Richard Packard

Office: 117 Birge
Main: (510) 642-1664
Other: (510) 642-4467
The Packard Group

Job title: 
Professor Emeritus
Bio/CV: 

Professor Packard received his Ph.D. in Physics from the University of Michigan in 1969. After a postdoctoral appointment at the University of California at Berkeley he was appointed to the faculty in 1971. Fellowships and honors include: The Donald Sterling Noyce Prize for Excellence in Undergraduate Teaching, Fellow of the American Physical Society, Fellow of the California Academy of Sciences, Fulbright Scholar and several visiting professorships at universities abroad.

Research Interests

Condensed Matter Physics, Experimental Low Temperature Physics, Quantum Liquids, Nanophysics.

Current Projects
Liquid helium is the simplest condensed matter system. It exists at temperatures down to absolute zero, is extremely pure, defect free, and devoid of spatial variations in temperature. Because of the simple nature of this system, it can be thought of as “the hydrogen atom” of condensed matter physics. It is an ideal system to test fundamental physical concepts.

The most important aspect of the Helium liquids involves Bose-Einstein Condensation (BEC) into a superfluid state. The superfluid states themselves have been very important model systems to test and demonstrate physical theories. One recent example includes work in which aspects of the Big Bang model are tested by observing quantized vortices. Another recent experiment uses superfluids to test models of intrinsic nucleation of defects.

Our Low Temperature group studies both 3He (a Cooper-paired Fermion system) and 4He (a Boson system) to test fundamental physical principles. We have cryostats which cool samples below 160µK. At such low temperatures, we can measure mass currents as low as 5x10-14 gm/s, determine hydrostatic pressures as small as 10-10 atm, and measure displacement as small as 10-15m. We have also developed micro-fabrication techniques to build entire experiments on the micron scale. Our techniques have led to a substantial number of “firsts” including: photographing quantized vortex lines in 4He, demonstrating that fluid circulation is quantized in 3He, proving that Cooper pairing is responsible for superfluidity in 3He, developing a superfluid gyroscope to detect the Earth’s motion, discovering the first superfluid 3He quantum weak links (Josephson junctions), detecting superfluid surface waves in 2-dimensional 3He and making the first superfluid dc-SQUID.

The group’s present research is focused on phenomena which exploit the properties of 3He weak links, 4He phase slippage, superfluid surface waves and He3:He4 mixtures. The specific projects include: 1. The development of a sensitive superfluid dc-SQUID to detect very small absolute rotation. 2. A study of the intrinsic limitations of 4He phase slip rotation sensors. 3. An investigation of the properties of 2-dimensional Fermi superfluid. 4. A demonstration of the Josephson frequency relation in 4He. 5. A search for quantized mass conductance in neutral matter.

A typical graduate student researcher in our group is involved with all aspects of his/her experiment, from the development of the experimental apparatus to the analysis and interpretation of the final data. Such training is intended to develop a well rounded scientist who has many of the skills expected in an experimental physicist.

The group consists of approximately three graduate students, one postdoctoral scientist and a technical assistant. We can accommodate one new graduate student in the group this year.

Publications

130 A continuously operating, flux locked, superfluid interferometer

A. Joshi and R. Packard, Journal of Low Temperature Physics (Online First), January 2013 

129 Superfluid helium interferometers

Y. Sato and R. E. Packard, Phys. Today 65, 31 (2012) 

128 Superfluid helium quantum interference devices: physics and applications

Y. Sato and R. E. Packard, Rep. Prog. Phys. 75 (2012) 016401 

127 On detecting absolute quantum mechanical phase differences with superfluid interferometers

Y. Sato and R. Packard, Physica E, vol. 43, Issue 3, Pages 702-706, January 2011 

126 DC-SQUID based neodymium magnet displacement sensor for superfluid experiments

Y. Sato and R. Packard, Review of Scientific Instruments 80, 055102 (2009) 

125 Fabricating nanoscale aperture arrays for superfluid helium-4 weak link experiments

A. Joshi, Y. Sato, and R. Packard, J. Phys.: Conf. Ser. 150 012018 (2009) 

124 Direct verification of the relation υs = (/m) ▽

Y. Sato, A. Joshi, and R. Packard, J. Phys.: Conf. Ser. 150, 032092 (2009) 

123 On the feasibility of detecting an Aharonov-Bohm phase shift in neutral matter

Y. Sato and R. Packard, J. Phys.: Conf. Ser. 150 032093 (2009) 

122 Superfluid 4He Quantum Interference Grating 

Y. Sato, A. Joshi, and R. Packard, Phys. Rev. Lett. 101, 085302 (2008)  

121 Simulations of Phase Slippage in an Aperture Array

Yuki Sato, Emile Hoskinson and Richard Packard, Journal of Low Temperature Physics, Volume 149, Numbers 5-6, Pages 222-229, 2007 

120 Flux locking a superfluid interferometer   (copyright info)

Y. Sato, A. Joshi, and R. Packard, Appl. Phys. Lett. 91, 074107 (2007) 

119 Observation of an extrinsic critical velocity using matter wave interferometry

Y. Sato, A. Joshi, and R. Packard, Phys. Rev. B 76, 052505 (2007) 

118 Direct Measurement of Quantum Phase Gradients in Superfluid 4He Flow

Y. Sato, A. Joshi, and R. Packard,  Phys. Rev. Lett. 98, 195302 (2007) 

117 Transition from synchronous to asynchronous superfluid phase slippage in an aperture array

 Y. Sato, E. Hoskinson, and R. E. Packard. Phys. Rev. B 74, 144502 (2006) 

116 Superfluid 4He interferometer operating near 2 K

E. Hoskinson, Y. Sato, and R. Packard. Phys. Rev. B 74, 100509 (2006) 

115 Transition from phase slips to the Josephson effect in a superfluid 4He weak link

E. Hoskinson, Y. Sato, I. Hahn and R. E. Packard, Nature Physics, Volume 2 No 1, pp23 - 26 (January 2006) 

114 A Chemical Potential “Battery” for Superfluid 4He Weak Links 

E. Hoskinson, Y. Sato, K. Penanen, and R. E. Packard, AIP Conf. Proc. 850, 117 (2006). [Proceedings of the 24th International Conference on Low Temperature Physics, August 2005] 

113 Calibration Technique for Superfluid 4He Weak-Link Cells Based on the Fountain Effect

E. Hoskinson and R. E. Packard, AIP Conf. Proc. 850, 119 (2006). [Proceedings of the 24th International Conference on Low Temperature Physics, August 2005]

112 Berkeley Experiments on Superfluid Macroscopic Quantum Effects

Richard Packard, AIP Conf. Proc. 850, 3 (2006) [2005 London Memorial Prize lecture] 

111 On the Feasibility of Detecting Quantized Conductance in Neutral Matter

Yuki Sato, Byeong-Ho Eom, and Richard Packard, Journal of Low Temperature Physics, Vol. 141, Nos. 3/4, November 2005 

110 Thermally Driven Josephson Oscillations in Superfluid 4He

E. Hoskinson, R. E. Packard, Physical Review Letters 94, 155303 (2005) 

109 Quantum Whistling in Superfluid He-4

E. Hoskinson, R.E. Packard, T.M. Haard; Nature, Vol 433, p 376, 27 January 2005 

108 Vortex Formation and Annihilation in Three Textures of Rotating Superfluid He-3-A

R. Ishiguro, M.Yamashita, O.Ishikawa, Y.Sasaki, K.Fukuda, M.Kubota H.Ishimoto, T.Mizusaki, T.Ohmi, T.Takagi, R.E.Packard; Physical Review Letters Vol 93, Num 12 Sept 2004 

107 Effect of He-3 on Third Sound Attenuation in Thick He-4 Films

K. Penanen, J.A.Hoffmann, J.C.Davis, R.E.Packard Journal of Low Temperature Physics, Vol134, Nos 5/6, March 2004 

106 Measurements of Attenuation of Third Sound: Evidence of Trapped Vorticity in Thick Films of Superfluid He-4

J.A.Hoffmann, K.Penanen, J.C.Davis, R.E.Packard; Journal of Low Temperature Physics Vol135, Nos.3/4 May2004 

105 Phase Slips and Josephson Weak Links in Superfluid Helium

R.E.Packard; Journal of Low Temperature Physics Vol.135 Nos. 5/6 June 2004

104 Velocity-dependent effective inertial mass in Superfluid He-3

K.Penanen, R.E.Packard PhysicalReview B 68 (092504) 2003 

103 Vortex nucleation and texture of rotating He-3-A in cylindrical cells with R similar or equal to 10 xi(D)

R. Ishiguro, M.Yamashita, T.Igarashi, E.Hayata, O.Ishikawa, Y.Sasaki, K.Fukuda, M.Kubota H.Ishimoto, T.Mizusaki, T.Ohmi, T.Takagi, R.E.Packard, Physica B (329-333) May 2003

102 Numerical Studies of Superfluid Shapiro effect

R.W.Simmonds, A.Marchenkov, J.C.Davis, R.E.Packard Physica B (329-333) 2003 

101 Development of a computer-based pulsed NMR thermometer

Hobeika A, Haard T.M., Hoskinson E.M., Packard R.E. Physica B-Condensed Matter 329, 1610 Part 2 May 2003 

100 Large area multiturn superfluid phase slip gyroscope

Bruckner N., Packard R. J. Of Appl. Phys. 93, 1798 Feb 2003 

99 Superfluid He-3 Josephson weak links

Davis J.C., Packard R.E. Rev. Of. Mod. Phys., 74, 741, Jul 2002 

98 A model for third sound attenuation in thick He-4 films

Penanen K., Packard R.E. J. Of Low Temp. Phys., 128, 25, Jul 2002 

97 Ballistic effusion of normal liquid He-3 through nanoscale apertures

Marchenkov A., Simmonds RW., Davis J.C., and Packard R., Phys. Rev. B, 65, 075414, Feb 2002 

96 Observation of the superfluid Shapiro effect in a He-3 weak link

Simmonds R.W., Marchenkov A., Davis J.C., and Packard R.E., Phys. Rev. Lett., 87, 035301, Jul 2001

95 Quantum interference of superfluid He-3

Simmonds R.W., Marchenkov A., Hoskinson E., Davis J.C., and Packard R.E., NATURE, 412 (6842): 55 Jul 2001 

94 An aperture array oscillator in superfluid He-4

Bruckner N, Packard R, Physica B, 284, 81, Part 1, Jul 2000 

93 NMR measurements of superfluid He-3-A in cylindrical cell under rotation

Ishikawa O, Ishiguro R, et al., Physica B, 284, 248, Part 1, Jul 2000 

92 Equilibrium thickness of saturated superfluid He-3 films on a copper substrate

Schechter A.M.R., Hoffmann J.A., Packard R.E., Davis J.C., Physica B, 284, 275, Part 1, Jul 2000 

91 Quality factor of a superfluid 3He weak link resonator

Proceedings of the 22d International Conference on Low Temperature Physics, LT22, August 1999. 

R. W. Simmonds, A. Marchenkov, J.C. Davis and R.E. Packard, August 1999 

90 Studies of a diaphragm-aperture array oscillator in superfluid 4He

N. Bruckner and R. Packard, Proceedings of the 22d International Conference on Low Temperature Physics, LT22, August 1999. 

89 New flow dissipation mechanisms in superfluid 3He

R.W. Simmonds, A Marchenkov, S. Vitale, J.C. Davis and R.E. Packard, Physical Review Letters, 84, 6062 (2000) 

88 The discovery of bi-stability in superfluid 3He weak links

A. Marchenkov, R.W. Simmonds, A. Loshak, J.C. Davis, and R. E. Packard, Physical Review Letters, 83, 3860 (1999) 

87 Observation of the Josephson Plasma mode for a superfluid 3He weak link

A. Marchenkov, R.W. Simmonds, A. Loshak, J.C. Davis, and R. E. Packard, Physical Review B, 61, 4196 (1999) 

86 Discovery of third sound in superfluid 3He films

A Schechter, R. Simmonds, R.E. Packard and J.C. Davis, Nature, 396, 554-557 (1998) 

85 Shot-noise acoustic radiation from a 4He phase slip aperture

S. Backhaus and R.E. Packard, Phys. Rev. Letters, 81, 1893 (1998). 

84 dc Supercurrents from Resonant Mixing of Josephson Oscillations in a He-3 Weak Link

R. W. Simmonds, A. Loshak, A. Marchenkov, S. Backhaus, S. Pereversev, S. Vitale, J. C. Davis, and R. E. Packard , Phys. Rev. Letters, 81, 1247 (1998) 

83 The role of the Josephson-Anderson equation in superfluid helium

R. Packard, Rev. Mod. Physics, 70, 641-652 ( 1998) 

82 Discovery of a metastable p state for a superfluid 3He weak link

S. Backhaus, R. Simmonds, A. Loshak, S. Pereversev, J.C. Davis and R. E. Packard, Nature 392, 687 (1998)

81 Detection of absolute rotation using superfluid 4He

K. Schwab, N. Brukner and R. Packard, Low Temp. Phys., 24, 102 (1998) 

80 The superfluid 4He analog of the rf-SQUID

K. Schwab, N. Bruckner and R.E. Packard, J. Of Low Temp. Phys., 110, 1043 (1998) 

79 Direct Measurement of the current-phase relationship of a superfluid 3He-B weak link

S. Backhaus, S. Pereversev, A. Loshak, J.C. Davis and R.E. Packard, Science 278, 1435 (1997) 

78 Thermoviscous effects in steady and oscillating flow of superfluid 4He experiments

S. Backhaus, K. Schwab, A. Loshak, S. Pereversev, N. Bruckner, J. C. Davis and R.E. Packard, J. Of Low Temp. Phys.,Vol 109 nos.3-4, pp 527-546, Nov 1997 

77 Quantum Oscillations in a superfluid 3He-B weak link

S.V. Pereversev, A Loshak, S. Backhaus, J.C. Davis and R. E. Packard, Nature, 338,  449-451, (1997) 

76 Detection of the Earth's rotation using superfluid phase coherence

K. Schwab, N. Bruckner and R.E. Packard, Nature, 386, 585 (1997) 

75 Phase slip memory effects in dissipation-free superflow

K. Schwab, J. Steinhauer and R.E. Packard, Phys. Rev. B, 55, 8094 (1997) 

74 An improved low temperature valve

N. Bruckner, S. Backhaus, and R.E. Packard, Proc. of the 21st International Conference on Low Temperature Physics, Czech. Journal of Physics, 46, 2741 (1996). 

73 A method to maintain superflow at constant pressure drive

S. Backhaus and R. E. Packard, Proc. of the 21st International Conference on Low Temperature Physics, Czech. Journal of Physics, 46, 2743(1996). 

72 The intrinsic critical velocity near T_lambda

Scott Backhaus, N. Bruckner, A. Loshak, K. Schwab and R. E. Packard, Proc. of the 21st International Conference on Low Temperature Physics, Czech. Journal of Physics, 46, 127 (1996)

71 A microfabricated superfluid 4He “RF Squid”,K. Schwab

J. C. Davis and R. E. Packard, Proc. of the 21st International Conference on Low Temperature Physics, Czech. Journal of Physics, 46, (1996) 

70 Study of an Array of superfluid 3He weak links

Yu. Mukharsky, A. Loshak, K. Schwab, J.C. Davis and R.E. Packard, Proc. of the 21st International Conference on Low Temperature Physics, Czech. Journal of Physics, 46, 115 (1996). 

69 Fabrication of a Silicon Based Superfluid Oscillator

K. Schwab, J. Steinhauer and R. E. Packard, IEEE Journal of Micromechanical Systems, 5, Sept. 1996 

68 The Relationship Between the Josephson Frequency and the Arrhenius Rate for Vortex Nucleation in Superfluid 4He

J. Steinhauer, S. Backhaus and Richard E. Packard. Phys. Rev. B, 52, 9654 (1995). 

67 The Determination of the Energy Barrier for Phase Slips in Superfluid 4He

J. Steinhauer, K. Schwab, Y. Mukharsky, J.C. Davis and R. E. Packard, J. Of Low Temp. Phys., 100, 281(1995). 

66 Vortex Nucleation in Superfluid 4He

J. Steinhauer, K. Schwab, Yu. Mukharsky, J.C. Davis and Richard Packard,  Phys. Rev. Letters, 74, 5056, (1995).

65 Liquid Helium

Macmillan Encyclopedia of Physics, accepted for publication 1995. 

64 Quantized Vortices

McGraw Hill Encyclopedia of Science and Technology, accepted for publication 1995. 

63 A Mechanical Measurement of Textural Relaxation in Superfluid 3He-A at Very Low Temperatures

R.J. Zieve, Yu. M. Mukharsky, J. C. Davis, and Richard Packard Jour. Of Low Temp. Phys.,99, 1 (1995).

62 Phase Slips in Space

Richard E. Packard,  Proc. of the NASA/JPL 1994 Microgravity Low Temperature Physics Workshop, JPL D-11775, 292 

61 Effect of 3He Impurities on the Nucleation of Phase Slips in Superfluid 4He

Y. M. Mukharsky, K. Schwab, J. Steinhauer, A.Amar, Y. Sasaki, J. C. Davis, and R.E. Packard, 20th International Conference on Low Temperature Physics, Aug 1993 

60 The Characteristic Response Curve, I(Ø), of a 3He Weak Link

J. Steinhauer, K. Schwab, Yu. M. Mukharsky, J.C. Davis and R.E. Packard, 20th International Conference on Low Temperature Physics, Aug 1993 

59 Investigations of Quantized Circulation in Superfluid 3He-B

R.J. Zieve, Yu. M. Mukharsky,  J. D. Close, J. C. Davis and R. E. Packard; J. Low Temp. Physics, 91, 315 (1993) 

58 Stable Circulation in Superfluid 3He-A

R. J. Zieve, Yu. Mukharsky, J. D. Close,J.C. Davis and R. E. Packard; J. of Low Temp. Physics, 89, 47 (1992) 

57 A Method to Fabricate Submicron Holes in Very Thin Silicon Nitride Membranes

A. Amar, R. L. Lozes and R.E. Packard,  J. of Vacuum Technology, April 1993 

56 New Experiments on Quantized Circulation in Superfluid 4He

R.J. Zieve,  J. D. Close, J, C, Davis and R. E. Packard,  J. of Low Temp. Physics 90, 243 (1993) 

55 Experiments on Quantized Circulation in Superfluid 3He

 J.C. Davis, J.D. Close, R. Zieve and Richard E. Packard. Physica 178, 73 (1992) 

54 Evidence for Quantum Tunneling of Phase-Slip Critical Velocities in Superfluid 4He

J. C. Davis, J. Steinhauer, K. Schwab, Yu. Mukharsky, A. Amar, Y. Sasaki and R. E. Packard,  Phys. Rev. Letters, 69, 323 (1992) 

53 Quantized Phase Slips in Superfluid 4He

A. Amar, Y. Sasaki, J. C. Davis and R.E. Packard,  Phys. Rev. Letters 68, 2624, 1992

52 Principles of Superfluid Gyroscopes

R. E. Packard and S. Vitale, Phys. Rev. B, 46, 3540 (1992) 

51 Precession of a Single Vortex Line in Superfluid 3He

R.J. Zieve, Yu. Mukharsky, J. D. Close, J, C, Davis and R. E. Packard, Phys. Rev. Letters, 68, 1327 (1992) 

50 Some Phenomenological Theoretical Aspects of Superfluid Critical Velocities

R.E. Packard and S. Vitale, Phys. Rev. B, 45 2512 (1992) 

49 The Superfluid Helium Gyroscope: An Emerging Technology for Earth Rotation Studies

J. C. Davis and R. E. Packard, Proc. of the AGU Chapman Conference on Geodetic VLBI: Monitoring Global Change, NOAA Technical Report Nos. 137 NGS 49 (1991) 

48 Observation of Quantized Circulation in Superfluid 3He

J.C. Davis, R.J. Zieve, J.D. Close and R.E. Packard, Phys. Rev. Letters, 66, 329 (1990) 

47 Vibrating Wire Measurements of Circulation in Superfluid 3He

J.C. Davis, R.J. Zieve, J.D. Close and R.E. Packard, Physica 165 and 166  (1990) 

46 Phase Slips in the Flow of Superfluid 4He Through a Submicron Orifice

A. Amar, J.C. Davis R.E. Packard and R.L. Lozes, Physica 165 and 166 753 (1990) 

45 Continuously pumped rotating millikelvin cryostat

J. D. Close, R. J. Zieve, J. C. Davis and R. E. Packard.  ; Physica B 165 and 166, 57 (1990). 

44 On the superfluidity of 3He films

J.C. Davis, A. Amar, J.P. Pekola and R.E. Packard. Phys. Rev. Lett. 60, 302 (1988). 

43 Evidence of thermally activated dissipation in flowing superfluid 3He

J. P. Pekola, J. C. Davis and R. E. Packard, J. Low Temp. Phys. 71, 141 (1988). 

42 Observations on the flow properties of 3He films below 1 mK

J. C. Davis, A. Amar, J. P. Pekola and R. E. Packard. , in Proceedings 18th Int. Conf. on Low Temperature Physics, Kyoto, p. 147 (1987), and Japanese J. of Appl. Phys. Vol. 26 Supplement 26-3 (1987). 

41 Suppression of the critical current and the superfluid transition temperature of 3He in a single submicron cylindrical channel

J. P. Pekola, J. C. Davis, Z. Yu-Qun, R. N. R. Spohr, P. B. Price, and R. E. Packard. J. Of Low Temp. Phys. 67, 47 (1987). 

40 Manufacture, observation, and test of membranes with locatable single pores

R. E. Packard, J. P. Pekola, P. B. Price, R. N. R. Spohr, K. H. Westmacott and Zhu Yu-Qun.  ; Rev. Sci. Instrum. 57 (8), 1654 (1986). 

39 Phase diagram of the first-order vortex-core transition in superfluid 3He-B

J. P. Pekola, J. T. Simola, P. J. Hakonen, M. Krusius, O. V. Lounasmaa, K. K. Nummila, G. Mamniashuili, G. E. Volovik and R. E. Packard. Phys.Rev. Lett. 53, 584 (1984). 

38 Persistent current experiments on superfluid 3He-Band  3He-A

J. P. Pekola, J. T. Simola, K. K. Nummila, O. V. Lounasmaa, and R. E. Packard.  Phys. Rev. Lett. 53, 70 (1984). 

37 A silicon fourth sound resonator

K. Daly and R. E. Packard.  , in Proceedings of the 17th International Conference on Low Temp. Physics, North Holland Park, California, 1984, U. Eckern, A. Schmid, W. Weber, H. Wuhl (eds), Elsevier Science Publishers B.V., p. 73-74 (1984). 

36 Persistent current experiments on superfluid 3He

Pekola, J. T. Simola, K. K. Nummila, O. V. Lounasmaa, R. E. Packard. , in Proceedings of the 17th International Conference on Low Temp. Physics, North Holland Park, California, 1984, U. Eckern, A. Schmid, W. Weber, H. Wuhl (eds), Elsevier Science Publishers B.V., p. 35-36 (1984). 

35 Observation of flow dissipation in 3He-B

J. P. Eisenstein and R. E. Packard. Phys. Rev. Lett. 49, 564 (1982). 

34 Photographic studies of quantized vortex lines.

E. J. Yarmchuk and R. E. Packard.    J. Low Temp. Phys. Nos. 5/6 (1982). 

33 Vortex photography in liquid helium

R. E. Packard. ; Physica 109 & 110B, 1474 (1982). 

32 A measurement of anisotropy in the dielectric constant of 3He-A

G. W. Swift, J. P. Eisenstein and R. E. Packard. Physica 107B, 283 (1981).

31 Helium gas purity monitor for recovery systems

S. L. Garrett, G. W. Swift and R. E. Packard.  Physica 107B, 601 (1981). 

30 Quasiparticle mean free path and Poiseuille flow in normal liquid 3He

J. P. Eisenstein, G.W. Swift and R. E. Packard. Physica 108B, 1061 (1981). 

29 Rapid shutdown and restart of a millikelvin cryostat

J. P. Eisenstein, G. W. Swift and R. E. Packard. Cryogenics, April 1981, p. 241 (1981). 

26 Measurement of anisotropy in the dielectric constant of 3He-A

G. W. Swift, J. P. Eisenstein and R. E. Packard. Phys. Rev. Lett. 45, 1955 (1980). 

25 Influence of a magnetic field on flowing superfluid 3He

J. P. Eisenstein, G. W. Swift and R. E. Packard. Phys. Rev. Lett. 45, 1569 (1980). 

24 The effect of quasiparticle mean free path on Poiseuille flow in normal liquid 3He

J. P. Eisenstein, G. W. Swift and R. E. Packard. Phys. Rev. Lett. 45, 1199 (1980). 

23 A technique for photographing vortex positions in rotating superfluid helium

G. A. Williams and R. Packard. J. Low Temp. Phys. 39, 553 (1980). 

22 A microprocessor controller for a nuclear demagnetization cryostat

J. P. Eisenstein, G. W. Swift and R. Packard. Cryogenics 19, 666 (1979). 

21 Observation of a critical current in 3He-B

J. Eisenstein, G. W. Swift and R. Packard. Phys. Rev. Lett. 43, 1676 (1979). 

20 Observation of stationary vortex arrays in rotating superfluid helium

E. J. Yarmchuk, M. J. V. Gordon and R. Packard. Phys. Rev. Lett. 43, 214 (1979). 

19 Thermal contraction of Vespel SP-22 and Stycast 1266 from 300K to 4K

G. W. Swift and R. Packard. Cryogenics 19, 362 (1979). 

18 Ion trapping on vortex lines in rotating 3He-4He mixtures

G. A. Williams and R. Packard. J. Low Temp. Phys. 33, 459 (1978). 

17 Vortex photography:  a progress report

M. Gordon, G. A. Williams and R. Packard.   in Proceedings of 15th International Low Temperature Conference, August 1979, J. de Physique, Colloque C6, 8, Tome 39, p.C6-1/2 (1978). 

16 Photography of vortex lines

G. A. Williams and R. Packard.  in McGraw-Hill Yearbook of Science and Technology, McGraw-Hill Book Co., New York, p. 204 (1975). 

15 Effect of 3He impurities on the lifetime of ions trapped on quantized vortex lines

G. A. Williams and R. Packard. Phys. Rev. Lett. 35, 237 (1975). 

14 Measurement of equilibrium critical velocities for vortex information in superfluid helium

K. DeConde and R. Packard. Phys. Rev. Lett. 35, 732 (1975); also covered in Measurement of critical velocities for vortex creation:  The attainment of the equilibrium state in rotating helium, 14th International Symposium of Low Temperature Physics (1975). 

13 Positive ion trapping on vortex lines in rotating He II

A. Williams, K. Deconde and R. Packard. Phys. Rev. Lett. 34, 924 (1975); also covered in Trapped ion lifetimes in 3He-4He superfluid mixtures, 14th International Symposium on Low Temperature Physics (1975). 

12 New factors affecting the measured lifetime of electrons trapped on vortex lines in He II

K. DeConde, G. A. Williams and R. Packard. Phys. Rev. Lett. 33, 683 (1974). 

11 A triaxial rotating vacuum seal

R. Packard and G. A. Williams. Rev. Sci. Instr. 45, 9 (1974).

10 Extraction of images from a very low temperature cryostat using fiber optics

G. A. Williams and R. Packard. Rev. Sci. Instr. 45, 1029 (1974). 

09 Photographs of quantized vortex lines in rotating He II

G. A. Williams and R. Packard. Phys. Rev. Lett. 33, 280 (1974). 

08 An upper limit to rotational cooling in superfluid helium

K. DeConde and R. Packard. Phys. Lett. 47A, 233 (1974). 

07 Thickness of the moving superfluid film at temperatures below 1K

A. Williams and R. Packard. Phys. Rev. Lett. 32, 587 (1974). 

06 An attempt to photograph the vortex lattice in rotating He II

R. Packard and G. A. Williams, in  Low Temperature Physics LT 13, K. D. Timmerhaus, W. G. O'Sullivan and E. F. Hammel (eds), Plenum Publishing Corp. New York, Vol. 1, p. 311 (1972). 

05 Observations of single vortex lines in rotating superfluid helium

R. Packard and T. M. Sanders. Phys. Rev. A 6, 799 (1972). 

04 Pulsar speedups related to metastability of the superfluid neutron-star core

R. Packard. Phys. Rev. Lett. 28, 1080 (1972). 

03 Ultraviolet emission spectra of electron-excited solid and liquid neon

F. Reif, R. Packard and C. M. Surko. Phys. Rev. Lett. 25, 1435 (1970). 

02 Spectroscopic study of the luminescence of liquid helium in the vacuum ultraviolet

C. M. Surko, G. J. Dick, R. Packard and F. Reif.  Phys. Rev. Lett. 23,  657 (1970). 

01 Detection of single quantized vortex lines in rotating He II

T. M. Sanders and R. Packard. Phys. Rev. Lett. 22, 823 (1969). 

* This article may be downloaded for personal use only. Any other use requires prior permission of the author and the American Institute of Physics. Reproduced from Appl. Phys. Lett. 91, 074107 (2007), Copyright 2007, American Institute of Physics.”


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