Team Supercool
Andy Lin
Chris Kinney
Naomi Kohen
David Schoen

Superconducting Actuator




Zero resistance at low T
Electrical actuator:
Electrical E  Mechanical E
American Superconductor
Goal: HTS solenoid punch

Why superconducting?
Low resistance  Higher efficiency
Higher current density  Larger field
Fewer turns  Simple design and manufacturing

Superconductor Physics

Impenetrable by external magnetic fields (up to a point)

Type I & II Superconductors

Cooper Pairs

BSSCO 2223: Our Tape





Provided by American
Superconductor
4 mm (w) x 0.21mm (t)
Critical Current rating 85
– 108 A
Critical Temp (T c
) 110K
Currently 2 pieces; 4 and
50 m long

BSSCO 2223: I
C vs. H

The Punch



Use solenoid for magnetic field
An iron core accelerates in the field
A strong field will produce a significant force.

Coil Dimensions

Inner Coil between 50 mm and 100 mm in diameter

Coil height approximately 75mm

Between 320 and 160 turns with 50 meters of wire

Critical Current Setup

Critical Current
Measurements
Voltage vs. Current
10
1
0.1
0.01
0 50 100
Current (A)
150
Trial 1, 77K, 2/28/04
Trial 2, 77K, 2/28/04
Trial 3, 77K, 3/2/04

Coil Radius Setup

0.1
0.01
0.001
0
1
Coil Radius Measurements
Voltage vs. Current
50
Current (A)
100 150
Trial 1
Trial 2

The Apparatus

The Apparatus

Materials Choice

PVC



Inexpensive
Machinable
Diamagnetic

Al




Inexpensive
Easily Machinable
Paramagnetic
Durable

400
300
200
100
Estimates
0.1
0.2
Displacement (m)
0.3
0.4

Estimates
120
100
80
60
40
20
0.1
0.2
Displacement (m)
0.3
0.4

Comparisons

Future Considerations

Running colder than 77K

Making a taller or shorter coil

Punch striking surface

Punch shape

Retraction Mechanism

Pulse (with capacitor)?

Tests

Obtain comparable copper solenoid

Magnetic field

Force

Energy density per mass

Schedule

Questions?

Calculating Force

For Loop
B

NIr
2
2 ( r
2  x
2
)
3
2

Force: dF

A

M
 
B
 dx

Magnetization of Iron: 334225 A/m