Engineering Papers⌕ Search

Engineering topics

Besson, D.

Publications and source records attributed to Besson, D..

At least 19 records

Macroscopic approach to the radar echo scatter from high-energy particle cascades

To probe the cosmic particle flux at the highest energies, large volumes of dense material like ice have to be monitored. This can be achieved by exploiting the radio signal. In this work, we provide a macroscopic model to predict the radar echo signatures found when a radio signal is reflected from a cosmic-ray or neutrino-induced particle cascade propagating in a dense medium like ice. Its macroscopic nature allows for an energy independent run-time, taking less than 10 s for simulating a single scatter event. As a first application, we discuss basic signal properties and simulate the expected signal for the T-576 beam-test experiment at the Stanford Linear Accelerator Center. Finally, we find good signal strength agreement with the only observed radar echo from a high-energy particle cascade to date.

79 ASTRONOMY AND ASTROPHYSICS↗

The Radar Echo Telescope for Cosmic Rays: Pathfinder experiment for a next-generation neutrino observatory

The Radar Echo Telescope for Cosmic Rays (RET-CR) is a recently funded experiment designed to detect the englacial cascade of a cosmic ray-initiated air shower via in-ice radar, toward the goal of a full-scale, next-generation experiment to detect ultrahigh energy neutrinos in polar ice. For cosmic rays with a primary energy greater than 10 PeV, roughly 10% of an air shower’s energy reaches the surface of a high elevation ice sheet (≳2 ˙km) concentrated into a radius of roughly 10 cm. This penetrating shower core creates an in-ice cascade orders of magnitude more dense than the preceding in-air cascade. Additionally, this dense cascade can be detected via the radar echo technique, where transmitted radio waves are reflected from the ionization deposit left in the wake of the cascade. RET-CR will test the radar echo method in nature, with the in-ice cascade of a cosmic ray-initiated air shower serving as a test beam. In this work, we present the projected event rate and sensitivity based upon a three part simulation using corsika, geant4, and radioscatter. RET-CR expects ~1 radar echo event per day.

79 ASTRONOMY AND ASTROPHYSICS↗

Observation of Radar Echoes from High-Energy Particle Cascades

We report here the observation of radar echoes from the ionization trails of high-energy particle cascades. Data were taken at the SLAC National Accelerator Laboratory, where the full electron beam ( ~ 10 9 e - at ~ 10 GeV / e - ) was directed into a plastic target to simulate an ultrahigh-energy neutrino interaction. The target was interrogated with radio waves, and coherent radio reflections from the cascades were detected with properties consistent with theoretical expectations. This is the first definitive observation of radar echoes from high-energy particle cascades, which could lead to a viable neutrino detection technology for energies ≳ 10 16 eV .

43 PARTICLE ACCELERATORS↗

Using the Hottest Particles in the Universe to Probe Icy Solar System Worlds

We present results of our Phase 1 NIAC Study to determine the feasibility of developing a competitive, low cost, low power, low mass passive instrument to measure ice depth on outer planet ice moons, such as Europa, Ganymede, Callisto, and Enceladus. Indirect measurements indicate that liquid water oceans are likely present beneath the icy shells of such moons (see e.g.,the JPL press release "The Solar System and Beyond is Awash in Water"), which has important astrobiological implications. Determining the thickness of these ice shells is challenging given spacecraft SWaP (Size, Weight and Power) resources. The current approach uses a suite of instruments, including a high power, massive ice penetrating radar. The instrument under study, called PRIDE (Passive Radio Ice Depth Experiment) exploits a remarkable confluence between methods from the high energy particle physics and the search for extraterrestrial life within the solar system. PRIDE is a passive receiver of a naturally occurring radio frequency (RF) signal generated by interactions of deep penetrating Extremely High Energy (> 10^18 eV) cosmic ray neutrinos. It could measure ice thickness directly, and at a significant savings to spacecraft resources. At RF frequencies the transparency of modeled Europan ice is up to many km, so an RF sensor in orbit can observe neutrino interactions to great depths, and thereby probe the thickness of the ice layer.

Exploration↗

Observation of an alternative χ c 0 ( 2 P ) candidate in e + e - → J / ψ D D ¯

IN this work, we perform a full amplitude analysis of the process e + e - → J / ψ D D ¯ , where D refers to either D 0 or D + . A new charmoniumlike state X * ( 3860 ) that decays to D D ¯ is determined with a significance of 6.5 σ . Its mass is ( 3862 - 32 + 26 - 13 + 40 ) MeV / c 2 , and its width is ( 201 - 67 + 154 - 82 + 88 ) MeV . The J P C = 0 + + hypothesis is favored over the 2 + + hypothesis at the level of 2.5 σ . The analysis is based on the 980 fb - 1 data sample collected by the Belle detector at the asymmetric-energy e + e - collider KEKB.

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS↗

First upper limits on the radar cross section of cosmic-ray induced extensive air showers

TARA (Telescope Array Radar) is a cosmic ray radar detection experiment colocated with Telescope Array, the conventional surface scintillation detector (SD) and fluorescence telescope detector (FD) near Delta, Utah, U.S.A. Furthermore, the TARA detector combines a 40 kW, 54.1 MHz VHF transmitter and high-gain transmitting antenna which broadcasts the radar carrier over the SD array and within the FD field of view, towards a 250 MS/s DAQ receiver. TARA has been collecting data since 2013 with the primary goal of observing the radar signatures of extensive air showers (EAS). Simulations indicate that echoes are expected to be short in duration (~10 µs) and exhibit rapidly changing frequency, with rates on the order 1 MHz/µs. The EAS radar cross-section (RCS) is currently unknown although it is the subject of over 70 years of speculation. One novel signal search technique is described in which the expected radar echo of a particular air shower is used as a matched filter template and compared to waveforms obtained by triggering the radar DAQ using the Telescope Array fluorescence detector. No evidence for the scattering of radio frequency radiation by EAS is obtained to date. Finally, we report the first quantitative RCS upper limits using EAS that triggered the Telescope Array Fluorescence Detector.

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS↗

Telescope Array Radar (TARA) Observatory for Ultra-High Energy Cosmic Rays

Construction was completed during summer 2013 on the Telescope Array RAdar (TARA) bi-static radar observatory for Ultra-High Energy Cosmic Rays (UHECR). TARA is co-located with the Telescope Array, the largest “conventional” cosmic ray detector in the Northern Hemisphere, in radio-quiet Western Utah. TARA employs an 8 MW Effective Radiated Power (ERP) VHF transmitter and smart receiver system based on a 250 MS/s data acquisition system in an effort to detect the scatter of sounding radiation by UHECR-induced atmospheric ionization. TARA seeks to demonstrate bi-static radar as a useful new remote sensing technique for UHECRs. In this report, we describe the design and performance of the TARA transmitter and receiver systems.

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS↗

Amplitude analyses of the decays χ c1 →ηπ⁺π⁻ and χ c1 →η'π⁺π⁻

Using a data sample of 2.59×10⁷ ψ(2S) decays obtained with the CLEO-c detector, we perform amplitude analyses of the complementary decay chains ψ(2S)→γχ c1 ; χ c1 →ηπ⁺π⁻ and ψ(2S)→γχ c1 ; χ c1 →η'π⁺π⁻. We find evidence for an exotic P-wave η'π amplitude, which, if interpreted as a resonance, would have parameters consistent with the π₁(1600) state reported in other production mechanisms. We also make the first observation of the decay a₀(980)→η'π and measure the ratio of branching fractions B(a₀(980)→η'π)/B(a₀(980)→ηπ)=0.064±0.014±0.014. The ππ spectrum produced with a recoiling η is compared to that with η' recoil.

Adams, G. S.↗