Wednesday, 24 April 2019

My first video abstract

With my collaborator, Yoritaka Iwata, I have just published a paper in the New Journal Of Physics.  The paper is about conditions under which two nuclei can react in such a way that the final state of the reaction looks just like the initial state, despite a strong interaction taking place between all the nucleons involved.  If we're right, then our calculations might have implications for inert parts of stars' cores, or one day in nuclear fusion reaction.

This is the first time I've published in the New Journal of Physics.  They offer the possibility of having a video abstract with our paper, so I opened, probably for the first time, the iMovie software on my computer, made some animations, wrote a script and put it all together.  The final result is on the journal website.

Wednesday, 17 April 2019

Peter Butler FRS

The Royal Society has announced its newly-elected set of Fellows. There is a nuclear physicist amongst the cohort:  Prof. Peter Butler from the University of Liverpool has been made a fellow for his work on experimental nuclear physics.  In particular, they cite his work in reflection-asymmetric nuclei, and the leadership of prorgrammes at laboratories around the world such as at Jyväskylä and CERN.

Congratulations, Peter!

Thursday, 4 April 2019

Mathpix is pretty neat

Here's a neat piece of software I spotted via a re–tweet from @eddedmondson on Twitter:
It's called Mathpix and it lets you take screen captures of equations which it then turns into LaTeX code.  I thought I'd try it out with something quite stretching in the form of a slightly poorly scanned pdf of Max Planck's paper from 1900 Ueber das Gesetz der Energieverteilung im Normalspectrum.  Here is a screencap of the original equation:

As you can see, it's not perfectly scanned in, especially in the horizontal lines of the fractions.  Mathpix, though, did a fine job.  It said "We had trouble reading that.  Try zooming in for a better result." but the result was exactly right.  Its LaTeX result is

$E=\frac{8 \pi c h}{\lambda^{5}} \cdot \frac{1}{e^{\frac{c h}{k \lambda \vartheta}}-1}$

and its own graphical rendering comes out as

So pretty good really.

Wednesday, 3 April 2019

Welcome to O-11

The discovery of a new isotope was announced last week in Physical Review Letters (paper here, but it seems no open-access version exists, even on the arXiv).  Oxygen–11, aka 11O, has 8 protons (because it's oxygen) and 3 neutrons (to give it overall mass number 11).  That's a pretty extreme form of Oxygen, whose lightest stable isotope has 8 protons and 8 neutrons.

To make it, the experimenters from the NSCL (National Superconducting Cyclotron Laboratory at Michigan State University) started from a beam of stable oxygen–16 nuclei which they collided on a beryllium–9 (4 protons, 5 neutrons) target.  This bombarding produced a range of nuclei lighter than the oxygen–16 beam from which a magnetic separator was used to focus the oxygen–13 component of the debris into a secondary beam.  This was then sent to another beryllium–9 target.  Some of the reactions between the oxygen–13 and beryllium–9 nuclei caused two neutrons to be knocked out of the oxygen–13 to give oxygen–11.  Oxygen–11 quickly decays to carbon–9 (6 protons, 3 neutrons) and two protons.  These decay products were detected;  their coincident detection and the ability to reconstruct from the detection the properties of the parent oxygen–11 nuclei, repeated through thousands of events enabled the research team to confirm that indeed oxygen–11 had been produced.

Oxygen–11 is so unstable that it decays not by one of the three traditional radioactive decay mechanisms (alpha, beta, or gamma) but by losing two of its protons, and hence undergoing "two proton radioactivity".  This puts it on the borderline of actually existing as a nucleus at all.  The nucleus is so short-lived and unstable that it does not have a well-defined mass (or equivalently its ground state is not a stationary state of the nuclear Hamiltonian).  The experimental values of the observed mass of 11O is seen to have a spread of values ranging over about 3 MeV/c2.

The picture above is taken from Ed Simpson's excellent Colourful Nuclear Chart.  It currently has a blank space where oxygen–11 will no doubt soon go, just above nitrogen–10, and to the left of oxygen–12.  The black tramlines in the plot show the so–called magic numbers which are numbers of protons and/or neutrons which confer extra stability to the nucleus.  These cross each other at oxygen–10.  I doubt if oxygen–10 will really turn out to be noticeably stable compared to its neighbours.  There is already enough evidence that the magic numbers don't apply in light nuclei so far from stability.  I wonder if the odd stray oxygen–10 nucleus was made in the experiment at NSCL, in too little a quantity to get a good measurement of.

Tuesday, 2 April 2019

Nuclear Physics Meetings in 2020

 Bormio: Location of meetings in Jan and Feb 2020
Here is a post, which I will add to over the next 18 months or so, listing (mostly low-energy) nuclear physics meetings taking place in 2020 that I hear about.  Feel free to contact me or comment below with details of any that you think should be added

20/01–24/01: 58th Winter Meeting on Nuclear Physics, Bormio, Italy
It's blurb calls it a long-standing conference, and indeed at #58, it may hold a record for the most-held nuclear physics meeting.  The remit is very broad, including what might once have been called nuclear physics, but is now particle physics.  It is preceded by a one-day pre-conference school for students, covering the basics of the main physics areas dealt with in the conference.

Bormio is in the Italian Alps, and I understand that there is ample time in the programme for leisure activities, such as skiing. [website]

20/01–24/01: XIII LANSPA: Latin-American Symposium on Nuclear Physics and Applications, San José, Costa Rica
Aimed as a forum for groups in Latin America to share their research, the conference is nevertheless advertised more widely and open to anyone to attend.  [website]

04/02–09/02: Vth Topical Workshop on Modern Aspects in Nuclear Structure, Bormio Italy
Subtitled "The many facets of nuclear structure" this workshop's aim is to explore topical issues in nuclear structure, bringing experimental and theoretical collaborators together.  It's part of a series taking place every two years.  This year, the meeting is preceeded by a one-day satellite meeting on 03/02 on Beta-decay studies: present and future campaigns [website]

24/02–28/02: Conference on Neutrino and Nuclear Physics (CNNP), Cape Town, South Africa
A conference for those working on the interaction between neutrinos and nuclei, whether it be for beta decay, reactor neutrino studies, dark matter searches, solar and supernova modelling and detector technologies.  Or anything else closely related.  This is the followup to a first CNNP meeting held in Catania in 2017 [website]

06/04–09/04: IoP Nuclear Physics Conferene, Edinburgh, Scotland
The annual UK Institute of Physics Nuclear Physics conference.  Date announced, and further details to come, presumably.  Update (Feb 2020): full details on [website]. Update CANCELLED DUE TO COVID-19

15/05–22/05: 13th International Spring Seminar on Nuclear Physics Perspectives and Challenges in Nuclear Structure after 70 Years of Shell Model, Ischia, Italy
A meeting organised by the theory group at the University of Naples, hosted on the island of Ischia.  The topics are fairly broad, covering anything in low-energy nuclear structure.  Should be good, and a lovely setting.  [website]

20/05-22/05: 2020 JINA-CEE Frontiers in Nuclear Astrophysics Conference, South Bend, IN, USA
A save-the-date announcement has gone out (as of Dec 2019) about this conference, with more details to follow.  Update (Feb 2020): here is the [website] Update POSTPONED DUE TO COVID-19

01/06–05/06: Nuclear Photonics 2020, Kurashiki, Japan
A conference on the emerging field of direct interaction and manipulation of nuclei with photons, coming about thanks to the new experimental sources of high-intensity lasers and monochromatic gamma rays.  [website] Update POSTPONED UNTIL 7-11/06/2021 DUE TO COVID-19

11/06–15/06: IWND2020: International Workshop on Nuclear Dynamics in Heavy-Ion Reactions, Zhuhai, China
A recurring workshop on what one learns from heavy-ion reactions.  Though an International workshop, it is China-based, focussing heavily on the research that takes place there.  [website]

14/06–19/06: ARIS 2020, Avignon, France
ARIS stands for Advances on Radioactive Isotope Science (sic), and the conference series grew out of a combination of the earlier ENAM (Exotic Nuclei and Atomic Masses, I think) and RNB (Radioactive Nuclear Beams) conferences.  It's quite a general, large conference for work coming out of radioactive beam facilities -- i.e. most of the big nuclear physics labs.  [website]  Update: Postponed to 05/09–10/09

29/06–03/07: DREB2020: Direct Reactions with Exotic Beams, Santiago de Compostella, Spain
A save-the-date email has been sent out for the latest in the series of DREB conferences.  The first circular, with more details, has been promised in Sep 2019:  Update (Feb 2020); here is the full [website]

22/06–26/06: CLUSTER'20: 12th International Conference on Clustering Aspects of Nuclear Structure and Dynamics, Dubna, Russia
For all things to do with the formation and existence of larger-than-nucleon substructures inside a nucleus.  I have recently done some work on reactions leading to the Hoyle state, which can be described as a three-alpha cluster (see here) so may just find myself going along to this.  Dubna is a nice place, though getting a Russian visa is a bit irksome. [website]

29/06–04/07: 10th Intl. Workshop on Quantum Phase Transitions in Nuclei and Many-body Systems, Dubrovnik, Croatia
"Quantum phase transitions" here means things like the change in shape or some other bulk property of a nucleus as a function of the number of particles with the emphasis being on the interpretation of such phenomena with the language and mathematics of phase transitions.  I enjoyed going to a couple of the earlier outings in this series, but don't really feel connected enough to the field to justify attending any more, interesting though it would be [website] Update POSTPONED DUE TO COVID-19

05/07–11/07: IWNT39-2020: 39th International Workshop on Nuclear Theory, Rila Mountains, Bulgaria
A venerable annual meeting organised by the nuclear theory group in Sofia.  I've been to a few of these in the past and have always enjoyed them for the rather relaxed environment with plenty of opportunity for discussion.  A nice way to end the academic year with a visit here [website]

06/07-10/07: EXON-2020: International Symposium on Exotic Nuclei, St Petersburg, Russia
A conference on the production and study of the most exotic, far-from-stability nuclei across the period table from lightest to heaviest.  Co-organised by labs around the world (JINR, RIKEN, GANIL, NSCL, GSI) [website]

26/07–31/07: Nuclear Structure 2020, Santa Cruz, CA, USA
Part of a series of conferences on nuclear structure run by US national labs.  One of the first conferences I attended was one of these, organised by Oak Ridge National Lab in Tennessee when I worked there.  This one is organised by Lawrence Berkeley National Lab,  and held in Santa Cruz, a little south of the San Francisco bay area.  [website]

19/08–23/08: APFB2020; Yamada Conference LXXII: The 8th Asia-Pacific Conference on Few-Body Problems in Physics, Kanazawa, Japan
This one was advertised to me at the European Few Body conference that I helped organise.  I'm not typically a few-body person (more many-body) so my chance of going to this one are slim, unless the organisers get particularly wowed by the conference proceeding I produced for the European Few Body conference on the triple-alpha reaction [website]

30/08–06/09: 55th Zakopane Conference on Nuclear Physics, Zakopane, Poland
A regular conference taking place in Poland.  The official theme is "extremes of the nuclear landscape" though it's really rather a general conference with talks covering a snapshot of current research in nuclear physics.  I have never been to a Zakopane conference but I understand them to be enjoyable events, with good discussions of physics, and networking in a really nice-sized event (in a nice location, too).  The circulars for this have come out when much of Europe is locked down due to the Covid-19 virus and they are currently (March 2020) planning to go ahead with organizing the conference [website]

31/08–04/09: CGS17: 17th International Symposium on Capture Gamma-Ray Spectroscopy and Related Topics, Grenoble, France
Capture gamma-ray spectroscopy marries capture reactions, in which a nucleus captures a projectile, with gamma ray spectroscopy to study the decay of the resulting compound system.  This is a venerable series, dating back to the 1960s.  Still an active area of research -- perhaps even more so than when it started thanks to the advent of radioactive ion beams [website]

31/08–04/09: PANIC 2020: Particles and Nuclei International Conference 2020, Lisbon, Portugal
A major conference taking place every three years which explores the interface between nuclear and particle physics.  It covers a wide range of topics, from dark matter and cosmology, to applications of nuclear and particle physics technology, with everything experimental and theoretical inbetween.  [website]

08/09–12/09:  7th IEA International workshop Clustering aspects in nuclei and reactions, São Paulo, Brazil
A workshop dedicated to the memory of Mahir Hussein, who died in 2019. [website]

13/09–19/09: Applied Nuclear Physics Conference 2020, Prague, Czechia
A new conference series being set up under the aegis of the European Physical Society Nuclear Physics Division.  As per the title, the conference covers applications of nuclear physics, with a stated particular emphasis on "energy, health, space, security, environment, material science, preservation and study of cultural heritage". Abstract submission opening in December 2019 [website]

02/11-06/09: Shapes and Symmetries in Nuclei, Gif-sur-Yvette, France
A conference on experimental and theoretical work to determine the underlying shapes of nuclei and the symmetries that give rise to them.  Part of a series, always held at Gif-sur-Yvette.  I've not been to these before but it might be a good place to highlight my work on shape-induced mixing of giant resonances that I've been working on inspired by some experimental work from Osaka [website]

15/11–20/11: FUSION20, Shizuoka, Japan
A conference on heavy-ion fusion at energies near the Coulomb barrier.  This topic is a mainstay of my research activities, so I expect to attend this one (as I did the previous outing of the conference in Hobart) [website]

24/11–27/11: International Worshop on Multi-facets of EOS and Clustering, Caen, France
An interesting slew of topics that are not often given co-prominence in a workshop (though of course all aspects of nuclear physics are part of a unified whole): "IWM-EC 2020 will focus on open questions in the domain of nuclear dynamics and thermodynamics, clustering phenomena and also the links between the nuclear Equation of state and Astrophysics." [website]