Publications - Publications

Adapting to change: transforming research libraries into catalysts for citizen science in a rapidly evolving world

Nielsen, K. H., Kaarsted, T., Overgaard, A. K., Okholm, A. L., Martek, A. — Mon, 01 Jan 2024 07:24:17 +0100

Forskere mod abort

Nielsen, K. H. — Fri, 15 Mar 2024 07:24:17 +0100

Problemet med Central Park

Nielsen, K. H. — Wed, 27 Mar 2024 07:24:17 +0100

To the discerning reader: Galileo's philosophical comedy in a new translation

Nielsen, K. — Sun, 24 Mar 2024 07:24:17 +0100

Single, double and triple ionization of Ne, Ar, Kr and Xe by 30-1000 keV p^- impact

Paludan, K., Bluhme, H., Knudsen, H., et al. — Sun, 14 Sep 1997 07:24:17 +0200

Experimental data for single, double and triple ionization of Ne, Ar, Kr and Xe by 30-1000 keV antiproton impact are presented and compared with existing proton data. It is found that the current phenomenological understanding of ionization developed from studies of light targets generally apply to heavy atomic targets as well. Inner-shell ionization followed by Auger decay is found to be an important channel for multiple ionization of the heaviest targets, and the projectile charge dependence of their multiple ionization cross sections must be understood as stemming from the underlying inner-shell ionization cross sections.

Experimental investigation of photon multiplicity and radiation cooling for 150 GeV electrons/positrons traversing diamond and Si crystals

Kirsebom, K., Medenwaldt, R., Mikkelsen, U., et al. — Tue, 01 Oct 1996 07:24:17 +0200

Detailed experimental investigations of photon multiplicities for 150 GeV electrons/positrons traversing thin diamond and Si crystals have been performed. Along axial directions up to 10 photons are emitted in 1.5 mm diamond for a radiative energy loss larger than 4 GeV. This corresponds to a mean free path for photon emission of about two orders of magnitude shorter than in an amorphous target. This is in agreement with an enhanced radiative energy loss of ∼30 times that in amorphous targets. The strongly enhanced photon emission leads to radiation cooling which can result in particles exiting the crystal with a reduced angle to the axis. For incidences along planar directions the average multiplicity is still above one, even for the thinnest crystals used in the present experiment, so a single-photon spectrum can only be obtained for thicknesses ≤50 μm, which, on the other hand, is comparable to the coherence lengths for GeV photons, leading to destruction of the coherent effects.

Ionization in collisions between 30-1000 keV antiprotons and atomic hydrogen

Paludan, K., Charlton, M., Kirsebom, K., et al. — Mon, 01 Jan 1996 07:24:17 +0100

Recently published data for impact of antiprotons in the energy range 30-1000 keV on atomic hydrogen are compared with analogous proton, electron, and positron measurements, and it is found that the ionization cross sections of atomic hydrogen follow the same pattern as similar cross sections obtained on He and H₂ targets, in accordance with the general phenomenological description of single ionization that has developed over the last decade. Further comparisons are made with various recent and advanced theoretical calculations for antiproton ionization of atomic hydrogen. These theoretical results agree well with the data obtained, but for lower impact energies the different methods do not, despite the simplicity of the system, agree on predicting even the form of the cross section.

Ionization of rare gases by particle-antiparticle impact

Paludan, K., Laricchia, G., Ashley, P., et al. — Sun, 14 Sep 1997 07:24:17 +0200

New data for single and double ionization of the rare gases Ne, Ar, Kr and Xe, by positron and antiproton impact are presented and compared with existing data for electron and proton impact. It is found that the current understanding of these processes obtained from studies involving low-Z targets only extends to high-Z atoms provided that certain target-dependent effects are taken into consideration. In particular, the static interaction between the projectile and the undistorted target is found to play a crucial role in the case of the lighter projectiles.

Ionization of atomic hydrogen by 30-1000 keV antiprotons

Knudsen, H., Mikkelsen, U., Paludan, K., et al. — Sun, 01 Jan 1995 07:24:17 +0100

Ionization in collisions between antiprotons and atomic hydrogen is perhaps the least complicated and most fundamental process that can be treated by atomic-collision theory. We present measurements of the ionization cross section for 30-1000 keV antiprotons colliding with atomic hydrogen.

One and two electron processes in fast collisions between protons and hydrogen molecules

Fri, 05 May 1995 07:24:17 +0200

The ratio of double to single ionization of hydrogen molecules caused by fast proton impact was measured over a wide velocity range (v = 6-24 a.u.) using the coincidence time-of-flight technique. This ratio, ∼ 0.13% at high velocities, is about a factor of 2 smaller than the same ratio for the He target. This difference is due mainly to the larger single ionization cross section for hydrogen molecules, i.e. σ⁺(H₂) ∼ 2 σ⁺(He). The double ionization cross section, on the other hand, is similar for both He and H₂. Furthermore, the ratio of double to single ionization of the hydrogen molecule by proton impact is smaller than the one caused by electron impact at the same velocity in a similar way as for the helium target.

Measurement of the Barkas effect around the stopping-power maximum for light and heavy targets

Møller, S. P., Uggerhøj, E., Bluhme, H., et al. — Wed, 01 Jan 1997 07:24:17 +0100

The first direct measurements of antiproton stopping powers around the stopping power maximum are presented. The LEAR antiproton-beam of 5.9 MeV is degraded to 50-700 keV, and the energy-loss is found by measuring the antiproton velocity before and after the target. The antiproton stopping powers of Si and Au are found to be reduced by 30 and 40% near the electronic stopping power maximum as compared to the equivalent proton stopping power. The Barkas effect, that is the stopping power difference between protons and antiprotons, is extracted and compared to theoretical estimates.

Ionization of helium and molecular hydrogen by slow antiprotons

Hvefplund, P., Knudsen, H., Mikkelsen, U., et al. — Mon, 14 Mar 1994 07:24:17 +0100

Measurements of the cross sections for single and double ionization or helium as well as for the creation of H⁺₂ and H⁺ ions from H₂ for impact of antiprotons in the energy range 13-500 keV are presented. The results are compared with our earlier, less accurate data and with data for equivelocity proton impact. The single ionization cross section of helium agrees remarkably well with a continuum distorted wave (CDW-EIS) calculation. The ratio between the double and the single ionization cross sections of helium increases dramatically with decreasing projectile energy. New theoretical calculations are called for.

Non-dissociative single ionization of molecular hydrogen by electron and positron impact

Jacobsen, F. M., Frandsen, N. P., Knudsen, H., Mikkelsen, U. — Tue, 14 Nov 1995 07:24:17 +0100

Present experimental results for impact ionization of molecular hydrogen by electrons and positrons for the range of impact energies from threshold to about 2 keV (0.42 keV for e⁻). Our electron data agree with the most recent ones measured by others. When we compare our positron results to earlier published single ioniznrion cross sections we find significant differences for impact energies from threshold to about 100 eV with the new cross sections being substantially smaller. In the present study an effort has been made to discriminate against false signals caused by pasitronium formation and other effects.

Non-dissociative and dissociative ionization of O₂ molecules by impact of 40-1000 keV antiprotons

Bluhme, H., Knudsen, J., Mikkelsen, U., et al. — Wed, 01 Jan 1997 07:24:17 +0100

The non-dissociative single-ionization cross section for 40-1000 keV antiproton impact on O₂ molecules has been measured. Furthermore, the ratio between the production of O⁺ and O₂⁺ ions was obtained. The experimental results agree qualitatively with similar data obtained previously for other molecular targets, and support the 'standard picture' of ionization that has emerged during the last decade after much experimental as well as theoretical work on ionization caused by particles and their antiparticles.

Ionization and excitation of hydrogen molecules by fast proton impact

Ben-Itzhak, I., Krishnamurthi, V., Carnes, K. D., et al. — Mon, 01 Jan 1996 07:24:17 +0100

The ratio of ionization-excitation to single ionization of hydrogen molecules caused by fast proton impact was measured over a wide velocity range (v = 6-24 au) using the coincidence time-of-flight technique. This ratio, approx. 2%, is independent of the collision velocity at high velocities. It differs from the ratio of total H⁺ to H₂⁺ production mostly due to a large contribution from the dissociation of the electronic ground state of the molecular ion. The dissociation fraction of H₂⁺ (1sσ) was measured and compares well with our calculations using the Franck-Condon approximation.

Direct measurements of the stopping power for antiprotons of light and heavy targets

Møller, S. P., Uggerhøj, E., Bluhme, H., et al. — Wed, 01 Jan 1997 07:24:17 +0100

Measurements of antiproton stopping powers around the stopping-power maximum are presented for targets of Al, Si, Ti, Cu, Ag, Ta, Pt, and Au. The Low Energy Antiproton Ring antiproton beam of 5.9 MeV is degraded to 50–700 keV, and the energy loss is found by measuring the antiproton velocity before and after the target. Target thicknesses have been determined accurately by weighing and Rutherford backscattering techniques. The antiproton stopping powers are found to be reduced by around 35% for both light and heavy elements near the electronic stopping-power maximum as compared to the equivalent proton stopping power. The antiproton stopping powers and the Barkas effect; that is, the difference in stopping power between protons and antiprotons is compared to theoretical estimates, based on a harmonic-oscillator model and an electron-gas model, and good agreement is obtained.

Electron capture and ionization of 33-TeV Pb ions in gas targets

Krause, H. F., Vane, C. R., Datz, S., et al. — Thu, 01 Mar 2001 07:24:17 +0100

The total cross sections for electron capture and ionization of 33-TeV Pb ions in argon, krypton and xenon gas targets were measured. Electron capture from pair production dominates the total capture cross sections. The ionization cross sections from capture experiment (growth) and ionization experiment (decay) curves were compared. The results depicted the effective ionization cross sections in solid targets to be 25% larger than in gases for ionization experiment.

Månefeber

Nielsen, K. H. — Fri, 02 Feb 2024 07:24:17 +0100

Professorens prutter

Nielsen, K. H. — Fri, 16 Feb 2024 07:24:17 +0100

Scientific and philosophical publication

Wray, K. B. — Fri, 01 Mar 2024 07:24:17 +0100

Predictivism and avoidance of ad hoc-ness: an empirical study

Schindler, S. — Mon, 01 Jan 2024 07:24:17 +0100

Normal Science: not dogmatic or uncritical

Schindler, S. — Mon, 01 Jan 2024 07:24:17 +0100

Beyond Footnotes: Lakatos's meta-philosophy and the history of science

Schindler, S. — Mon, 01 Jan 2024 07:24:17 +0100

AI kan få forskningen ud af elfenbenstårnet – men også misinformere masserne

Fuglsang, S., Fage-Butler, A., Nielsen, K. H. — Thu, 18 Jan 2024 07:24:17 +0100

Uro i sindet

Nielsen, K. H. — Fri, 05 Jan 2024 07:24:17 +0100

En slagplan mod wokeness

Nielsen, K. H. — Fri, 12 Jan 2024 07:24:17 +0100

Editorial

Boschiero, L., Wray, K. B. — Sun, 01 Mar 2015 07:24:17 +0100

David Oldroyd 1936–2014

Boschiero, L., Wray, K. B. — Sun, 01 Mar 2015 07:24:17 +0100

Metascience

Boschiero, L., Wray, K. B. — Fri, 01 Jul 2016 07:24:17 +0200

Supporting the “metascientific” community

Boschiero, L., Wray, K. B. — Sun, 01 Nov 2015 07:24:18 +0100

Resisting Scientific Realism

Wray, K. B. — Mon, 01 Jan 2018 07:24:18 +0100

In this book K. Brad Wray provides a comprehensive survey of the arguments against scientific realism. In addition to presenting logical considerations that undermine the realists' inferences to the likely truth or approximate truth of our theories, he provides a thorough assessment of the evidence from the history of science. He also examines grounds for a defence of anti-realism, including an anti-realist explanation for the success of our current theories, an account of why false theories can be empirically successful, and an explanation for why we should expect radical changes of theory in the future. His arguments are supported and illustrated by cases from the history of science, including a sustained study of the Copernican Revolution, and a study of the revolution in early twentieth century chemistry, when chemists came to classify elements by their atomic number rather than by their atomic weight.

Suggesting reviewers affects outcome? [2] (multiple letters)

Ackerley, D. F., Wray, K. B. — Fri, 11 Nov 2005 07:24:18 +0100

Financial conflicts of interest worth knowing

Wray, K. B. — Fri, 01 Jan 2010 07:24:18 +0100

Cognitive aging data will take time

Wray, K. B. — Fri, 17 Jul 2009 07:24:18 +0200

The age-old question of researcher innovation [2]

Wray, K. B. — Fri, 07 Dec 2007 07:24:18 +0100

A look behind the curtain

Wray, K. B., Boschiero, L. — Tue, 01 Nov 2016 07:24:18 +0100

Evaluating Scientists

Wray, K. B. — Thu, 01 Jan 2009 07:24:18 +0100

This chapter examines a variety of contexts in which scientists evaluate their peers and the impact such evaluations have on science. Section 4.2 draws the distinction between implicit and explicit judgments of competence and give examples of each sort of judgment. Section 4.3 reviews a number of studies that suggest scientists are influenced by nonepistemic values when they make explicit judgments of competence. In particular, scientists are affected by sexism and nepotism. Section 4.4 examines the epistemic consequences of scientists' biased explicit judgments of competence and focus on the adverse effects of nepotism. Section 4.5 explains why scientists are not prone to the same problems when making implicit judgments of competence.

Middle-aged scientists are most potent

Wray, K. B. — Mon, 22 Nov 2004 07:24:18 +0100

Exciting days

Boschiero, L., Wray, K. B. — Wed, 01 Mar 2017 07:24:18 +0100

Metascience, 1 year later

Wray, K. B., Boschiero, L. — Tue, 01 Mar 2016 07:24:18 +0100

Older scientists get their due

Wray, K. B. — Fri, 21 Nov 2014 07:24:18 +0100

Introduction

Wray, K. B. — Fri, 01 Jan 2010 07:24:18 +0100

The literature on collective belief and collective intentionality has grown rapidly and is now quite extensive. Philosophers have applied the concepts of “collective belief” and “collective intentionality” in a variety of contexts, including political and legal contexts as well as scientific contexts, specifically to model the behavior of research teams and scientific specialties.

Why do team-authored papers get cited more? [4]

Wray, K. B. — Fri, 14 Sep 2007 07:24:18 +0200

Opprustningens onde spiraler

Nielsen, H., Andersen, C. — Tue, 02 Jan 2024 07:24:18 +0100

Supporting Sustainable Institutional Changes to Promote Citizen Science

Nielsen, K. H., Kragh, G. — Fri, 01 Dec 2023 07:24:18 +0100

This is a free course resource that was developed as a guide for designing your own course on the topics discussed. It includes resources such as detailed session/workshop outlines and PowerPoint slides. It could also be used as a course in itself, though was not specifically set up as such.

Artificial intelligence and identity: the rise of the statistical individual

Bjerring, J. C., Busch, J. — Thu, 11 Jan 2024 07:24:18 +0100

Book review: Public Relations and Neoliberalism: The Language Practices of Knowledge Formation

Nielsen, K. H. — Mon, 11 Dec 2023 07:24:18 +0100

D1.1 State of the art of Open and Responsible trainings

Lagido, C., Kragh, G., Nielsen, K. H. — Fri, 22 Dec 2023 07:24:18 +0100

D4.3: Final version of the Description of TIME4CS training programs

Nielsen, K. H., Kragh, G. — Thu, 21 Dec 2023 07:24:18 +0100

Engaging young people in science communication about mental health during COVID-19

Poulsen, S. H., Maindal, N., Oddershede, K., et al. — Mon, 22 Jan 2024 07:24:18 +0100

Many young people struggle with their mental health and the COVID-19 pandemic compounded these challenges. However, young people are rarely involved in research and communication about causes and coping strategies. We used an online game as a conversation starter and co-created a list of coping strategies with young people to apply the dialogue model of science communication and facilitate social conversation about mental health during COVID-19. The young people found the involvement was valuable as it led to self-reflection, social reflection with peers and an experience of recognition and contribution. We discuss challenges and urge researchers to explore ways for open dialogue and co-creation as strategic and contributing parts of the research process.

Publications - Publications

Adapting to change: transforming research libraries into catalysts for citizen science in a rapidly evolving world

Forskere mod abort

Problemet med Central Park

To the discerning reader: Galileo's philosophical comedy in a new translation

Single, double and triple ionization of Ne, Ar, Kr and Xe by 30-1000 keV p- impact

Experimental investigation of photon multiplicity and radiation cooling for 150 GeV electrons/positrons traversing diamond and Si crystals

Ionization in collisions between 30-1000 keV antiprotons and atomic hydrogen

Ionization of rare gases by particle-antiparticle impact

Ionization of atomic hydrogen by 30-1000 keV antiprotons

One and two electron processes in fast collisions between protons and hydrogen molecules

Measurement of the Barkas effect around the stopping-power maximum for light and heavy targets

Ionization of helium and molecular hydrogen by slow antiprotons

Non-dissociative single ionization of molecular hydrogen by electron and positron impact

Non-dissociative and dissociative ionization of O2 molecules by impact of 40-1000 keV antiprotons

Ionization and excitation of hydrogen molecules by fast proton impact

Direct measurements of the stopping power for antiprotons of light and heavy targets

Electron capture and ionization of 33-TeV Pb ions in gas targets

Månefeber

Professorens prutter

Scientific and philosophical publication

Predictivism and avoidance of ad hoc-ness: an empirical study

Normal Science: not dogmatic or uncritical

Beyond Footnotes: Lakatos's meta-philosophy and the history of science

AI kan få forskningen ud af elfenbenstårnet – men også misinformere masserne

Uro i sindet

En slagplan mod wokeness

Editorial

David Oldroyd 1936–2014

Metascience

Supporting the “metascientific” community

Resisting Scientific Realism

Suggesting reviewers affects outcome? [2] (multiple letters)

Financial conflicts of interest worth knowing

Cognitive aging data will take time

The age-old question of researcher innovation [2]

A look behind the curtain

Evaluating Scientists

Middle-aged scientists are most potent

Exciting days

Metascience, 1 year later

Older scientists get their due

Introduction

Why do team-authored papers get cited more? [4]

Opprust­ningens onde spiraler

Supporting Sustainable Institutional Changes to Promote Citizen Science

Artificial intelligence and identity: the rise of the statistical individual

Book review: Public Relations and Neoliberalism: The Language Practices of Knowledge Formation

D1.1 State of the art of Open and Responsible trainings

D4.3: Final version of the Description of TIME4CS training programs

Engaging young people in science communication about mental health during COVID-19

Single, double and triple ionization of Ne, Ar, Kr and Xe by 30-1000 keV p^- impact

Non-dissociative and dissociative ionization of O₂ molecules by impact of 40-1000 keV antiprotons

Opprustningens onde spiraler