A significant difference in mammalian-cell polyploidy induction between plateau and ''star'' regions of a negative pion beam
Biological effectiveness of negative pion beam on mice with abdominal lymphoma
TUMOR↗
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Search indexed NASA NTRS and DOE OSTI research on propulsion, heat transfer, battery materials and energy systems. Follow report and document links to the original sources.
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Radiation-induced light flashes observed by human subjects in fast neutron, X-ray and positive pion beams
Radiation induced visual phosphenes observed by dark adapted human subjects in fast neutron, X ray and positive pion beams at Berkeley comparative to primary cosmic ray effects
Budinger, T. F.↗
Performance of the CMS High Granularity Calorimeter prototype to charged pion beams of 20–300 GeV/c
The upgrade of the CMS experiment for the high luminosity operation of the LHC comprises the replacement of the current endcap calorimeter by a high granularity sampling calorimeter (HGCAL). The electromagnetic section of the HGCAL is based on silicon sensors interspersed between lead and copper (or copper tungsten) absorbers. The hadronic section uses layers of stainless steel as an absorbing medium and silicon sensors as an active medium in the regions of high radiation exposure, and scintillator tiles directly read out by silicon photomultipliers in the remaining regions. As part of the development of the detector and its readout electronic components, a section of a silicon-based HGCAL prototype detector along with a section of the CALICE AHCAL prototype was exposed to muons, electrons and charged pions in beam test experiments at the H2 beamline at the CERN SPS in October 2018. The AHCAL uses the same technology as foreseen for the HGCAL but with much finer longitudinal segmentation. The performance of the calorimeters in terms of energy response and resolution, longitudinal and transverse shower profiles is studied using negatively charged pions, and is compared to GEANT4 predictions. This is the first report summarizing results of hadronic showers measured by the HGCAL prototype using beam test data.
46 INSTRUMENTATION RELATED TO NUCLEAR SCIENCE AND ↗
Observations by human subjects on radiation- induced light flashes in fast-neutron, X-ray, and positive-pion beams
Exposure of human subjects to fast neutron beam to determine cause of light flashes observed by astronauts on lunar missions
Budinger, T. F.↗
High energy particle detection with large area superconducting microwire array
We present the first detailed study of an 8-channel2×2 mm$^{2}$ WSi superconducting microwire single photondetector (SMSPD) array exposed to 120 GeV proton beam and 8 GeVelectron and pion beam at the Fermilab Test Beam Facility. TheSMSPD detection efficiency was measured for the first time forprotons, electrons, and pions, enabled by the use of a silicontracking telescope that provided precise spatial resolution of30 μm for 120 GeV protons and 130 μm for 8 GeVelectrons and pions. The result demonstrated consistent detectionefficiency across pixels and at different bias currents. Timeresolution of 1.15 ns was measured for the first time for SMSPDwith proton, electron, and pions, enabled by the use of an MCP-PMTwhich provided a ps-level reference time stamp. The resultspresented is the first step towards developing SMSPD array systemsoptimized for high energy particle detection and identification forfuture accelerator-based experiments.
46 INSTRUMENTATION RELATED TO NUCLEAR SCIENCE AND ↗
A measurement of the lifetime of the positive pion
Decay of positive pions measured by electronic techniques and low-energy pion beams
SPECTROSCOPY↗
Performance of the Advanced Thin Ionization Calorimeter (ATIC)
The ATIC instrument is a balloon-borne experiment capable of measuring cosmic ray elemental spectra from 50 GeV to 100 TeV for nuclei from H to Fe with a fully active Bismuth Germanate calorimeter. Several Long Duration Balloon flights from McMurdo station, Antarctica are scheduled. The detector was tested with high energy electron, proton, and pion beams at CERN. We present results for 150 and 375 GeV protons, and 150 GeV pions and comparison with a GEANT Monte Carlo.
Case, G.↗
Low Energy Muon Capture and Transport from a Heavy Target
The MeV Test Area (MTA) secondary beamline is currently designed to produce and capture a low energy pion beam that then produces a tertiary muon beam via decay along the secondary line. The challenge presented in capturing muons from low-energy decay-in-flight pions, is the large decay angle that results from the low momentum. The current air-core quadruples lack the strength to bend/capture muons at large angles. Recently much stronger 400- MeV Linac quadrupoles have become available which are capable of strong focusing and large-angle capture. Initial results from this upgrade and reconfiguration indicate a major improvements in angle acceptance and transport ability for low-energy muons.
Winter, Wesley↗
Pion studies with silicon detectors.
Most probable energy loss in silicon for pions with energies from 365 to 50 mev, examining pion beam behavior through different absorption material thicknesses
MUON↗
Secondary Beamline Lattice Design at the MeV Test Area (MTA)
The MTA is currently configured to produce a secondary pion beam from a tungsten target, which subsequently generates muons from decay in flight. In its present lattice configuration, the currently installed air core quadrupoles are strength-limited in their ability to deliver a high muon flux to the end user. Recently, seven strong iron-core quadrupole spares from the 400-MeV Linac were acquired. Based on these quadrupoles, a new lattice has been designed that maximizes both pion transport and muon capture the line based on significantly shorter magnetic lengths, strong magnetic gradients, and consequently an enhanced angular acceptance. For this project, we demonstrated that the ratio of muons to pions increased by over an order of magnitude (approximately 75 for lattice configurations were studied), successfully capturing a phase space area as large as 13.2 [mm] x 24 [mRad] in simulation.
Winter, Wesley↗
High-energy $η^{(')}π$ photoproduction and the nature of exotic waves
The observation of hybrid mesons in photoproduction experiments can provide essential insight into the inner workings of quantum chromodynamics in the strong coupling regime. In particular, the study of final $η^{(')}π$ states is of great interest due to the presence of the lowest lying hybrid candidate with manifestly exotic quantum numbers, the $π_1$(1600). In this work, a double-vector exchange model with Reggeized $ρ$ and $ω$ trajectories is developed to describe the photoproduction of $η^{(')}π$ in the high-mass region. Results are presented for the differential cross sections and forward-backward asymmetries in the energy region of interest to the GlueX experiment. The model contains no free parameters, and reproduces the magnitude and t-dependence of existing CLAS data at $E_γ$ = 5 GeV. The model predicts a stronger asymmetry in the $η'π$ channel than in the $ηπ$ channel, consistent with what has previously been observed in pion beam experiments. This suggests that the sizeable production of exotic odd waves in $η'π$ is not necessarily related to the presence of gluon-rich environments. Confirmation of these predicted asymmetries from forthcoming GlueX data would enable further predictions of the low-energy spectrum.
Montaña, Glòria [Thomas Jefferson National Acceler↗
Strangeness production via resonances in heavy-ion collisions at energies available at the GSI Schwerionensynchrotron
Production of strange hadrons in elementary and heavy-ion reactions is studied with the hadronic transport approach called simulating many accelerated strongly interacting hadrons. The poorly known branching ratios of the relevant hadronic resonances are constrained from the known elementary hadronic cross sections and from invariant mass spectra of dileptons. The constrained model is employed as a baseline to compare to heavy-ion-collision experiments at low energies [E kin = (1-2) A GeV] and to predict some of the upcoming pion-beam results at the High-Acceptance Di-Electron Spectrometer, which are expected to be sensitive to the resonance properties. The employed vacuum-resonance approach proves to be viable for small systems at these energies, but for large systems additional in-medium effects might be required.
73 NUCLEAR PHYSICS AND RADIATION PHYSICS↗
New physical processes for extracting GPDs with a better sensitivity to partonic structure
We introduce a new type of exclusive processes for a better study of generalized parton distributions (GPDs), which we refer to as single-diffractive hard exclusive processes (SDHEPs). We advocate a two-stage framework for picturing SDHEPs based on the separation of scales, which gives a clear description both kinematically and dynamically. We examine the sensitivity of the SDHEP to the parton momentum fraction x -dependence of GPDs, and demonstrate it quantitatively with two specific processes that can be readily measured at J-PARC or AMBER using a pion beam and at JLab using a photon beam, respectively. Both processes are capable of providing enhanced sensitivity to the x -dependence, overcoming the problem of shadow GPDs, and disentangling different types of GPDs with various spin asymmetries.
Qiu, Jianwei↗
Search for bound states of the eta-meson in light nuclei
A search for nuclear-bound states of the eta meson was carried out. Targets of lithium, carbon, oxygen, and aluminum were placed in a pion(+) beam at 800 MeV/c. A predicted eta bound state in O-15* (E sub x approx. = 540 MeV) with a width of approx. 9 MeV was not observed. A bound state of a size 1/3 of the predicted cross section would have been seen in this experiment at a confidence level of 3sigma (P is greater than 0.9987).
Chrien, R. E.↗
Preliminary Results From The First Flight of ATIC
The Advanced Thin Ionization Calorimeter (ATIC) instrument is designed to measure the composition and energy spectra of Z = 1 to 28 cosmic rays over the energy range approximately 10 GeV - 100 TeV. The instrument was calibrated in September 1999 at CERN using accelerated electron, proton and pion beams. ATIC was launched as a long duration balloon test flight on 12/28/00 local time from McMurdo, Antarctica. After flying successfully for about 16 days the payload was recovered in excellent condition. Absolute calibration of the detector response was made using cosmic-ray muons. The data analysis algorithm which was developed with Monte Carlo simulations and validated with the CERN beam test will be used for the flight data analysis. Preliminary results of the proton and helium spectra will be reported in this paper.
Seo, E. S.↗
Preliminary Results From the First Flight of ATIC
The Advanced Thin Ionization Calorimeter (ATIC) instrument is designed to measure the composition C and energy spectra of Z = 1 to 28 cosmic rays over the energy range approximately 10 GeV - 100 TeV. The instrument was calibrated in September 1999 at CERN using accelerated electron, proton and pion beams. ATIC was launched as a long duration balloon test flight on 12/28/00 local time from McMurdo, Antarctica. After flying successfully for about 16 days the payload was recovered in excellent condition. Absolute calibration of the detector response was made using cosmic-ray muons. The data analysis algorithm which was developed with Monte Carlo simulations and validated with the CERN beam test will be used for the flight data analysis. Preliminary results of the protons and C helium spectra will be reported in this paper.
Seo, E. S.↗
Accelerator Tests of the KLEM Prototypes
The Kinematic Lightweight Energy Meter (KLEM) device is planned for direct measurement of the elemental energy spectra of high-energy (10(exp 11)-10(exp 16) eV) cosmic rays. The first KLEM prototype has been tested at CERN with 180 GeV pion beam in 2001. A modified KLEM prototype will be tested in proton and heavy ion beams to give more experimental data on energy resolution and charge resolution with KLEM method. The first test results are presented and compared with simulations.
Bashindzhagyan, G.↗
PIONEER: Studies of Rare Pion Decays
A next-generation rare pion decay experiment, PIONEER, is strongly motivated by several inconsistencies between Standard Model (SM) predictions and data pointing towards the potential violation of lepton flavor universality. It will probe non-SM explanations of these anomalies through sensitivity to quantum effects of new particles even if their masses are at very high scales. Measurement of the charged-pion branching ratio to electrons vs. muons $R_{e/\mu}$ is extremely sensitive to new physics effects. At present, the SM prediction for $R_{e/\mu}$ is known to 1 part in $10^4$, which is 15 times more precise than the current experimental result. An experiment reaching the theoretical accuracy will test lepton flavor universality at an unprecedented level, probing mass scales up to the PeV range. Measurement of pion beta decay, $\pi^+\to \pi^0 e^+ \nu (\gamma)$, with 3 to 10-fold improvement in sensitivity, will determine $V_{ud}$ in a theoretically pristine manner and test CKM unitarity, which is very important in light of the recently emerged tensions. In addition, various exotic rare decays involving sterile neutrinos and axions will be searched for with unprecedented sensitivity. The experiment design benefits from experience with the recent PIENU and PEN experiments at TRIUMF and the Paul Scherrer Institut (PSI). Excellent energy and time resolutions, greatly increased calorimeter depth, high-speed detector and electronics response, large solid angle coverage, and complete event reconstruction are all critical aspects of the approach. The PIONEER experiment design includes a 3$\pi$ sr 25 radiation length calorimeter, a segmented low gain avalanche detector stopping target, a positron tracker, and other detectors. Using intense pion beams, and state-of-the-art instrumentation and computational resources, the experiments can be performed at the PSI ring cyclotron.
46 INSTRUMENTATION RELATED TO NUCLEAR SCIENCE AND ↗