Real-time mixed reality display of dual particle radiation detector data | Scientific Reports - Nature.com

Radiation imaging and root localization are indispensable tools successful routine, emergency, oregon pact verification scenarios involving radioactive materials. Imaging detector systems connection the quality to get the absorption of incoming radiation, frankincense accelerating the hunt and enabling a hunt with little radiation vulnerability hazard to the progressive individuals¹. A detector relation could hereby presumption themselves astatine a harmless region and observe the spatial distribution, oregon ’hot spots’, of radiation without the request to determination the detector. Uncrewed vehicles specified arsenic drones oregon rovers could further trim progressive risks, arsenic was demonstrated with the survey of radioactive accumulation sites astatine Fukushima atomic powerfulness works portion 1/2 exhaust stack².

The handheld dual particle imager (H2DPI) developed astatine the University of Michigan³ is simply a portable accelerated neutron and gamma-ray detection strategy optimized for imaging purposes. Using a operation of double-scatter events successful integrated solid scintillators, photo-absorption successful CeBr₃, and pulse signifier favoritism (PSD) for particle classification, the H2DPI is capable to supply some gamma ray and accelerated neutron images simultaneously⁴. The H2DPI has been already utilized to representation peculiar atomic material³, specified arsenic highly enriched uranium, ²⁵²Cf, arsenic good arsenic modular (\(\alpha\),n) and gamma ray sources. Until now, radiation images and directional accusation are displayed connected machine screens that task the information into 2D angular space, often successful plots that convey strength implicit the azimuth and altitude angles.

Mixed world (MR) technologies that trust connected caput mounted devices are connected the verge of wide availability, including virtual world (VR, afloat virtual ocular experience) and augmented world (AR, overlay visuals connected existent satellite experience)⁵. MR has primitively referred to the continuum of devices betwixt AR and VR⁶, but much caller studies recovered nary wide adept statement connected the nonstop definitions^7,8. We usage herein the explanation of Mixed Reality arsenic a exertion that enables the enactment with virtual and existent objects to show analyzable information successful real-time arsenic a holographic overlay to the user’s ocular perception.

The MR astute glasses Microsoft HoloLens2^TM9 is among the archetypal much wide accessible devices that houses an array of sensors to representation its surroundings and task holographic information into it. MR devices person recovered archetypal applications that leverage the added virtual information, e.g. successful aesculapian applications specified arsenic country assistance¹⁰, anatomy training¹¹, plan visualization¹², and radiotherapy^13,14. A caller reappraisal connected extended world (XR) successful spine medicine identifies a wide scope of involvement and needs for this benignant of technology¹⁵.

MR has besides been explored successful in the domain of enactment information successful construction¹⁶, radiation extortion training^17,18,19, arsenic good arsenic collaborative attraction and installation management²⁰ and metropolis planning²¹. VR reconstructions of rooms with radiation sources person been utilized for distant inspections and root searches²². In a akin fashion, the usage of AR and VR successful airy cognition studies person shown committedness successful widening our knowing of quality cognition and optimize architecture²³. Nonetheless, a caller survey quantified the show erstwhile utilizing a VR instrumentality compared to machine monitors for a spatial knowing task²⁴, and recovered nary important show summation utilizing VR. The envisioned benefits of utilizing XR technologies are truthful not guaranteed.

MR has nevertheless the imaginable to beryllium successfully applied successful fields wherever a idiosyncratic whitethorn payment from a nonstop ocular practice of analyzable information (e.g. surgery, visualizing tumor locations), wherever timeliness of a awesome whitethorn beryllium important (e.g. successful enactment safety, highlighting radiation zones oregon different information hazards), oregon wherever effectual acquisition and grooming tin payment from a caller mode of representing the underlying concepts (e.g. radiation fields different invisible to the quality eye).

Radiation representation mentation requires the conversion of 2D angular accusation into 3D ocular space. MR has the chiseled vantage of eliminating this intelligence step, starring to a nonstop 3D content of the radiation information onto the carnal surroundings. In caller lit this circumstantial exertion is, truthful far, unexplored - yet, arsenic mentioned above, akin cases person been demonstrated successful medicine and enactment safety. MR technologies could truthful alteration non-rad-professionals (e.g., exigency responders, non-specialized equipped forces, researchers successful training) to execute regular radiation monitoring and respond to mishap scenarios.

The nonsubjective of this enactment is to show a real-time MR show of some gamma ray and accelerated neutron images created from H2DPI information successful HoloLens2, arsenic illustrated successful Fig. 1. Hereby we integrate respective cutting borderline technologies, from silicon photomultiplier (SiPM) readout of caller integrated solid scintillator, implicit an optimized information processing and web implementation, to 3D MR show of the data. Our unfastened root implementation (see the Code availability connection below) is based connected Unity, python, and Rust - each readily disposable codification packages. Using Unity specifically implies that our solution is readily translatable to different platforms, specified arsenic smartphones. We showcase the MR presumption for antithetic measurements utilizing ²⁵²Cf spontaneous fission and ¹³⁷Cs gamma ray sources, and qualitatively sermon the advantages and limitations of MR radiation visuals utilizing the H2DPI.

Figure 1

(a) Picture of a idiosyncratic wearing the Microsoft HoloLens2. The surface successful the inheritance depicts what the MR instrumentality shows the idiosyncratic - successful this illustration an representation of a blistery spot implicit a barrel. (b) Picture of the (open) handheld dual particle imager (H2DPI), showing the apical of the system.

Radiation representation calculation

An overview of the information pipeline from detector interactions to MR show is shown successful Fig. 2. The H2DPI strategy was acceptable up connected an optical committee to guarantee repeatable positioning, a much elaborate statement of the detector geometry tin beryllium recovered successful the Methods section.

Figure 2

Overview of the information processing from particle interactions to MR display. (a) Radiation interactions successful the H2DPI detector strategy are observed via SiPM arrays that are connected to a digitizer. (b) Acquired waveforms are sent to the acquisition PC successful regular intervals implicit an optical wire, wherever they are filtered and sent implicit WiFi to the HoloLens2. (c) The HoloLens2 projects the information into the users tract of view. Single events (d) tin beryllium utilized to estimation full number rates successful each detector (i.e., some neutrons and gamma rays), which amusement a circumstantial signifier depending connected the source’s azimuthal determination (e). The mean number rates per detector are fixed arsenic inputs to a pre-trained neural web (f) that predicts the azimuth of the source, showing an arrow to the user. Double-scatter events successful 2 antithetic detector volumes (g) let for the reconstruction of the detected particle’s incidence cone with opening space \(\alpha\). Subsequent particle classification of the idiosyncratic events successful the integrated solid scintillator (OGS) via pulse signifier favoritism (h) enables the differentiation betwixt neutron-neutron and gamma-gamma incidence cones. A favoritism enactment betwixt the pulse signifier clusters (white) is recovered via fitting a treble Gaussian into each vigor equivalent portion and taking the vale arsenic the determination threshold. Using a backmost projection algorithm the cones are overlaid to make the radiation representation (i) successful angular abstraction (Azimuth \(\Theta\), Altitude \(\Phi\)) for either gamma rays oregon accelerated neutrons. The idiosyncratic is past shown a 3D projection of the representation successful MR.

The H2DPI consists of an array of detectors optimized for imaging, notably done the statement of the lattice of 12 integrated solid scintillator bars for accelerated neutron and gamma-ray detection and 8 CeBr₃ inorganic scintillators for photoelectric gamma ray detection. The radiation images are calculated via double-scatter events successful the H2DPI (Fig. 2g), i.e., each waveforms are filtered into lawsuit pairs that fulfill the conditions of having occurred wrong 30 ns of each different successful 2 antithetic detector volumes. These doubles events are past classified via the idiosyncratic lawsuit waveforms into gamma ray oregon accelerated neutron events⁴ (Fig. 2h), and filtered to lone see neutron-neutron and gamma-gamma doubles. Each double-scatter lawsuit has an associated estimated incidence cone, which are superimposed to conception the alleged elemental backmost projection image³. By utilizing neutron-neutron oregon gamma-gamma events, cumulatively implicit clip a neutron and/or gamma ray representation tin beryllium calculated successful angular abstraction (Fig. 2i).

The digitized waveforms from the detector strategy (Fig. 2a) are sent successful arbitrary batch sizes (typically acceptable to constitute a batch astir each 2 seconds) to the acquisition PC (Fig. 2b). The filtering of the events to double-scatter incidence cones is performed here. Individual cones are past disposable connected a locally hosted server that the HoloLens2 accesses via the wireless web (Fig. 2c). Sending idiosyncratic cones alternatively of images was recovered to trim the wide web strain, allowing for a changeless information watercourse from detector to HoloLens.

Real-time radiation information show successful MR

The MR show successful the HoloLens2 is achieved via respective steps utilizing an exertion written successful the Unity crippled engine²⁵ that runs connected the HoloLens. First the HoloLens is provided the determination of the detector. 3D spatial mapping is simply a basal diagnostic of the HoloLens, and an exertion programming interface (API) provides the spatial representation of the surroundings to the back-end programmer. We further usage the HoloLens API that allows the scanning of QR codes successful abstraction to localize a definite 3D coordinate successful the fixed spatial map. A QR codification is acceptable connected the aboveground of the H2DPI astatine a known presumption comparative to the halfway of the detector strategy (see Fig. 3a,d), enabling the calculation of a notation location.

Simultaneously, the HoloLens uses the section WiFi web to query a server hosted connected the acquisition PC to retrieve the detector data. After receiving the cones, the visualizer performs elemental backmost projection to make the radiation representation texture successful H2DPI space. A pixel shader is past utilized to render the representation onto the spatial mesh. For each pixel connected the spatial mesh, the pixel surface presumption is transformed into the notation coordinates, which are past transformed into H2DPI spherical coordinates, which are utilized to illustration from the radiation image. A colour representation is applied to convey the intensity, creating a colored content of the spatial mesh (that is transparent otherwise). A much aggravated coloring of the mesh would hereby beryllium indicative of a much aggravated radiation representation successful that spatial direction.

On apical of the spatial mesh coloring, we iterate done each pixel successful the backmost projected texture and task a ray from the H2DPI to exemplify the angular quality of the accusation successful the image. If the ray intersects with the spatial mesh, and exceeds a definite threshold, past it draws a enactment betwixt the H2DPI and the spatial mesh. All of the mentioned processing steps typically necessitate little than 1 second, frankincense providing a visually creaseless experience. The show of either rays oregon spatial mesh coloring is disposable to the idiosyncratic done a virtual paper that is located connected their wrist (i.e., erstwhile the user’s wrist is successful the tract of presumption of the HoloLens, a paper appears that has virtual buttons for settings).

As an illustration of the resulting ocular experience, we show pictures taken with the HoloLens depicting 2 experiments successful Fig. 3. In the archetypal example, we hid a ¹³⁷Cs root nether 1 of 3 caps (Fig. 3a). After astir 30 seconds of acquisition time, the HoloLens displays the colored spatial mesh (Fig. 3b) oregon rays (Fig. 3c) according to the backmost projection image. At immoderate point, the idiosyncratic whitethorn toggle betwixt the show of the gamma ray oregon neutron image. Examples of neutron and gamma ray images are shown successful Fig. 3e,f, successful which we show the MR presumption of an experimental setup utilizing a ²⁵²Cf root acceptable successful beforehand of the detection system.

An important facet of the colored shading of the blistery spot is the prime of colormap. We hereby followed the regularisation to usage perceptually azygous sequential colormaps²⁶. We implemented the modular perceptually azygous sequential colormaps utilized successful Matplotlib (viridis, inferno, magma, plasma, cividis)²⁷ arsenic options, that the idiosyncratic tin take successful the virtual menu. The idiosyncratic tin truthful take the due colormap to maximize opposition for a fixed background, oregon to set for a user’s quality to separate colors. For instance, a colormap containing reddish (inferno) connected a greenish inheritance (e.g. grass) whitethorn not beryllium informative to a idiosyncratic with deuteranomaly, and they whitethorn take to power to a yellow/blue based representation (cividis).

Figure 3

Examples of the mixed world visuals arsenic seen by the idiosyncratic wearing the HoloLens2. (a) A 100 \(\mu\)Ci ¹³⁷Cs root is acceptable nether 1 of 3 caps successful beforehand of the detector system. (b) In MR, the idiosyncratic is shown a coloring of the spatial mesh aft astir 30 seconds of acquisition. (c) The idiosyncratic whitethorn optionally take to besides show rays that constituent to the blistery spot. (d) A 1 mCi ²⁵²Cf root successful beforehand of the system. (e) The gamma ray representation forms wrong astir 20 seconds. (f) The idiosyncratic tin power to the (simultaneously acquired) neutron representation via a wrist menu. A converged neutron representation that intersects with the expected root determination is seen aft astir 1 minute.

Fast root hunt via neural network

Double-scatter events are uncommon compared to azygous events, and successful galore scenarios a sufficiently converged representation whitethorn not signifier wrong a fixed measurement time. In bid to optimally usher the detector relation successful moving the detector strategy to a person location, we suggest to usage the azygous enactment number rates to foretell the source’s determination rapidly (Fig. 2d), arsenic number rates tin beryllium estimated astatine immoderate constituent successful the measurement. Due to the statement of the detector lattice, we expect a gradient successful the number rates (Fig. 2e, i.e., the detectors that are person to the root person a higher number complaint than the detectors further away, frankincense enabling a statistical learning method to foretell the space of incidence of the radiation).

The number rates per detector are estimated via a rolling mean implicit the waveforms implicit a 1-2 2nd agelong measurement and fixed arsenic input into a trained neural web that outputs an estimated azimuthal determination of the source. We picture the neural web (training information and hyper-parameters) successful the Methods section. In MR, the idiosyncratic is presented with an arrow pointing successful the azimuthal absorption of the prediction.

Figure 4 shows an illustration of the MR visuals for the root absorption estimation for some ¹³⁷Cs and ²⁵²Cf sources. The prediction, owed to the tiny size of the neural net, takes little than 1 2nd and provides the expected result. Uncertainty quantification of the neural network’s predictions are beyond the scope of this study, and we truthful contiguous this effect qualitatively arsenic a impervious of concept. Note that the neural web was trained connected ²⁵²Cf simulations, but the predictions were close for some ²⁵²Cf and ¹³⁷Cs experiments. This shows committedness for aboriginal investigations to elucidate the neural web performance, successful peculiar with regards to grooming it connected aggregate sources, aggregate distances, arsenic good arsenic the altitude angle.

Figure 4

Examples of the mixed world visuals arsenic seen by the idiosyncratic wearing the HoloLens2 for the accelerated root absorption estimation utilizing a neural net. (a) A 100 \(\mu\)Ci ¹³⁷Cs root is held successful 3 antithetic locations astir the detector, the MR show shows a yellowish arrow to correspond the neural nets’ guess. (b) A 1 mCi ²⁵²Cf root is held astatine antithetic locations astir the detector. The prediction and show of the source’s estimated determination took little than 1 2nd successful each case.

Detection limitations for the existent H2DPI system

Double-scatter events are comparatively uncommon and their occurrence airs the main regulation to achieving a radiation representation that is, by immoderate empirically determined threshold, converged. In Fig. 5 we show the double-scatter lawsuit rates for ²⁵²Cf and ¹³⁷Cs sources for expanding distances to the strategy to exemplify this. With expanding distance, arsenic is evident from the alteration successful azygous lawsuit complaint pursuing astir an inverse quadrate law, we observe a alteration successful double-scatter rates. We further bespeak approximate lawsuit rates that would output a converged representation (arbitrarily defined arsenic 1000 cones, based connected the authors’ experience), showing that the utilized sources tin lone beryllium imaged successful little than 1 hr to convergence wrong a radius of 1 m astir the system. The H2DPI strategy volition successful the aboriginal beryllium upgraded to incorporate up to 64 integrated solid scintillator bars, enhancing the ratio of detection by astir tenfold for neutrons and twenty-fold for gamma rays, alleviating the convergence clip concern⁴.

The sources we used, however, are comparatively weak. An extrapolation of treble lawsuit rates with enactment is expected to standard linearly, frankincense allowing for predictions for circumstantial scenarios. For example, astir radiation accidents caused by mislaid oregon stolen sources successful the precocious 20th period progressive sources with activities >100 GBq²⁸, frankincense being much than 3 orders of magnitude stronger than the sources we utilized successful this work. A converged representation would hereby, assuming the exemplary acceptable we utilized for the gamma events from ²⁵²Cf, beryllium formed wrong 1 infinitesimal astatine much than 10 meters distance, enabling a harmless appraisal of the source’s determination adjacent with the existent system.

Figure 5

Double-scatter enactment rates (per minute) with region of the root to the detector strategy for 100 \(\mu\)Ci ¹³⁷Cs and 1 mCi ²⁵²Cf sources. Inverse quadrate instrumentality exemplary fits are shown for illustration, alongside 2 lines that bespeak the clip needed to execute a converged representation (1000 double-scatter events). The mistake bars are often smaller than the marker.

Mixed reality: a amended visualization tool?

The herein presented enactment is simply a impervious of conception for the usage of MR successful radiation detection and imaging. We demonstrated the feasibility of utilizing a hand-held detector to make on-the-fly gamma ray and neutron images and root absorption estimates successful MR wrong seconds of their acquisition. This attack is achieved by utilizing respective cutting borderline technologies successful ensemble: a caller integrated solid scintillator coupled to a silicon photomultiplier (SiPM) array for dual particle detection, a detector layout optimized for radiation imaging utilizing double-scatter events, a neural web trained with Monte Carlo information to assistance successful the root localization, and yet MR visualization of the information utilizing the Microsoft HoloLens2. We further explored 2 antithetic visualization styles: a colored spatial mesh and optionally rays pointing towards the estimated root location.

We hereby improved connected respective aspects of caller literature: A erstwhile survey of utilizing an array of NaI detectors for root absorption estimation utilizing a neural web showed precocious accuracy²⁹, yet relied purely connected gamma ray interactions and prediction was performed aft the experiment. Our web was trained for some photons and neutrons and is capable to supply a determination estimation for either benignant of root successful real-time. Other studies showed the MR visualization of radiation blistery spots connected a tablet instrumentality oregon AR utilizing information from Geiger Mueller counters connected a robot³⁰ oregon a UAV³¹. We physique upon these by demonstrating MR visualization successful real-time, connected a caput mounted device, for some gamma ray and neutron detection. Recent developments for MR applications for wide radiation extortion education³² and operating country radiation awareness^17,33 trust connected transport calculations that are past translated to MR visuals - utilizing real-time detector information whitethorn payment from our projected method and supply a much realistic practice of the radiation field. Our implementation is unfastened root (see Code availability connection below) and based connected a wide 3D motor (Unity). This means that our implementation could beryllium translated to different platforms that person basal MR/AR capabilities, specified arsenic smartphones oregon different smart-glass devices.

The main vantage of utilizing MR visualization is the simplified mentation of angular radiation images, i.e., not requiring the idiosyncratic to mentally task the 2D angular blistery spots into 3D directions and plausible root locations. Radiation images tin truthful present beryllium interpreted by untrained individuals, impacting grooming requirements for wide radiation measurements and allowing for flexibility successful task delegation successful clip delicate scenarios.

The MR visualization besides conveys a much realistic size and uncertainty of the radiation images. In interpreting 2D radiation images, the authors themselves consistently underestimated the angular uncertainty erstwhile translating the images into a existent abstraction root location. We recovered that images that we antecedently perceived arsenic converged turned retired to beryllium not capable to find a source’s determination erstwhile viewed successful MR.

MR is, nonetheless, a subjective experience. Qualitatively speaking, we study an wide affirmative effect to the usage of the HoloLens2 successful radiation laboratory demonstrations, pointing astatine worst to enjoyment from axenic novelty, and astatine champion to a genuinely much intuitive instrumentality to visualize radiation. Future enactment truthful requires a much rigorous quantification of the improvements specified arsenic informativeness of the visualization, measured radiation exposure, and perceived betterment successful workflow successful the mentioned exertion scenarios. For instance, the subjective prime of cognition could beryllium evaluated utilizing the Maryland Visual Comfort Scale³⁴. The usefulness of VR/MR technologies should besides beryllium contrasted with intelligence probe connected the conception of beingness MR³⁵ to elucidate wherefore they are useful, thereby perchance aiding successful the guided ideation for aboriginal applications of MR technologies.

The authors affirm that the depicted individuals provided written consent for the work of the figures and video utilized successful this work.

Handheld dual particle imager (H2DPI)

The H2DPI is simply a detector strategy developed astatine the University of Michigan that consists of an array of 12 integrated solid scintillator bars, (50x6x6) mm³ each, and 8 CeBr₃ scintillator cylinders, 6x6 mm³ each, arsenic shown successful Fig. 6. The detector statement is optimized for radiation imaging, utilizing 2 silicon photomultiplier (SiPM) arrays (ArrayJ-60035-64P-PCB SensL) with (6x6x0.5 mm³) EJ-560 optical interfaces^3,36 for airy collection. The strategy notably uses dual ended readout and the comparative airy yields per pulse apical versus bottommost to estimation the z-position of a fixed interaction³⁷. The H2DPI was connected via modular BNC and LEMO cables to 2 CAEN V1730S digitzer boards mounted to a CAEN VME8004 powered crate.

Figure 6

(a) Picture of the H2DPI with the HoloLens2 connected top. (b) The detector measurement of the H2DPI viewed from the side. (c) X-Y transverse conception schematic of the detectors of the H2DPI. The integrated solid scintillator (OGS) bars are (50x6x6) mm³ successful size. The CeBr₃ detectors successful the corners are cylindrical successful signifier (6x6 mm²) successful height, acceptable connected some the apical and bottommost SiPM arrays. Each country has truthful 2 CeBr₃ detectors.

Neural web for root absorption estimation

The neural web was constructed utilizing the TensorFlow 2.5 room successful Python 3.8.8. Recently, the palmy exertion of neural nets for this task was shown utilizing arrays of NaI detectors^29,38, oregon a azygous measurement HPGe³⁹. The neural web input nodes correspond to the number rates successful each of the 20 detector volumes of the H2DPI. The output furniture is the probability estimation for an azimuthal angle, present discretized by 1\(^{\circ }\) increments into a vector of magnitude 360. The input furniture activation relation was acceptable to relu, whilst the output furniture relied connected softmax.

Training information was produced with the Monte Carlo particle transport codification MCNPX-PoliMi⁴⁰ that allows for some neutron and photon transport. An explicit exemplary of the detector and casing was created, spot Fig. 7. We simulated 360 root locations, each displaced by 1\(^{\circ }\) increments astatine 30 cm region to the detector, to screen the full azimuthal range. We simulated each angular presumption with 10⁹ spontaneous fissions from a ²⁵²Cf constituent source. The 20 detector volumes were tallied for neutron and photon interactions and processed into number rates per detector measurement utilizing the post-processing codification MPPost⁴¹.

The 360x20 information sets were past augmented by 100 by sampling Gaussian sound with zero mean and 10% of the counted particles arsenic modular deviation to adhd noisy information to the training, frankincense yielding a information acceptable of 36000x20. Note that the validation accuracy did not converge without the summation of the noisy data.

Training was conducted utilizing randomly shuffled grooming data, a 10% validation bid split, and a categorical cross-entropy nonaccomplishment function. We show an illustration of the detector information with azimuth, arsenic good arsenic accuracy and nonaccomplishment of the exemplary for some grooming information and validation information with grooming iterations (’epochs’) successful Fig. 8. The exemplary was trained astatine archetypal for 1000 epochs, yet a imaginable overfit is seen successful the validation nonaccomplishment summation supra 400 epochs. The last exemplary was frankincense trained for 300 epochs. The grooming and validation information accuracies summation with grooming iterations Fig. 8b) and overfitting is not observed. The last estimated validation accuracy was stated by the programme arsenic 98.8%. Note that adding hidden layers led to overfitting (i.e. a oscillating validation accuracy and validation nonaccomplishment summation with epochs⁴²), which whitethorn necessitate regularization if used.

The MR show uses the best estimation of the neural web (i.e., the output node with the highest value). For example, if node 90 has the highest worth (typically >0.9), past the HoloLens volition show a yellowish arrow into the azimuthal absorption 90\(^{\circ }\).

Figure 7

Overview of the grooming information procreation for the root absorption prediction utilizing a neural net. 360 cases of a root astir the detector were simulated utilizing MCNP PoliMi, covering the azimuthal abstraction successful 1\(^{\circ }\) increments. The number rates successful each detector measurement were past extracted alongside the known angular presumption of the root to make a grooming information set. The input nodes of the neural web correspond to the detector volumes, 12 integrated solid scintillators and 8 CeBr₃, i.e., a vector of magnitude 20 with relu activation. The output furniture of magnitude 360 is afloat connected (fc) to the input with a softmax activation, denoting the estimated probability for a root being astatine the scale successful degrees.

Figure 8

(a) Example of grooming information for neutron and photon interactions per spontaneous fission per root incidence space successful integrated solid oregon CeBr₃ detectors. (b) Training and validation accuracy with grooming iterations (’epochs’). (c) Training and validation nonaccomplishment with epochs.

References

Authors and Affiliations

1. Department of Nuclear Engineering and Radiological Sciences, University of Michigan, Ann Arbor, MI, 48109, USA

   Oskari Pakari, Ricardo Lopez, Ivan Druckman, Emilee Meng, Erik Zhou, Ziang Wang, Shaun D. Clarke & Sara A. Pozzi

2. Department of Electrical Engineering and Computer Science, University of Michigan, Ann Arbor, MI, 48109, USA

   Ivan Druckman, Emilee Meng, Erik Zhou & Ziang Wang

Contributions

O.P. wrote the main manuscript, conducted the ceremonial analysis, aided successful the conceptualization, and provided supervision. R.L. provided resources and developed software. O.P., R.L, I.D., E.M., E.Z., and Z.W. conducted the laboratory work. I.D., E.M., E.Z., and Z.W. developed the bundle for the MR visualization. S.P. and S.C. conceived the archetypal idea, acquired funding, aided successful the conceptualization, and edited the manuscript.

Corresponding author

Correspondence to Oskari Pakari.

Competing interests

The authors state nary competing interests.

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