1. A method for manufacturing an x-ray target, the method comprising:
combining a base material and a grain growth inhibitor material;
depositing the combined base material and grain growth inhibitor material onto a substrate; and
processing the combined base material and the grain growth inhibitor material to form a target track material by heat treating the target track material in a vacuum furnace at a temperature of 1,700 degrees Celsius for a period of about four to twelve hours to increase the density of the target track material.
2. The method as recited in claim 1, wherein the combining comprises combining the base material and the grain growth inhibitor material in a feedstock powder form before depositing the feedstock powder on the substrate.
3. The method as recited in claim 2, further comprising processing the feedstock powder to achieve a feedstock particle size of about 0.5 \u03bcm or smaller.
4. The method as recited in claim 1, wherein the combining comprises combining the base material and the grain growth inhibitor material in a feedstock powder form and depositing comprises a Vacuum Plasma Spray (VPS) process.
5. The method as recited in claim 1, further comprising placing a backing in thermal communication with the substrate,
6. The method as recited in claim 1, further comprising affixing a backing to the substrate with a bond layer.
7. The method as recited in claim 6, wherein the bond layer is formed with a braze process.
8. The method as recited in claim 7, wherein the braze process comprises:
placing one or more washers between the substrate and the backing;
heating the one or more washers for a predetermined time and at a predetermined temperature so as to form a braze bond layer.
9. The method as recited in claim 7, wherein the braze process comprises:
placing a hydride paste containing a braze material between the substrate and the backing
10. The method as recited in claim 6, wherein the bond layer is formed with a carbon management layer.
11. The method as recited in claim 10, wherein the carbon management layer is formed by:
coating the backing with a carbide forming metal to a predetermined thickness that is sufficient to retard carbon diffusion from the backing; and
processing the coating to form the carbon management layer.
12. The method as recited in claim 11, wherein the processing of the coating comprises a vacuum outgassing process.
13. The method as recited in claim 1, wherein the depositing comprises depositing the combined base material and grain growth inhibitor material onto the substrate as a single layer.
14. A method for manufacturing an x-ray target, the method comprising:
combining a base material and a grain growth inhibitor material;
depositing the combined base material and grain growth inhibitor material onto a substrate;
processing the combined base material and the grain growth inhibitor material to form a target track material; and
affixing a backing to the substrate with a bond layer, the bond layer formed with a braze process by placing a hydride paste containing a braze material between the substrate and the backing.
15. The method as recited in claim 14, wherein the base material and the grain growth inhibitor material are combined in a feedstock powder form before depositing the feedstock powder on the substrate.
16. The method as recited in claim 15, further comprising processing the feedstock powder to achieve a feedstock particle size of about 0.5 \u03bcm or smaller.
17. The method as recited in claim 14, wherein the base material and the grain growth inhibitor material are combined in a feedstock powder form and then deposited onto a substrate with a Vacuum Plasma Spray (VPS) process.
18. A method for manufacturing an x-ray target, the method comprising:
combining a base material and a grain growth inhibitor material;
depositing the combined base material and grain growth inhibitor material onto a substrate;
processing the combined base material and the grain growth inhibitor material to form a target track material; and
affixing a backing to the substrate with a bond layer, the bond layer formed with a carbon management layer and wherein the carbon management layer is formed by:
coating the backing with a carbide forming metal to a predetermined thickness that is sufficient to retard carbon diffusion from the backing; and
processing the coating to form the carbon management layer with a vacuum outgassing process.
The claims below are in addition to those above.
All refrences to claim(s) which appear below refer to the numbering after this setence.
1. Device for control of an electric power converter comprising control means for controlling turn-on of semi-conductor legs,
said electric power converter comprising:
DC voltage supply lines,
conversion means having at least three legs connected between said DC voltage supply lines and outputs to convert said DC voltage into output AC voltages, and
control means for controlling turn-on of said legs of the conversion means,
said control means comprising:
processing means to supply modulation signals of control signals of said legs,
means for determining a general control component for processing an over-modulation, said general control component being determined according to first modulation signals of the legs of the conversion means to process second modulation signals of the legs of the conversion means
wherein said means for determining comprise means for detecting a detection signal detecting current flowing in the outputs of the legs of said converter to be used in selection of at least one modulation signal receiving an over-modulation, said means for determining determining said general control component according to the first modulation signals and according to said detection signal detected by the means for detecting.
2. Device according to claim 1 wherein said detection signal is representative of an output line or of a phase in a three-phase system.
3. Device according to claim 1 wherein the means for detecting detect said detection signal in instantaneous current, quasi-instantaneous current, or with current signals with a small lag or a very low integration.
4. Device according to claim 1 wherein said means for detecting detect a first detection signal representative of a highest current in absolute value to supply a first detection signal acting as over-modulation reference, said means for determining comprising first processing means to supply a first general control component with over-modulation dependent on said first detection signal or on a modulation signal selected according to said detection signal.
5. Device according to claim 1 wherein said means for determining comprise means for controlling limiting of the general control component.
6. Device according to claim 5 wherein said means for controlling limiting receive modulation signals to supply negative and positive limiting values defining a limiting zone.
7. Device according to claim 5 wherein said means for detecting detect a second detection signal of a high current lower than the highest first current in absolute value to supply a second detection signal acting as over-modulation reference, said means for determining comprising second processing means to supply a second general control component with over-modulation dependent on said second detection signal or on a second modulation signal selected according to said second detection signal.
8. Device according to claim 7 wherein said means for controlling limiting receive:
a first signal representative of said first detection signal or of a modulation signal selected according to said first detection signal,
a second signal representative of said second detection signal or of a modulation signal selected according to said second detection signal, and
a control signal representative of a risk of over-modulation overshoot supplied by means for detecting an overshoot,
said means for controlling limiting supplying a selected detection or modulation signal representative of said first detection signal if a risk of overshoot is not detected or representative of said second detection signal if a risk of overshoot is detected to determine a general control component.
9. Device according to claim 7 wherein said means for controlling limiting receive:
a first signal representative of a first general control component dependent on said first detection signal,
a second signal representative of a second general control component dependent on said second detection signal, and
a control signal representative of a risk of over-modulation overshoot supplied by means for detecting an overshoot,
said means for controlling limiting supplying a general control component representative of the first general control component if a risk of overshoot is not detected or of the second general control component if a risk of overshoot is detected.
10. Electric power converter comprising:
DC voltage supply lines,
conversion means having at least three legs connected between said DC voltage supply lines and outputs to convert said DC voltage into output AC voltages,
control means for controlling turn-on of said legs of the conversion means,
at least one control device according claim 1; and
current measuring means arranged on output conductor lines and connected to said control device to supply signals representative of currents to said means for determining to be used in determining the general control component.
11. Method for controlling an electric power converter comprising:
conversion means having at least three legs connected between said DC voltage lines and outputs to convert said DC voltage into output AC voltages,
control means for controlling turn-on of the legs of said conversion means and comprising processing means to supply modulation signals of control signals of said legs,
said method comprising:
detection of a detection signal representative of a line where a highest current in absolute value is flowing,
selection of a modulation signal for application of an over-modulation, and
determination of a general control component according to signals resulting from detection of said detection signal, and from selection of a modulation signal.
12. Method according to claim 11 comprising computation of limit values of the general control component or of over-modulation
13. Method according to claim 12 comprising control of limiting of the general control component according to said limit values.
14. Method according to claim 11 comprising:
a first detection of a first detection signal representative of a line where a highest current in absolute value is flowing,
a first selection of a modulation signal for application of an over-modulation,
a first determination of a first general control component according to signals resulting from the first detection of a first detection signal, and from the first selection of a modulation signal,
a second detection of a second detection signal representative of a line where a high current lower than the first highest current in absolute value is flowing,
a second selection of a modulation signal for application of an over-modulation, and
a second determination of a second general control component according to signals resulting from the second detection of a second detection signal, and from the second selection of a modulation signal.
15. Method according to claim 14 comprising:
computation of limit values of the general control component or of over-modulation,
control of limiting of the first general control component to detect a risk of overshoot of the limit values, and
supply of a signal of a general control component representative of the first general control component if a risk of overshoot is not detected or of the second general control component if a risk of overshoot is detected.