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Lawrence Wiencke

Publications and source records attributed to Lawrence Wiencke.

27 records · Page 2Linked to original sources

Prospects for macroscopic dark matter detection at space-based and suborbital experiments

We compare two different formalisms for modeling the energy deposition of macroscopically sized/massive quark nuggets (a.k.a. macros) in the Earth's atmosphere. We show that for a reference mass of 1 g, there is a discrepancy in the macro luminosity of about 14 orders of magnitude between the predictions of the two formalisms. Armed with our finding we estimate the sensitivity for macro detection at space-based (Mini-EUSO and POEMMA) and suborbital (EUSO-SPB2) experiments.

hep-ph↗

Performance and science reach of POEMMA for ultrahigh-energy particles

The Probe Of Extreme Multi-Messenger Astrophysics (POEMMA) is a potential NASA Astrophysics Probe-class mission designed to observe ultra-high energy cosmic rays (UHECRs) and cosmic neutrinos from space. POEMMA will monitor colossal volumes of the Earth's atmosphere to detect extensive air showers (EASs) produced by extremely energetic cosmic messengers: UHECRs above 20 EeV over the full sky and cosmic neutrinos above 20 PeV. We focus most of this study on the impact of POEMMA for UHECR science by simulating the detector response and mission performance for EAS from UHECRs. We show that POEMMA will provide a significant increase in the statistics of observed UHECRs at the highest energies over the entire sky. POEMMA will be the first UHECR fluorescence detector deployed in space that will provide high-quality stereoscopic observations of the longitudinal development of air showers. Therefore, it will be able to provide event-by-event estimates of the calorimetric energy and nuclear mass of UHECRs. The particle physics in the interactions limits the interpretation of the shower maximum on an event by event basis. In contrast, the calorimetric energy measurement is significantly less sensitive to the different possible final states in the early interactions. We study the prospects to discover the origin and nature of UHECRs using expectations for measurements of the energy spectrum, the distribution of arrival direction, and the atmospheric column depth at which the EAS longitudinal development reaches maximum. We also explore supplementary science capabilities of POEMMA through its sensitivity to particle interactions at extreme energies and its ability to detect ultra-high energy neutrinos and photons produced by top-down models including cosmic strings and super-heavy dark matter particle decay in the halo of the Milky Way.

astro-ph.HE↗

Laser test with Mini-EUSO

Mini-EUSO (Extreme Universe Space Observatory) is a small-scale prototype cosmic-ray detector that will measure Earth`s UV emission and other atmospheric phenomena from space. It will be placed in the International Space Station (ISS) behind a UV-transparent window looking to the nadir. The launch is planned this year (2019). Consisting of a multi-anode photomultiplier (MAPMT) camera and a $25$ cm diameter Fresnel lens system, Mini-EUSO has a \ang{44} field of view (FoV), a $6.5$ km$^2$ spatial resolution on the ground and a $2.5\ μ$s temporal resolution. In principle, Mini-EUSO will be sensitive to extensive air shower (EAS) from cosmic-rays with energies above $10^{21}$ eV. A mobile, steerable UV laser system will be used to test the expected energy threshold and performance of Mini-EUSO. The laser system will be driven to remote locations in the Western US and aimed across the field of view of Mini-EUSO when the ISS passes overhead during dark nights. It will emit pulsed $355$ nm UV laser light to produce a short speed-of-light track in the detector. The brightness of this track will be similar to the track from an EAS resulting from a cosmic-ray of up to $10^{21}$ eV. The laser energy is selectable with a maximum of around $90$ mJ per pulse. The energy calibration factor is stable within $5\ \% $. The characteristics of the laser system and Mini-EUSO have been implemented inside the JEM-EUSO OffLine software framework, and laser simulation studies are ongoing to determine the best way to perform a field measurement.

astro-ph.IM↗

Development of a Cherenkov Telescope for the Detection of Ultrahigh Energy Neutrinos with EUSO-SPB2 and POEMMA

The detection of astrophysical neutrinos by IceCube and the potential to constrain source models of ultra-high energy cosmic rays provide the motivation to develop instruments for the observation of neutrinos above $10^7$ GeV. Among the different techniques to detect ultra-high energy neutrinos is the Earth-skimming technique. It makes use of the fact that the tau produced in a tau neutrino interaction inside the Earth can emerge from the ground and initiate an upward-going particle shower in the atmosphere. The particle shower and thus the neutrino can be reconstructed by measuring the Cherenkov and radio emission from the shower particles. In this presentation, we discuss our ongoing development of a Cherenkov telescope for the detection of tau neutrinos, which is to be deployed on the Extreme Universe Space Observatory Super Pressure Balloon 2 (EUSO-SPB2) and is a precursor experiment for the proposed Probe of Extreme Multi-Messenger Astrophysics (POEMMA) mission. POEMMA aims at the detection of ultrahigh energy cosmic rays and ultrahigh energy neutrinos from low earth orbit. The 1 m$^2$ Cherenkov telescope for EUSO-SPB2 will use silicon photomultipliers coupled to a 100 MS/s readout based on the ASIC for General Electronics for TPC`s (AGET) switch capacitor ring sampler. We present the optics, results from our studies to qualify the readout concept and the design of the mechanical integration of the photon detectors and the readout into the telescope.

astro-ph.IM↗

What is the nature and origin of the highest-energy particles in the universe?

This white paper was submitted to the US Astronomy and Astrophysics Decadal Survey (Astro2020) and defines the science questions to be answered in the next decade in the field of Ultra-High Energy Cosmic-Rays. Following a review of the recent experimental and theoretical advances in the field, the paper outlines strategies and requirements desirable for the design of future experiments.

astro-ph.HE↗

Ultrahigh-Energy Cosmic Ray Composition from the Distribution of Arrival Directions

The sources of ultrahigh-energy cosmic rays (UHECRs) have been difficult to catch. It was recently pointed out that while sources of UHECR protons exhibit anisotropy patterns that become denser and compressed with rising energy, nucleus-emitting-sources give rise to a cepa stratis (onion-like) structure with layers that become more distant from the source position with rising energy. The peculiar shape of the hot spots from nucleus-accelerators is steered by the competition between energy loss during propagation and deflection on the Galactic magnetic field (GMF). Here, we run a full-blown simulation study to accurately characterize the deflections of UHECR nuclei in the GMF. We show that while the cepa stratis structure provides a global description of anisotropy patterns produced by UHECR nuclei en route to Earth, the hot spots are elongated depending on their location in the sky due to the regular structure of the GMF. We demonstrate that with a high-statistics sample at the high-energy-end of the spectrum, like the one to be collected by NASA's POEMMA mission, the energy dependence of the hot-spot contours could become a useful observable to identify the nuclear composition of UHECRs. This new method to determine the nature of the particle species is complementary to those using observables of extensive air showers, and therefore is unaffected by the large systematic uncertainties of hadronic interaction models.

astro-ph.HE↗

White paper on EUSO-SPB2

EUSO-SPB2 is a second generation Extreme Universe Space Observatory (EUSO) on a Super-Pressure Balloon (SPB). This document describes the physics capabilities, the proposed technical design of the instruments, and the simulation and analysis software.

astro-ph.HE↗

Calibrating laser test-beams for cosmic-ray observatories

Pulsed UV lasers can provide useful "testbeams" for observatories that use optical detectors, especially fluorescence detectors, to measure high energy cosmic-rays. The light observed by the detector is proportional to the energy of the laser pulse. Since the absolute laser energy can be measured locally, a well-calibrated laser offers a practical way to test the photometric calibration of the cosmic-ray detector including atmospheric corrections. This poster will describe a robotic system for laser polarization and energy calibration. Laboratory measurements of laser energies and polarizations by energy probes from different manufactures will be presented

astro-ph.IM↗

Extracting first science measurements from the southern detector of the Pierre Auger observatory

The world's largest cosmic-ray detector is nearing completion in the remote Pampas of Argentina. This instrument measures extensive air-showers with energies from ${10^{18}-10^{20}}$ eV and beyond. A surface detector array of area 3000 ${km^2}$ records the lateral distribution of charged particles at ground level. A fluorescence detector overlooking the surface detector records the longitudinal light profiles of showers in the atmosphere to make a calorimetric energy measurement. A ``test beam'' for the fluorescence detector is generated by a calibrated laser near the array center. This talk will focus on detector characterizations essential to the first science results that have been reported from the observatory. Plans to construct a larger instrument in the northern hemisphere will also be outlined.

astro-ph↗