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Article: Gamma Ray Glow Observations at 20-km Altitude.

Østgaard, N / Christian, H J / Grove, J E / Sarria, D / Mezentsev, A / Kochkin, P / Lehtinen, N / Quick, M / Al-Nussirat, S / Wulf, E / Genov, G / Ullaland, K / Marisaldi, M / Yang, S / Blakeslee, R J

Journal of geophysical research. Atmospheres : JGR

2019 Volume 124, Issue 13, Page(s) 7236–7254

Abstract: In the spring of 2017 an ER-2 aircraft campaign was undertaken over continental United States to observe energetic radiation from thunderstorms and lightning. The payload consisted of a suite of instruments designed to detect optical signals, electric ... ...

Abstract	In the spring of 2017 an ER-2 aircraft campaign was undertaken over continental United States to observe energetic radiation from thunderstorms and lightning. The payload consisted of a suite of instruments designed to detect optical signals, electric fields, and gamma rays from lightning. Starting from Georgia, USA, 16 flights were performed, for a total of about 70 flight hours at a cruise altitude of 20 km. Of these, 45 flight hours were over thunderstorm regions. An analysis of two gamma ray glow events that were observed over Colorado at 21:47 UT on 8 May 2017 is presented. We explore the charge structure of the cloud system, as well as possible mechanisms that can produce the gamma ray glows. The thundercloud system we passed during the gamma ray glow observation had strong convection in the core of the cloud system. Electric field measurements combined with radar and radio measurements suggest an inverted charge structure, with an upper negative charge layer and a lower positive charge layer. Based on modeling results, we were not able to unambiguously determine the production mechanism. Possible mechanisms are either an enhancement of cosmic background locally (above or below 20 km) by an electric field below the local threshold or an enhancement of the cosmic background inside the cloud but then with normal polarity and an electric field well above the Relativistic Runaway Electron Avalanche threshold.
Language	English
Publishing date	2019-07-08
Publishing country	United States
Document type	Journal Article
ZDB-ID	710256-2
ISSN	2169-8996 ; 2169-897X ; 0148-0227
ISSN (online)	2169-8996
ISSN	2169-897X ; 0148-0227
DOI	10.1029/2019JD030312
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Article ; Online: Image quality of list-mode proton imaging without front trackers.

Rambo Sølie, Jarle / Volz, Lennart / Egil Seime Pettersen, Helge / Piersimoni, Pierluigi / Harald Odland, Odd / Röhrich, Dieter / Helstrup, Håvard / Peitzmann, Thomas / Ullaland, Kjetil / Varga-Kofarago, Monika / Mehendale, Shruti / Slettevoll Grøttvik, Ola / Nilsen Eikeland, Viljar / Meric, Ilker / Seco, Joao

Physics in medicine and biology

2020 Volume 65, Issue 13, Page(s) 135012

Abstract: List mode proton imaging relies on accurate reconstruction of the proton most likely path (MLP) through the patient. This typically requires two sets of position sensitive detector systems, one upstream (front) and one downstream (rear) of the patient. ... ...

Abstract	List mode proton imaging relies on accurate reconstruction of the proton most likely path (MLP) through the patient. This typically requires two sets of position sensitive detector systems, one upstream (front) and one downstream (rear) of the patient. However, for a clinical implementation it can be preferable to omit the front trackers (single-sided proton imaging). For such a system, the MLP can be computed from information available through the beam delivery system and the remaining rear tracker set. In this work, we use Monte Carlo simulations to compare a conventional double-sided (using both front and rear detector systems) with a single-sided system (only rear detector system) by evaluating the spatial resolution of proton radiographs (pRad) and proton CT images (pCT) acquired with these set-ups. Both the pencil beam spot size, as well as the spacing between spots was also adjusted to identify the impact of these beam parameters on the image quality. Relying only on the pencil beam central position for computing the MLP resulted in severe image artifacts both in pRad and pCT. Using the recently extended-MLP formalism that incorporate pencil beam uncertainty removed these image artifacts. However, using a more focused pencil beam with this algorithm induced image artifacts when the spot spacing was the same as the beam spot size. The spatial resolution tested with a sharp edge gradient technique was reduced by 40% for single-sided (MTF
MeSH term(s)	Algorithms ; Child ; Head/diagnostic imaging ; Humans ; Image Processing, Computer-Assisted ; Monte Carlo Method ; Phantoms, Imaging ; Protons ; Quality Control ; Tomography, X-Ray Computed/methods
Chemical Substances	Protons
Language	English
Publishing date	2020-07-09
Publishing country	England
Document type	Journal Article ; Research Support, Non-U.S. Gov't
ZDB-ID	208857-5
ISSN	1361-6560 ; 0031-9155
ISSN (online)	1361-6560
ISSN	0031-9155
DOI	10.1088/1361-6560/ab8ddb
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Article ; Online: Very-high-frequency oscillations in the main peak of a magnetar giant flare.

Castro-Tirado, A J / Østgaard, N / Göǧüş, E / Sánchez-Gil, C / Pascual-Granado, J / Reglero, V / Mezentsev, A / Gabler, M / Marisaldi, M / Neubert, T / Budtz-Jørgensen, C / Lindanger, A / Sarria, D / Kuvvetli, I / Cerdá-Durán, P / Navarro-González, J / Font, J A / Zhang, B-B / Lund, N /

Nature

2021 Volume 600, Issue 7890, Page(s) 621–624

Abstract: Magnetars are strongly magnetized, isolated neutron ... ...

Abstract	Magnetars are strongly magnetized, isolated neutron stars
MeSH term(s)	Atmosphere ; Stars, Celestial
Language	English
Publishing date	2021-12-22
Publishing country	England
Document type	Journal Article ; Research Support, Non-U.S. Gov't
ZDB-ID	120714-3
ISSN	1476-4687 ; 0028-0836
ISSN (online)	1476-4687
ISSN	0028-0836
DOI	10.1038/s41586-021-04101-1
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Article ; Online: A terrestrial gamma-ray flash and ionospheric ultraviolet emissions powered by lightning.

Neubert, Torsten / Østgaard, Nikolai / Reglero, Victor / Chanrion, Olivier / Heumesser, Matthias / Dimitriadou, Krystallia / Christiansen, Freddy / Budtz-Jørgensen, Carl / Kuvvetli, Irfan / Rasmussen, Ib Lundgaard / Mezentsev, Andrey / Marisaldi, Martino / Ullaland, Kjetil / Genov, Georgi / Yang, Shiming / Kochkin, Pavlo / Navarro-Gonzalez, Javier / Connell, Paul H / Eyles, Chris J

Science (New York, N.Y.)

2019 Volume 367, Issue 6474, Page(s) 183–186

Abstract: Terrestrial gamma-ray flashes (TGFs) are transient gamma-ray emissions from thunderstorms, generated by electrons accelerated to relativistic energies in electric fields. Elves are ultraviolet and optical emissions excited in the lower ionosphere by ... ...

Abstract	Terrestrial gamma-ray flashes (TGFs) are transient gamma-ray emissions from thunderstorms, generated by electrons accelerated to relativistic energies in electric fields. Elves are ultraviolet and optical emissions excited in the lower ionosphere by electromagnetic waves radiated from lightning current pulses. We observed a TGF and an associated elve using the Atmosphere-Space Interactions Monitor on the International Space Station. The TGF occurred at the onset of a lightning current pulse that generated an elve, in the early stage of a lightning flash. Our measurements suggest that the current onset is fast and has a high amplitude-a prerequisite for elves-and that the TGF is generated in the electric fields associated with the lightning leader.
Language	English
Publishing date	2019-12-11
Publishing country	United States
Document type	Journal Article ; Research Support, Non-U.S. Gov't
ZDB-ID	128410-1
ISSN	1095-9203 ; 0036-8075
ISSN (online)	1095-9203
ISSN	0036-8075
DOI	10.1126/science.aax3872
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Article ; Online: Exploration of differentiability in a proton computed tomography simulation framework.

Aehle, Max / Alme, Johan / Gábor Barnaföldi, Gergely / Blühdorn, Johannes / Bodova, Tea / Borshchov, Vyacheslav / van den Brink, Anthony / Eikeland, Viljar / Feofilov, Gregory / Garth, Christoph / Gauger, Nicolas R / Grøttvik, Ola / Helstrup, Håvard / Igolkin, Sergey / Keidel, Ralf / Kobdaj, Chinorat / Kortus, Tobias / Kusch, Lisa / Leonhardt, Viktor /

Mehendale, Shruti / Ningappa Mulawade, Raju / Harald Odland, Odd / O'Neill, George / Papp, Gábor / Peitzmann, Thomas / Pettersen, Helge Egil Seime / Piersimoni, Pierluigi / Pochampalli, Rohit / Protsenko, Maksym / Rauch, Max / Ur Rehman, Attiq / Richter, Matthias / Röhrich, Dieter / Sagebaum, Max / Santana, Joshua / Schilling, Alexander / Seco, Joao / Songmoolnak, Arnon / Sudár, Ákos / Tambave, Ganesh / Tymchuk, Ihor / Ullaland, Kjetil / Varga-Kofarago, Monika / Volz, Lennart / Wagner, Boris / Wendzel, Steffen / Wiebel, Alexander / Xiao, RenZheng / Yang, Shiming / Zillien, Sebastian

Physics in medicine and biology

2023 Volume 68, Issue 24

Abstract: Objective. ...

Abstract	Objective.
MeSH term(s)	Computer Simulation ; Protons ; Phantoms, Imaging ; Tomography, X-Ray Computed/methods ; Software ; Algorithms ; Monte Carlo Method
Chemical Substances	Protons
Language	English
Publishing date	2023-12-15
Publishing country	England
Document type	Review ; Journal Article
ZDB-ID	208857-5
ISSN	1361-6560 ; 0031-9155
ISSN (online)	1361-6560
ISSN	0031-9155
DOI	10.1088/1361-6560/ad0bdd
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Article ; Online: Uncertainty-aware spot rejection rate as quality metric for proton therapy using a digital tracking calorimeter.

Schilling, Alexander / Aehle, Max / Alme, Johan / Barnaföldi, Gergely Gábor / Bodova, Tea / Borshchov, Vyacheslav / van den Brink, Anthony / Eikeland, Viljar / Feofilov, Gregory / Garth, Christoph / Gauger, Nicolas R / Grøttvik, Ola / Helstrup, Håvard / Igolkin, Sergey / Keidel, Ralf / Kobdaj, Chinorat / Kortus, Tobias / Leonhardt, Viktor / Mehendale, Shruti /

Ningappa Mulawade, Raju / Harald Odland, Odd / O'Neill, George / Papp, Gábor / Peitzmann, Thomas / Pettersen, Helge Egil Seime / Piersimoni, Pierluigi / Protsenko, Maksym / Rauch, Max / Ur Rehman, Attiq / Richter, Matthias / Röhrich, Dieter / Santana, Joshua / Seco, Joao / Songmoolnak, Arnon / Sudár, Ákos / Tambave, Ganesh / Tymchuk, Ihor / Ullaland, Kjetil / Varga-Kofarago, Monika / Volz, Lennart / Wagner, Boris / Wendzel, Steffen / Wiebel, Alexander / Xiao, RenZheng / Yang, Shiming / Zillien, Sebastian

Physics in medicine and biology

2023 Volume 68, Issue 19

Abstract: Objective. ...

Abstract	Objective.
MeSH term(s)	Proton Therapy ; Uncertainty ; Protons ; Machine Learning ; Neural Networks, Computer
Chemical Substances	Protons
Language	English
Publishing date	2023-09-20
Publishing country	England
Document type	Journal Article ; Research Support, Non-U.S. Gov't
ZDB-ID	208857-5
ISSN	1361-6560 ; 0031-9155
ISSN (online)	1361-6560
ISSN	0031-9155
DOI	10.1088/1361-6560/acf5c2
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Book ; Online: Development of Wireless Techniques in Data and Power Transmission - Application for Particle Physics Detectors

Brenner, R. / Ceuterickx, S. / Dehos, C. / De Lurgio, P. / Djurcic, Z. / Drake, G. / Gimenez, J. L. Gonzalez / Gustafsson, L. / Kim, D. W. / Locci, E. / Roehrich, D. / Schoening, A. / Siligaris, A. / Soltveit, H. K. / Ullaland, K. / Vincent, P. / Wiednert, D. / Yang, S.

2015

Abstract: Wireless techniques have developed extremely fast over the last decade and using them for data and power transmission in particle physics detectors is not science- fiction any more. During the last years several research groups have independently thought ...

Abstract	Wireless techniques have developed extremely fast over the last decade and using them for data and power transmission in particle physics detectors is not science- fiction any more. During the last years several research groups have independently thought of making it a reality. Wireless techniques became a mature field for research and new developments might have impact on future particle physics experiments. The Instrumentation Frontier was set up as a part of the SnowMass 2013 Community Summer Study [1] to examine the instrumentation R&D for the particle physics research over the coming decades: {\guillemotleft} To succeed we need to make technical and scientific innovation a priority in the field {\guillemotright}. Wireless data transmission was identified as one of the innovations that could revolutionize the transmission of data out of the detector. Power delivery was another challenge mentioned in the same report. We propose a collaboration to identify the specific needs of different projects that might benefit from wireless techniques. The objective is to provide a common platform for research and development in order to optimize effectiveness and cost, with the aim of designing and testing wireless demonstrators for large instrumentation systems.
Keywords	Physics - Instrumentation and Detectors ; Computer Science - Networking and Internet Architecture ; High Energy Physics - Experiment
Subject code	306
Publishing date	2015-11-18
Publishing country	us
Document type	Book ; Online
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Article ; Online: Design optimization of a pixel-based range telescope for proton computed tomography.

Pettersen, Helge Egil Seime / Alme, Johan / Barnaföldi, Gergely Gábor / Barthel, Rene / van den Brink, Anthony / Chaar, Mamdouh / Eikeland, Viljar / García-Santos, Alba / Genov, Georgi / Grimstad, Silje / Grøttvik, Ola / Helstrup, Håvard / Hetland, Kristin Fanebust / Mehendale, Shruti / Meric, Ilker / Odland, Odd Harald / Papp, Gábor / Peitzmann, Thomas / Piersimoni, Pierluigi /

Ur Rehman, Attiq / Richter, Matthias / Samnøy, Andreas Tefre / Seco, Joao / Shafiee, Hesam / Skjæveland, Eivind Vågslid / Sølie, Jarle Rambo / Tambave, Ganesh / Ullaland, Kjetil / Varga-Kofarago, Monika / Volz, Lennart / Wagner, Boris / Yang, Shiming / Röhrich, Dieter

Physica medica : PM : an international journal devoted to the applications of physics to medicine and biology : official journal of the Italian Association of Biomedical Physics (AIFB)

2019 Volume 63, Page(s) 87–97

Abstract: Purpose: A pixel-based range telescope for tracking particles during proton imaging is described. The detector applies a 3D matrix of stacked Monolithic Active Pixel Sensors with fast readout speeds. This study evaluates different design alternatives of ...

Abstract	Purpose: A pixel-based range telescope for tracking particles during proton imaging is described. The detector applies a 3D matrix of stacked Monolithic Active Pixel Sensors with fast readout speeds. This study evaluates different design alternatives of the range telescope on basis of the protons' range accuracy and the track reconstruction efficiency. Method: Detector designs with different thicknesses of the energy-absorbing plates between each sensor layer are simulated using the GATE/Geant4 Monte Carlo software. Proton tracks traversing the detector layers are individually reconstructed, and a Bragg curve fitting procedure is applied for the calculation of each proton's range. Results: Simulations show that the setups with 4 mm and thinner absorber layers of aluminum have a low range uncertainty compared to the physical range straggling, systematic errors below 0.3 mm water equivalent thickness and a track reconstruction capability exceeding ten million protons per second. Conclusions: In order to restrict the total number of layers and to yield the required tracking and range resolution properties, a design recommendation is reached where the proposed range telescope applies 3.5 mm thick aluminum absorber slabs between each sensor layer.
MeSH term(s)	Equipment Design ; Image Processing, Computer-Assisted ; Monte Carlo Method ; Phantoms, Imaging ; Protons ; Scattering, Radiation ; Software ; Telescopes ; Tomography, X-Ray Computed/instrumentation
Chemical Substances	Protons
Language	English
Publishing date	2019-06-06
Publishing country	Italy
Document type	Journal Article
ZDB-ID	1122650-x
ISSN	1724-191X ; 1120-1797
ISSN (online)	1724-191X
ISSN	1120-1797
DOI	10.1016/j.ejmp.2019.05.026
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Article ; Online: Investigating particle track topology for range telescopes in particle radiography using convolutional neural networks.

Pettersen, Helge Egil Seime / Aehle, Max / Alme, Johan / Barnaföldi, Gergely Gábor / Borshchov, Vyacheslav / van den Brink, Anthony / Chaar, Mamdouh / Eikeland, Viljar / Feofilov, Grigory / Garth, Christoph / Gauger, Nicolas R / Genov, Georgi / Grøttvik, Ola / Helstrup, Håvard / Igolkin, Sergey / Keidel, Ralf / Kobdaj, Chinorat / Kortus, Tobias / Leonhardt, Viktor /

Mehendale, Shruti / Mulawade, Raju Ningappa / Odland, Odd Harald / Papp, Gábor / Peitzmann, Thomas / Piersimoni, Pierluigi / Protsenko, Maksym / Rehman, Attiq Ur / Richter, Matthias / Santana, Joshua / Schilling, Alexander / Seco, Joao / Songmoolnak, Arnon / Sølie, Jarle Rambo / Tambave, Ganesh / Tymchuk, Ihor / Ullaland, Kjetil / Varga-Kofarago, Monika / Volz, Lennart / Wagner, Boris / Wendzel, Steffen / Wiebel, Alexander / Xiao, RenZheng / Yang, Shiming / Yokoyama, Hiroki / Zillien, Sebastian / Röhrich, Dieter

Acta oncologica (Stockholm, Sweden)

2021 Volume 60, Issue 11, Page(s) 1413–1418

Abstract: Background: Proton computed tomography (pCT) and radiography (pRad) are proposed modalities for improved treatment plan accuracy and : Material and methods: The CNN was trained by simulation and reconstruction of tens of millions of proton and helium ...

Abstract	Background: Proton computed tomography (pCT) and radiography (pRad) are proposed modalities for improved treatment plan accuracy and Material and methods: The CNN was trained by simulation and reconstruction of tens of millions of proton and helium tracks. The CNN filter was then compared to simple energy loss threshold methods using the Area Under the Receiver Operating Characteristics curve (AUROC), and by comparing the image quality and Water Equivalent Path Length (WEPL) error of proton and helium radiographs filtered with the same methods. Results: The CNN method led to a considerable improvement of the AUROC, from 74.3% to 97.5% with protons and from 94.2% to 99.5% with helium. The CNN filtering reduced the WEPL error in the helium radiograph from 1.03 mm to 0.93 mm while no improvement was seen in the CNN filtered pRads. Conclusion: The CNN improved the filtering of proton and helium tracks. Only in the helium radiograph did this lead to improved image quality.
MeSH term(s)	Humans ; Image Processing, Computer-Assisted ; Monte Carlo Method ; Neural Networks, Computer ; Phantoms, Imaging ; Radiography ; Telescopes
Language	English
Publishing date	2021-07-14
Publishing country	England
Document type	Journal Article
ZDB-ID	896449-x
ISSN	1651-226X ; 0349-652X ; 0284-186X ; 1100-1704
ISSN (online)	1651-226X
ISSN	0349-652X ; 0284-186X ; 1100-1704
DOI	10.1080/0284186X.2021.1949037
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Article ; Online: Helium radiography with a digital tracking calorimeter-a Monte Carlo study for secondary track rejection.

Pettersen, Helge Egil Seime / Volz, Lennart / Sølie, Jarle Rambo / Alme, Johan / Barnaföldi, Gergely Gábor / Barthel, Rene / van den Brink, Anthony / Borshchov, Vyacheslav / Chaar, Mamdouh / Eikeland, Viljar / Genov, Georgi / Grøttvik, Ola / Helstrup, Håvard / Keidel, Ralf / Kobdaj, Chinorat / van der Kolk, Naomi / Mehendale, Shruti / Meric, Ilker / Harald Odland, Odd /

Papp, Gábor / Peitzmann, Thomas / Piersimoni, Pierluigi / Protsenko, Maksym / Ur Rehman, Attiq / Richter, Matthias / Tefre Samnøy, Andreas / Seco, Joao / Shafiee, Hesam / Songmoolnak, Arnon / Tambave, Ganesh / Tymchuk, Ihor / Ullaland, Kjetil / Varga-Kofarago, Monika / Wagner, Boris / Xiao, RenZheng / Yang, Shiming / Yokoyama, Hiroki / Röhrich, Dieter

Physics in medicine and biology

2021 Volume 66, Issue 3, Page(s) 35004

Abstract: Radiation therapy using protons and heavier ions is a fast-growing therapeutic option for cancer patients. A clinical system for particle imaging in particle therapy would enable online patient position verification, estimation of the dose deposition ... ...

Abstract	Radiation therapy using protons and heavier ions is a fast-growing therapeutic option for cancer patients. A clinical system for particle imaging in particle therapy would enable online patient position verification, estimation of the dose deposition through range monitoring and a reduction of uncertainties in the calculation of the relative stopping power of the patient. Several prototype imaging modalities offer radiography and computed tomography using protons and heavy ions. A Digital Tracking Calorimeter (DTC), currently under development, has been proposed as one such detector. In the DTC 43 longitudinal layers of laterally stacked ALPIDE CMOS monolithic active pixel sensor chips are able to reconstruct a large number of simultaneously recorded proton tracks. In this study, we explored the capability of the DTC for helium imaging which offers favorable spatial resolution over proton imaging. Helium ions exhibit a larger cross section for inelastic nuclear interactions, increasing the number of produced secondaries in the imaged object and in the detector itself. To that end, a filtering process able to remove a large fraction of the secondaries was identified, and the track reconstruction process was adapted for helium ions. By filtering on the energy loss along the tracks, on the incoming angle and on the particle ranges, 97.5% of the secondaries were removed. After passing through 16 cm water, 50.0% of the primary helium ions survived; after the proposed filtering 42.4% of the primaries remained; finally after subsequent image reconstruction 31% of the primaries remained. Helium track reconstruction leads to more track matching errors compared to protons due to the increased available focus strength of the helium beam. In a head phantom radiograph, the Water Equivalent Path Length error envelope was 1.0 mm for helium and 1.1 mm for protons. This accuracy is expected to be sufficient for helium imaging for pre-treatment verification purposes.
MeSH term(s)	Calorimetry/instrumentation ; Helium ; Humans ; Monte Carlo Method ; Phantoms, Imaging ; Protons ; Radiography
Chemical Substances	Protons ; Helium (206GF3GB41)
Language	English
Publishing date	2021-01-26
Publishing country	England
Document type	Journal Article ; Research Support, Non-U.S. Gov't
ZDB-ID	208857-5
ISSN	1361-6560 ; 0031-9155
ISSN (online)	1361-6560
ISSN	0031-9155
DOI	10.1088/1361-6560/abca03
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