High Energy Particle Detector Research Articles

Measurement of the low-energy charged particle background with the space detector HEPD

Spaceborne gamma-ray telescopes are operated within a dominant background of charged particles, mainly primary cosmic rays and Earth albedo particles. Dedicated anti-coincidence devices and on-board rejection techniques are needed to reject this background, as well as the best available background models. The high-energy particle detector (HEPD) is a space detector for high-energy particles, which can identify electrons, protons and light nuclei in the energy range from few MeV to many hundreds of MeV, and measure their fluxes. It consists of a high-precision silicon tracker, a versatile trigger system, a range calorimeter, and an anti-coincidence system. HEPD will extend PAMELA and the AMS-02 measurements to lower energies and characterize the orbital radiation environment, then providing very useful data for the future gamma-ray mission development, especially for the optimization of the on-board background rejection.

Feasibility study of neutron production at SLRI beam test facility

SLRI Beam Test Facility (SLRI-BTF) has been constructed in order to increase usage of the Siam Photo Source injector. SLRI-BTF aims to provide electron test beams for calibration and testing of high-energy particle detectors and diagnostic instrumentations. The test-beam energy varies from 40 MeV to 1.2 GeV with adjustable intensity from a few to several millions of electrons per repetition rate. Since the test-beam energy is sufficiently large, the electron test beam can be used to produce photoneutrons resulted from collision of high-energy electrons to metal targets. Similar to the electron test beams, this neutron source will be utilized for calibration and testing of neutron detectors and instrumentations. In this work, the neutron production and its angular dependence has been investigated using the PHITS simulation code. The results show that photoneutrons generated by collision of the high-energy electron beam on a tungsten target are in range of intermediate and fast neutrons or 0.01 - 10 MeV with peak contribution at 0.6 ± 0.1 MeV and uniformly distributed in angular direction. For the primary beam of 108 electrons per spill at SLRI-BTF, the photoneutron flux is predicted to be around 50 neutrons/cm2. Based on this study, the possibility to service a neutron source for users in the future will be determined further.

Scientific Goals and In-orbit Performance of the High-energy Particle Detector on Board the CSES

Abstract The China Seismo-Electromagnetic Satellite (CSES) aims to monitor electromagnetic, particle, and plasma perturbations in the iono-magnetosphere and inner Van Allen radiation belts originated by electromagnetic sources external and internal to the geomagnetic cavity, cosmic rays, and solar events. In particular, the objective of the space mission is to investigate lithosphere–atmosphere–ionosphere coupling mechanisms (including the effects of lightning, earthquakes, volcanoes, and artificial electromagnetic emissions) that induce perturbations of the top side of the ionosphere and lower boundary of the radiation belts. To this purpose, the mission has been conceived to take advantage of a multi-instrument payload comprising nine detectors for the measurement of electromagnetic field components, plasma parameters, and energetic particles, as well as X-ray flux. The Italian team participating in the CSES mission has built one of these devices, the High-Energy Particle Detector (HEPD), for high-precision observations of electrons, protons, and light nuclei. During its trip along the orbit, and thanks to the large set of detectors operated on board, CSES completely monitors the Earth, acting as an excellent instrument for space weather. The satellite was launched on 2018 February 2, with an expected life span of 5 yr. This article describes the CSES mission with a particular focus on the HEPD apparatus and its in-flight performance.

Probability, Causality and False Alarms using Correlations Between Strong Earthquakes and NOAA High Energy Electron Bursts

A proposal for testing the feasibility of strong earthquake forecasting from space, using on board high energy particle detectors of existing NOAA polar satellites, is given. Previously, exceptional increases of particle fluxes prior to and after the largest quakes that struck the Indonesian and the Philippine areas were recently recognised utilising NOAA-15 particle telescopes. A statistically significant correlation between electron bursts of 30 – 100 keV and large seismic events was calculated in previous publications, occurring 2 – 3 hours between seismic events having M ≥ 6 and electron bursts. The 2 – 3 hour correlation supports the hypothesis that there is a physical link between ionospheric charged particle motions at around 2,000 km and seismic activities when earthquake depths are less than 200 km. Taking into account the corresponding electron drift periods and the detector energy corrections, the time interval of a possible physical interaction between high energy electrons of the inner radiation belts and the earth's crust of the future earthquake epicentre has been reduced to about 4 – 6.5 hours. A causal model is proposed for the entire process. Cross-correlation coefficients are calculated starting from the previously obtained correlations, so that a probability of earthquake forecasting corresponding to the 2 – 3 hour peak can be evaluated. Based on these results, false alarms can be reduced in an experiment where such probability is used for one year of average seismic and electron loss detections. Finally, an experiment is proposed here, which is currently feasible using ongoing NOAA satellites and USA West Coast antennas to test the forecasting.

Development of the SLRI beam test facility for characterization of monolithic active pixel sensors

Abstract Synchrotron Light Research Institute (SLRI) has successfully constructed a new experimental station, a Beam Test Facility (BTF), to the current SLRI accelerator complex. SLRI-BTF is capable of producing electron test beams with the number of electrons ranging from a few to millions of electrons per spill and with tunable energy from 40 MeV up to 1.2 GeV. The required intensity and energy of the test beam are obtained using a combination of a metal target to reduce high-intensity primary beam and a synchrotron booster to accelerate secondary beam to desired energy. The repetition rate of the test beam is up to 0.5 Hz depending on the selected energy and the pulse width is 90 ns. SLRI-BTF targets to service electron test beams with defined intensity and energy for testing and calibration of high-energy particle detectors as well as other beam diagnostic instrumentations. In commissioning, a pixel sensor telescope was employed as a detector to measure the number of electrons and as a preparation to investigate efficiency of mono active pixel sensors. The results confirm production of the low multiplicity of high-energy electrons at SLRI-BTF and the efficiency of a test pixel sensor is successfully calculated.

Montecarlo simulation of the High Energy Particle Detector on board the satellite CSES

The High-Energy Particle Detector (HEPD) is an instrument devoted to the measurement of cosmic particles from few MeV up to hundreds of MeV. The HEPD will contribute to the China Seismo-Electromagnetic Satellite mission by measuring the precipitation of trapped particles and by studying the solar-terrestrial environment especially during impulsive events like coronal mass ejections and solar energetic particle emissions. A Monte Carlo software was realized to study the performance of HEPD, such as its particle discrimination capability, the energy threshold for trigger and the maximum energy detectable in full containment. This contribution reports the main features of the HEPD Monte Carlo simulation and some results of the detector performance based on it. A comparison with beam tests was carried out, showing a good agreement with the simulation.

The Limadou-HEPD Segmented Calorimeter

The core of the High-Energy Particle Detector (HEPD) on board of the China Seismo-Electromagnetic Satellite (CSES) is a segmented calorimeter, which is composed with an upper tower of plastic scintillator counters and a bottom array of LYSO large crystals. Electrons with energy below 100MeV, protons and light nuclei, below few hundreds ofMeV/nucleon are fully contained within this calorimeter. Mainly the LYSO array (density 7.3 g/cm3, thickness around 29.2 g/cm2) extends the HEPD energy range, allowing those measurements (solar energetic particles, low-energy cosmic rays) which are more related to astroparticle physics topics. Two identical copies of HEPD, and then of its calorimeter, exist: the Flight (FM) and the Qualification (QM) models. While the FM has achieved the orbit on board of the CSES satellite in February 2018, the Qualification Model, is used, at ground, for tests and calibrations. A report on the characterization of this compact particle space detector and on preliminary studies and results, will be given.

Observation of the Energy Dependence of Primary and Secondary Cosmic Rays with the AMS Detector on the International Space Station

Precision study of cosmic nuclei provides detailed knowledge on the origin and propagation of cosmic rays. AMS is a multi-purpose high energy particle detector designed to measure and identify cosmic ray nuclei with unprecedented precision. It is able to provide precision studies of nuclei simultaneously to multi-TeV energies. In 7 years on the Space Station, AMS has collected more than 120 billion both primary and secondary cosmic rays. Primary cosmic rays, such as p, He, C and O, are believed to be mainly produced and accelerated in supernova remnants, while secondary cosmic rays, such as Li, Be and B are thought to be produced by collisions of heavier nuclei with interstellar matter. Primary cosmic rays such as He, C, and O are found to have identical rigidity dependence, similarly to secondary cosmic rays (such as Li, Be and B) which share the same the same spectral shape. The peculiar case of Nitrogen being a mixture of a primary and secondary component will also be shown.

The technology of space plasma in-situ measurement on the China Seismo-Electromagnetic Satellite

The China Seismo-Electromagnetic satellite (CSES) was designed to study the ionospheric disturbances associated with earthquakes. Satellite payload includes nine instruments. Among them, we recall instruments for plasma analysis, electric, magnetic fields and high energy particle detectors. Langmuir probe (LP) and plasma analyzer package (PAP) are the in-situ payloads to measure space plasma. Its scientific objective is to research space plasma physics phenomena and the ionosphere changes caused by seismic. It is the first application of in-situ measurement technology in the field of space exploration in China. The Langmuir probe and Plasma Analyzer Package have been tested and calibrated to verify the performance in INAF-IAPS. Currently, on-orbit testing is being performed with satellites.

The HEPD detector on board CSES satellite: In flight performance

Abstract CSES (China Seismo-Electromagnetic Satellite) is a scientific mission dedicated to monitoring electromagnetic field , plasma and particles perturbations of atmosphere and inner Van Allen belts caused by solar and terrestrial phenomena and to the study of the low energy component of the cosmic rays. The satellite hosts several instruments onboard: two magnetometers , an electrical field detector, a plasma analyser, a Langmuir probe and two particle detectors . It has been successfully launched from the Jiuquan Satellite Launch Center located in west of inner Mongolia on February 2 2018 and is now orbiting in nominal condition. The high energy particle detector (HEPD), designed and built by the Italian “Limadou” collaboration, aims at investigating precipitation of trapped particles induced by atmospheric EM emissions, as well as by the seismo-electromagnetic disturbances. HEPD provides good energy resolution and high angular resolution for electrons (3–100 MeV) and proton (30–200 MeV). The instrument consists of: 2 planes of double-side silicon microstrip sensors placed on the top of the instrument (direction of particle); 2 two layers of plastic scintillators (trigger) and a calorimeter (constituted by other 16 scintillators and a layer of LYSO sensors). A scintillator veto system completes the instrument. The commissioning of the HEPD and the other instruments on board is in progress and will last several months. In this contribution we will describe the HEPD detector and the (preliminary) performance in flight.

Growth and properties of CdZnTe films on different substrates

High quality CdZnTe films were deposited on polished CdZnTe film, Si wafer and fluorine doped tin oxide (FTO) glass by close spaced sublimation (CSS) method. The influences of different substrates on the growth rate, composition, structural and electrical properties of CdZnTe films were investigated. The results showed that the CdZnTe film prepared on the polished CdZnTe film substrate had a higher growth rate and a better crystalline quality. The film prepared on the polished CdZnTe film substrate also exhibited lower leakage current, which is promising for high energy particle detection.

Fabrication and optical properties of cerium doped Lu3Ga3Al2O12 scintillation ceramics

Cerium doped lutetium aluminum garnet single crystal has been drawing great research interest of scientists due to its superior performance in scintillation material for high energy particle detection. However, the problem about slow components in the scintillation response restricts the further improving. Here, we utilize the “band-gap engineering” strategy that the admixture of Ga3+ in Lu3Al5O12 can lower the conduction band edge and bury shallow traps, and get the Ce3+ doped Lu3Ga3Al2O12 scintillation ceramics sintered in the oxygen atmosphere and hot isostatic pressing post-treated. The luminescence and scintillation properties are investigated. A shortened dominant decay time and the presence of some second slower components in the photoluminescence decays prove that the admixture of Ga3+ in Lu3Al5O12 can lower the conduction band edge and consequently also the ionization barrier for Ce3+ emission from 5d1 level. Meanwhile, the Ce:Lu3Ga3Al2O12 ceramic sample shows good steady-state scintillation efficiency under the X-ray excitation. Furthermore, it performs excellent in terms of the fast-to-slow emission ratio in scintillation response with a LY0.5μs/LY6μs values ratio up to 92%.

The extremely high-energy electron experiment (XEP) onboard the Arase (ERG) satellite

The extremely high-energy electron experiment (XEP) onboard the Arase (ERG) satellite is designed to measure high-energy electrons in the Earth’s radiation belts. The XEP was developed by taking advantage of our technical heritage of high-energy particle detectors that are onboard Earth observation satellites of the Japan Aerospace Exploration Agency (JAXA) as the radiation monitor. The main target of the XEP is to precisely measure variations of relativistic electrons in the outer radiation belt even during magnetic storms. The measurement is scientifically required to address physical mechanisms of electron acceleration and loss. The XEP consists of five solid-state silicon detectors (SSDs) and a single-crystal inorganic scintillator of cerium-doped gadolinium orthosilicate (GSO) to measure electrons in the energy range of 0.4–20 MeV and has a 20° single field of view (FOV). It is also equipped with a plastic scintillator that surrounds the GSO scintillator to prevent particles from entering the detectors from outside the FOV. The XEP has started its observation of relativistic electrons and has successfully observed dynamic variations of relativistic electron fluxes in the outer radiation belt during magnetic storms. This paper describes the instrumentation of the XEP and presents an example of initial observation results.

Crystallization control toward colorless cerium-doped scintillating glass.

The construction of cerium-doped materials is of great technological importance for various applications, including smart lighting, biological shielding and high-energy ray and particle detection. A major challenge is the efficient prevention of the undesired colorization after cerium doping. Here we present the nanocrystallization method for constructing colorless cerium-doped glass with extremely high cerium concentration (15 mol%). The structure and optical characterizations confirm that the notable color change of glass is associated with the precipitation of CeF3 crystalline phase during heat-treatment. The chemical state investigation shows that most of cerium ions exist in the form of Ce3+ in both the glass and glass-ceramic samples. The chemical environment study indicates a dramatic change in the local structure unit from -Ce-O- to -Ce-F-, which is believed to dominate the decoloring phenomenon in cerium doped glass. As a result, a significant improvement in the ultraviolet excited luminescence (~35 times enhancement in intensity) and scintillating performance can be achieved, pointing to potential applications in X-ray detection.

Wavelength-shifting properties of luminescence nanoparticles for high energy particle detection and specific physics process observation

Ultraviolet (UV) photon detection is becoming increasingly important in the quest to understand the fundamental building blocks of our universe. Basic properties of neutrinos and Dark Matter are currently being explored through interactions with noble elements. In response to interactions with fundamental particles, these elements emit scintillation photons in the UV range. However, most available detectors have poor response in the UV so it is typically necessary to shift UV to a wavelength, matching the sensitivity of the viable detectors. We report on development of UV-enhanced photosensors using wavelength-shifting properties of nanoparticles. Several nanoparticle coatings were tested for absorption of UV light with subsequent emission in the visible wavelength for high energy particle detection. ZnS:Mn,Eu, ZnS:Mn, CuCy (Copper Cysteamine) and CdTe nanoparticles all exhibited enhanced detection for wavelengths in the range 200–320 nm in several different tests, while ZnS:Ag and CdS nanoparticle showed little or no enhancement in that range. In addition, various LaF3:Ce nanoparticle concentrations in approximately constant thickness of 2,5-diphenyloxazole (PPO)/polystyrene bases were also tested to optimize the nanoparticle concentration for the best outcome. Our studies indicated that ZnS:Mn,Eu, ZnS:Mn, Cu-Cy, CdTe and LaF3:Ce nanoparticles show potential for light detection from fundamental particle interactions.

HEPD on NEXTSat-1: A High Energy Particle Detector for Measurements of Precipitating Radiation Belt Electrons

Radiation belt particles of the inner magnetosphere precipitate into the atmosphere in the subauroral regions when they are pitch-angle scattered into the loss cone by wave-particle interactions. Such particle precipitations are known to be especially enhanced during space storms, though they can also occur during quiet times. The observed characteristics of precipitating electrons can be distinctively different, in their time series as well as in their spectra, depending on the waves involved. The present paper describes the High Energy Particle Detector (HEPD) on board the Next Generation Small Satellite-1 (NEXTSat-1), which will measure these radiation belt electrons from a low-Earth polar orbit satellite to study the mechanisms related to electron precipitation in the sub-auroral regions. The HEPD is based on silicon barrier detectors and consists of three telescopes that are mounted on the satellite to have angles of 0 ◦, 45 ◦, and 90 ◦, respectively with the local geomagnetic field during observations. With a high time resolution of 32 Hz and a high spectral resolution of 11 channels over the energy range from ~ 350 keV to ~ 2 MeV, together with the pitch angle information provided by the three telescopes, HEPD is capable of identifying physical processes, such as microbursts and dust-side relativistic electron precipitation (DREP) events associated with electron precipitations. NextSat-1 is scheduled for launch in early 2018.

The HEPD particle detector of the CSES satellite mission for investigating seismo-associated perturbations of the Van Allen belts

CSES (China Seismo-Electromagnetic Satellite) is a mission developed by CNSA (Chinese National Space Administration) and ASI (Italian Space Agency), to investigate the near-Earth electromagnetic, plasma and particle environment, for studying the seismo-associated disturbances in the ionosphere-magnetosphere transition zone. The anthropogenic and electromagnetic noise, as well as the natural non-seismic electromagnetic emissions is mainly due to tropospheric activity. In particular, the mission aims to confirming the existence of possible temporal correlations between the occurrence of earthquakes for medium and strong magnitude and the observation in space of electromagnetic perturbations, plasma variations and precipitation of bursts with high-energy charged particles from the inner Van Allen belt. In this framework, the high energy particle detector (HEPD) of the CSES mission has been developed by the Italian LIMADOU Collaboration. HEPD is an advanced detector based on a tower of scintillators and a silicon tracker that provides good energy and angular resolution and a wide angular acceptance, for electrons of 3–100 MeV, protons of 30–200 MeV and light nuclei up to the oxygen. CSES satellite has been launched on February 2$^{\rm~nd}$, 2018 from the Jiuquan Satellite Launch Center (China).

Colorimetric energy sensitive scintillator detectors based on luminescent multilayer designs

In this work we present a new concept for energy sensitive radiation-beam scintillator detectors based on a luminescent multilayer design, where each layer within the stack consists of a rare-earth-doped highly transparent oxide. For a given type of particle beam (i.e., protons, α particles, etc.), its penetration depth, and therefore its energy loss at a particular buried layer, depends on its initial kinetic energy. Relying on this principle and since the intensity of the luminescent response of each layer and substrate should be proportional to the energy deposited by the radiation beam, we prove that a characteristic energy dependent color emission is obtained depending on both the phosphors integrated in the luminescent stack and on the primary energy and type of particle beam. Phosphor doping, emission efficiency, layer thickness, and multilayer structure design are key parameters to achieve a broad gamut in colorimetric response. The developed scintillators are designed to operate in a transmission geometry (light detection from the opposite side of the incident radiation) which is well suited for high energy particle detection in fields such as oncotherapy, space radiation, or of fusion studies. The principles of the method are illustrated with a case example typical of ion beam accelerators devoted to materials analysis. It is obtained that the kinetic energy of protons/alpha particle beams can be distinguished and evaluated with a sensitivity of 0.06/0.25 chromaticity units per MeV in the 0.7–2.0 MeV range.

The electronics of the HEPD of the CSES experiment

The China Seismo Electromagnetic Satellite (CSES) aims to contribute to the monitoring of earthquakes from space. This space mission, lead by a Chinese-Italian collaboration, will study phenomena of electromagnetic nature and their correlation with the geophysical activity. The satellite will be launched in 2017 and will host several instruments onboard: two magnetometers, an electrical field detector, a plasma analyzer, a Langmiur probe and the High Energy Particle Detector (HEPD). The HEPD, built by the Italian collaboration, will study the temporal stability of the inner Van Allen radiation belts, investigating precipitation of trapped particles induced by magnetospheric, ionosferic and tropospheric electromagnetic emissions, as well as by seismo-electromagnetic disturbances. It consists of one layer of plastic scintillators for trigger and a calorimeter. The direction of the incident particle is provided by two planes of double-side silicon microstrip detectors. HEPD is capable of separating electrons and protons and identify nuclei up to Iron. The HEPD will study the low energy component of cosmic rays too. The HEPD comprises the following subsystems: detector, electronics, power supply and mechanics. The electronics can be divided in three blocks: silicon detector, scintillator detectors (trigger, energy and veto detectors) and global control and data managing.

Study of the performance of the HEPD apparatus for the CSES mission

The High-Energy Particle Detector (HEPD) is one of the payloads of the CSES space mission. The CSES (China Seismo-Electromagnetic Satellite) mission will investigate the structure and the dynamic of the topside ionosphere, will monitor electric and magnetic field and high energy particle fluctuations, searching for their correlations with the geophysical activity, in order to contribute to the monitoring of earthquakes from space. The HEPD is built by the Italian collaboration and has different goals. It will study the temporal stability of the inner Van Allen radiation belts, the precipitation of trapped particles in the atmosphere and the low energy component of the cosmic rays (5 - 100 MeV for electrons and 15 - 300 MeV for protons). Here is presented a study of the performance of the apparatus to separate electrons and protons and identify nuclei up to iron.