Dr. Alex Friedman

Superconductivity

1. Development of a Superconducting Magnet Energy Storage (SMES) device using high temperature superconducting (HTS) coil operating in liquid nitrogen - demonstration model was built and satisfied the test. New concept of the converter is patented.

2. Study of the behavior of HTS (BSCCO and YBCO based) wire and coils carrying direct current in alternating magnetic field.

3. Development of Fault Current Limiters (FCL) based on "saturated core" concept. Several designs are patented. Demonstration model of 120 kVA was built and satisfied the test.

4. Methods of HTS coils manufacturing.

5. AC losses in HTS coils

6. Development of Nb₃Sn superconducting coils made by 'wind and react' method for 200kVA generator. Manufacturing technologies are patented. Similarity of mechanical properties of Nb₃Sn and BSSCO wires makes these technologies suitable for HTS coils.

7. Study of the fine structure of superconducting materials and multifilamentary wires and its correlation with magnetic and transport properties.  Influence of the process parameters on pinning centers distribution. The results of this research were used for improving manufacturing technology of the Nb-Ti superconducting wires.

   Other topics: HTS persistent current switch, HTS transformer

Magnetic materials, permanent magnets and magnetic systems

1. Study of the crystal structure of hard magnetic materials and its correlation with coercitivity. Some new kinds of modulated structures are described. Distortion of the crystal lattices of magnetic and nonmagnetic phases defined.

2. Design of magnetic systems including permanent magnets and coils.

3. Development of manufacturing technology of permanent magnets for special motors and other applications. Cast, rare earth and ceramic magnets. Magnetic measurements. Most of the developed magnets were used in the unique designs of the motors and other devices.

4. Design and manufacturing of coils for study of neurons behavior under magnetic field pulses (relating to Transcranial Magnetic Stimulation - TMS)

Other topics: magnetic separation

Other activities

-   Study and development of dry lubricant materials operating in hard conditions. On the base of the new approach to component's interaction two new patented dry lubricants are developed. Thermodynamic calculations of systems including molibden and tungsten chalcogenides with transition metals were performed.

-   Metal - titanium nitride composites: study of materials and technology development. Some rocket nozzles were made and tested.

2020

Phase Coupling Effects in Three-Phase Inductive Fault-Current Limiter Based on Permanent Magnets
John Linden, Yasha Nikulshin , Alex Friedman, Yosef Yeshurun and Shuki Wolfus
IEEE Transactions on Magnetics, 56, 8600107 (2020).

2019

Design and testing of a system for measuring high-frequency AC losses in superconducting wires and coils carrying DC and AC currents.
Y. Nikulshin, V. Ginodman, A. Friedman, Y. Yeshurun, and S. Wolfus
Review of Scientific Instruments 90, 065111 (2019).

Design Optimization of a Permanent-Magnet Saturated-Core Fault-Current Limiter
John Linden, Yasha Nikulshin , Alex Friedman, Yosef Yeshurun and Shuki Wolfus
Energies 12, 1823 (2019).

2018

Monel contribution to AC losses in MgB₂ wires in frequencies up to 18 kHz
Y. Nikulshin, Y. Wolfus, A. Friedman, V. Ginodman, G. Grasso, M. Tropeano, G. Bovone,
M. Vignolo, C. Ferdeghini, and Y. Yeshurun
IEEE Transaction on Applied Superconductivity 28, 6200906 (2018).

AC losses in MgB2 wires and tapes in frequencies up to 18 kHz
Y. Nikulshin, S. Wolfus, V. Ginodman, A. Friedman, M. Tropeano, G. Grasso and Y. Yeshurun
IEEE Transactions on Applied Superconductivity 28, 8201504 (2018).

2016

Saturated Cores Fault Current Limiters  in a Live Grid

Y. Nikulshin, Y. Wolfus, A. Friedman, Y. Yeshurun, V. Rozenshtein, D. Landwer, and U. Garbi

IEEE Transactions on Applied Superconductivity  26, 5601504 (2016).

2015

Improving the performance of Saturated Cores Fault Current Limiters by varying winding density in the AC coils.

Y. Nikulshin, Y. Wolfus, A. Friedman, and Y. Yeshurun

 IEEE Transactions on Applied Superconductivity 25, 5602705 (2015).     
 

Dynamic Inductance in Saturated Cores Fault Current Limiters

Y. Nikulshin, Y. Wolfus, A. Friedman, Y. Yeshurun

Proc. ICMS Conf., Antalya, invited  (2014).

Journal of Superconductivity and Novel Magnetism, 28, 579 (2015).

2014

Double-Storey, Three-Phase, Novel Saturated-Cores Fault-Current-Limiter

Y Wolfus, Y Nikulshin, A Friedman and Y Yeshurun

Journal of Physics: Conf. Series (EUCAS) 507, 032058 (2014).

Vortex structure and magnetic properties of BaFe₂(As_1-xP_x)₂ single crystals

L Vinnikov, A Friedman, I. Felner, A Troshina ,and Y Yeshurun

Journal of Physics: Conf. Series (EUCAS) 507, 012013 (2014).

Dynamic Inductance in Saturated Cores Fault Current Limiters

Y. Nikulshin, Y. Wolfus, A. Friedman, Y. Yeshurun

Proc. ICMS Conf., Antalya, invited  (2014).

Journal of Superconductivity and Novel Magnetism

2013

Dynamic core length in saturated core fault current limiters

Y. Nikulshin, Y. Wolfus, A. Friedman and Y. Yeshurun

Supercond. Sci. Technol. 26, 095013 (2013).

2012

Dynamic Desaturation Process in Saturated Cores Fault Current Limiters

Nikulshin, Y.; Friedman, A.; Wolfus, Y.; Rozenshtein, V.; Yeshurun, Y. IEEE Transactions on Applied Superconductivity, 2012 Vol. 22, Issue: 3 , Page(s): 5601704

Critical currents and AC losses in YBCO Coils

Friedman Alex, Wolfus Yehoshua, Kopansky Faina, and Yeshurun Yosef

Physics Procedia 36, 1169 (2012).

2011

Mechanisms of Magnetic Stimulation of Central Nervous System Neurons

Tamar Pashut, Shuki Wolfus, Alex Friedman, Michal Lavidor, Izhar Bar-Gad, Yosef Yeshurun, and Alon Korngreen
PLoS Computational Biology 7, e1002022(2011).

Mini-coil for magnetic stimulation in the behaving primate H. Tischler, Y. Wolfus, A. Friedman, E. Perel, T. Pashut, M. Lavidor,A. Korngreen, Y. Yeshurun and I. Bar-Gad
Journal of Neuroscience Methods 194, 242 (2011).

2010

AC losses in HTS multi-pancake coils made of BSCCO-tape
Friedman Alex , Wolfus Yeoshua , Kopansky Faina and Yeshurun Yosef
J. Phys.: Conf. Ser. 234, 032014 (2010)

2009

Voltage response of current carrying Y–Ba–Cu–O tapes to alternating magnetic field
A. Uksusman, Y. Wolfus, A. Friedman, A. Shaulov, and Y. Yeshurun
J. Appl. Phys. 105, 093921 (2009).

2008

High-temperature superconducting magnet for use in Saturated core FCL

Z Bar-Haim, A Friedman, Y Wolfus, V Rozenshtein, F Kopansky, Z Ron E Harel, N Pundak and Y Yeshurun Proceedings of EUCAS2007 J. Physics: Conference Series 97,012294 (2008)

2007

 Saturated cores FCL- A new approach
V. Rozenshtein, A. Friedman, Y. Wolfus, F. Kopansky, E. Perel, Y. Yeshurun, Z. Bar-Haim, Z. Ron, E. Harel, and N. Pundak
IEEE Transactions on Applied Superconductivity 17, 1756 (2007).

 Energy loss and regimes of flux dynamics in Bscco tapes above the engineering critical current  
G. Lukovsky, A. Friedman, Y. Wolfus, L. Burlachkov and Y.Yeshurun
IEEE Transaction on Applied Superconductivity 17, 3137 (2007).

2006

 Electric field in Bi-223 tape carrying DC current and exposed to AC parallel magnetic  field

S. Asulay, A. Friedman, Y. Wolfus, F. Kopansky and Y.Yeshurun

Paper THA02PO14 presented at MT-19, Genova, Sep.2005

IEEE Transasactions on Applied Superconductivity,16 (2006)

Time dependent electric field and E-I curves in Bi-2223 tapes carrying DC currents and exposed to perpendicular AC magnetic fields Paper

A Friedman, G Lukovsky, V Roitberg, Y Wolfus, F Kopansky, B Kalisky and  Y Yeshurun

 Journal of Physics: Conference Series 43 (2006) 572–575

Calculated E-I characteristics of HTS pancakes and coils exposed to inhomogeneous magnetic fields

Y. Adanny, Y. Wolfus, A. Friedman, F. Kopansky and Y. Yeshurun

 Journal of Physics: Conference Series 43 (2006) 1068–1071

 Electric field in Bi-2223 tape carrying DC current and exposed to AC parallel magnetic field 

S. Asulay, A. Friedman, Y. Wolfus, F. Kopansky, and Y. Yeshurun

IEEE TRANSACTIONS ON APPLIED SUPERCONDUCTIVITY, VOL. 16, NO. 2, JUNE 2006 1067-1070

2005

I-V Curves of BSCCO Tape Carrying DC Current Exposed to Perpendicular and Parallel AC Fields 
A. Friedman, Y. Wolfus, F. Kopansky, I. Soshnikov, V. Roitberg, S. Asulay, B. Kalisky, and Y. Yeshurun
IEEE Trans. Appl. Supercond., 15, No. 2 (2005)

Compact HTS Cryogen-Free Magnet for Magneto-Optics Research Setup  
Y. Wolfus, A. Friedman, F. Kopansky, Y. Yeshurun, Z. Bar-Haim, Z. Ron, and N. Pundak
IEEE Trans. Appl. Supercond., 15, No. 2 (2005) 

Design of a laminated-steel magnetic core for use in a HT-SMES  
A. Friedman, M. Zarudi, N. Shaked, M. Sinvani, Y. Wolfus, Y. Yeshurun
Journal of Materials Processing Technology, 161, 28 (2005)

Core losses of the ‘saturated core’ FCL  
M. Zarudi, A. Friedman
Proceedings of EUCAS, p 781 (2005)

2004

 I-V curves of bifilar BSCCO tape exposed to AC magnetic field
N. Shaked, A. Friedman, M. Sinvani, F. Kopansky, Y. Wolfus and Y.  Yeshurun
Physica C,  401, 201 (2004).

 Estimation of the critical current of BSCCO coils based on the field dependent I-V curves of BSCCO tapes
Y. Wolfus, Y. Fleger, A. Friedman, F. Kopansky, B. Kalisky, and Y. Yeshurun, Z. Bar-Haim, Z. Ron, L. Ying, and N. Pundak     Physica C,  401, 222 (2004). 

2003

Design of a laminated-steel magnetic core for use in a HT-SMES
 A. Friedman, M. Zarudi, N. Shaked, M. Sinvani, Y. Wolfus and Y. Yeshurun
 Proceeding of JAPMED 3 , 13 (2003).

 HT-SMES Operating at Liquid Nitrogen Temperatures for Electric Power Quality Improvement Demonstrating
A. Friedman, N. Shaked, E. Perel, F. Gartzman, M. Sinvani, Y. Wolfus, D. Kottick, J. Furman, and Y. Yeshurun
IEEE Trans. Appl. Supercond., 13, No. 2 (2003)

2001

Effects of external magnetic field on the critical current in single and bifilar Bi-2223 tapes
N. Shaked, A. Friedman, M. Sinvani, I. A. Al-Omari, Y. Wolfus, A.. Shaulov and Y. Yeshurun
Physica C 354 (2001), 237.

1999

Superconducting Magnetic Energy Storage device operating at liquid nitrogen temperatures
A. Friedman, N. Shaked, E. Perel, M. Sinvani, Y. Wolfus, and Y. Yeshurun
Cryogenics 39, 53 (1999).

1998

  AC-induced DC voltage in HTS coil
I. A. Al-Omari, N. Shaked, A. Friedman, Y. Wolfus, A. Shaulov, M. Sinvani, and Y. Yeshurun
Proceedings of the International Cryogenic Materials Conference (ICMC98), Holland, 1998
Physica C 310, 111 (1998).

Direct current voltage increment due to AC coupling in a high-TC superconducting coil
N. Shaked, I. A. Al-Omari, A. Friedman, Y. Wolfus, M. Sinvani, A. Shaulov, and Y. Yeshurun
Appl. Phys. Lett. 73, 3932 (1998).

1997

Demonstration of a liquid nitrogen cooled high-TC superconducting magnetic energy storage
 A. Friedman, E. Perel, N. Shaked, M. Sinvani, Y. Wolfus, Y.Yeshurun
Proceedings of the Energy Power and Motion Control conference (EPMC97), Tel Aviv, p.17 (1997).

Relationship of solubility parameter (x), powder properties and phase formation in Nd1+xBa2-xCu3O6.5+x/2+d system
P. Yossefov, G. E. Shter, M. Reisner, A. Friedman, Y. Yeshurun, G. S. Grader
Physica C 275, 299 (1997).
                           See also Previous publications in English

Name:                                      Alexander  Friedman

Educational Background:   Ph.D. in Solid State Physics, Institute of Physical Metallurgy,

                                                   Russian  Academy of Science      1968

                                                  M.Sc. in Mathematics, Moscow State University, Russia    1965

                                                  M.Sc. in Powder Metallurgy, Moscow Institute of Steel, Russia  1959

Positions held:      1994-present  Senior Researcher,

                                                            National Center for Magnetic Measurements

                                  1990-1991  Head of Permanent Magnets Laboratory,

                                                        Institute of Electronics of Automotive Industry, Moscow, Russia

                                  1964-1990  Senior Researcher,  Laboratory of Physical Metallurgy,

         Institute of Electromechanics (VNIIEM), Moscow, Russia

                      1958-1962  Senior engineer, Institute of Hard Metals(Tverdych Splavov),

                                                         Moscow, Russia

LANGUAGES: Hebrew, English, French and Russian (native)