A Particle Telescope Verification at an Accelerator Facility

The environment around Earth hosts several particle populations. This region is affected by particles from the galactic cosmic rays, solar wind, and the trapped particles in the radiation belts. The solar wind carries energetic electrons, protons, and heavy ions into space. These conditions deeply affect our presence in the near-Earth environment. Protons and heavy ions can damage satellites, they can also trigger radiation hazards at aviation altitudes, and radio communications can experience interference. Energetic charged particles can affect spacecraft electronics. It is vital to analyse satellite anomalies and to understand the particles' path through the magnetosphere. The number of orbiting satellites in the near-Earth environment is growing. The presence of satellites and spacecraft creates much debris that is also on the rise. Eventually, our use of space can be threatened if further studies are not carried out. Earth's magnetic field provides the conditions for the particle populations to inhabit the region. However, the near-Earth radiation environment is deeply affected by the solar wind and the magnetospheric processes. FORESAIL-1 is a nanosatellite mission that aims to assess the situation in the near-Earth space with sustainable deorbiting technology. The mission will observe energetic particles in the radiation belts, quantify electronic precipitation, and measure energetic neutral atoms of solar origin. Its findings shall improve our understanding of solar eruption energy and can provide in site data of the near-Earth radiation environment. FORESAIL-1 carries PATE, a Finnish particle telescope onboard. This thesis presents the the method for the instrument calibration and results of a calibration rehearsal for the future analysis of data captured by PATE, during its calibration campaign. PATE has undergone preliminary tests at the RADEF cyclotron facility of the University of Jyväskyla, where it was exposed to monoenergetic proton beams. Using its eight active detector areas, PATE detected particle hits from the 10.5 MeV and 55 MeV proton beams at various angles and energies. Using a Geant4 model, we were able to simulate how the detector would respond to different conditions and predict the number of events within a range of particle energies.The simulations were adapted to controlled conditions that sought to replicate the testing facility RADEF environment. Here, we discuss the similarities and mismatches between the pulse-height data recorded and simulated for the 10.5 MeV beam, highlight possible solutions, and explain what the discrepancies can teach us about the detector and our current understanding of its operation

COTS Components Radiation Test Activity and Results at MSSL

This paper reports a full radiation test results for two popular commercial off the shelf (COTS) devices ADC128S102 and DAC121S101, targeted for use in MSSL's VIS instrument on ESA's EUCLID mission. The tests include total ionization dose (TID) and single event effect (SEE). The TID test shows both devices have passed 30krad test limit. Single event latch-up (SEL) has been observed at both devices at LET of 60 MeV.cm2.mg-1 or below

Sub-LET Threshold SEE cross section dependency with ion energy

This study focuses on the ion species and energy dependence of the heavy ion SEE cross section in the sub-LET threshold region through a set of experimental data. In addition, a Monte Carlo based model is introduced and applied, showing a good agreement with the data in the several hundred MeV/n range while evidencing large discrepancies with the measurements in the 10-30 MeV/n interval, notably for the Ne ion. Such discrepancies are carefully analyzed and discussed

Pollinator attractors: petaloidy and petal epidermal cell shape in close relatives of snapdragon

The diversity of angiosperms in floral form and development has been an area of interest for biologists. A multitude of studies investigating the evolution of flowering plants have attempted to determine why angiosperms are so diverse. One possible major contributor to flower form diversity is pollinator pressure. The interactions between flowers and their pollinators have important ecological and evolutionary consequences, with co-evolution often occuring. Many studies have looked at suites of floral traits that affect pollinator visitation, which have been coined pollination syndromes (Fenster et al., 2004). These traits include but are not limited to, flower color, flower orientation, landing platforms, and nectar guides. With the increase in genetic tools, and the utilization of model species such as Antirrhinum majus(Plantaginaceae) and Arabidopsis thaliana (Brassicaeae), many studies are looking at the geneitc architecture of floral traits. Studies have determined the genetic blueprint for floral oragn identity, as well as in traits asociated with pollination syndromes including flower color and symmetry. Using members of the Antirrhineae tribe (Plantaginaceae) makes it easier to effectively use the resources from A. majus, or snapdragon. Chapter 1 investigates the applicability of the sliding boundary model for petaloid sepal formation in Rhodochiton atrosanguineum, a close relative of snapdragon. We were interested in determing if the petaloid sepals of R. atrosanguineum had true petal identity, or were merely just colorful sepals. Chapter 2 focuses on possible petal function, and not merely petal identity. Conical cells are found on roughly 80% of angiosperms (Kay et al., 1981) and are thought to be a marker for petal identity. However, conical cells are thought to be absent mostly in hummingbird pollinated flowers, though no studies have looked at this in depth (Christensen and Hansen, 1998). For this chapter, we investigated possible correlated evolution between petal epidermal cell shape and pollination system

Status report of the JYFL-ECR ion sources

"Ion beam cocktails" are mixtures of ions with near-identical charge-to-mass ratios. In conjunction with the JYFL-ECRIS, the K130-cyclotron acts as a mass analyzer: the switch from one ion to another within the same cocktail is simple and fast. In the case of the first ion beam cocktail, the oxygen and argon gases were mixed into the gas feed line. At the same time the magnesium and iron ion beams were produced using the MIVOC method. Magnesocene and ferrocene compounds were both mixed into the MIVOC chamber. This capability is especially useful in the study of single event effects (SEE) in space electronics. All gaseous elements from H to Xe can be produced. The non-gaseous elements produced so far are C, Mg, Al, Si, S, Ca, Ti, Cr, Fe, Co, Ni, Cu, Zn and Ge. A major technical modification since the construction (in 1990) of the JYFL-ECRIS was made in January 98: a negatively biased disc replaces now the first plasma stage. After a couple of months experience with the modified source the change was found to be towards a correct direction. The source is now much easier to use and the good operating conditions are well repeated. A real advantage is the new magnetic field settings which are practically the same for all kind of beams, gaseous and solids. Due to the requirements of ion beams with higher charges and heavier elements than the present JYFL-ECRIS can produce, JYFL decided to begin a design and construction project of a new ECR ion source, called as ECRIS 2. The project aims to a source that is based mainly on the design of the 14 GHz AECR-U source at the LBNL. Some modifications made into the similar source under construction at the NSCL/MSU will be utilized here. The new source will be installed horizontally in the basement of the ECRIS laboratory. It requires a new beam-line from the source to the cyclotron injection line, since the old vertically located JYFL-ECRIS will be preserved in operation. The new source is planned to be operational during the year 2000

Validation of NIEL for >1MeV electrons in silicon using the CCD47-20

For future space missions that are visiting hostile electron radiation environments, such as ESA’s JUICE mission, it is important to understand the effects of electron irradiation on silicon devices. This paper outlines a study to validate and improve upon the Non-Ionising Energy Loss (NIEL) model for high energy electrons in silicon using Charge Coupled Devices (CCD), CMOS Imaging Sensors (CIS) and PIPS photodiodes. Initial results of radiation effects in an e2v technologies CCD47-20 after irradiation to 10 krad of 1 MeV electrons are presented with future results and analysis to be presented in future publications

Improved stability of black silicon detectors using aluminum oxide surface passivation

Publisher Copyright: © 2021 ESA and CNESWe have studied how high-energy electron irradiation (12 MeV, total dose 66 krad(Si)) and long term humidity exposure (75%, 75 °C, 500 hours) influence the induced junction black silicon or planar photodiode characteristics. In our case, the induced junction is formed using n-type silicon and atomic-layer deposited aluminum oxide (Al2O3), which contains a large negative fixed charge. We compare the results with corresponding planar pn-junction detectors passivated with either with silicon dioxide (SiO2) or Al2O3. The results show that the induced junction detectors remain stable as their responsivity remains nearly unaffected during the electron beam irradiation. On the other hand, the SiO2 passivated counterparts that included conventional pn-junction degrade heavily, which is seen as strongly reduced UV response. Similarly, after humidity test the response of the induced junction detector remains unaffected, while the pn-junction detectors passivated with SiO2 degrade significantly, for instance, the response at 200 nm reduces to 50% from the original value. Interestingly, the pn-junction detectors passivated with Al2O3 exhibit no degradation of UV response, indicating that the surface passivation properties of Al2O3 are more stable than SiO2 under the studied conditions. This phenomenon is further confirmed with PC1D simulations suggesting that the UV degradation results from increased surface recombination velocity. To conclude, the results presented here suggest that black silicon photodiodes containing Al2O3-based induced junction are highly promising alternatives for applications that require the best performance and long-term stability under ionizing and humid conditions.Peer reviewe

Radiation effects on V0 detector elements

ALIC

Study of Radiation Effects on 28nm UTBB FDSOI Technology

With the evolution of modern Complementary Metal-Oxide-Semiconductor (CMOS) technology, transistor feature size has been scaled down to nanometers. The scaling has resulted in tremendous advantages to the integrated circuits (ICs), such as higher speed, smaller circuit size, and lower operating voltage. However, it also creates some reliability concerns. In particular, small device dimensions and low operating voltages have caused nanoscale ICs to become highly sensitive to operational disturbances, such as signal coupling, supply and substrate noise, and single event effects (SEEs) caused by ionizing particles, like cosmic neutrons and alpha particles. SEEs found in ICs can introduce transient pulses in circuit nodes or data upsets in storage cells. In well-designed ICs, SEEs appear to be the most troublesome in a space environment or at high altitudes in terrestrial environment. Techniques from the manufacturing process level up to the system design level have been developed to mitigate radiation effects. Among them, silicon-on-insulator (SOI) technologies have proven to be an effective approach to reduce single-event effects in ICs. So far, 28nm ultra-thin body and buried oxide (UTBB) Fully Depleted SOI (FDSOI) by STMicroelectronics is one of the most advanced SOI technologies in commercial applications. Its resilience to radiation effects has not been fully explored and it is of prevalent interest in the radiation effects community. Therefore, two test chips, namely ST1 and AR0, were designed and tested to study SEEs in logic circuits fabricated with this technology. The ST1 test chip was designed to evaluate SET pulse widths in logic gates. Three kinds of the on-chip pulse-width measurement detectors, namely the Vernier detector, the Pulse Capture detector and the Pulse Filter detector, were implemented in the ST1 chip. Moreover, a Circuit for Radiation Effects Self-Test (CREST) chain with combinational logic was designed to study both SET and SEU effects. The ST1 chip was tested using a heavy ion irradiation beam source in Radiation Effects Facility (RADEF), Finland. The experiment results showed that the cross-section of the 28nm UTBB-FDSOI technology is two orders lower than its bulk competitors. Laser tests were also applied to this chip to research the pulse distortion effects and the relationship between SET, SEU and the clock frequency. Total Ionizing Dose experiments were carried out at the University of Saskatchewan and European Space Agency with Co-60 gammacell radiation sources. The test results showed the devices implemented in the 28nm UTBB-FDSOI technology can maintain its functionality up to 1 Mrad(Si). In the AR0 chip, we designed five ARM Cortex-M0 cores with different logic protection levels to investigate the performance of approximate logic protecting methods. There are three custom-designed SRAM blocks in the test chip, which can also be used to measure the SEU rate. From the simulation result, we concluded that the approximate logic methodology can protect the digital logic efficiently. This research comprehensively evaluates the radiation effects in the 28nm UTBB-FDSOI technology, which provides the baseline for later radiation-hardened system designs in this technology