Space Application of Timepix Radiati on Monitor
Project duration: 2012 až 2015
Project leader: Carlos Granja
SATRAM is a highly compact low-mass and low-power spacecraft payload operating in open space in low Earth orbit (LEO) at 820 km altitude onboard ESA’s Proba-V satellite launched 7th May 2013. It is a new technology platform for spacecraft providing integrated high-sensitivity (quantum counting) wide-dynamic range radiation monitoring and characterization of mixed radiation fields. The instrument is equipped with state-of-the-art position-sensitive hybrid semiconductor pixel technology Timepix developed by the Medipix Collaboration based at CERN to which the IEAP is member. Data products include particle fluxes (total, particle type – light charged particles, protons, ions, X-rays; partially low-energy gamma-ray; neutron sensitivity is possible by additional converters), energy loss spectra and directional information for energetic charged particles.
Following commissioning SATRAM went through a process of finetuning of its operation configuration and measurement settings while successfully taking data which presently is at the rate of 6000 frames per day. The instrument is being operated continuously and it takes a significant amount of the spacecraft CPU and memory allocation as well as of the data downlink capacity. Data are retrieved to the ESA's Redu satellite center in Belgium from where they are relayed directly to the IEAP on a daily basis. The continuous and high frame rate operation allows for complete mapping of the space radiation and of the satellite environment with quantum-counting sensitivity and high spatial resolution provided by the embedded Timepix detector chip. Results and data products have the form of particle fluxes, dose rate, directional distributions of energetic charged particles as well as mixed radiation field composition and spectral (energy loss) distribution according particle types between light and heavy charged particles (electrons, protons, ions) and X-rays. First results are being published (article has been submitted to ASR journal) and are made available to ESA. Comparison with conventional instruments such as the EPT onboard of Proba-V has been ongoing since 2014. Inclusion of SATRAM evaluated data into ESA space weather system database is also underway.
The SATRAM/Timepix spacecraft payload is the first deployment of Timepix/Medipix technology in open space. The instrument was proposed and is operated by the IEAP CTU Prague. It was constructed and space-qualified by CSRC Brno in close cooperation with ESA. The research is performed in frame of the CERN Medipix Collaboration to which the IEAP CTU is long-term member.
Project was funded by the European Space Agency, Grant No. 4000105089/11/NL/CBi. Response testing and calibration verification measurements of Timepix chips were performed at the Van de Graaff light ion accelerator of the IEAP CTU in Prague in frame of the Grant Research Infrastructure No. LM2011030 of the Ministry of Education, Youth and Sports of the Czech Republic.
The Institute of Experimental and Applied Physics
IEAP is the research center of the Czech Technical University in Prague (CTU) for applied and fundamental research in experimental physics of the microworld. R&D focuses on advanced instrumentation and new methods with novel applications in biomedical imaging and space. The IEAP CTU has presently over 80 staff members with one fifth of foreigners and many Ph.D. students and young researchers. The institute is equipped with modern facilities such as high-resolution micro-tomography units and widerange gamma-ray source facilities designed and constructed by IEAP teams. The latter facilities serve for calibration of spacecraft instruments including a transportable station for remote onsite measurements at ESA Test Centers. The institute operates also a Van de Graaff accelerator which provides light ion and mono-energetic fast neutron sources for space-related research.
What would you name as main benefits of the project to you and your company?
“The project brought the possibility to deploy our core technology of advanced position-sensitive quantumcounting radiation detectors into space. We got access to the high-tech space sector as well as new applications and subjects of research such as space radiation physics and space weather. The new technology platform for spacecraft payloads created a new market product of a Czech high-tech company (CSRC). Last but not least, we had the possibility to exploit and transfer our know-how and experience in radiation detection, imaging and spectrometry acquired in ground-based facilities and applications into space.”