Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Technical Note: A fast and monolithic prototype clinical proton
  radiography system optimized for pencil beam scanning   Purpose: To demonstrate a proton imaging system based on well-established
fast scintillator technology to achieve high performance with low cost and
complexity, with the potential of a straightforward translation into clinical
use. Methods: The system tracks individual protons through one (X, Y)
scintillating fiber tracker plane upstream and downstream of the object and
into a 13 cm-thick scintillating block residual energy detector. The fibers in
the tracker planes are multiplexed into silicon photomultipliers (SiPMs) to
reduce the number of electronics channels. The light signal from the residual
energy detector is collected by 16 photomultiplier tubes (PMTs). Only four
signals from the PMTs are output from each event, which allows for fast signal
readout. A robust calibration method of the PMT signal to residual energy has
been developed to obtain accurate proton images. The development of
patient-specific scan patterns using multiple input energies allows for an
image to be produced with minimal excess dose delivered to the patient.
Results: The calibration of signals in the energy detector produces accurate
residual range measurements limited by intrinsic range straggling. We measured
the water-equivalent thickness (WET) of a block of solid water (physical
thickness of 6.10 mm) with a proton radiograph. The mean WET from all pixels in
the block was 6.13 cm (SD 0.02 cm). The use of patient-specific scan patterns
using multiple input energies enables imaging with a compact range detector.
Conclusions: We have developed a prototype clinical proton radiography system
for pretreatment imaging in proton radiation therapy. We have optimized the
system for use with pencil beam scanning systems and have achieved a reduction
of size and complexity compared to previous designs.

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The categories of this paper are: quant-ph
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The categories of this paper are: atom-ph
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The categories of this paper are: nlin
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The categories of this paper are: q-bio
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The categories of this paper are: hep-ex
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The categories of this paper are: chem-ph
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The categories of this paper are: gr-qc
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The categories of this paper are: mtrl-th
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The categories of this paper are: bayes-an
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The categories of this paper are: ao-sci
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The categories of this paper are: nucl-ex
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The categories of this paper are: hep-lat
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The categories of this paper are: supr-con
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The categories of this paper are: econ
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The categories of this paper are: patt-sol
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The categories of this paper are: solv-int