increases by a factor of 10 5, making thermal equilibration problematic; Cryogenics V31, Issue 2, February 1991, Pages 94-98

9 Noise thermometer Josephson Junction Noise Thermometer Current Sensing Noise Thermometer Magnetic Field Fluctuation Thermometer Extremely large temperature range: 50 µk K. Distinguish or suppress influence of non-thermal noise Journal of Applied Physics 74, 771 (1993); doi: /

10 Secondary thermometer Must be calibrated at known T 1. Thermocouples. 2. Diodes. 3. Resistance. 4. Capacitance.

11 Thermocouples V = S H, T dt, S(H,T) is the Seebeck coefficient. Cryogenics Volume 38, Issue 3, March 1998, Pages w.wikiwand.com/en/se ebeck_coef ficient

12 Thermocouples T V = T T0 S AuFe 0, T dt X T S AuFe H, T dt T - T TX S Cu H, T dt 0 T S Cu 0, T dt If we let T = T X, then,v = T0 T x S Cu 0, T dt S AuFe 0, T dt dt Journal of Applied Physics 40, 3836 (1969);

13 Types of Thermocouples Letter Code Alloy Combination (by weight) Temperature Range Standard limits of Error K Nickel-Chromium / Nickel-Alumel(95%Ni, 2% Al, 2% Mn, and 1% SI) 270 to 1260C +/- 2.2C or +/-.75% J Iron/Constantan(Cu-Ni) -210 to 760C +/- 2.2C or +/-.75% T Copper/Constantan -270 to 370C +/- 1.0C or +/-.75% E Nickel-Chromium/Constantan -270 to 870C +/- 1.7C or +/- 0.5% N Nicrosil (Ni alloy Cr..)/ Nisil(Ni alloy Si..) -270 to 392C +/- 2.2C or +/-.75% S Platinum Rhodium - 10% / Platinum -50 to 1480C +/- 1.5C or +/-.25% R Platinum Rhodium -13% / Platinum -50 to 1480C +/- 1.5C or +/-.25% B Pt Rhodium 30% / Pt Rhodium 6% 0 to 1700C +/- 0.5% G Tungsten/Tungsten 26% Rhenium 0 to 2320C 1% to 2320C, 4.5C to 425C C Tungsten 5% Rhenium/W 26% Rhenium 0 to 2320C 1% to 2320C, 4.5C to 425C D Tungsten 3% Rhenium/W 25% Rhenium 0 to 2320C 1% to 2320C, 4.5C to 425C

14 Diodes GaAs, Si, GaAlAs GaAlAs Temperature range is 1.4K-325K. It still work in moderate magnetic fields up to 5T. GaAs works from 1K to 400K. Its relative( compare with resistant thermometer) magnetic field insensitivity. For example, in the temperature range from 2 to 40 K, the apparent temperature error is approximately 0.1 K in a magnetic field of 2 T. This error increases to between 0.6 and 1 K for magnetic fields of 4 T. Small, fast response,field dependent, Moderate sensitivity over large T- range Cryogenics V14, Issue2, February 1974, Pages 67-70

15 PTC Resistance Thermometers PTC = Positive Temperature Coefficient. That is, the resistance increases as the temperature increases. :Pt, Rh- Fe. Platinum resistance thermometers are extremely stable, but their temperature response limits them to use above 13 K(10-30K,30K above). Rhodium iron resistance thermometers cover the 0.65 K to 400 K temperature range but perform badly in magnetic fields.

16 PTC Resistance Thermometers The common positive magnetor esistance in metals. PTC resisters are used for heater. PHYSICAL REVIEW B VOLUME 25, NUMBER 8

17 NTC Resistance Thermometers CGR(carbon glass) 1.4 K to 100 K and in magnetic fields up to 20 tesla, worse long time stable. GR 0.05 K to 100 K are available for germanium resister, resistors very useful for submillikelvin control at 4.2 K and below. Use in a magnetic field is not recommended. RuO2, Ruthenium oxide works from 10mK to 40K with most models suitable for use in applications involving magnetic fields. Cernox (a sapphire substrate via reactive sputtering of zirconium in an oxygen-nitrogen-argon atmosphere.), below 4.2 K with low magnetic field-induced calibration offsets at fields ranging to 10 T. AIP Conference Proceedings 684, 393 (2003); doi: /

18 Capacitance Glass-ceramic exhibited a large, temperature-dependent dielectric permittivity at low temperatures to 300K, and in magnetic fields up to 15T from 1.5 to 4.2 K. Insensitive to magnetic field and circuit requires care and attention. low signal-to-noise ratio Cu and Kapton sensitive to temperature, insensitive to rapidly changing high magnetic fields.(100mk?-4.5k) Lawless, W. N. Advances in Cryogenic Engineering 16 (1971) 261 Lawless, W. N., Radebaugh, R., and Soulen, R. J. Rev Sei Instr 42 (1971) 567 Lawless, W. N. Rev Scilnstr 42 (1971) 561 Rev. Sci. Instrum., Vol. 72, No. 8, August 2001

19 Thanks!