Anja Kohfeldt

D. Becker, M. Lachmann, S. Seidel, H. Ahlers, A. Dinkelaker, J. Grosse, O. Hellmig, H. Müntinga, V. Schkolnik, T. Wendrich, A. Wenzlawski, B. Weps, R. Corgier, T. Franz, N. Gaaloul, W. Herr, D. Lüdtke, M. Popp, S. Amri, H. Duncker, M. Erbe, A. Kohfeldt, A. Kubelka-Lange, C. Braxmaier, E. Charron, W. Ertmer, M. Krutzik, C. Lämmerzahl, A. Peters, W. Schleich, K. Sengstock, R. Walser, A. Wicht, P. Windpassinger, and E. M. Rasel (2018). "Space-borne Bose-Einstein condensation for precision interferometry", Nature, vol. 562, pp. 391-395

Østgaard, Nikolai; Balling, Jan E.; Bjørnsen, Thomas Riis; Brauer, Peter; Budtz-Jørgensen, Carl; Bujwan, Waldemar; Carlson, Brant Edward; Christiansen, Freddy; Connell, Paul; Eyles, Chris; Fehlker, Dominik; Genov, Georgi; Grudzinski, Pawel; Kochkin, Pavlo; Kohfeldt, Anja; Kuvvetli, Irfan; Thomsen, Per Lundahl; Pedersen, Søren Møller; Navarro-Gonzalez, Javier; Neubert, Torsten; Njøten, Kåre; Orleanski, Piotr; Qureshi, Bilal Hasan; Cenkeramaddi, Linga Reddy; Reglero, Victor; Reina, Manuel; Rodrigo, Juan Manuel; Rostad, Maja Elise; Sabau, Maria D.; Kristensen, Steen Savstrup; Skogseide, Yngve; Solberg, Arne Olav; Stadsnes, Johan; Ullaland, Kjetil & Yang, Shiming (2019). "The modular X- and gamma-ray sensor (MXGS) of the ASIM Payload on the International Space Station". Space Science Reviews.  ISSN 0038-6308.  215:23(2), s 1- 28 . doi: 10.1007/s11214-018-0573-7 Fulltekst i vitenarkiv.

• Retselis, Anastasios-Faidon; Knutsen, Elise Wright; Holdcroft, Sam; Viet, Shayla; Wahlén, Rebecka & Virdis, Mario [Show all 19 contributors for this article] (2026). CENSSAT-1: A space weather mission and an educational platform. In Detrell, Gisela; Alarcia, Ramón María García; Messina, Vincenzo & Kinnaird, Alexander (Ed.), Proceedings of the 5th Symposium on Space Educational Activities (SSEA). Technical University of Munich. p. 852–857. doi: 10.14459/2026MD1857465. Full text in Research Archive Show summary

  The Symposium on Space Educational Activities (SSEA), organised by the European Space Agency’s Education Office, provides a forum for university students, professionals working in education, and other professionals in industry or agencies to present and discuss their experiences organising, running and/or participating in Educational Activities related to Space. After successful past events in Padova (2015), Budapest (2018), Leicester (2019), and Barcelona (2022), the 5th SSEA was held in April 2026 (the 8th, 9th, and 10th) in the TUM Aerospace Campus in Willy-Messerschmitt-Strasse 5, Taufkirchen, Germany. The local organisation team was led by the Technical University of Munich (TUM), involving Professors, PostDocs, PhD Candidates, and Master’s and Bachelor’s students, in close collaboration with the Bavarian aerospace ecosystem partners.

• Kohfeldt, Anja; Wahlén, Rebecka; Jebali, Ramsey Al & Teodoro, Luis Filipe Alves (2024). A Hybrid Gamma-Ray and Neutron Detector for In-Situ Resource Utilization. Proceedings of the International Astronautical Congress. ISSN 0074-1795. p. 962–967. doi: 10.52202/078357-0109. Full text in Research Archive Show summary

  Gamma-ray spectroscopy, as well as neutron detection (GRND) are powerful tools for mapping available resources both remotely and in-situ. GRND allows us to characterize the abundance of hydrogen and elemental composition of the top meter of airless celestial bodies , or asteroids. Compact instruments can be deployed on orbiters, landers or rovers for either mapping larger areas or narrowing down locations with targeted materials. For instance, Lunar Prospector (LP) quantied the abundances of ice water at the lunar polar regions during the last decade of the previous century. To achieve better resolution than these maps a satellite in a low altitude orbit or low periselene, below 30km, from the lunar surface is needed. This can be accomplished by a small satellite, like a CubeSat. We propose a hybrid gamma-ray and neutron detector based on scintillator technology for space exploration, sensitive to both gamma-rays in the spectral range of 30 keV to 8MeV and thermal to epithermal neutrons. The detector consists of an array of CLLBC scintillators that are read out by silicon photomultipliers attached to partially space-qualied read-out electronics developed by Integrated Detector Electronics AS (IDEAS). In the targeted conguration, the compact instrument will have the size of less than two CubeSat units (2U), where one unit is covered in Cd to allow for the distinction between epithermal and thermal neutrons. An understanding of the targeted radiation environment is vital for optimizing the instrument's design parameters before assembly. We report an environmental analysis for the Moon with the detector response simulated in GEANT4. With the detector response simulation, the detector design can be analyzed, and characterization measurement data from the physical instrument can be verifed. In this paper, we present preliminary results for the simulated detector response and compare them with measurements taken by a laboratory demonstrator, which was assembled and tested in a laboratory in 2023. First results look promising, showing that the targeted energy range for gamma-ray and neutrons can be detected. The performance of a monolithic prototype instrument will be elaborated and design decisions as well as the roadmap for the exploration instrument will be discussed.

• Virdis, Mario; Knutsen, Elise Wright; Kohfeldt, Anja; Jebali, Ramsey Al; Teodoro, Luis Filipe Alves & Skauli, Torbjørn [Show all 12 contributors for this article] (2024). University of Oslo CENSSAT-1 mission concept. Proceedings of the International Astronautical Congress. ISSN 0074-1795. Full text in Research Archive
• Ölçek, Deniz; Jebali, Ramsey Al; Meier, Dirk; Haavik, Andreas Fagerland; Gheorghe, Codin & Gjennestad, Magne Sødal [Show all 9 contributors for this article] (2024). Development of a compact scintillator-based gamma-ray neutron detector for terrestrial and space applications. Journal of Instrumentation (JINST). 19. doi: 10.1088/1748-0221/19/01/C01030. Full text in Research Archive
• Kohfeldt, Anja; Knutsen, Elise Wright; Enoksen, Kristian; Pérez, José Miguel González & Grande, Jøran (2024). Lessons from the Launch: Reflections from the First Semester of UiO's Space Systems Project Course. Proceedings of the International Astronautical Congress. ISSN 0074-1795. p. 311–316. doi: 10.52202/078378-0035. Full text in Research Archive
• Østgaard, Nikolai; Balling, Jan E.; Bjørnsen, Thomas Riis; Brauer, Peter; Budtz-Jørgensen, Carl & Bujwan, Waldemar [Show all 35 contributors for this article] (2019). The modular X- and gamma-ray sensor (MXGS) of the ASIM Payload on the International Space Station. Space Science Reviews. ISSN 0038-6308. 215:23(2), p. 1–28. doi: 10.1007/s11214-018-0573-7. Full text in Research Archive Show summary

  The Modular X- and Gamma-ray Sensor (MXGS) is an imaging and spectral X- and Gamma-ray instrument mounted on the starboard side of the Columbus module on the International Space Station. Together with the Modular Multi-Spectral Imaging Assembly (MMIA) (Chanrion et al. this issue) MXGS constitutes the instruments of the Atmosphere-Space Interactions Monitor (ASIM) (Neubert et al. this issue). The main objectives of MXGS are to image and measure the spectrum of X- and γ-rays from lightning discharges, known as Terrestrial Gamma-ray Flashes (TGFs), and for MMIA to image and perform high speed photometry of Transient Luminous Events (TLEs) and lightning discharges. With these two instruments specifically designed to explore the relation between electrical discharges, TLEs and TGFs, ASIM is the first mission of its kind. With an imaging system and a large detector area MXGS will, for the first time, allow estimation of the location of the source region and characterization of the energy spectrum of individual events. The sensors have fast readout electronics to minimize pileup effects, giving high time resolution of photon detection for comparison with measurements on μs-time scales of lightning processes measured by the MMIA and other sensors in space or on the ground. The detectors cover the large energy range of the relevant photon energies. In this paper we describe the scientific objectives, design, performance, imaging capabilities and operational modes of the MXGS instrument.

• Cenkeramaddi, Linga Reddy; Genov, Georgi; Kohfeldt, Anja; Njøten, Kåre; Rostad, Maja Elise & Skogseide, Yngve [Show all 15 contributors for this article] (2012). Low-energy CZT detector array for the ASIM mission. IEEE Instrumentation and Measurement Technology Conference. Proceedings. ISSN 1091-5281. p. 2119–2123. doi: 10.1109/i2mtc.2012.6229184. Full text in Research Archive

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• Østmoe, Torbjørn; Benoit, Sebastian; Øya, Petter; Choe, Jusong; Stein, Timo Alexander & Meier, Dirk [Show all 9 contributors for this article] (2021). Single Event Effects in IDE3466 Readout IC for the RADEM and NORM Space Radiation Monitors. IEEE (Institute of Electrical and Electronics Engineers). ISBN 9781665437943. doi: 10.1109/RADECS53308.2021.9954524. Full text in Research Archive Show summary

  The IDE3466, a mixed-signal ASIC used as detector readout in space radiation monitors Radiation-hard Electron Monitor/Jupiter Icy Moons Explorer (RADEM / JUICE) and Norwegian Radiation Monitor/Arctic Satellite Broadband Mission (NORM / ASBM), shows no single event latch-up below 81.5 MeV cm 2 /mg, no single event upset below 55 MeV cm 2 /mg, and no single event transient below 3.3 MeV cm 2 /mg.

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• Kohfeldt, Anja; Knutsen, Elise Wright; Guzik, Matylda N. & Perez, Jose Miguel Gonzalez (2026). Project-based Learning in the Space Systems Master’s Degree Programme at the University of Oslo. doi: 10.14459/2026md1857555. Full text in Research Archive Show summary

  In 2023 the University of Oslo (UiO), Department of Technology Systems (ITS) established a new master’s degree study programme in Space Systems. From the beginning we focused on a system approach, setting space technology in the context of their operational environment and applications. Thus, we incorporate not only technology-focused theoretical lectures but also a diverse range of practical experiences and exercises, workshops in systems engineering, and numerous project opportunities. A highlight of our programme is the project course in the second semester. In a cooperation with Andøya Space Education, students develop a mini-mission concept, design the payload, build, integrate, test, launch the probe, and analyse the collected data. Throughout this process, they meet all standard milestones, gaining valuable experience in documentation, presentation skills, teamwork, and deliverables management under time constraints. To deepen specific field knowledge and foster engagement, we recommend a two-semester master’s thesis project, during which students profit from the research environment at ITS and the Centre for Space Sensors and Systems (CENSSS), with collaborating institutions and industry partners. CENSSS is currently developing CENSSAT-1, a 16U CubeSat for monitoring the interaction between solar activity and Earth’s atmosphere. This CubeSat mission primarily involves PhD fellows and master’s students and offers a wide array of relevant master’s thesis topics, providing direct experience with real space mission development. In this paper, we share our approach to hands-on education within the master’s programme in Space Systems and summarise our insights gained over almost three years of operation.

• Kohfeldt, Anja; Wahlén, Rebecka; Holdcroft, Sam; Teodoro, Luis Filipe Alves & Werner, Stephanie C. (2025). Element abundance mapping with the SER3NE Gamma-ray and neutron spectrometer. doi: 10.5194/epsc-dps2025-1439. Full text in Research Archive Show summary

  Selene’s Explorer for Roughness, Regolith, Resources, Neutrons and Elements (SER3NE) is a proposed small satellite mission in lunar orbit, aiming to characterize the lunar surface to unravel its volatile origin and delivery processes, in addition to uncovering the geological processes that shaped the Moon. Global element abundance mapping will prospect lunar resources for ISRU at future landing sites. Further, the mission is aiming to determine a more precise space-based neutron lifetime and the orbital evolution of the Earth-Moon system. To achieve these goals, SER3NE will host three instruments: a gamma-ray and neutron spectrometer (GRiNS, by UiO), the Lunar Infrared Point spectrometer (LIPS, by ROB/BIRA-IASB), and the SER3NE Laser Altimeter (S3LA, by DLR).Here, we present the current Gamma-Ray-including-Neutrons Spectrometer (GRiNS) design, performance specifications and preliminary results of the GRiNS laboratory demonstrator. GRiNS is part of the CLUNGAS family, that was reported on earlier.1By detecting gamma-ray and neutron radiation moderated by the lunar surface after GCR impact, GRiNS will be able to create global compositional maps and their abundances of different elements, such as Al, Ca, Fe, K, Mg, Si, Ti, Th, as well as hydrogen. In previous missions2 this was demonstrated with LaBr3 as main gamma-ray detector, proving the suitability of this technology. The default approach for hydrogen mapping are He3 pressurized tubes3, however, recently mission approaches with scintillator-based neutron detectors were launched4. In our approach we combine gamma-ray and neutron detection in one hybrid detector for reducing weight, cost, and space, and enabling deployment on small satellite missions.   GRiNS is a compact detector  capable of gamma-ray detection in the range of 100 keV to 8 MeV as well as the detection of thermal to epithermal neutrons. There shall be two detector units, facing nadir (for mapping) and zenith (in addition for neutron lifetime), as depicted in fig.1. The comparison of the ascending and descending gravitational bound thermal neutrons allow for the determination of the neutron lifetime along their flight path. The primary detecting material is a CLLBC (Cs2LiLa(Br,Cl)6:Ce), a dual-mode scintillator capable of both high-resolution gamma-ray spectroscopy and thermal to epi-thermal neutron detection. The preliminary detector layout aims for a 2x2 array where CLLBC is accompanied by lanthanum bromide (LaBr3), a crystal scintillator used in previous lunar mission2 for high-resolution gamma-ray spectroscopy, for improved gamma-ray – neutron discrimination. CLLBC and LaBr3 provide a good spectral resolution of

• Wahlén, Rebecka; Jebali, Ramsey Al; Teodoro, Luis & Kohfeldt, Anja (2025). A Gamma Ray and Neutron Spectrometer (GRNS) for mapping lunar surface composition and water abundance on the SER3NE mission. doi: 10.5194/egusphere-egu25-17007. Full text in Research Archive Show summary

  Selene's Explorer for Roughness, Regolith, Resources, Neutrons and Elements (SER3NE) is a lunar orbiter mission designed to map the topmost composition of the lunar surface, including elemental composition and water abundance. Planned instruments include a Gamma Ray and Neutron Spectrometer (GRNS) for elemental composition, including hydrogen indicating water, a Laser Altimeter (LA) for surface roughness and albedo observations, and a near-infrared spectrometer (LIPS) to determine water forms. The GRNS detector is designed for both in situ utilization as well as remote sensing. It has a core of CLLBC and LaBr3 crystal scintillators in a chessboard pattern for high-resolution gamma-ray detection (30 keV-8MeV) and thermal to epithermal neutron sensitivity. Gd foil on CLLBC allows separation of thermal and epithermal neutrons, while LaB3 and CLLBC enable advanced neutron detection analysis. Encapsulated by EJ-248M plastic scintillators, the detector includes anti-coincidence detector for charged particle rejection. With gamma-ray spectroscopy, rock-forming elements as well as KREEP and trace elements can be detected in the shallow surface of the moon. The local count rates of thermal and epithermal neutrons allow for the analysis of the distribution of hydrogen on the lunar surface, as well as for estimation of neutron lifetime from the lunar orbit. A demonstrator of the GRNS instrument has been successfully tested in the lab. A prototype of this lunar GRNS instrument will fly on the CENSSat-1 Bifrost CubeSat mission, scheduled for launch 2027.In this presentation, the GRNS instrument concept will be presented, focusing on the detector design and suitability for elemental composition analysis on a lunar orbiter.

• Holdcroft, Sam; Bocci, Alessio; Scholtz, Laura-Kristin; Retselis, Anastasios-Faidon; Knutsen, Elise Wright & Jebali, Ramsey Al [Show all 20 contributors for this article] (2025). CENSSAT-1 mission concept: a CubeSat for space weather monitoring. doi: 10.5281/ZENODO.17036544. Full text in Research Archive Show summary

  This paper presents an introduction to the CENSSAT-1 mission, an 8U CubeSat, which aims to study space situational awareness. It will investigate the effects of space weather on Earth from a 500 km orbit, using a camera, multi-purpose particle detector, and a Langmuir probe. It will additionally monitor space debris using a radar instrument, and conduct experiments on optimal control and drag based manoeuvring. CENSSAT-1 is aiming for launch in 2027.

• Kohfeldt, Anja; Jebali, Ramsey Al & Teodoro, Luis Filipe Alves (2024). A Compact Lunar Neutron and Gamma-Ray Spectrometer on Board SER3NE mission. doi: 10.5194/epsc2024-580. Full text in Research Archive Show summary

  The Compact Lunar Neutron and Gamma-ray Spectrometer (CLUNGAS) is targeting planetary science and in-situ resource utilisation (ISRU) such as mapping sub-surface water on celestial bodies. CLUNGAS is the primary payload in the small lunar mission proposal for Selene's Explorer for Roughness, Regolith, Resources, Neutrons and Elements (SER3NE). SER3NE is a small satellite mission performing gamma-ray and neutron spectroscopy, hyperspectral near-infrared spectroscopy, and laser altimetry, roughness, and albedo observations at unprecedented spectral and ground resolution. The aim is to characterise the lunar surface to unravel its volatile origin and delivery processes, uncover the geological processes that shaped the Moon to prospect lunar resources for ISRU at future landing sites, estimate the neutron lifetime and the orbital evolution of the Earth-Moon system. n this paper, we present the preliminary design of CLUNGAS tailored for the SER3NE mission, as well as environmental analysis to determine design parameters for the detector CLUNGAS is a compact solid-state detector capable of gamma-ray imaging in the range of 30 keV - 8 MeV with an energy resolution of < 4% FWHM at 662 keV as well as the detection of thermal to epithermal neutrons The primary detecting material is a CLLBC (Cs2LiLa(Br,Cl)6:Ce) dual-mode scintillator capable of both high-resolution gamma-ray spectroscopy and thermal to epi-thermal neutron detection. The preliminary detector layout aims for a 4x4 chessboard design where CLLBC is accompanied by lanthanum bromide (LaBr3), as depicted in figure 3, for improved gamma-ray &#8211; neutron distinction. The detector core scintillators are surrounded by plastic scintillators serving as an anti-coincidence shield against highly charged particles. Mitigation techniques for secondary neutrons generated by impact of Galactic Cosmic Rays (GCR) and Solar Energetic Particles (SEP) on the spacecraft will be evaluated as well. The detector readout is based on the ROSSPAD module provided by IDEAS, hosting the low power space-grade detector read-out integrated circuit (ROIC) SIPHRA coupled to a number of Si photomultipliers (SiPM). SIPHRA is radiation tested and has flight heritage. &#160;The power consumption will be below 4W per module and the instrument weight below per unit, with the scintillator volume and shielding requirements as the main design driver. The proposed instrument consists of two units, one covered with few mm thick Gd shield, enabling the distinct detection of both thermal and epithermal neutrons. It will fit into 2U, with the electronics being compatible with the PC104 format. We plan to keep the form factor also for other missions and demonstrations on other platforms. Using existing data, such as Apollo and LP, we can estimate the expected lunar radiation environment. This is vital to tune the detector design and estimate the background noise such as secondaries generated by the spacecraft itself. The use of Geant4 allows us to track the creation of secondaries (e.g., protons, electrons/positrons, Kaons, muons, pions, and gamma-rays) and their transport in the shallow planetary sub-surfaces. Figure 1 shows the expected neutron flux generated in different lunar soil types due to Galactic cosmic ray impact. The ratio between thermal and epi-thermal neutrons count rates allows for the identification of different sub-surface elements, such as hydrogen content and thus the potential amount of water in the soil. The gamma-ray leakage flux for different lunar soils is presented in figure 2. With the gamma-ray spectrum the composition of the soil can be characterised. Further, we simulated the response of the preliminary detector design. Figure 3 shows the simulated design in Geant4, with the green light symbolising scintillation photons. Figure 4 visualises the gamma-ray response for 662 keV (Cs-137) stimulation. In the summed energy spectrum over all scintillators, the 662 keV peak, as well as Compton radiation, clearly is visible. &#160;Figure 5 demonstrates the detection of neutrons in CLLBC scintillators by the peak of gamma-equivalent energy at 3.2 MeV, as well as effect of the thermal neutron shield (here Cd). &#160;Detected neutrons in the shielded CLLBC scintillators are reduced by almost 50%, which is equivalent to the expected number of thermal neutrons in the non-shielded peak. First measurements with an engineering model, based on the terrestrial version of the ROSSPAD module provided promising results. We tested the read-out electronics and CLLBC scintillator with various gamma sources, such as Cs-137 and Co-60, as well as neutron source AmBe and were able to demonstrate the spectroscopy capabilities within the targeted specifications, as well as the detection of thermal and epithermal neutrons. In conclusion, we are developing a hybrid gamma-ray and neutron detector for lunar ISRU onboard the SER3NE mission. Detector simulations and laboratory demonstrations show the capability of neutron and gamma-ray spectroscopy. Environmental simulations support the detector design and prepare for future science data analysis. Next steps are fine tuning and verification of the detector simulation model, extended measurement campaigns of an engineering model, as well as adaption of the electronics design to accommodate spacecraft interfaces.&#160;&#160;Figure 1 : Neutron flux spectra for the following lunar compositions: A11, A17, FAN, L20 and L24. We have used the following Geant4 Physics libraries: 1) QGSP, and 2) BERT. The full neutron energy range from thermal to fast neutron is shown. Figure 2: Gamma-rays flux spectra for the following lunar compositions: A11, A17, FAN, L20 and L24. We also have used the following Geant 4 Physics libraries: 1) QGSP, and 2) BERT. The different spectra present arbitrary normalisation. Figure 3 Simulated detector design in Geant4. 2 units with a 4x4 chessboard with CLLBC and LaBr scintillators, one unit covered in 0.5mm Cd foil. Inter-scintillator shielding with 0.5mm Al. Figure 4: Gamma-ray detection capability with simulated detector design in Geant4. Left: Gamma equivalent energy spectrum for each scintillator for gamma source. Right: summed energy spectra over all scintillators, Compton radiation and expected peak at 662keV.Figure 5: Neutron detection capability with simulated detector design in Geant4. Left: summed energy spectra for both scintillators. Right: comparison between the Cd covered and the uncovered unit.

• Birkeland, Roger; Orlandic, Milica; Johansen, Tor Arne; Kohfeldt, Anja; Røed, Ketil & Berger, Tor [Show all 12 contributors for this article] (2024). An update on Norwegian Space Education. Full text in Research Archive
• Kohfeldt, Anja; Jebali, Ramsey Al; Ölçek, Deniz & Teodoro, Luis Filipe Alves (2023). A Compact Gamma-Ray and Neutron Detector for a CubeSat: The CLUGAS demonstrator. Full text in Research Archive
• Kohfeldt, Anja; Benoit, Sebastian & Stein, Timo Alexander (2020). NORM: Norwegian Radiation Monitor for a long-term mission in highly-elliptical orbit. Full text in Research Archive

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