Monte Carlo simulations of energy losses by space protons in the CRaTER detector (original) (raw)
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Design, development, and calibration of a high energy proton telescope for space radiation studies
Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment, 2002
A compact particle telescope has been developed to measure highly penetrating protons in space, measuring the differential energy spectrum of protons between 25 and 440 MeV and the integral flux above 440 MeV. This instrument combines new detector materials, an innovative sensor geometry, and a combination of active and passive shielding to obtain accurate measurements of highly penetrating protons in an instrument compact and light weight enough for space flight. r 2002 Elsevier Science B.V. All rights reserved. PACS: 95.55.Àn; 95.55.Vj; 96.40.Fg; 29.30.Ep
Low-Energy Proton Effects on Detectors on X-Ray Astronomy Missions
It has been found that protons of energies in the range of hundreds of keV to a few MeV can scatter at low angles through the mirror shells of space-based X-ray astronomy missions. These protons, because of their low energy can produce a high non-ionising dose in unshielded CCDs and are therefore a potential threat. This paper discusses the efforts made in the con-text of the ESA X-ray Multi-Mirror (XMM) mission to simulate the processes involved in the transport of protons and generation of non-ionising dose in CCD's. The tools used for this analysis included the Geant4 Monte-Carlo toolkit, used for fully three-dimensional calcula-tions. Another code, TRIM, was used to examine details of the low angle scattering in one dimension.
Space Weather, 2014
The Cosmic Ray Telescope for the Effects of Radiation (CRaTER), an instrument carried on the Lunar Reconnaissance Orbiter spacecraft, directly measures the energy depositions by solar and galactic cosmic radiations in its silicon wafer detectors. These energy depositions are converted to linear energy transfer (LET) spectra. High LET particles, which are mainly high-energy heavy ions found in the incident cosmic ray spectrum, or target fragments and recoils produced by protons and heavier ions, are of particular importance because of their potential to cause significant damage to human tissue and electronic components. Aside from providing LET data useful for space radiation risk analyses for lunar missions, the observed LET spectra can also be used to help validate space radiation transport codes, used for shielding design and risk assessment applications, which is a major thrust of this work. In this work the Monte Carlo transport code HETC-HEDS (High-Energy Transport Code-Human Exploration and Development in Space) is used to estimate LET contributions from the incident primary ions and their charged secondaries produced by nuclear collisions as they pass through the three pairs of silicon detectors. Also in this work, the contributions to the LET of the primary ions and their charged secondaries are analyzed and compared with estimates obtained using the deterministic space radiation code HZETRN 2010, developed at NASA Langley Research Center. LET estimates obtained from the two transport codes are compared with measurements of LET from the CRaTER instrument during the mission. Overall, a comparison of the LET predictions of the HETC-HEDS code to the predictions of the HZETRN code displays good agreement. The code predictions are also in good agreement with the CRaTER LET measurements above 15 keV/μm but differ from the measurements for smaller values of LET. A possible reason for this disagreement between measured and calculated spectra below 15 keV/μm is an inadequate representation of the light ion spectra in HETC-HEDS and HZETRN code calculations. It is also clear from the results of this work that Vavilov distributions need to be incorporated into the HETC-HJEDS code before it will be able to recreate the observed LET spectra measured by the CRaTER instrument. HETC-HEDS (High-Energy Transport Code-Human Exploration and Development in Space), a three-dimensional Monte Carlo radiation transport code, is used to estimate the LET in each of CRaTER's components [Townsend et al., 2005]. For comparison, estimates are also made using the HZETRN 2010 transport code. HZETRN (High Z and Energy Transport) is a one-dimensional, deterministic transport code, developed at NASA Langley Research Center, that is commonly used for estimating space radiation risk and shielding requirements [Slaba et al., 2010].
The Lunar Radiation Environment: Comparisons between PHITS, HETC-HEDS, and the CRaTER Instrument
Aerospace
Understanding the radiation environment near the lunar surface is a key step towards planning for future missions to the Moon. However, the complex variety of energies and particle types constituting the space radiation environment makes the process of replicating such environment very difficult in Earth-based laboratories. Radiation transport codes provide a practical alternative covering a wider range of particle energy, angle, and type than can be experimentally attainable. Comparing actual measurements with simulation results help in validating particle flux input models, and input collision models and databases involving nuclear and electromagnetic interactions. Thus, in this work, we compare the LET spectra simulated using the Monte Carlo transport code PHITS with measurements made by the CRaTER instrument that is currently orbiting the Moon studying its radiation environment. In addition, we utilize a feature in PHITS that allows the user to run the simulations without Vavilo...
Solar Physics and Space Weather Instrumentation III, 2009
HEPS was designed to measure high energy protons, with energies between 25 and 400 MeV, in the space environment,. The instrument uses a collection of solid state Si particle detectors and Gadolinium Silicate (GSO) crystal scintillators to detect the protons and measure their energy. The sensors form a coaxial arrangement of four Si detectors, to provide an event trigger when struck by an incident proton. The energy measurement for each event is provided by the measurement of its energy losses in the two scintillator elements. Energy losses are determined by photodiodes that collect light produced in GSO by the protons. The HEPS flight unit was extensively calibrated in the 30 -217 MeV energy range. The beam measurements were carried out at a series of angles in the instrument field-of-view as well as at larger angles to test its rejection capabilities. An extensive program of computer modeling of HEPS response has been carried out using the Monte Carlo particle interaction code MCNPX. Calibration data will be compared to the results of the calculations. Conclusions concerning the calibrated geometric factors will be discussed.
Calibration of imaging plate detectors to mono-energetic protons in the range 1-200 MeV
The Review of scientific instruments, 2017
Responses of Fuji Imaging Plates (IPs) to proton have been measured in the range 1-200 MeV. Mono-energetic protons were produced with the 15 MV ALTO-Tandem accelerator of the Institute of Nuclear Physics (Orsay, France) and, at higher energies, with the 200-MeV isochronous cyclotron of the Institut Curie-Centre de Protonthérapie d'Orsay (Orsay, France). The experimental setups are described and the measured photo-stimulated luminescence responses for MS, SR, and TR IPs are presented and compared to existing data. For the interpretation of the results, a sensitivity model based on the Monte Carlo GEANT4 code has been developed. It enables the calculation of the response functions in a large energy range, from 0.1 to 200 MeV. Finally, we show that our model reproduces accurately the response of more complex detectors, i.e., stack of high-Z filters and IPs, which could be of great interest for diagnostics of Petawatt laser accelerated particles.
In flight calibration of NOAA POES proton detectors - derivation of the MEPED correction factors
Journal of Geophysical Research: Space Physics, 2015
The MEPED instruments on board the NOAA POES and MetOp satellites have been continuously measuring energetic particles in the magnetosphere since 1978. However, degradation of the proton detectors over time leads to an increase in the energy thresholds of the instrument and imposes great challenges to studies of long-term variability in the near-Earth space environment as well as a general quantification of the proton fluxes. By comparing monthly mean accumulated integral flux from a new and an old satellite at the same magnetic local time (MLT) and time period, we estimate the change in energy thresholds. The first 12 monthly energy spectra of the new satellite are used as a reference, and the derived monthly correction factors over a year for an old satellite show a small spread, indicating a robust calibration procedure. The method enables us to determine for the first time the correction factors also for the highest-energy channels of the proton detector. In addition, we make use of the newest satellite in orbit (MetOp-01) to find correction factors for 2013 for the NOAA 17 and MetOp-02 satellites. Without taking into account the level of degradation, the proton data from one satellite cannot be used quantitatively for more than 2 to 3 years after launch. As the electron detectors are vulnerable to contamination from energetic protons, the corrected proton measurements will be of value for electron flux measurements too. Thus, the correction factors ensure the correctness of both the proton and electron measurements.
Proton irradiation test on the flight model radiation monitor for LISA Pathfinder
Journal of Physics: Conference Series, 2010
The design of the Radiation Monitor in the LISA Technology Package on board LISA Pathfinder is based on two silicon PIN diodes, placed parallel to each other in a telescopic configuration. One of them will be able to record spectral information of the particle hitting the diode. A test campaign for the Flight Model Radiation Monitor is proposed to verify its performance. This paper shows the results obtained with a simulated flight model geometry using GEANT4, to be compared with the real data that will be obtained in a proton irradiation facility.