Beam monitor and methods of use

A beam monitor for monitoring a beam from a linear accelerator, the beam monitor comprising:

• a body having a beam cavity defined therein and extending along an x-y plane, wherein the beam cavity is generally rounded about a central axis extending in a z-direction;
• an input in communication with the beam cavity, the input configured for transmittal of an accelerated beam into the beam cavity, the input having an input diameter;
• an output in communication with the beam cavity, the output configured for transmittal of the accelerated energy beam out from the beam cavity, the output having an output diameter that is equal to or larger than the input diameter:
• wherein the input and output extend from a center of the cavity along a z-axis perpendicular to the x-y plane, the input and output extending in opposite directions;
• one or more windows in the beam cavity disposed at a location of a respective excitation mode of the beam cavity;
• and
• one or more waveguides coupled to the one or more windows configured for measuring one or more beam characteristics from one or more signals generated by beam energy transmitted into the one or more waveguides through the one or more windows of the beam cavity, wherein the one or more beam characteristics include any of:
• beam intensity, charge, current, size, position, emittance or any combination thereof;
• wherein the beam cavity, the input diameter, the output diameter, and the one or more windows are dimensioned and arranged so that only a suitable fraction of the beam energy from the accelerated beam is transmitted through the one or more windows.

A beam monitor for monitoring a beam from a linear accelerator, the beam monitor comprising:

• a body having a beam cavity defined therein and extending along an x-y plane, wherein the beam cavity is generally rounded about a central axis extending in a z-direction;
• an input in communication with the beam cavity, the input configured for transmittal of an accelerated beam into the beam cavity, the input having an input diameter;
• an output in communication with the beam cavity, the output configured for transmittal of the accelerated energy beam out from the beam cavity, the output having an output diameter that is equal to or larger than the input diameter;
• wherein the input and output extend from a center of the cavity along a z-axis perpendicular to the x-y plane, the input and output extending in opposite directions;
• one or more windows in the beam cavity disposed at a location of a respective excitation mode of the beam cavity;
• and
• one or more waveguides coupled to the one or more windows configured for measuring one or more beam characteristics from one or more signals generated by beam energy transmitted into the one or more waveguides through the one or more windows of the beam cavity, wherein the one or more beam characteristics include any of:
• beam intensity, charge, current, size, position, emittance or any combination thereof;
• wherein the beam cavity is distal of a plurality of buncher cavities of the linear accelerator for acceleration of the beam along the beam line, wherein the beam cavity has a volume that is less than 25% of each of the volumes of the plurality of buncher cavities.

A beam monitor for monitoring a beam from a linear accelerator, the beam monitor comprising:

• a body having a beam cavity defined therein and extending along an x-y plane, wherein the beam cavity is generally rounded about a central axis extending in a z-direction;
• an input in communication with the beam cavity, the input configured for transmittal of an accelerated beam into the beam cavity, the input having an input diameter;
• an output in communication with the beam cavity, the output configured for transmittal of the accelerated energy beam out from the beam cavity, the output having an output diameter that is equal to or larger than the input diameter;
• wherein the input and output extend from a center of the cavity along a z-axis perpendicular to the x-y plane, the input and output extending in opposite directions;
• one or more windows in the beam cavity disposed at a location of a respective excitation mode of the beam cavity;
• and
• one or more waveguides coupled to the one or more windows configured for measuring one or more beam characteristics from one or more signals generated by beam energy transmitted into the one or more waveguides through the one or more windows of the beam cavity, wherein the one or more beam characteristics include any of:
• beam intensity, charge, current, size, position, emittance or any combination thereof;
• wherein the beam cavity is distal of a plurality of buncher cavities of the linear accelerator for acceleration of the beam along the beam line, wherein the beam cavity has a volume that is less than 10% of the volumes of each of the plurality of buncher cavities.

A beam monitor for monitoring a beam from a linear accelerator, the beam monitor comprising:

• a body having a beam cavity defined therein and extending along an x-y plane, wherein the beam cavity is generally rounded about a central axis extending in a z-direction;
• an input in communication with the beam cavity, the input configured for transmittal of an accelerated beam into the beam cavity, the input having an input diameter;
• an output in communication with the beam cavity, the output configured for transmittal of the accelerated energy beam out from the beam cavity, the output having an output diameter that is equal to or larger than the input diameter;
• wherein the input and output extend from a center of the cavity along a z-axis perpendicular to the x-y plane, the input and output extending in opposite directions;
• one or more windows in the beam cavity disposed at a location of a respective excitation mode of the beam cavity;
• and
• one or more waveguides coupled to the one or more windows configured for measuring one or more beam characteristics from one or more signals generated by beam energy transmitted into the one or more waveguides through the one or more windows of the beam cavity, wherein the one or more beam characteristics include any of:
• beam intensity, charge, current, size, position, emittance or any combination thereof;
• wherein the output diameter is at least four times that of the input diameter.

A beam monitor for monitoring a beam from a linear accelerator, the beam monitor comprising:

• a body having a beam cavity defined therein and extending along an x-y plane, wherein the beam cavity is generally rounded about a central axis extending in a z-direction;
• an input in communication with the beam cavity, the input configured for transmittal of an accelerated beam into the beam cavity, the input having an input diameter;
• an output in communication with the beam cavity, the output configured for transmittal of the accelerated energy beam out from the beam cavity, the output having an output diameter that is equal to or larger than the input diameter;
• wherein the input and output extend from a center of the cavity along a z-axis perpendicular to the x-y plane, the input and output extending in opposite directions;
• one or more windows in the beam cavity disposed at a location of a respective excitation mode of the beam cavity;
• and
• one or more waveguides coupled to the one or more windows configured for measuring one or more beam characteristics from one or more signals generated by beam energy transmitted into the one or more waveguides through the one or more windows of the beam cavity, wherein the one or more beam characteristics include any of:
• beam intensity, charge, current, size, position, emittance or any combination thereof;
• wherein the cavity is elliptical in shape, an x-dimension of the cavity being greater than a y-dimension so as to separate the modal frequency of different polarizations of the beam cavity;
• wherein the one or more windows comprise a plurality of windows on the beam cavity;
• and
• wherein the one or more waveguides comprise a plurality of waveguides coupled to the plurality of windows and configured for measuring a plurality of beam characteristics from a plurality of signals generated by beam energy transmitted into the plurality of waveguides through the plurality of windows, wherein the one or more beam characteristics include at least:
• a beam charge, a beam position and a beam size.

A method of monitoring a beam from a linear accelerator, the method comprising:

• transmitting an accelerated energy beam generated by the linear accelerator into a rounded beam cavity disposed along a distal end of a beamline of the energy beam;
• transmitting a fraction of the beam energy through a ceramic window of the beam cavity into a waveguide coupled to the beam cavity at a location corresponding to an excitation mode of the beam cavity, wherein the fraction comprises 100 kW or less for a 3 MW beam;
• measuring a signal from the waveguide with a processing unit;
• and
• determining a beam intensity or charge from the signal.

A method of monitoring beam characteristics comprising:

• transmitting an accelerated energy beam generated by a linear accelerator into a rounded beam cavity along a beamline of the energy beam, wherein the beam cavity is elliptical;
• transmitting a fraction of the beam energy through a plurality of ceramic filled openings into a plurality of waveguides coupled to the beam cavity at differing locations, each location corresponding to a differing excitation mode of the beam cavity;
• measuring a plurality of signal from the plurality of waveguides with a processing unit;
• and
• determining, from the plurality of signals, a plurality of beam characteristics that include at least:
• a beam charge, a beam position and a beam size.