Apparatus and procedure to characterize the surface quality of conductors by measuring the rate of cathode emission as a function of surface electric field strength
A device and method for characterizing quality of a conducting surface. The device including a gaseous ionizing chamber having centrally located inside the chamber a conducting sample to be tested to which a negative potential is applied, a plurality of anode or “sense” wires spaced regularly about the central test wire, a plurality of “field wires” at a negative potential are spaced regularly around the sense, and a plurality of “guard wires” at a positive potential are spaced regularly around the field wires in the chamber. The method utilizing the device to measure emission currents from the conductor.
1. A device for determining surface smoothness of wires, the device comprising:
a. a gaseous ionization chamber, the gaseous ionization chamber including a conducting wall;
b. a test wire sample positioned centrally In the gaseous ionizing chamber and wherein the test wire sample has a test wire surface that is a cathode;
c. a plurality of sense wires positioned in the gaseous ionizing chamber in predetermined positions around the test wire and wherein each sense wire has a sense wire surface that is an anode;
d. a plurality of field wires positioned in the gaseous ionizing chamber in predetermined positions around the sense wires; and
e. a plurality of guard wires in the gaseous ionizing chamber in predetermined positions around the field wires.
2. The device of claim 1 wherein the field wires have a negative potential and the guard wires have a positive potential.
3. The device of claim 1 , wherein the gaseous ionizing chamber contains an amplifying gas.
4. The device of claim 3 , wherein the amplifying gas is a mixture of argon and carbon dioxide.
5. The device of claim 1 , wherein the sense wires receive a plurality of electrons from the test wire and produce a signal.
6. The device of claim 5 , therein the device further comprises a discriminator and wherein the signal is transmitted to the discriminator and the discriminator has an output.
7. The device of claim 6 further comprising a counting scaler for recording and displaying the output.
8. The device of claim 1 further comprising an algorithm for determining an operating voltage for the test wire, the sense wires, the field wires and the guard wires.
9. The device of claim 8 , wherein the algorithm determines operating voltages that maintain a constant sense wire electric field at the sense wire surface and a test wire electric field at the surface of the test wire wherein the test wire electric field is changeable in pre-determined steps.
10. A method for determining surface smoothness of fine wires, the method comprising:
a. providing a device, the device comprising a gaseous ionization chamber, the gaseous ionization chamber including a conducting wall; a test wire sample positioned in the gaseous ionizing chamber and wherein the test wire sample has a test wire surface that is a cathode; a plurality of sense wires positioned in the gaseous ionizing chamber in predetermined positions around the test wire and wherein each sense wire has a sense wire surface that is an anode; a plurality of field wires positioned in the gaseous ionizing chamber in predetermined positions around the sense wires; and a plurality of guard wires in the gaseous ionizing chamber in predetermined positions around the field wires wherein the sensing wires receive a plurality of electrons from the test wire and produce a signal;
b. applying a voltage independently to each of the test wire, the sensing wires, the field wires and the guard wires;
c. adjusting the voltages independently to the test wire, the sensing wires, the field wires and the guard wires to form a constant sense wire electric field at the surface of the sense wire and a changeable, predetermined test wire electric field at the surface of the test wire; and
d. measuring the signal.
11. The method of claim 10 wherein the field wires have a negative potential and the guard wires have a positive potential.
12. The method of claim 10 , wherein the gaseous Ionizing chamber contains an amplifying gas.
13. The method of claim 10 wherein the signal is transmitted to a discriminator and the discriminator produces a discriminator output signal.
14. The method of claim 13 wherein the discriminator output signal is measured and recorded using a counting scaler.
15. The method of claim 10 wherein each field wire has a field wire surface and a field wire surface electric field is formed at the field wire surface and wherein the field wire surface electric field is maintained essentially constant and below about 8 Kv/cm.
16. A device for determining surface smoothness of a conductive surface, the device comprising:
a. a gaseous ionization chamber, the gaseous ionization chamber including a conducting wall;
b. a test sample comprising a conductive surface positioned in the gaseous ionizing chamber and wherein the conductive surface is a cathode;
c. a plurality of sense wires positioned in the gaseous ionizing chamber in predetermined positions around the test sample and wherein each sense wire has a sense wire surface that is an anode;
d. a plurality of field wires positioned in the gaseous ionizing chamber in predetermined positions around the sense wires; and
e. a plurality of guard wires in the gaseous ionizing chamber in predetermined positions around the field wires.
17. The device of claim 16 wherein the field wires have a negative potential and the guard wires have a positive potential.
18. The device of claim 16 , wherein the gaseous ionizing chamber contains an amplifying gas.
19. The device of claim 6 wherein the sense wires receive a plurality of electrons from the test sample conductive surface and produce a signal.