1. An x-ray tube comprising:
a) a rotating anode having at least one structure for determining a property of a focal spot, wherein the structure is selected from a radial slit, a radial groove, a single pit, a series of pits that are offset to each other in radial and azimuthal direction, a spiral groove, a grooved spiral line, a slit with varying width in radial direction, and a groove with varying width in radial direction;
b) at least one cathode for emitting electrons that are accelerated towards the rotating anode such that the electrons impinge on the surface of the rotating anode and form the focal spot;
wherein the x-ray tube is adapted to produce a detection signal S(t) that changes when the structure on the rotating anode passes the focal spot.
2. The x-ray tube of claim 1, wherein the property is the focal spot width current distribution.
3. The x-ray tube of claim 1, wherein the slit with varying width in radial direction has a triangular shape.
4. The x-ray tube of claim 1, wherein the slit with varying width in radial direction has a double triangular shape.
5. The x-ray tube of claim 1, wherein the single pit is elongated in radial direction.
6. The x-ray tube of claim 1, wherein the spiral groove is adapted so that the change in the detection signal S(t) is proportional to the length of the focal spot.
7. The x-ray tube of claim 1, further comprising an auxiliary primary electron beam and an extra cathode for determining the width of slits.
8. A computer tomograph system comprising an x-ray tube as claimed in claim 1.
9. A method for determining a property of a focal spot of an x-ray tube, the x-ray tube having a rotating anode and a cathode, the method comprising the steps of:
a) rotating the anode, wherein the anode has a structure for generating a detection signal S(t) that changes when the structure on the rotating anode passes the focal spot, the structure comprising a radial slit, a radial groove, a single pit, a series of pits that are offset to each other in radial and azimuthal direction, a spiral groove, a grooved spiral line, a slit with varying width in radial direction, or a groove with varying width in radial direction;
b) emitting electrons from the cathode and accelerating the electrons towards the rotating anode such that the electrons impinge on the surface of the rotating anode and form the focal spot;
c) detecting the detection signal S(t); and
d) determining the property of the focal spot from changes of the detection signal S(t).
10. The method of claim 9, wherein the property is the focal spot width current distribution.
11. A computer configured to determine a property of a focal spot on a rotating anode of an x-ray tube, the x-ray tube having a rotating anode and a cathode, the computer configured to control the steps of:
a) rotating the anode, wherein the anode has a structure for generating a detection signal S(t) that changes when the structure on the rotating anode passes the focal spot, the structure comprising a radial slit, a radial groove, a single pit, a series of pits that are offset to each other in radial and azimuthal direction, a spiral groove, a grooved spiral line, a slit with varying width in radial direction, or a groove with varying width in radial direction;
b) emitting electrons from the cathode and accelerating the electrons towards the rotating anode such that the electrons impinge on the surface of the rotating anode and form the focal spot;
c) detecting the detection signal S(t); and
d) determining the property of the focal spot from changes of the detection signal S(t).
12. The computer of claim 11, wherein the property is the focal spot width current distribution.
13. A computer readable storage medium comprising instructions for performing a method for determining a property of a focal spot on a rotating anode of an x-ray tube, the x-ray tube having a rotating anode and a cathode, the method comprising:
a) rotating the anode, wherein the anode has a structure for generating a detection signal S(t) that changes when the structure on the rotating anode passes the focal spot, the structure comprising a radial slit, a radial groove, a single pit, a series of pits that are offset to each other in radial and azimuthal direction, a spiral groove, a grooved spiral line, a slit with varying width in radial direction, or a groove with varying width in radial direction;
b) emitting electrons from the cathode and accelerating the electrons towards the rotating anode such that the electrons impinge on the surface of the rotating anode and form the focal spot;
c) detecting the detection signal S(t); and
d) determining the property of the focal spot from changes of the detection signal S(t).
14. The computer readable storage medium of claim 13, wherein the property is the focal spot width current distribution.
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. A method of depositing a tellurium-comprising phase change material onto a substrate, comprising:
forming a monolayer comprising Te(OR)t onto a substrate from gaseous Te(OR)4, where R is alkyl and t is less than 4; and
providing a reducing agent to the monolayer to remove (OR)t ligand from the Te and forming there-from a tellurium-comprising phase change material on the substrate.
2. The method of claim 1 wherein the providing produces the phase change material to have no greater than 10 atomic percent oxygen.
3. The method of claim 1 wherein the providing produces the phase change material to have no greater than 5 atomic percent oxygen.
4. The method of claim 1 wherein the providing produces the phase change material to have no detectable oxygen therein.
5. The method of claim 1 wherein the reducing agent comprises at least one of NH3, H2, CH2O, and CH2O2.
6. The method of claim 5 wherein the reducing agent comprises NH3.
7. The method of claim 1 wherein the tellurium-comprising phase change material further comprises Ge.
8. The method of claim 1 wherein the tellurium-comprising phase change metal further comprises Ge and Sb.
9. The method of claim 1 comprising forming the monolayer to also comprise Te(OR)wQz from gaseous Te(OR)xQy, where Q is a halogen, x is less than 4, and y is 4\u2212x; and where at least one of w is less than x, or z is less than y.
10. A method of forming memory, comprising:
forming inner electrode material over a substrate;
forming phase change material over the inner electrode material, the forming of phase change material comprising:
forming a monolayer comprising Te(OR)t onto a substrate from gaseous Te(OR)4, where R is alkyl and t is less than 4; and
providing a reducing agent to the monolayer to remove (OR)t ligand from the Te and forming there-from a tellurium-comprising phase change material on the substrate.
11. The method of claim 10 further comprising forming an outer electrode material over the tellurium-comprising phase change material.
12. The method of claim 10 comprising forming the monolayer to also comprise Te(OR)wQz from gaseous Te(OR)xQy, where Q is a halogen, x is less than 4, and y is 4\u2212x; and where at least one of w is less than x, or z is less than y.
13. A method of depositing a phase change material onto a substrate, comprising:
forming a monolayer comprising Te(OR)wQz onto a substrate from gaseous Te(OR)xQy, where R is alkyl, Q is a halogen, x is less than 4, and y is 4-x; and where at least one of w is less than x, or z is less than y; and
providing a reducing agent to the monolayer to remove (OR)w ligand and Q from the Te and forming there-from a tellurium-comprising phase change material on the substrate.
14. The method of claim 13 wherein the phase change material has no greater than 10 atomic percent oxygen and comprising another metal in addition to tellurium.
15. The method of claim 13 wherein both of w is less than x and z is less than y.
16. The method of claim 13 wherein only one of w is less than x and z is less than y.
17. The method of claim 16 wherein w is less than x.
18. The method of claim 16 wherein z is less than y.
19. The method of claim 13 wherein the forming the phase change material comprises forming the phase change material over an inner electrode material.
20. The method of claim 19 wherein the inner electrode material comprises at least one of tungsten and titanium nitride.