Jonathan J. Hahne

Function: Senior Engineering Scientist

Biography

Mr. Hahne joined UT-CEM in 1986.  He has been involved with the design and fabrication of a high power current distribution buswork for the 60 MJ, 9MA Balcones Homopolar Generator power supply; has designed and fabricated a 3.2 MA, 10 KV buswork system for the 90 mm round-bore tactical railgun program; and helped develop and implement high power, explosively operated opening and closing switches for controlling high power pulsed-power systems.

As part of the U.S. Army's EM Gun Focused Technology Program (FTP), Mr. Hahne designed and fabricated a stainless steel spin test bed for proof testing high-speed ceramic ball bearings, squeeze-film dampers, and segmented carbon shaft seals.  He then designed and fabricated the first composite stator tube assembly for a high power compulsator.  The stator and three-phase armature were rated for 1.2 MA and 8 KV with a peak discharge torque of 4E6 ft-lbs.  This six-pole, three-phase armature design required the design and testing of a new glass wrap reinforcing scheme to hold the armature conductors during discharge.

Mr. Hahne was responsible for the redesign and rebuild of the high-speed rotor and field coil assembly for the sub-scale FTP compulsator.  The field coil was a two-layer, six-pole design with the conductor geometry optimized for improved impedance and the gap between conductors optimized for applied strain on the composite matrix.  This rotor assembly is rated for 12,000 rpm with a peak field current of 48 KA and 17 KV.  The rebuild of this rotor field coil required developing and testing a new high-strain insulation system for the high voltage coil.  Mr. Hahne was also the project engineer in charge of testing and operating the sub-scale FTP compulsator system.  This system successfully reached program goals by discharging at full speed into a railgun and a fixed resistance load.

As part of the follow-on effort in the US Army Electric Gun program, Mr. Hahne was the assistant program manager for the EM Gun programs at UT-CEM.  The follow-on efforts included the design, development, and manufacturing of two, counter-rotating pulsed alternator rotors for the US Army ATO EM Gun power supply demonstration project.  These rotors were the first actively cooled pulsed alternator rotors and well as the first with composite growth matching arbors.  This program pioneered the design, manufacturing, and assembly processes for these advanced high power density rotating devices.  The development efforts also focused on the next generation pulsed alternator technology challenges for more compact and power dense power supplies for mobile applications.

Mr. Hahne was a part-time undergraduate lab assistant at UT-CEM for four years prior to graduating from UT.  He was involved in the distributed energy storage railgun project, the ultrahigh-velocity “GEDI” experiments, the design and fabrication of a 50 kJ capacitor bank and small plasma railgun system for industrial applications research, and the initial work for the development of solid armatures.

Current Projects

* Electric motors efficiency study and prototype manufacturing

* Trapped field magnet activation testing including development and design of 1 MW cryogenic prototype motor

* High slew rate rotational turret drive

Research Areas/Areas of Interest

* Development, design, manufacturing, and testing of prototype rotating electrical machines.  High strength composites development and application-driven manufacturing.

Education

* B.S., Mechanical Engineering, The University of Texas at Austin, 1986

Awards

* Explosively Actuated Thermal Opening Switch, (with J.L. Upshaw, R.J. Hayes, R.C. Zowarka, Jr., J.P. Kajs, and R.L. Sledge, II), U.S. Patent No. 5,360,999, November 1994