1. An apparatus for accelerating and compressing plasma, comprising:
a plasma accelerator comprising a tubular outer electrode and a tubular inner electrode extending inside the outer electrode such that an annular plasma propagation channel is defined therebetween for accelerating and compressing a plasma torus therethrough, the accelerator having an inlet for receiving the plasma torus from a plasma generator, an outlet for discharging an accelerated and compressed plasma torus, the plasma propagation channel having a lengthwise elongated section with an upstream end in fluid communication with the inlet and a downstream end in fluid communication with the outlet, and wherein a cross-sectional annular gap defined as a radial distance between the inner and outer electrodes decreases non linearly in a downstream direction along the length of the elongated section; and
a power source electrically coupled to the accelerator and configured to provide an electrical acceleration pulse that produces a current that flows in the accelerator and generates a magnetic pushing flux behind the plasma torus that is sufficient to push the plasma torus from the upstream end and through the elongated section to the downstream end and the outlet of the accelerator;
wherein the apparatus is configured to have a sufficient inductance before the elongated section that the plasma torus is accelerated and compressed throughout the elongated section by an expansion of the magnetic pushing flux, and wherein the dimensions of the plasma propagation channel are selected such that for a selected inductance of the elongated section and selected inductance before the elongated section, the current flowing in the elongated section at the downstream end is smaller than at the upstream end of the elongated section and a plasma torus pressure is greater at the downstream end of the elongated section than at the upstream end of the elongated section.
2. An apparatus as claimed in claim 1 wherein the elongated section has a plasma torus radial compression ratio of between 1 and 2.
3. An apparatus as claimed in claim 1 wherein the power source is configured to produce an acceleration pulse that provides simultaneous acceleration and compression of the plasma torus therethrough from the inlet of the accelerator to the outlet of the accelerator.
4. An apparatus as claimed in claim 1 wherein the plasma propagation channel further comprises a high compression funnel section between the inlet and the upstream end of the elongated section, the funnel section comprising an upstream end in fluid communication with the inlet and a downstream end in fluid communication with the upstream end of the elongated section, wherein a cross-sectional annular gap in the funnel section defined as a radial distance between the inner and outer electrodes decreases in a downstream direction along the length of the funnel section.
5. An apparatus as claimed in claim 4 wherein the funnel section has a radial compression ratio of between 3 and 10.
6. An apparatus as claimed in claim 1 wherein the elongated section has a fixed ratio of inner electrode and outer electrode radiuses, and the radius r(z) of one of the inner or outer electrodes along a lengthwise position z of the elongated section is defined by
1
r
\ue8a0
(
z
)
=
a
–
b
1
+
c
\ue8a0
(
z
–
z
0
)
wherein z0 is a lengthwise position of the elongated section at the upstream end, c is a ratio of inductance per unit length L\u2032 of the elongated section to inductance L0 before the elongated section,
a=b+1r0
wherein r0 is the radius of the inner or outer electrode at the upstream end, and
b
=
1
r
1
–
1
r
0
1
–
1
1
+
c
\ue8a0
(
z
1
–
z
0
)
wherein r1 and z1 are the respective radius of the inner or outer electrode and the lengthwise position of the elongated section at the downstream end.
7. An apparatus as claimed in claim 1 wherein the radius r(z) of each of the inner and outer electrodes along a lengthwise position z of the elongated section is defined by
1
r
\ue8a0
(
z
)
=
a
–
b
1
+
c
\ue8a0
(
z
–
z
0
)
wherein z0 is a lengthwise position of the elongated section at the upstream end, c is the ratio of inductance per unit length L\u2032 of the elongated section to inductance L0 before the elongated section,
a=b+1r0
wherein r0 is the radius of the inner or outer electrode at the upstream end, and
b
=
1
r
1
–
1
r
0
1
–
1
1
+
c
\ue8a0
(
z
1
–
z
0
)
wherein r1 and z1 are the respective radius of the inner or outer electrode and the lengthwise position of the elongated section at the downstream end.
8. An apparatus as claimed in claim 1 wherein the power source is configured to generate an electrical acceleration pulse that stops once the plasma torus enters the elongated section.
9. An apparatus as claimed in claim 8 wherein the power source is configured to generate an electrical acceleration pulse with a timing, duration and current amplitude that results in a constant pushing flux when the plasma torus travels along the elongated section.
10. A system comprising
the apparatus for accelerating and compressing plasma as claimed in claim 1, and
a plasma generator comprising a tubular outer electrode and a tubular inner electrode extending inside the outer electrode to define an annular plasma formation channel therebetween,
wherein the outer electrode of the accelerator is physically connected to the outer electrode of the plasma generator, and wherein the annular plasma formation channel is aligned and in fluid communication with the annular plasma propagation channel.
11. A system as claimed in claim 10, further comprising a plasma torus relaxation region defined by an inner wall of the outer electrode and a space between the upstream end of the accelerator inner electrode and a downstream end of the plasma generator inner electrode, and wherein the relaxation region is in fluid communication with the plasma formation channel and the plasma propagation channel.
12. A system as claimed in claim 11 wherein the relaxation region comprises an inward expansion zone formed at the upstream end of the accelerator inner electrode.
13. A system as claimed in claim 11 wherein the relaxation region comprises an outward expansion zone formed at the upstream end of the accelerator at the outer electrode.
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. An image processing apparatus for transmitting and receiving data tofrom an external apparatus that has a storage apparatus, the image processing apparatus comprising:
a first data acquiring unit that acquires image data to be subjected to image processing;
a storage unit that stores the acquired image data;
a transmission unit that transmits the acquired image data to the external apparatus so that the acquired image data is stored in both the storage apparatus thereof and the storage unit;
a judgment unit that judges, prior to commencement of the image processing, whether the image data is stored in the storage unit;
a second data acquiring unit that acquires the image data from the external apparatus if the judgment unit judges negatively; and
an image processing unit that executes the image processing using the image data stored in the storage unit if the judgment unit judges positively, and executes the image processing using the image data acquired by the second data acquiring unit if the judgment unit judges negatively.
2. The image processing apparatus of claim 1 further comprising a deletion instructing unit that, after the image
processing is completed, sends to the external apparatus an instruction to delete the image data from the storage apparatus.
3. The image processing apparatus of claim 1, wherein
the transmission unit transmits the acquired image data page by page to the external apparatus.
4. The image processing apparatus of claim 3, wherein
the storage unit has a capacity only sufficient to store one page of the image data, and
each time the image processing unit completes image processing for one page of the image data stored in the storage unit, the second data acquiring unit acquires from the external apparatus another one page of the image data to be subjected to the image processing next.
5. The image processing apparatus of claim 1 further comprising a memory that stores information regarding progress of the image processing, wherein
when executing the image processing using the image data acquired by the second data acquiring unit, the image processing unit refers to the information stored in the memory and executes the image processing for a part of the image data that has not been subjected to the image processing yet.
6. The image processing apparatus of claim 5, wherein
the information stored in the memory indicates pages of the image data that have already been subjected to the image processing.
7. The image processing apparatus of claim 5, wherein the memory is a nonvolatile memory.
8. The image processing apparatus of claim 1, wherein the external apparatus functions as a mail server, the transmission unit transmits to the external
apparatus an electronic mail addressed to the image processing apparatus and containing the acquired image data, and
the second data acquiring unit, if the judgment unit judges negatively, acquires the electronic mail from the external apparatus and extracts the image data from the acquired electronic mail.
9. The image processing apparatus of claim 8, wherein the transmission unit converts the acquired image data into Tag Image File Format, and transmits to the external apparatus an electronic mail addressed to the image processing apparatus and containing the image data having been converted into Tag Image File Format, as an attached file.
10. The image processing apparatus of claim 1, wherein the storage unit is a volatile memory.
11. The image processing apparatus of claim 1, wherein the judgment unit judges whether the image data is stored in the storage unit each time power is turned on or each time the image processing apparatus recovers from a power failure.
12. The image processing apparatus of claim 11 further comprising:
a reception unit that receives image processing jobs each of which contains information specifying a start time at which an image processing job is to be subjected to the image processing; and
a start time judging unit that judges, each time power is turned on or each time the image processing apparatus recovers from a power failure, whether any of the image processing jobs received by the reception unit has a start time that has already reached, wherein
if the judgment unit judges negatively, and if there is an image processing job that has been judged by the start time judging unit as having a start time that has already reached, the second data acquiring unit acquires image data for the image processing job from the external apparatus earlier than image data for the remaining image processing jobs received by the reception unit.
13. The image processing apparatus of claim 1, wherein
the image processing is an image forming process.
14. The image processing apparatus of claim 1, wherein
the image processing is a fax transmission process.
15. The image processing apparatus of claim 1, wherein
the first data acquiring unit is a receiving unit that receives print data from an external terminal connected with the image processing apparatus via a network.
16. The image processing apparatus of claim 1, wherein
the first data acquiring unit is a fax receiving unit that receives fax data from an external fax apparatus.
17. An image processing method for use in an image processing apparatus that is operable to transmit and receive data tofrom an external apparatus that has a storage apparatus, the image processing method comprising:
a first data acquiring step for acquiring image data to be subjected to image processing;
a storage step for storing the acquired image data in a storage unit;
a transmission step for transmitting the acquired image data to the external apparatus so that the acquired image data is stored in both the storage apparatus and the storage unit;
a judgment step for judging, prior to commencement of the image processing, whether the image data is stored in the storage unit;
a second data acquiring step for acquiring the image data from the external apparatus if the judgment unit judges negatively; and
an image processing step for executing the image processing using the image data stored in the storage unit if the judgment unit judges positively, and executing the image processing using the image data acquired by the second data acquiring step if the judgment step judges negatively.
18. A program that is run in an image processing apparatus that is operable to transmit and receive data tofrom an external apparatus that has a storage apparatus, the program embodied on a non-transitory computer-readable medium and causing the image processing apparatus to execute:
a first data acquiring step for acquiring image data to be subjected to image processing;
a storage step for storing the acquired image data in a storage unit;
a transmission step for transmitting the acquired image data to the external apparatus so that the acquired image data is stored in both the storage apparatus and the storage unit;
a judgment step for judging, prior to commencement of the image processing, whether the image data is stored in the storage unit;
a second data acquiring step for acquiring the image data from the external apparatus if the judgment unit judges negatively; and
an image processing step for executing the image processing using the image data stored in the storage unit if the judgment unit judges positively, and executing the image processing using the image data acquired by the second data acquiring step if the judgment step judges negatively.
19. The image processing apparatus of claim 1, wherein the first data acquiring unit is an image reading unit which scans documents.
20. The image processing apparatus of claim 1, wherein the storage unit stores image data expanded based on the image data acquired by the first data acquiring unit.
21. The image processing apparatus of claim 1, wherein
the external apparatus is provided as a first-external apparatus,
the first data acquiring unit has a receiving unit that receives the image data from a second external apparatus,
the transmission unit transmits the acquired image data received from the second external apparatus to the first external apparatus, and
the image processing unit executes a printing process using the image data stored in the storage unit if the judgment unit judges positively, and executes the printing process using the image data acquired by the second data acquiring unit if the judgment unit judges negatively.
22. The image processing apparatus of claim 1, wherein
the first data acquiring unit has an image reading unit that acquires image data through scanning a document,
the transmission unit transmits the acquired image data read by the image reading unit to the external apparatus, and
the image processing unit executes a fax transmission process using the image data stored in the storage unit if the judgment unit judges positively, and executes the fax transmission process using the image data acquired by the second data acquiring unit if the judgment unit judges negatively.