Patent Publication Number: US-2021166832-A1

Title: Systems, devices, and methods for beam position monitoring and beam imaging

Description:
CROSS-REFERENCE TO RELATED APPLICATIONS 
     The present application claims priority to U.S. Provisional Application Ser. No. 63/065,448, titled “SYSTEMS, DEVICES, AND METHODS FOR FAST BEAM POSITION MONITORING,” filed Aug. 13, 2020, and to U.S. Provisional Application Ser. No. 63/065,442, titled “SYSTEMS, DEVICES, AND METHODS FOR GAS PUFF BEAM IMAGING,” filed Aug. 13, 2020, and to U.S. Provisional Application Ser. No. 62/894,290, titled “SYSTEMS, DEVICES, AND METHODS FOR FAST BEAM POSITION MONITORING,” filed Aug. 30, 2019, and to U.S. Provisional Application Ser. No. 62/894,220, titled “SYSTEMS, DEVICES, AND METHODS FOR GAS PUFF BEAM IMAGING,” filed Aug. 30, 2019, all of which are incorporated by reference herein in their entirety. 
    
    
     FIELD 
     The subject matter described herein relates generally to beam systems and, in particular, to beam diagnostics of the charged particle beamline of the beam system, and, further in particular, systems and methods for facilitating fast beam position monitoring for detection of beam misalignment in the beamline. The subject matter further relates to systems and methods for facilitating non-invasive beam diagnostics. 
     BACKGROUND 
     Boron neutron capture therapy (BNCT) is a modality of treatment of a variety of types of cancer, including some of the most difficult types. BNCT is a technique that selectively aims to treat tumor cells while sparing the normal cells using a boron compound. A substance that contains boron is injected into a blood vessel, and the boron collects in tumor cells. The patient then receives radiation therapy with neutrons (e.g., in the form of a neutron beam). The neutrons react with the boron to kill the tumor cells while reducing or eliminating harm to normal cells. Prolonged clinical research has proven that a beam of neutrons with an energy spectrum within 3-30 kiloelectronvolts (keV) may be preferable to achieve a more efficient cancer treatment while decreasing a radiation load on a patient. This energy spectrum or range is frequently referred to as epithermal. 
     Most conventional methods for the generation of epithermal neutrons (e.g., epithermal neutron beams) are based on nuclear reactions of protons (e.g., a proton beam) with either beryllium or lithium (e.g., a beryllium target or a lithium target). 
     For solutions based on electrostatic accelerators, beam diagnostics is an intrinsic part of the charged particle beamline design. A critical task in beam transport is to ensure that the beam is correctly positioned inside the beamline (e.g., there is no direct beam interaction with beamline components and walls). Any impact of placement or use of such beam diagnostics can be proportional to the beam energy as the beam destructive power goes up with beam energy. This is especially true for the transport of direct current (DC) beams where irreversible damage to the beamline components can be created at millisecond time scale. Therefore, continuous monitoring of the beam position is a key to success with the beam transport in accelerator based solutions. 
     A conventional beam position monitor (BPM) based on arrays of secondary emission monitors demonstrates reliable operation with millimeter resolution. However, the conventional BPM has a relatively low beam power acceptance threshold due to direct interaction of its probes (thin foils) with the beam. Accordingly, beam monitoring based on arrays of secondary emission monitors is not preferred for beams up to 3.5 megawatts (MW). 
     Non-destructive beam position monitors (BPMs) are typically based on detection of beam impedance. Such non-destructive BPMs are mostly capacitive type BPMs (e.g., linear-cut, button types, and stripline BPMs). The principle of operation of such beam impedance detection devices results in their use being limited to pulsed beams. 
     Conventional systems appear 1) unable to successfully operate with DC beams, 2) to lack a millisecond response time, 3) to be unable to accept beams having power up to 2.5 megaelectronvolts (MeV) per nuclei, 4) to lack simplicity, and 5) to lack reliability. 
     For accelerator based solutions, the deliverables of such beam diagnostics also include providing information about beam parameters and characteristics which are extensively d for arrangement and control of beamline elements, beam shaping, beam focusing, beam bending, cleaning and rotation or beamline elements, beam monitoring and statistics, and more. Conventionally, the most developed and utilized beam diagnostics are what may be referred to as invasive diagnostics whose effect on the beam (e.g., during the process of measurement) commonly results in undesired perturbation of one or more beam parameters. 
     Conventional invasive beam diagnostics for measuring beam size and cross-sectional profile include slit grid and Allison emittance scanners, wire beam profilers, and the like. However, such invasive beam diagnostics are not well suited for real time beam tracking because they a) perturb the beam in a way that typically results in undesired termination of the beam after a short duration, and b) are limited in terms of acceptable beam power due to direct interaction with the beam particulates. 
     The use of a conventional beam wire scanner is limited by the probe collected beam power. Therefore, a direct current (DC) beam can only be probed in the region of the low beam energy (e.g., 30 kiloelectronvolts (keV) in a relatively low energy beamline at 15 milliamps (mA) current). To overcome this limitation, a pulsed beam can be used that allows the use of a wire scanner with beams of higher energy (determined by the beam pulse duration). However, both approaches (e.g., with or without a pulsed beam) are not suitable for continuous monitoring of the beam parameters (location and size) because of beam distortion during the measurements. 
     It is important to note that interaction of the energetic beam particulates with a probe is typically accompanied by various phenomena, some of which may drastically complicate signal interpretation. For example, secondary electron emission (SEE) phenomenon modifies the current measured on a probe (the signal). The common approach of SEE suppression via probe biasing does not ensure diminishing the SEE contribution into the signal for arbitrary energy of beam particulates. Furthermore, possible plasma formation near the probe surface and rapid heating of the probe are processes affecting the signal as well. The contributions of these phenomena are difficult to predict and account for. 
     To monitor high power DC beams (up to 5 kilowatts (kW)) and deliver basic beam characteristics such as beam position, size, and profile, a truly non-invasive beam diagnostics is desirable. In addition, availability of such non-invasive beam diagnostics may facilitate a real-time feedback loop for beam control systems. 
     For these and other reasons, a need exists for improved, efficient, and compact systems, devices, and methods that monitor beam position within a beam system as well as improved, efficient, and compact systems, devices, and methods that provide non-invasive beam diagnostics within a neutron beam system. 
     SUMMARY 
     Example embodiments of systems, devices, and methods are described herein for beam systems, and, more particularly, systems and methods for facilitating fast beam position monitoring for detection of beam misalignment in a beamline. In certain example embodiments, a beam position monitor (BPM) (e.g., also referred to herein as a fast beam position monitor or FBPM) is provided for an example beam system configured as a neutron beam systems (NBS). 
     In certain example embodiments, the beam position monitor (BPM) can include multiple electrodes extending into the interior of the beamline of the beam system. In these embodiments, the beam position monitor (BPM) can operate by collection of the beam halo current by the electrodes. The electrodes can be galvanically isolated from a wall of the BPM and biased using an external power supply. Biasing relative to the BPM wall can reduce contribution of secondary electron emission (SEE) current to the signal and can increase the beam halo current collected from the beam generated plasma. 
     The beam position monitor (BPM) can include a detection sensitivity level associated with reducing or eliminating beam-induced damage to beamline components while minimizing disturbance to the beam advancing through the beam line. That is, a minimal amount of a beam current of the beam passing through the component of the beam line can be reduced due to the electrodes. 
     Embodiments of systems, devices, and methods further relate to accelerator based beam systems and, more particularly, systems and methods for facilitating non-invasive beam diagnostics. In example embodiments, a non-invasive beam diagnostics system includes a gas puff beam imaging (GPBI) diagnostics system suitable for a beamline, for example a beamline serving as part of a neutron beam system (NBS). The gas puff beam imaging (GPBI) diagnostics system can be adapted to deliver information about the beam position and size in real time without substantial beam perturbation. The non-invasive beam diagnostics system is time-resolved and space-resolved and works for wide ranges of different beam powers. Moreover, the present gas puff beam imaging (GPBI) diagnostics system is suitable for a high energy beamline (HEBL), or in or near a tandem accelerator as part of a neutron beam system (NB S). 
     Example embodiments overcome the aforementioned limitations associated with conventional invasive beam monitoring solutions by enabling non-invasive continuous monitoring of the beam and acquisition of critical beam parameters (size, location, profile) for a beam control system without restrictions on the upper limit of the beam power. In addition, both temporal and spatial resolution of the present GPBI diagnostics system is improved over conventional diagnostics. For example, the time resolution of the present GPBI diagnostics system is approximately hundreds of milliseconds, which is a significant improvement over the measurement timescale of the wire scanners (several seconds). 
     In example embodiments, the fluorescence of residual (background) or puffed gases produced due to collisions with energetic beam particulates is used as part of a non-destructive diagnostic technique for measuring transverse beam sizes (profiles) and beam position. To measure beam parameters (e.g., transverse size, location, inclination), a glow of fluorescence from the beam-gas interaction region is recorded by recording devices or imaging components (e.g., cameras) of beam imaging diagnostics providing data on beam transversal size, beam location, and inclination. 
     Other systems, devices, methods, features and advantages of the subject matter described herein will be or will become apparent to one with skill in the art upon examination of the following figures and detailed description. It is intended that all such additional systems, methods, features and advantages be included within this description, be within the scope of the subject matter described herein and be protected by the accompanying claims. In no way should the features of the example embodiments be construed as limiting the appended claims, absent express recitation of those features in the claims. 
    
    
     
       BRIEF DESCRIPTION OF FIGURES 
       The details of the subject matter set forth herein, both as to its structure and operation, may be apparent by study of the accompanying figures, in which like reference numerals refer to like parts. The components in the figures are not necessarily to scale, emphasis instead being placed upon illustrating the principles of the subject matter. Moreover, all illustrations are intended to convey concepts, where relative sizes, shapes and other detailed attributes may be illustrated schematically rather than literally or precisely. 
         FIG. 1A  is a schematic diagram of an example embodiment of a neutron beam system for use with embodiments of the present disclosure. 
         FIG. 1B  is a schematic diagram of an example embodiment of a neutron beam system for use in boron neutron capture therapy (BNCT). 
         FIG. 2  illustrates an example pre-accelerator system or ion beam injector for use with embodiments of the present disclosure. 
         FIG. 3  is a perspective view of an example embodiment of a beam position monitor (BPM) of the ion beam injector system shown in  FIG. 2 . 
         FIG. 4  is a graph image illustrating example waveforms of current collected on electrodes of an example beam position monitor (BPM) during artificial mis-alignment. 
         FIG. 5  is a perspective view of an embodiment of the pumping chamber of the ion beam injector system shown in  FIG. 2  with a beam imaging (e.g., GPBI) diagnostics system. 
         FIG. 6  is a perspective view of an imaging component of the beam imaging (GPBI) diagnostics system for a pulsed beam. 
         FIG. 7  illustrates an example timing scheme for use with embodiments of the present disclosure. 
         FIG. 8  is an example beam image acquired by the gas puff beam imaging (GPBI) diagnostic system. 
         FIG. 9  is an example of a post-processed image shown in  FIG. 8 . 
         FIG. 10  is a graph showing an example of the measured beam line-integrated profile. 
         FIGS. 11A and 11B  illustrate block diagrams depicting example embodiments of a control system with which embodiments of the present disclosure may operate. 
         FIG. 12  is a block diagram depicting an example embodiment of a computing apparatus that may be used with embodiments of the present disclosure. 
     
    
    
     DETAILED DESCRIPTION 
     Before the present subject matter is described in detail, it is to be understood that this disclosure is not limited to the particular embodiments described, as such may, of course, vary. It is also to be understood that the terminology used herein is for the purpose of describing particular embodiments only, and is not intended to be limiting, since the scope of the present disclosure will be limited only by the appended claims. 
     The term “particle” is used broadly herein and, unless otherwise limited, can be used to describe an electron, a proton (or H+ ion), or a neutral, as well as a species having more than one electron, proton, and/or neutron (e.g., other ions, atoms, and molecules). 
     Example embodiments of systems, devices, and methods are described herein for diagnostics in a beam system (e.g., including a particle accelerator). The embodiments described herein can be used with any type of particle accelerator or in any particle accelerator application involving production of a charged particle beam at specified energies for supply to the particle accelerator. Embodiments herein can be used in numerous applications, an example of which is as a neutron beam system for generation of a neutron beam for use in boron neutron capture therapy (BNCT). For ease of description, many embodiments described herein will be done so in the context of a neutron beam system for use in BNCT, although the embodiments are not limited to just the generation of neutron beams nor BNCT applications in particular. 
       FIG. 1A  is a schematic diagram of an example embodiment of a beam system for use with embodiments of the present disclosure. Here, beam system  10  includes a source  22 , a low-energy beamline (LEBL)  190 , an accelerator  40  coupled to the low-energy beamline (LEBL)  190 , and a high-energy beamline (HEBL)  50  extending from accelerator  40  to a target assembly housing a target  196 . LEBL  190  is configured to transport a beam from source  22  to accelerator  40 , which is configured to accelerate the beam HEBL  50  transfers the beam from an output of accelerator  40  to a target  196 . 
     Example embodiments of systems, devices, and methods are described herein for facilitating fast beam position monitoring for detection of beam misalignment in a beamline of a beam system  10 . In example embodiments, a simple and reliable beam position monitor (BPM) is provided. In certain example embodiments, the beam position monitor (BPM) can include multiple electrodes extending into the interior of the beamline of the neutron beam system (NB S). In these embodiments, the beam position monitor (BPM) can operate by collection of the beam halo current by the electrodes. The electrodes can be galvanically isolated from a wall of the BPM and biased using an external power supply. Biasing relative to the BPM wall can reduce contribution of secondary electron emission (SEE) current to the signal and can increase the beam halo current collected from the beam generated plasma. 
     In example embodiments, the beam position monitor (BPM) is configured to signal or indicate to a control system when a beam advancing through the beam line is off axis. 
     The beam position monitor (BPM) can include a detection sensitivity level associated with reducing or eliminating beam-induced damage to beamline components while minimizing disturbance to the beam advancing through the beam line. That is, a minimal amount of a beam current of the beam passing through the component of the beam line can be reduced as a result of current collection by the electrodes. Example embodiments of the BPM can advantageously operate with direct current (DC) beams, have millisecond (or faster) response time, and/or accept beam powers of 2.5 MeV (and higher) per nuclei. 
     In some example embodiments, the BPM can be part of a beam system configured for producing a neutron beam from a ion beam. The beam system can include an LEBL, serving as an ion beam injector system, a high voltage (HV) tandem accelerator coupled to the ion beam injector system, and an HEBL extending from the tandem accelerator to a neutron target assembly housing a neutron-producing target. In these example embodiments, the ion beam injector can include an ion source, beam optics incorporated into a low-energy beamline extending from the ion source, a pre-accelerator tube, beam diagnostics and a pumping chamber coupled to the tandem accelerator. The ion source can generate charged particles in the plasma volume which can be extracted, accelerated, conditioned and eventually used to produce neutrons when delivered to the neutron producing target. Such improved, efficient, and compact systems, devices, and methods that monitor the beam position enable preservation of neutron beam system equipment while maintaining operative efficacy. 
     System  10  can also include a gas based or substantially non-invasive beam diagnostics system. This diagnostics system can include gas puff beam imaging (GPBI) suitable for the LEBL, serving as the beam injector of the beam system, where the GPBI is adapted to deliver information about the beam position and size in real time without beam perturbation. Moreover, the present GPBI diagnostics system is suitable for a high energy beamline (HEBL), or in or near the accelerator. The non-invasive beam diagnostics system is time-and space-resolved and has no upper limit on the beam power. 
     In example embodiments, the fluorescence of residual (background) or puffed gases produced due to collisions with energetic beam particulates is used as part of a non-destructive diagnostic technique for measuring transverse beam sizes (profiles) and beam position. The propagation of charged particles through a gas environment leads to the emission of light due to collisional excitation of gas atoms and molecules. To measure beam parameters (transverse size, location, inclination), the glow of fluorescence from the beam-gas interaction region is recorded by recording devices or imaging components (e.g., cameras) providing data on beam transversal size, beam location and inclination. Obtained images can be further correlated with the actual beam profile via Abel inversion (under certain assumptions, e.g., beam axial symmetry) or using tomographic techniques. 
     In example embodiments, a GPBI diagnostics system includes one or more imaging components, and in many embodiments at least two (2) orthogonally oriented imaging components, coupled to and extending into an interior of a pumping chamber and a gas puff port extending from the pumping chamber and providing a passage into the pumping chamber. 
     The gas puff port is controllable such that a number of neutrals introduced into the GPBI diagnostics system is regulated to avoid interaction with the beam that is to be measured or observed. That is, the beam passing through the beamline, while being observed by the GPBI diagnostics system, passes through a cloud of neutrals without being substantially disturbed. In embodiments, the gas puffed in embodiments of the present disclosure comprises one or more of argon or xenon. 
       FIG. 1B  is a schematic diagram illustrating an example neutron beam system  10  for use in boron neutron capture therapy (BNCT), according to embodiments of the present disclosure. The neutron beam system  10  includes a pre-accelerator system  20  forming at least a portion of the LEBL, where the pre-accelerator system  20  serves as a charged particle beam injector as shown in  FIG. 2 , a high voltage (HV) tandem accelerator  40  coupled to the pre-accelerator system  20 , and a high-energy beamline  50  extending from the tandem accelerator  40  to a neutron target assembly  200  housing the neutron-producing target. In this embodiment beam source  22  is an ion source and the charged particle beam is a negative ion beam prior to conversion to a proton beam within tandem accelerator  40 . It will be appreciated that neutron beam system  10  as well as pre-accelerator system  20  can also be used for other applications, such as cargo inspection and others, and is not limited to BNCT. 
     Pre-accelerator system  20  (also referred to herein as the charged particle beam injector or ion beam injector) is configured to transfer the ion beam from the ion source  22  to the input (e.g., an input aperture) of the tandem accelerator  40 . 
     Tandem accelerator  40 , which is powered by a high voltage power supply  42  coupled thereto, can, in many embodiments, produce a proton beam with an energy generally equal to twice the voltage applied to the accelerating electrodes positioned within the tandem accelerator  40 . The energy level of the proton beam is achieved by accelerating the beam of negative hydrogen ions from the input of the tandem accelerator  40  to the innermost high-potential electrode, stripping two electrons from each ion, and then accelerating the resulting protons downstream by the same voltages encountered in reverse order. 
     The high-energy beamline  50  transfers the proton beam from the output of the tandem accelerator  40  to the neutron-generating target in the neutron target assembly  200  positioned at the end of a branch  70  of the beamline extending into a patient treatment room. System  10  can be configured to direct the proton beam to any number of one or more targets and associated treatment areas. In this embodiment, the high-energy beamline  50  includes three branches  70 ,  80  and  90  to extend into three different patient treatment rooms. The high-energy beamline  50  includes a pumping chamber  51 , quadrupole magnets  52  and  72  to prevent de-focusing of the beam, dipole or bending magnets  56  and  58  to steer the beam into treatment rooms, beam correctors  53 , diagnostics such as current monitors  54  and  76 , fast beam position monitor  55  section, and a scanning magnet  74 . 
     The design of the high-energy beamline  50  may depend on the configuration of the treatment facility (e.g., a single-story configuration of a treatment facility, a two-story configuration of a treatment facility, and the like). The beam can be delivered to a target assembly (e.g., positioned near a treatment room)  200  with the use of the bending magnet  56 . Quadrupole magnets  72  can be included to then focus the beam to a certain size at the target. Then, the beam passes one or more scanning magnets  74 , which provides lateral movement of the beam onto the target surface in a desired pattern (e.g., spiral, curved, stepped in rows and columns, combinations thereof, and others). The beam lateral movement can help achieve smooth and even time-averaged distribution of the proton beam on the lithium target, preventing overheating and making the neutron generation as uniform as possible within the lithium layer. 
     After entering the scanning magnets  74 , the beam can be delivered into a current monitor  76 , which measures beam current. The measured beam current value can be used to operate a safety interlock. The target assembly  200  can be physically separated from the high energy beamline volume with a gate valve  77 . The main function of the gate valve is separation of the vacuum volume of the beamline from the target while target exchange/loading. In embodiments, the beam may not be bent by 90 degrees by a bending magnet  56 , it rather goes straight to the right, then it enters the quadrupole magnets  52 , which are located in the horizontal beamline. After, the beam could be bent by another bending magnet  58  to a needed angle, depending on the room configuration. Otherwise, the bending magnet  58  could be replaced with a Y-shaped magnet in order to split the beamline into two directions for two different treatment rooms located on the same floor. 
       FIG. 2  illustrates an example of a pre-accelerator system or ion beam injector for use with embodiments of the present disclosure. In this example, pre-accelerator system  20  includes an einzel lens (not shown), a pre-accelerator tube  26 , and a solenoid  510 , and is configured to accelerate a negative ion beam injected from ion source  22 . The pre-accelerator system  20  is configured to provide acceleration of the beam particles to the energies required for tandem accelerator  40 , and to provide overall convergence of the negative ion beam to match input aperture area at an input aperture or entrance of the tandem accelerator  40 . The pre-accelerator system  20  is further configured to minimize or defocus backflow as it passes from the tandem accelerator  40  through the pre-accelerator system in order to reduce the possibility of damage to ion source and/or the backflow reaching the filaments of the ion source. 
     In embodiments, the ion source  22  is configured to provide a negative ion beam downstream to the einzel lens (not shown), and the negative ion beam continues to pass through pre-accelerator tube  26  and a solenoid  510 . The solenoid  510  is positioned between the pre-accelerator tube the tandem accelerator and is electrically couplable with a power supply. The negative ion beam passes through the solenoid  510  to the tandem accelerator  40 . 
     Pre-accelerator system  20  can also include an ion source vacuum box  24 , and a pumping chamber  28 , which, with pre-accelerator tube  26  as well as the other elements described above are part of a relatively low energy beamline leading to the tandem accelerator  40 . The ion source vacuum box  24 , within which the einzel lens (not shown) is positioned, extends from the ion source  22 . The pre-accelerator tube  26  can be coupled to the ion source vacuum box  24 , and solenoid  510  can be coupled to the pre-accelerator tube  26 . A pumping chamber  28  can be coupled to the solenoid  510  and the tandem accelerator  40 . The ion source  22  serves as a source of charged particles which can be accelerated, conditioned and eventually used to produce neutrons when delivered to a neutron producing target. The example embodiments will be described herein with reference to an ion source producing a negative hydrogen ion beam, although embodiments are not limited to such, and other positive or negative particles can be produced by the source. 
     The pre-accelerator system  20  can have zero, one, or multiple magnetic elements for purposes such as focusing and/or adjusting alignment of the beam. For example, any such magnetic elements can be used to match the beam to the beamline axis and the acceptance angle of the tandem accelerator  40 . The ion vacuum box  24  may have ion optics positioned therein. 
     There are two types of negative ion sources  22 , which differ by the mechanism of generation of negative ions: the surface type and the volume type. The surface type generally requires the presence of cesium (Cs) on specific internal surfaces. The volume type relies on formation of negative ions in the volume of a high current discharge plasma. While both types of ion sources can deliver the desired negative ion current for applications related to tandem accelerators, surface type negative ion sources are undesirable for modulation. That is, for modulation of a negative ion beam in embodiments described herein, negative ion sources of the volume type (e.g., without employing cesium (Cs)) are preferred. 
     Turning to  FIG. 3 , an example beam position monitor (BPM) (e.g., or fast beam position monitor)  30  includes a cylindrical wall  32  extending between a pair of flanges  34  adapted to mount the beam position monitor (BPM)  30  along the beam line (e.g., low energy beamline (LEBL) including pre-accelerator system  20 , accelerator  40 , high energy beamline (HEBL)  50 ). In examples where the beam position monitor (BPM)  30  is mounted along the low energy beamline (LEBL), the beam position monitor (BPM) may be mounted between the pre-accelerator tube  26  and pumping chamber  28 . The operation of the beam position monitor (BPM)  30  may be based on collection of the beam halo current by electrodes  36  protruding from the wall  32  and extending into the interior of the beam line. In example embodiments, electrodes  36  may be cooled by way of one or more cooling devices  41 . In example embodiments, the one or more cooling devices may comprise water cooling devices. 
     In  FIG. 3 , the beam position monitor (BPM)  30  is shown to include four electrodes  36 , although embodiments are not limited to four electrodes (e.g., any number of electrodes may be employed within the scope of the present disclosure). The electrodes  36  are preferably shaped as cylinders and made of one or more of tantalum (Ta) or tungsten (W) to increase resistance to the heat flux. The electrodes  36  may also be made of composite materials that are able to withstand the thermal load generated by the beam. The insertion length (e.g., electrode extension distance into the interior of the beam line) of an electrode  36  can be adjusted separately for each electrode  36  (e.g., using a control system, not shown in  FIG. 3 ), allowing a user to adapt the beam position monitor (BPM)  30  for beams of arbitrary dimensions. The electrodes  36  are intended to be exposed to the beam halo current, therefore the collected power flux is anticipated to be much lower. Moreover, the plasma formed near the region of the beam-residual gas interaction expands to the beam outer boundary forming an additional signal for the beam position monitor (BPM)  30 . 
     Electrodes  36  can be galvanically isolated from the BPM wall  32  and biased using an external power supply. Biasing relative to the BPM wall  32  a) can reduce contribution of secondary electron emission (SEE) current to the signal and b) can increase the beam halo current collected from the beam generated plasma. 
     While the beam system is operating and a beam is being extracted from a source (e.g.,  22 ) and propagated through components (e.g.,  190 ,  40 ,  50 ,  196 ) of an example beam system g.,  10 ), the beam position monitor (BPM)  30  enables a control system to actively monitor the beam position. Each electrode  36  may have associated with it a current threshold (e.g., a signal threshold). When collected current (e.g., or signal) by a given electrode exceeds its current threshold, the beam may be deemed to have deflected too far toward that electrode and, as such, be off axis. The beam position monitor ( 30 ) can provide an indication that current collected by the electrode has exceeded its current threshold to the control system, and the control system can adjust parameters of one or more components of the entire beam system (e.g.,  10 ) to move the beam back on axis. Examples of adjustable parameters may include inputs provided to beam steering magnets such that positions of the beam steering magnets are altered to move the beam back onto the desired axis. In this manner, the beam position monitor (BPM)  30  along with the control system continuously/repeatedly and in real time provide feedback to the beam steering magnets and/or other components of the beam system. 
     In embodiments, a current threshold associated with a given electrode may be different from a current threshold associated with another electrode of the beam position monitor ( 30 ). Further, a given electrode may have associated with it multiple current thresholds for more granular detection of beam position. That is, multiple current thresholds can be used with the electrodes of the beam position monitor (e.g.,  30 ). Detection of movement of the beam off axis in a direction between electrodes may be based on multiple current thresholds associated with adjacent electrodes. 
     For example, a pair of adjacent electrodes may both register an increase in signal level (e.g., current collected), however the increase in signal level may exceed a second, lower current threshold associated with each electrode of the pair of adjacent electrodes. In such an example, the signal level exceeding the second, lower current threshold associated with each electrode of the pair of adjacent electrodes may indicate that the beam is in an off axis direction between the electrodes. 
     Accordingly, the control system may adjust the beam steering magnets based on an indication that the signal level exceeds a single threshold for a single electrode of the beam position monitor (BPM)  30 , or based on an indication that the signal level exceeds two lower thresholds for adjacent electrodes. 
     Moreover, the control system may monitor the magnitudes of signal on each of the electrodes and extrapolate a degree of beam deflection in a particular direction based on the magnitudes of the signal (e.g., independent of or in combination with one or more current thresholds associated with the electrodes). The control system may then adjust the beam steering magnets, or other parameters, based on the extrapolated degree(s) of beam deflection in order to compensate for the beam deflection and bring the beam back to its desired axis. In such examples, the control system can continuously and in real-time adjust beam line parameters, such as positions of the beam steering magnets, based on a minimum amount of detected deflection (e.g., a deflection threshold). 
     In examples, it may be difficult to predict the signal level on the BPM electrodes  36 . Accordingly, calibration of the BPM  30  prior to operation may be desired and performed. Calibration may be accomplished by controllable and safe shifting of a beam off of the beamline axis and collecting the current on the BPM electrodes  36 . 
     Pulsed mode of beam operation may be preferable during calibration of the BPM  30  to reduce the total beam deposited energy on the BPM  30  and other beam line components. Other beam position diagnostics (e.g., gas puff beam imaging) may also be involved in concert with the BPM calibration to meet safety or other regulations. 
     In examples, operation of the example BPM  30  was tested on an example low energy beamline (LEBL) (e.g.,  190  including pre-accelerator system  20 ) of an example neutron beam system (NB S)  10 . In the tests, a total negative hydrogen ion beam current in the LEBL was approximately 12 milliamps (mA). To demonstrate performance of the BPM  30 , the beam was intentionally deviated from the beamline axis using X- and Y-steering magnets. The current waveforms collected by each BPM electrode  36  are shown in  FIG. 4 . Shown in  FIG. 4 , the BPM electrodes  36  collect larger currents when the beam is intentionally mis-aligned using the X- and Y-steering magnets. The maximum current values are displayed as well as minimum current values. Based on the results illustrated in  FIG. 4 , the threshold current for each FBPM electrode  36  may be defined to signal to the control system that the beam is misaligned. The response time of the BPM  30  was 4 microseconds (μs) in the tests used for generation of the results depicted in  FIG. 4 . 
     The small magnitude of the beam current collected by the BPM electrodes  36  during normal operation advantageously ensures a long life time of the BPM  30 . That is, due to the small magnitude of the beam current collected by the BPM electrodes  36 , beam induced damage resulting in expiration of one or more components of the BPM  30  may be avoided or significantly delayed. 
     The example BPM advantageously enables detection of abnormal beam behavior with microsecond resolution. In certain embodiments, a response time of the BPM may be based on acquisition rates of the reading electronics. The BPM advantageously provides a rapid alarming/notification of beam misalignment to a control system. 
     The BPM  30  advantageously allows independent adjustment of the insertion length of each electrode  36  (e.g., an extension distance of the electrode into an interior of the beamline) so that small beam deviations can be detected faster (e.g., with a reduced response time) with larger signals. This improves the BPM&#39;s reaction time for beams of arbitrary (including rather complex) shape. 
     Each electrode  36  may be associated with a unique electrode position within the beam position monitor (BPM), and each unique electrode position may be adjustable. Accordingly, while a pair of electrodes may be separated by a given distance, such distance is also adjustable. 
     BPM  30  is not limited to use in the specific examples described herein, and can also be used in beam systems implemented in industrial or manufacturing processes, such as the manufacturing of semiconductor chips, the alteration of material properties (such as surface treatment), the irradiation of food, and pathogen destruction in medical sterilization. BPM  30  can further be used in imaging applications, such as cargo or container inspection. And by way of another non-exhaustive example, BPM  30  can be used in particle accelerators for medical applications, such as medical diagnostic systems, medical imaging systems, or other non-BNCT radiation therapy systems. 
     Turning to  FIG. 5 , a pumping chamber  28  may have multiple sets (e.g., two, as depicted in  FIG. 5 ) of beam imaging diagnostics  500  installed in transverse (e.g., orthogonal) directions to a beam propagation axis B. Such an arrangement of beam imaging diagnostics  500  enables characterization of the beam in a direction transverse to that of beam propagation. A gas puff port  31  (partially shown) extends from the pumping chamber  28  and provides a passage into the interior of the pumping chamber  28 . A turbomolecular pump  29  on the top of the pumping chamber  28  may be used to pump out gas puffed in through the gas puff port  31 . The turbomolecular pump  29  may also maintain a desired or required background gas pressure in the low energy beam line  20 . 
       FIG. 6  illustrates an example embodiment of a beam imaging diagnostics system  500 . In embodiments, a recording device or imaging component  33  (e.g., camera) may be coupled with a lens  35 . The lens  35  may be used to determine a field of view and spatial resolution of the beam imaging diagnostics system  500 . An aperture  39  at the end of an optical tube  38  may be matched or aligned with the recording device (e.g., camera)  33  and lens  35  and used to cut off most of a background light which otherwise may reach a sensor (not shown) of the recording device or imaging component (e.g., camera). To further reduce the background noise (e.g., background light), an interference bandpass filter (not shown) can optionally be installed inside a filter holder  37 , which may be positioned between the optical tube  38  and lens  35 . 
     A gas puff may be driven by a gas valve (not shown), coupled to the gas puff valve  31  (shown in  FIG. 5 ). The gas valve (not shown) may drive the gas puff with a controlled duration of the gas valve open state enabling control of an amount of gas puffed into the pumping chamber  28  as well as control or selection of a time when the gas is puffed into the pumping chamber  28 . 
     The gas valve, recording device(s) and other components of the beam imaging diagnostics system  500  may be controlled by way of a control system (not shown; an example of which is depicted in  FIGS. 11A and 11B ). 
     It may be desirable to select a location of the gas puffing and the nozzle structure in order to achieve uniform distribution of the gas within the field of view of the recording device or imaging component  33  (e.g., camera). This can significantly improve the linearity of the collected signal and simplify the data analysis. 
     In example embodiments, an example beam imaging diagnostic system  500  may be configured to track a charged particle beam of a beam system operating in both DC and pulsed modes. This may be implemented according to an example timing scheme shown in  FIG. 7 . The triggering of the beam imaging diagnostic system  500  may be arbitrary for DC beams. In the case of pulsed beam generation, the gas valve may be triggered prior to the beam pulse in order to ensure presence of the gas within the diagnostic field of view of the beam diagnostics system  500 , as well as uniformity of the gas. The recording device or imaging component (e.g., camera) trigger may be delayed relative to the beam pulse in order to accommodate for beam equilibration time as well as fluorescent emission delay. A camera detector exposure time may be adjusted to accumulate as much of the signal as possible while keeping the signal-to-noise (SNR) ratio at the highest level. 
     A raw image acquired by an example recording device (e.g., camera) of an example beam imaging diagnostics system  500  is shown in  FIG. 8 . The beam visible in the middle of the image. That is, 30 keV, 12 mA of negative hydrogen ions is propagating from the left to right in the image of  FIG. 8 . The uniform black background is formed by a viewing dump (not shown) installed inside the vacuum chamber. The post-processed image with background subtracted, artificially rescaled to emphasize the beam and showing about 10 millimeter (mm) beam length is presented in  FIG. 9 . 
     The image in  FIG. 9 , cleared from the background light, may be further used to obtain the beam position inside the LEBL, transverse size, and beam inclination which in real-time are transferred to a control system (see, e.g.,  FIGS. 11A, 11B ). The beam size is estimated at 90% of the beam current. This level can be adjusted depending on either assumed or measured beam current distribution. The image SNR can be further improved by using the bandpass filter (see, e.g.,  FIG. 6 ) to restrict collection to useful signal and enable more effective cutting off of the background light. 
     An example of the measured beam line-integrated profile is shown in  FIG. 10 , which illustrates the Gaussian like beam current distribution and shows that the beam size is about 10 mm calculated at 90% level of the beam current. The radial distance in  FIG. 10  is zeroed at the beam centroid (compare with  FIG. 9 ). The actual beam profile can be reconstructed from  FIG. 10  using, for example, the Abel inversion algorithm (based on a symmetry of the beam), or using tomographic techniques. 
     To estimate the beam inclination relative to an axis of the low energy beam line (LEBL), the beam centroids are calculated along the beam propagation and compared with beamline axis coordinates obtained during calibration of the beam imaging diagnostic system. 
     Beam imaging diagnostics system  500  can be placed in any desired location of the beamline, either on the lower energy side of the accelerator, in the accelerator itself, or on the higher energy side. System  500  is not limited to use in the specific examples described herein, and can also be used in beam systems implemented in industrial or manufacturing processes, such as the manufacturing of semiconductor chips, the alteration of material properties (such as surface treatment), the irradiation of food, and pathogen destruction in medical sterilization. System  500  can further be used in imaging applications, such as cargo or container inspection. And by way of another non-exhaustive example, system  500  can be used in particle accelerators for medical applications, such as medical diagnostic systems, medical imaging systems, or other non-BNCT radiation therapy systems. 
       FIGS. 11A and 11B  are block diagrams depicting example embodiments of a control system with which embodiments of the present disclosure may operate. For example, the illustrated example system includes beam system  10  and one or more computing devices  3002 . In embodiments, beam system  10  may be part of an example neutron beam system (e.g., system  10  above). In such embodiments, the beam system  10  may employ one or more control systems  3001 A with which one or more computing devices  3002  may communicate in order to interact with the systems and components of the beam system  10  (e.g., neutron beam system  10 ). Each of these devices and/or systems are configured to communicate directly with one another or via a local network, such as network  3004 . 
     Computing devices  3002  may be embodied by various user devices, systems, computing apparatuses, and the like. For example, a first computing device  3002  may be a desktop computer associated with a particular user, while another computing device  3002  may be a laptop computer associated with a particular user, and yet another computing device  3002  may be a mobile device (e.g., a tablet or smart device). Each of the computing devices  3002  may be configured to communicate with the beam system  10 , for example through a user interface accessible via the computing device. For example, a user may execute a desktop application on the computing device  3002 , which is configured to communicate with the beam system  10 . 
     By using a computing device  3002  to communicate with beam system  10 , a user may provide operating parameters for the beam system  10  (e.g., operating voltages, and the like) according to embodiments described herein. In embodiments, beam system  10  may include a control system  3001 A by which beam system  10  may receive and apply operating parameters from computing device  3002 . 
     Control system  3001 A may be configured to receive measurements, signals, or other data from components of the beam system  10 . For example, control system  3001 A may receive signals from an example beam position monitor (BPM)  30  (e.g.,  FIG. 11A ) indicative of a position of a beam passing through the beam system  10 . The control system  3001 A, depending on the position of the beam passing through the beam system, may provide adjustments to inputs of one or more beam line components  3006 , such as beam steering magnets, to alter the position of the beam according to the methods described herein. The control system  3001 A may also provide information collected from any of the components of the beam system  10 , including the beam position monitor (BPM)  30  (e.g.,  FIG. 11A ), to the computing device  3002  either directly or via communications network  3004 . 
     For example, control system  3001 A may receive signals from an example beam diagnostics system  500  (e.g.,  FIG. 11B ) indicative of a beam position of a beam passing through the beam system  10 , a transverse size of the beam, a beam inclination of the beam, beam current distribution, and the like. The control system  3001 A, depending on the received signals, may provide adjustments to inputs of one or more beam line components  3006 , to alter the position or other parameters of the beam according to the methods described herein. For example, the control system  3001 A may trigger a gas valve prior to a beam pulse in order to ensure presence of the gas within the diagnostic field of view of a beam diagnostics system  500  (e.g.,  FIG. 11B ), as well as uniformity of the gas. The control system  3001 A may further delay a trigger of a recording device or imaging component (e.g., camera) relative to the beam pulse in order to accommodate for beam equilibration time as well as fluorescent emission delay. The control system  3001 A may further adjust a camera detector exposure time to accumulate as much of the signal as possible while keeping the signal-to-noise (SNR) ratio at the highest level. 
     The control system  3001 A may also provide information collected from any of the components of the beam system  10 , including the beam diagnostics system  500  (e.g.,  FIG. 11B ), to the computing device  3002  either directly or via communications network  3004 . 
     Communications network  3004  may include any wired or wireless communication network including, for example, a wired or wireless local area network (LAN), personal area network (PAN), metropolitan area network (MAN), wide area network (WAN), or the like, as well as any hardware, software and/or firmware required to implement it (such as, e.g., network routers, etc.). For example, communications network  3004  may include an 802.11, 802.16, 802.20, and/or WiMax network. Further, the communications network  3004  may include a public network, such as the Internet, a private network, such as an intranet, or combinations thereof, and may utilize a variety of networking protocols now available or later developed including, but not limited to TCP/IP based networking protocols. 
     The computing device  3002  and control system  3001 A may be embodied by one or more computing systems, such as apparatus  3100  shown in  FIG. 12 . As illustrated in  FIG. 12 , the apparatus  3100  may include a processor  3102 , a memory  3104 , an input and/or output circuitry  3106 , and communications device or circuitry  3108 . It should also be understood that certain of these components  3102 - 3108  may include similar hardware. For example, two components may both leverage use of the same processor, network interface, storage medium, or the like to perform their associated functions, such that duplicate hardware is not required for each device. The use of the terms “device” and/or “circuitry” as used herein with respect to components of the apparatus therefore can encompass particular hardware configured with software to perform the functions associated with that particular device, as described herein. 
     The terms “device” and/or “circuitry” should be understood broadly to include hardware, in some embodiments, device and/or circuitry may also include software for configuring the hardware. For example, in some embodiments, device and/or circuitry may include processing circuitry, storage media, network interfaces, input/output devices, and the like. In some embodiments, other elements of the apparatus  3100  may provide or supplement the functionality of particular device(s). For example, the processor  3102  may provide processing functionality, the memory  3104  may provide storage functionality, the communications device or circuitry  3108  may provide network interface functionality, and the like. 
     In some embodiments, the processor  3102  (and/or co-processor or any other processing circuitry assisting or otherwise associated with the processor) may be in communication with the memory  3104  via a bus for passing information among components of the apparatus. The memory  3104  may be non-transitory and may include, for example, one or more volatile and/or non-volatile memories. In other words, for example, the memory may be an electronic storage device (e.g., a computer readable storage medium.) The memory  3104  may be configured to store information, data, content, applications, instructions, or the like, for enabling the apparatus to carry out various functions in accordance with example embodiments of the present disclosure. 
     The processor  3102  may be embodied in a number of different ways and may, for example, include one or more processing devices configured to perform independently. Additionally or alternatively, the processor may include one or more processors configured in tandem via a bus to enable independent execution of instructions, pipelining, and/or multithreading. The use of the terms “processing device” and/or “processing circuitry” may be understood to include a single core processor, a multi-core processor, multiple processors internal to the apparatus, and/or remote or “cloud” processors. 
     In an example embodiment, the processor  3102  may be configured to execute instructions stored in the memory  3104  or otherwise accessible to the processor. Alternatively or additionally, the processor may be configured to execute hard-coded functionality. As such, whether configured by hardware or software methods, or by a combination of hardware with software, the processor may represent an entity (e.g., physically embodied in circuitry) capable of performing operations according to an embodiment of the present disclosure while configured accordingly. Alternatively, as another example, when the processor is embodied as an executor of software instructions, the instructions may specifically configure the processor to perform the algorithms and/or operations described herein when the instructions are executed. 
     In some embodiments, the apparatus  3100  may include input/output device  3106  that may, in turn, be in communication with processor  3102  to provide output to the user and, in some embodiments, to receive input from the user. The input/output device  3106  may include a user interface and may include a device display, such as a user device display, that may include a web user interface, a mobile application, a client device, or the like. In some embodiments, the input/output device  3106  may also include a keyboard, a mouse, a joystick, a touch screen, touch areas, soft keys, a microphone, a speaker, or other input/output mechanisms. The processor and/or user interface circuitry including the processor may be configured to control one or more functions of one or more user interface elements through computer program instructions (e.g., software and/or firmware) stored on a memory accessible to the processor (e.g., memory  3104 , and/or the like). 
     The communications device or circuitry  3108  may be any means such as a device or circuitry embodied in either hardware or a combination of hardware and software that is configured to receive and/or transmit data from/to a network and/or any other device or circuitry in communication with the apparatus  3100 . In this regard, the communications device or circuitry  3108  may include, for example, a network interface for enabling communications with a wired or wireless communication network. For example, the communications device or circuitry  3108  may include one or more network interface cards, antennas, buses, switches, routers, modems, and supporting hardware and/or software, or any other device suitable for enabling communications via a network. Additionally or alternatively, the communication interface may include the circuitry for interacting with the antenna(s) to cause transmission of signals via the antenna(s) or to handle receipt of signals received via the antenna(s). These signals may be transmitted by the apparatus  3100  using any of a number of wireless personal area network (PAN) technologies, such as current and future Bluetooth standards (including Bluetooth and Bluetooth Low Energy (BLE)), infrared wireless (e.g., IrDA), FREC, ultra-wideband (UWB), induction wireless transmission, or the like. In addition, it should be understood that these signals may be transmitted using Wi-Fi, Near Field Communications (NFC), Worldwide Interoperability for Microwave Access (WiMAX), or other proximity-based communications protocols. 
     As will be appreciated, any such computer program instructions and/or other type of code may be loaded onto a computer, processor, or other programmable apparatus&#39; circuitry to produce a machine, such that the computer, processor, or other programmable circuitry that executes the code on the machine creates the means for implementing various functions, including those described herein. 
     As described above and as will be appreciated based on this disclosure, embodiments of the present disclosure may be configured as systems, methods, mobile devices, backend network devices, and the like. Accordingly, embodiments may comprise various means including entirely of hardware or any combination of software and hardware. Furthermore, embodiments may take the form of a computer program product on at least one non-transitory computer-readable storage medium having computer-readable program instructions (e.g., computer software) embodied in the storage medium. Any suitable computer-readable storage medium may be utilized including non-transitory hard disks, CD-ROMs, flash memory, optical storage devices, or magnetic storage devices. 
     Processing circuitry for use with embodiments of the present disclosure can include one or more processors, microprocessors, controllers, and/or microcontrollers, each of which can be a discrete chip or distributed amongst (and a portion of) a number of different chips. Processing circuitry for use with embodiments of the present disclosure can include a digital signal processor, which can be implemented in hardware and/or software of the processing circuitry for use with embodiments of the present disclosure. Processing circuitry for use with embodiments of the present disclosure can be communicatively coupled with the other components of the figures herein. Processing circuitry for use with embodiments of the present disclosure can execute software instructions stored on memory that cause the processing circuitry to take a host of different actions and control the other components in figures herein. 
     Memory for use with embodiments of the present disclosure can be shared by one or more of the various functional units, or can be distributed amongst two or more of them (e.g., as separate memories present within different chips). Memory can also be a separate chip of its own. Memory can be non-transitory, and can be volatile (e.g., RAM, etc.) and/or non-volatile memory (e.g., ROM, flash memory, F-RAM, etc.). 
     Computer program instructions for carrying out operations in accordance with the described subject matter may be written in any combination of one or more programming languages, including an object oriented programming language such as Java, JavaScript, Smalltalk, C++, C #, Transact-SQL, XML, PHP or the like and conventional procedural programming languages, such as the “C” programming language or similar programming languages. 
     Various aspects of the present subject matter are set forth below, in review of, and/or in supplementation to, the embodiments described thus far, with the emphasis here being on the interrelation and interchangeability of the following embodiments. In other words, an emphasis is on the fact that each feature of the embodiments can be combined with each and every other feature unless explicitly stated otherwise or logically implausible. 
     In some embodiments, a beam position monitor includes multiple electrodes extending into an interior of a component of a beam line. In some of these embodiments, the beam position monitor is configured to detect a position of a beam passing through the component of the beam line based on halo current of the beam. In some of these embodiments, the beam position monitor further includes a cooling device. 
     In some of these embodiments, each electrode of the multiple electrodes is associated with a current threshold. In some of these embodiments, at least one electrode of the multiple electrodes is associated with a different current threshold than one or more other electrodes of the multiple electrodes. In some of these embodiments, each electrode of the multiple electrodes is associated with multiple current thresholds. 
     In some of these embodiments, the beam position monitor is configured to transmit a signal to a control system when a measured current by one or more electrode of the multiple electrodes exceeds its associated current threshold. In some of these embodiments, the beam position monitor is configured to transmit a signal to a control system when a measured current by adjacent electrodes of the multiple electrodes exceeds a lower threshold of the multiple current thresholds associated with each electrode of the adjacent electrodes. 
     In some of these embodiments, each electrode of the multiple electrodes is associated with an electrode extension distance. In some of these embodiments, the electrode extension distance represents a distance into the interior of the component that the electrode extends. In some of these embodiments, each electrode extension distance is adjustable. 
     In some of these embodiments, the multiple electrodes are galvanically isolated from a wall of the beam position monitor. In some of these embodiments, the multiple electrodes are configured to be biased by an external power supply. 
     In some of these embodiments, the beam position monitor is configured to transmit a signal to a control system when a beam advancing through the beam line is off axis. In some of these embodiments, a minimal amount of a beam current of the beam passing through the component of the beam line is reduced due to the multiple electrodes. 
     In some embodiments, a beam system includes a beam position monitor configured to detect a position of a beam passing through a component of a beam line based on halo current of the beam. In some of these embodiments, the beam system further includes a control system configured to adjust beam line parameters based on the position of the beam. 
     In some of these embodiments, the beam position monitor includes multiple electrodes extending into an interior of the component of the beam line. 
     In some of these embodiments, the control system includes at least one processor and at least one memory storing instructions that, when executed by the at least one processor, cause the control system to receive one or more signals from the beam position monitor and, based on the one or more signals, transmit instructions to discontinue operation of the beam system. 
     In some of these embodiments, the control system includes at least one processor and at least one memory storing instructions that, when executed by the at least one processor, cause the control system to receive one or more signals from the beam position monitor and, based on the one or more signals, transmit data representative of the one or more signals to a computing device. 
     In some of these embodiments, the control system includes at least one processor and at least one memory storing instructions that, when executed by the at least one processor, cause the control system to receive one or more signals from the beam position monitor. In some of these embodiments, the control system is caused to, based on the one or more signals, determine that the beam is off a desired axis, and transmit adjustment signals to one or more beam line components to adjust the position of the beam such that it returns to the desired axis. 
     In some of these embodiments, the control system includes at least one processor and at least one memory storing instructions that, when executed by the at least one processor, cause the control system to receive one or more signals from the beam position monitor. In some of these embodiments, the control system is further caused to, based on the one or more signals, determine a degree of beam deflection off a desired axis, and transmit adjustment signals to one or more beam line components to compensate for the degree of beam deflection off the desired axis. 
     In some of these embodiments, the one or more beam line components include one or more beam steering magnets. In some of these embodiments, the adjustment signals adjust positions of the one or more beam steering magnets. 
     In some of these embodiments, the one or more signals represent measured current by one or more electrodes of the multiple electrodes. 
     In some of these embodiments, the one or more signals represent measured current by one or more electrodes of the multiple electrodes exceeding a current threshold associated with the one or more electrodes. 
     In some of these embodiments, the one or more signals represent measured current by adjacent electrodes of the multiple electrodes exceeding a current threshold associated with the adjacent electrodes. 
     In some of these embodiments, the beam system includes a beam position monitor according to any of the foregoing embodiments. 
     In some of these embodiments, the beam system includes an ion source configured to generate ions and a tandem accelerator configured to accelerate ions propagated from the ion source. In some of these embodiments, one or more beam position monitors are positioned one or more of upstream the tandem accelerator or downstream the tandem accelerator. 
     In some embodiments, a neutron beam system includes a pre-accelerator system configured to accelerate ions from an ion source, a tandem accelerator configured to accelerate ions from the pre-accelerator system, and a beam position monitor according to any of the foregoing embodiments. In some of these embodiments, the ion source is configured to generate ions. 
     In some of these embodiments, the neutron beam system further includes a beamline coupled to an outlet of the tandem accelerator, and the pre-accelerator system coupled to an inlet of the tandem accelerator. 
     In some of these embodiments, the pre-accelerator system includes one or more of an einzel lens, a pre-accelerator tube, a magnetic focusing elements, or a pumping chamber. 
     In some embodiments, a method of monitoring a position of a beam advancing through a beam line includes measuring a magnitude of a current at one or more individual electrodes of multiple electrodes positioned within a beam line as a beam advances through the beam line. In some of these embodiments, each individual electrode of the multiple electrodes is associated with one or more current thresholds. 
     In some of these embodiments, the method further includes determining whether the beam advancing through the beam line is off axis by comparing the magnitude of the current at one or more of the one or more individual electrodes against one or more current thresholds. 
     In some of these embodiments, the method further includes determining whether the beam advancing through the beam line is off axis by comparing a first magnitude of current at a first electrode of the one or more individual electrodes to a first current threshold and a second magnitude of current at a second electrode of the one or more individual electrodes to a second current threshold. In some of these embodiments, the first electrode and the second electrode are positioned adjacent one another. 
     In some of these embodiments, the method further includes signaling to a control system that the beam is off axis when the magnitude of the current at one or more of the one or more individual electrodes exceeds or is below the one or more current thresholds. 
     In some of these embodiments, the method further includes signaling to a control system that the beam is off axis when the first magnitude of current at the first electrode exceeds or is below the first current threshold and the second magnitude of current at the second electrode exceeds or is below the second current threshold. 
     In some of these embodiments, the method further includes biasing the multiple electrodes using an external power supply. In some of these embodiments, the method further includes water cooling the multiple electrodes. 
     In some of these embodiments, each individual electrode of the plurality of electrodes is associated with an electrode extension distance. In some of these embodiments, an electrode extension distance represents a distance into the interior of a component of the beam line that an electrode extends. 
     In some of these embodiments, each individual electrode is associated with a unique predetermined threshold current. 
     In some embodiments, a method of controlling a position of a beam advancing through a beam line of a beam system includes receiving, from a beam position monitor, one or more signals, and determining, based on the one or more signals, whether the beam advancing through the beam line is off axis. 
     In some of these embodiments, the beam position monitor includes multiple electrodes extending into an interior of a component of the beam line. 
     In some of these embodiments, the method further includes, based on the one or more signals, transmitting instructions to discontinue operation of the beam system. In some of these embodiments, the method further includes, based on the one or more signals, transmitting data representative of the one or more signals to a computing device. In some of these embodiments, the method further includes, upon determining that the beam is off a desired axis, transmitting adjustment signals to one or more beam line components to adjust the position of the beam such that it returns to the desired axis. 
     In some of these embodiments, the method further includes, based on the one or more signals, determining a degree of beam deflection off a desired axis and transmitting adjustment signals to one or more beam line components to compensate for the degree of beam deflection off the desired axis. 
     In some of these embodiments, the one or more beam line components comprise one or more beam steering magnets. In some of these embodiments, the adjustment signals adjust positions of the one or more beam steering magnets. 
     In some of these embodiments, the one or more signals represent measured current by one or more electrodes of the multiple electrodes. In some of these embodiments, the one or more signals represent measured current by one or more electrodes of the multiple electrodes exceeding a current threshold associated with the one or more electrodes. In some of these embodiments, the one or more signals represent measured current by adjacent electrodes of the multiple electrodes exceeding a current threshold associated with the adjacent electrodes. 
     In some of these embodiments, the degree of beam deflection quantifies how far off axis the beam is traveling. 
     In some embodiments, a beam imaging diagnostics system includes two (2) or more imaging components coupled to and extending into an interior of a pumping chamber and orthogonally oriented to a beam propagation axis of the pumping chamber. In some of these embodiments, the pumping chamber is positionable along a beam line. In some of these embodiments, the two (2) or more imaging components are configured to substantially non-invasively monitor a beam advancing through the beam line with the injection of a gas. In some of these embodiments, the beam imaging diagnostics system is configured to monitor beam parameters of the beam advancing through the beam line. In some of these embodiments, beam parameters comprise one or more of size, location, inclination, or profile. 
     In some of these embodiments, the beam imaging diagnostics system further includes a gas puff port extending from the pumping chamber and providing a passage into the pumping chamber. In some of these embodiments, the two (2) or more imaging components include a camera coupled with a lens. In some of these embodiments, an optical tube is one or more of indirectly or directly coupled with the lens. In some of these embodiments, an end of the optical tube that is farthest from the camera includes an aperture having an opening of a specific shape. In some of these embodiments, the aperture is matched with the camera and configured to cut off most of a background light which otherwise may reach a camera sensor of the camera. In some of these embodiments, the two (2) or more imaging components further include an interference bandpass filter positioned between the optical tube and the lens. 
     In some of these embodiments, the gas puff port is driven by a gas valve. 
     In some of these embodiments, the two (2) or more imaging components include an adjustable detector exposure time. In some of these embodiments, the adjustable detector exposure time is adjustable to provide for accumulation of as much of a signal as possible while maintaining a highest possible signal-to-noise ratio (SNR). 
     In some of these embodiments, the gas valve is configured to control an amount of gas puffed and a time when the amount of gas is puffed into the pumping chamber. In some of these embodiments, the gas valve is further configured to control a location of gas puffed into the pumping chamber such that a uniform distribution of gas is achieved within a field of view of the two (2) or more imaging components. 
     In some of these embodiments, the camera includes one or more of a time resolution, a signal-to-noise ratio, or a size. In some of these embodiments, the time resolution is 2 milliseconds or less. In some of these embodiments, the signal-to-noise ratio exceeds 40:1. 
     In some embodiments, a beam system includes a beam imaging diagnostics system positioned along the beam system. In some of these embodiments, the beam imaging diagnostics system is configured to non-invasively monitor a beam advancing through the beam system. In some of these embodiments, the beam system further includes a control system configured to receive one or more signals from the beam imaging diagnostics system. 
     In some of these embodiments, the beam imaging diagnostics system includes a beam imaging diagnostics system according to any of the foregoing embodiments. 
     In some of these embodiments, the control system includes at least one processor and at least one memory storing instructions that, when executed by the at least one processor, cause the control system to, based on the one or more signals, determine one or more beam parameters comprising one or more of size, location, inclination, or profile. 
     In some of these embodiments, the control system includes at least one processor and at least one memory storing instructions that, when executed by the at least one processor, cause the control system to, based on the one or more signals, transmit a control signal to one or more of a gas valve or one or more imaging components of the beam imaging diagnostics system. 
     In some of these embodiments, the beam system further includes a low-energy beamline (LEBL). In some of these embodiments, the LEBL includes one or more of a negative ion source, beam optics, a pre-accelerator system, beam diagnostics, or a pumping chamber. In some of these embodiments, the beam system further includes an accelerator downstream the LEBL. In some of these embodiments, a first beam imaging diagnostics system according to any of the foregoing embodiments is positioned upstream the accelerator. In some of these embodiments, a second beam imaging diagnostics system according to any of the foregoing embodiments is positioned downstream the accelerator. 
     In some embodiments, a neutron beam system includes a pre-accelerator system configured to accelerate ions from an ion source, a tandem accelerator configured to accelerate ions from the pre-accelerator system, and a beam imaging diagnostics system according to any of the foregoing embodiments. 
     In some of these embodiments, the neutron beam system further includes an ion source configured to generate ions. In some of these embodiments, the neutron beam system further includes a high-energy beamline (HEBL) coupled to an outlet of the tandem accelerator, and the pre-accelerator system coupled to an inlet of the tandem accelerator. In some of these embodiments, the pre-accelerator system includes one or more of an einzel lens, a pre-accelerator tube, a magnetic focusing elements, or a pumping chamber. 
     In some of these embodiments, the neutron beam system further includes a control system configured to receive one or more signals from the beam imaging diagnostics system. 
     In some of these embodiments, the control system includes at least one processor and at least one memory storing instructions that, when executed by the at least one processor, cause the control system to, based on the one or more signals, determine one or more beam parameters comprising one or more of size, location, inclination, or profile. 
     In some of these embodiments, the control system includes at least one processor and at least one memory storing instructions that, when executed by the at least one processor, cause the control system to, based on the one or more signals, transmit a control signal to one or more of a gas valve or one or more imaging components of the beam imaging diagnostics system. 
     In some embodiments, a method of noninvasively monitoring parameters of a beam advancing along a beam line includes puffing gas into a pumping chamber and measuring one or more beam parameters based on fluorescence resulting from collisions of energetic beam particulates of a beam advancing through the beam line. 
     In some of these embodiments, the method further includes puffing the gas into the pumping chamber while the beam advances through the beam line. 
     In some of these embodiments, the method further includes puffing the gas into the pumping chamber along the beam line such that disturbance to the beam advancing through the beam line is minimized. 
     In some of these embodiments, the method further includes measuring the one or more beam parameters such that disturbance to the beam advancing through the beam line is minimized. 
     In some of these embodiments, the method further includes puffing the gas into the pumping chamber prior to a pulse of the beam advancing through the beam line. 
     In some of these embodiments, the one or more beam parameters include one or more of a transverse beam size (profile) or a beam position. 
     In some of these embodiments, measuring includes recording a glow of fluorescence from a beam-gas interaction region. In some of these embodiments, recording the glow of fluorescence includes recording using two or more orthogonally oriented imaging components. In some of these embodiments, the method further includes delaying a trigger for the two or more orthogonally oriented imaging components relative to a pulse of the beam. In some of these embodiments, the trigger is delayed to accommodate for one or more of beam equilibration time or fluorescent emission delay. 
     In some of these embodiments, the method further includes transferring one or more beam parameters to a control system. In some of these embodiments, the one or more beam parameters include beam position, transverse size, and beam inclination. In some of these embodiments, the method further includes transferring the one or more beam parameters to the control system in real-time. 
     In some of these embodiments, the method further includes calculating beam centroids along a beam propagation, and comparing the beam centroids with beamline axis coordinates. In some of these embodiments, the method further includes obtaining the beamline axis coordinates during calibration of a beam imaging diagnostics system. 
     In some of these embodiments, the method further includes measuring the one or more beam parameters one or more of before treatment, during treatment, or after treatment. 
     In some of these embodiments, the gas includes one or more of argon or xenon. 
     It should be noted that all features, elements, components, functions, and steps described with respect to any embodiment provided herein are intended to be freely combinable and substitutable with those from any other embodiment. If a certain feature, element, component, function, or step is described with respect to only one embodiment, then it should be understood that that feature, element, component, function, or step can be used with every other embodiment described herein unless explicitly stated otherwise. This paragraph therefore serves as antecedent basis and written support for the introduction of claims, at any time, that combine features, elements, components, functions, and steps from different embodiments, or that substitute features, elements, components, functions, and steps from one embodiment with those of another, even if the following description does not explicitly state, in a particular instance, that such combinations or substitutions are possible. It is explicitly acknowledged that express recitation of every possible combination and substitution is overly burdensome, especially given that the permissibility of each and every such combination and substitution will be readily recognized by those of ordinary skill in the art. 
     To the extent the embodiments disclosed herein include or operate in association with memory, storage, and/or computer readable media, then that memory, storage, and/or computer readable media are non-transitory. Accordingly, to the extent that memory, storage, and/or computer readable media are covered by one or more claims, then that memory, storage, and/or computer readable media is only non-transitory. 
     As used herein and in the appended claims, the singular forms “a,” “an,” and “the” include plural referents unless the context clearly dictates otherwise. 
     While the embodiments are susceptible to various modifications and alternative forms, specific examples thereof have been shown in the drawings and are herein described in detail. It should be understood, however, that these embodiments are not to be limited to the particular form disclosed, but to the contrary, these embodiments are to cover all modifications, equivalents, and alternatives falling within the spirit of the disclosure. Furthermore, any features, functions, steps, or elements of the embodiments may be recited in or added to the claims, as well as negative limitations that define the inventive scope of the claims by features, functions, steps, or elements that are not within that scope.