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The challenge in the philosophical understanding of ‘suicide’ is aptly a rarely researched aspect of Yoruba social history. The recent conscious of the concept depicts an anti-social behaviour which the society disapproved, while the pre-colonial understanding of it paints an honour and heroic move often made not only by the Alaafins but as well as other well-respected individuals in the society. However, the key to accepting the position of suicide hides in the Yorubas’ general understanding of death as well as their multilayered history of their traditional political leaders and military heritage. This paper opines that the philosophy behind the concept of suicide in Old Oyo Empire is motivated by the heroic understanding of death as well as a power play. This paper, however, stresses the role in which this belief has helped grow and negatively affect the empire. The research will however assist in understanding the philosophy of suicide in the state formation and growth of the old Oyo Empire. The work relied on both primary and secondary sources. It employed both descriptive and analytic methods in analyzing the data used for the study.

The Cosmic Ray Energetics And Mass for the International Space Station (ISS-CREAM) experiment successfully recorded data for 539 days from 2017 August to 2019 February. We report the energy spectrum of cosmic-ray protons from the ISS-CREAM experiment at energies from 1.60 × 103 to 6.55 × 105 GeV. The measured spectrum deviates from a single power law. A smoothly broken power-law fit to the data, including statistical and systematic uncertainties, shows the spectral index change at 9.0 × 103 GeV from 2.57 ± 0.03 to 2.82 ± 0.02 with a significance of greater than 3σ. This bump-like structure is consistent with a spectral softening recently reported by the balloon-borne CREAM, DAMPE, and NUCLEON, but ISS-CREAM extends measurements to higher energies.

Cosmic Ray Energetics And Mass for the International Space Station (ISS-CREAM) was designed to study high-energy cosmic rays up to PeV and recorded data from August 22nd, 2017 to February 12th, 2019 on the ISS. In this analysis, the Silicon Charge Detector (SCD), CALorimeter (CAL), and Top and Bottom Counting Detectors (TCD/BCD) are used. The SCD is composed of four layers and provides the measurement of cosmic-ray charges with a resolution of $\sim$0.2e. The CAL comprises 20 interleaved tungsten plates and scintillators, measures the incident cosmic-ray particles' energies, and provides a high energy trigger. The TCD/BCDs consist of photodiode arrays and plastic scintillators and provide a low-energy trigger. In this analysis, the SCD top layer is used for charge determination. Here, we present the heavy nuclei analysis using the ISS-CREAM instrument.

One of the consequences of having a high-density calorimeter as part of an experiment is a large number of secondary shower particles generated in the calorimeter -- some of which scatter back up towards the charge measurement devices. This so-called "backscatter effect" can interfere severely with accurate charge measurement of the primary nucleus, especially at high energies, as the number of backscattered particles increases with the incident energy. In this analysis, we study the effect of backscattered particles on particle identification by simulating the ISS-CREAM instrument model detector response using the GEANT3 simulation package [1] with the FLUKA hadronic model [2]. Our study shows the importance of the fine segmentation of charge detectors above the calorimeter. It can minimize backscattered particle contamination in the same charge detector segment as the incident particle to avoid its charge misidentification. We present simulation results regarding charge measurements, including the tracking resolution, backscattering effects, and charge determination efficiency.

The Cosmic Ray Energetics And Mass for the International Space Station (ISS-CREAM) experiment successfully recorded the data for about 539 days from August 2017 to February 2019. In this talk, we report the measurement of the cosmic-ray proton energy spectrum from the ISS-CREAM experiment in the energy range of 2.5 TeV - 650 TeV. For the analysis, we used the silicon charge detector (SCD) placed at the top of the ISS-CREAM payload to identify the incoming cosmic-ray charge. The SCD is finely segmented to minimize charge misidentification due to backscatter effects. The four-layer SCD consists of 10,752 silicon pixels, each of which is 1.37×1.57×0.05 cm^3 in size. The calorimeter (CAL) consists of 20 layers of tungsten/scintillating fibers preceded by carbon targets. It provided cosmic-ray tracking, energy determination, and the high-energy trigger. The Top and Bottom Counting detectors (T/BCD) are above and below the CAL, respectively, and provided the low energy trigger. Each T/BCD is composed of an array of 20×20 photodiodes on plastic scintillators. The measured proton spectral index of 2.67±0.02 between 2.5 and 12.5 TeV is consistent with prior CREAM measurements. The spectrum softens above∼10 TeV consistent with the bump-like structure as reported by CREAM-I+III, DAMPE, and NUCLEON, but ISS-CREAM extends measurements to higher energies than those prior measurement

International audience; Cosmic Ray Energetics And Mass for the International Space Station (ISS-CREAM) experi-ment is designed to study the composition and energy spectra of cosmic-ray particles from 10^12 to 10^15 eV. ISS-CREAM was launched and deployed to the ISS in August 2017. The ISS-CREAM payload employs a Silicon Charge Detector for charge measurements, Top and Bot-tom Counting Detector for electron-hadron separation and a low-energy trigger, a Boronated Scintillator Detector for additional electron-hadron separation, and a Calorimeter (CAL) for en-ergy measurements and a high-energy trigger. The CAL is constructed of 20 layers of tungsten plates interleaved with scintillating fiber ribbons read out by hybrid-photodiodes (HPDs) and densified carbon targets. Each CAL layer is made of 3.5 mm (1 X_0) thick tungsten plates alter-nating with fifty 0.5 mm thick and 1 cm wide scintillating fiber ribbons. Consecutive layers of fiber ribbons are installed orthogonal to each other. Energy deposition in the CAL determines the particle energy and provides tracking information to determine which segment(s) of the charge detectors to use for the charge measurement. Tracking for showers is accomplished by extrapolating each shower axis back to the charge detectors. The performance of the ISS-CREAM CAL during flight is presented.

International audience; Cosmic Ray Energetics And Mass for the International Space Station (ISS-CREAM) is an experiment for studying the origin, acceleration, and propagation mechanisms of high-energy cosmic rays. The ISS-CREAM instrument was launched on the 14th of August 2017 to the ISS aboard the SpaceX-12 Dragon spacecraft. The Top and Bottom Counting Detectors (TCD/BCD) are parts of the ISS-CREAM instrument and designed for studying electron and gamma-ray physics. The TCD/BCD each consist of an array of 20 × 20 photodiodes on a plastic scintillator. The TCD/BCD can separate electrons from protons by using the difference between the shapes of electromagnetic and hadronic showers in the high energy region. The Boosted Decision Tree (BDT) method, which is a deep learning method, is used in this separation study. We will present results of the electron/proton separation study and rejection power in various energy ranges.

International audience; The Cosmic Ray Energetics And Mass experiment for the International Space Station (ISS-CREAM) is designed and built to measure the elemental energy spectra of cosmic-ray particles (1 ≤ Z ≤ 26) and electrons. It measures the energy of incident cosmic rays from 10^12 to 10^15 eV. ISS-CREAM was launched and deployed to the ISS in August 2017. The Science Operations Center (SOC) at the University of Maryland has been operating the payload on the Interna-tional Space Station (ISS) in coordination with the Payload Operations Integration Center (POIC) at NASA’s Marshall Space Flight Center. The SOC has been responsible for sending commands to and receiving data from the Science Flight Computer (SFC) on board ISS-CREAM. The ISS-CREAM data taking program interfaces with the POIC using the Telescience Resources Kit through the Software Toolkit for Ethernet Lab-Like Architecture developed by the Boeing Company. The command uplink and data downlink have been through the Track-ing and Data Relay Satellite System. We present the ISS-CREAM flight operations including ISS communications, SFC performance, etc.

International audience; Cosmic Ray Energetics and Mass for the International Space Station (ISS-CREAM) is designed to directly measure the energy spectra of high-energy cosmic rays, encompassing proton to iron nuclei, over the energy range from 1012 to 1015 eV [1]. The capability to measure an extended energy range enables us to probe the origin and acceleration mechanisms of cosmic rays. The ISS-CREAM instrument is configured with the balloon-borne CREAM calorimeter (CAL) for energy measurements and four layers of a finely segmented Silicon Charge Detector (SCD) for charge measurements. In addition, two new compact detectors have been developed for electron/proton separation: Top and Bottom scintillator-based counting detectors (TCD/BCD) and a boronated scintillator detector (BSD). Simulations use the GEANT3 package [2] with the FLUKA hadronic model [3]. An isotropic event generator was developed for the ISS-CREAM geometry with particles incident from the upper hemisphere. We will present simulation results regarding ISS-CREAM performance, including trigger rates, energy resolution, energy response, tracking resolution, charge efficiency, etc.

International audience; The Cosmic Ray Energetics And Mass experiment for the International Space Station (ISS-CREAM) is a direct cosmic-ray detection experiment deployed on the ISS in August 2017. It aims to reveal the sources, acceleration processes, and propagation of cosmic rays by observing individual elemental spectra at energies in the TeV-PeV range. ISS-CREAM consists of multiple complementary particle detectors. This work utilizes the Silicon Charge Detector (SCD) to measure cosmic-ray charges from protons to iron nuclei with a resolution of 0.1-0.3e, and the calorimeter (CAL) to determine the cosmic-ray track and measure its energy by sampling the shower energy deposit of secondary particles. With more than 1-year of observations, we analyzed cosmic-ray spectra of various prominent species such as protons, helium, carbon and oxygen nuclei. We will report preliminary elemental spectra of cosmic rays for energies greater than about 10 TeV.

International audience; The ISS-CREAM payload was launched on the SpaceX-12 Commercial Resupply Service mission to the International Space Station (ISS) from NASA’s Kennedy Space Center on August 14, 2017. It was successfully installed and activated on the ISS Japanese Experiment Module Exposed Facility as an attached payload on August 22, 2017. The ISS-CREAM instrument is configured with complementary particle detectors capable of measuring elemental spectra for Z = 1 - 26 nuclei in the energy range ~10^12 – 10^15 eV; as well as electrons at multi-TeV energies. The four layers of its finely segmented Silicon Charge Detectors provide precise charge measurements, and its ionization Calorimeter provides energy measurements. In addition, scintillator-based Top and Bottom Counting Detectors and a Boronated Scintillator Detector distinguish electrons from nuclei. The goal is to understand cosmic ray origin, acceleration and propagation by extending direct measurements of cosmic rays to the highest practical energy. On-orbit performance of the instrument and preliminary results from the ongoing analysis are presented.