A new parliament

I've been back at work from paternity leave for a week, and busy with marking and catching up on work bureaucracy, and my research group.  The big news hanging over everything has been the general election.  Ever since it was called several weeks ago I had supposed that it would not go well (for people of a progressive bent) since PM Johnson was leading the voices to call it and was doing so as he thought the timing was right to secure a Conservative victory, with the main opposition polling badly.  

And so it turned out to be. The campaigns proved to be rather dark and depressing.  In particular, things like the fake news being spread with absolutely no consequence, with the current Conservative Party (presumably led by the Machiavellian advisor Dominic Cummings) seemingly the worst offenders.  

This comes along with frightening anti-foreigner rhetoric with Johnson bemoaning that EU citizens in the UK had been treating it like their own home.  These are citizens who have come and made the country their home, and been welcomed.  

This, too, comes after Johnson threw moderate MPs out of his party, illegally suspended parliament, and made a series of ridiculous sloganistic promises he couldn't possibly deliver (I will deliver Brexit, do or die!) in the last parliament.  

The media have largely colluded with him, with attacks by the press on the judiciary, on parliament when it opposes the government.  This has all led, in my view, to a very extreme Conservative party, which has little bearing to Conservative parties of the recent past. God knows I was not much of a fan of those, but today's version has burnt up the rule book of even the pretence of fair play, and stoked up mass hatred and a them-and-us situation.  The word traitor is bandied about frequently.  Hacked Twitter posts threw doubt on a story of a boy sleeping on a floor in a hospital and BBC journalists hungrily lapped up the fake news, with inconsequential apologies after the damage was done.  Most reports begin "according to a government source" as the news media simply relays Cummings's proganda.

When Johnson first became PM, elected by the Conservative party then, not the general public, he announced without apparent irony that the mantra was to "Deliver Brexit, Unite the Country, and defeat Jeremy Corbyn". Clearly it is not possible to put as a top priority defeating the opposition while at the same time uniting the country, and he has been particualrly divisive.  Those Conservative MPs that sought to moderate him were simply expelled.  The Conservatives policies mean that the Brexit Party stood down candidates so as not to compete against them, and why not, when the Conservatives have absorbed much of what the Brexit party stand for.

So, today the results of the election are known and Boris Johnson remains our PM, and parliament reconvenes on Monday with a Conservative majority. 

The Conservative manifesto has been pretty light with promises (except the repeated mantra to Get Brexit Done), though they have promised to double research spending.   Of course, that is something that a research scientist might like the sound of, but so far I have only heard dismay amongst my colleagues about the election result, fearing that we all will pay a heavy price one way or another.  Of course, some of my colleagues, though not many, are right-leaning.  I don't know if they approve of the current form of the Conservative party or not... please comment below if so / not!

Johnson also specifically mentioned nuclear physicists when talking about who would be allowed to come into the country in future:   

He told Sky News: "People who, you know, are first violinists, nuclear physicists, prima ballerinas, whatever - they're going to come in, startup kings and queens, they're going to come in, simply by virtue of what they can contribute.

I don't suppose many nuclear physicists will want to come to Britain as entrepreneurs, but we'll see.

Well, that's my feelings today when everything appears darkest.  It will appear lightest to many, since after all this is what the vote of the population gave us.  Life will go on...

This is the Kit

This blog's quietude over the last month has been largely due to this being the time of year when my teaching and administrative duties are concentrated.  Not that this means I can't find the time to pass on some nuclear physics news, or more personal musings, via this blog, but I haven't done so.  Partly this is due to a kind of depression at the state of politics in the UK right now (which is a whole blog post in itself).  The other reason I've been preoccupied is trying to ensure I get everything I need to done before my son is born. It's not necessarily ever possible to "get everything done I need to" because there is always more stuff to do, but in any case, the arrival yesterday of a boy, Kit, means that I am going on paternity leave from Monday.  Here he is, being hugged by two of his his siblings, and with a bit of head support from mum:

Prize-winning 288 Bar and Wok

I often buy the Observer on Sundays and usually don't read the Food Monthly magazine on those weeks when it appears.  Yesterday, however, I did open it to enjoy reading about the prize given to 288 Bar and Wok in Cheltenham in Observer Food Monthly's awards, in the category "Best Cheap Eats".  The owners, Jody and Pak Wai Hung are friends of mine, dating back to school days, where I first met Jody.  We haven't been brilliant at keeping in touch (story of my life) but we stayed with them a couple of years ago when we were in Cheltenham and had a lovely couple of days with them and their family.  And lots of great food.

One of the other winners of an award (in the category of Best Food Personality) is Jamie Oliver.  I half-knew Jamie from school.  He was in the year below me, and I certainly knew who he was, but I can't claim that we were friends.  I knew his wife Jools a bit better, as she came to my school in the sixth form (like Jody did - it was a boys school up to sixth form) and was then in the same year as me.  

It's a funny coincidence for a so-so state comprehensive school in Essex that I doubt very many people have picked up on, that it produced two winners in this years Observer Food Monthly awards.  Anyway, congratulations to Jody, Pak Wai, and Jamie.

Fission in York

Just had a busy and productive three days in York, attending a workshop in which we (the attendees) boldly have been trying to hash out the remaining problems in the theory of nuclear fission.  It's one of the most complicated processes that nuclei undergo, so the remaining problems in terms of a fully microscopic quantum theory are more or less "everything".

We will be producing a white paper as a statement of where we see the future of the field in due course, with a deadline for producing something in just a couple of weeks away to make sure we don't let the discussions be forgotten.  I excused myself from leading the coordiantion of part I am most involved in as I will be on paternity leave at an unspecified (but soon) future date.

York is a lovely city, and I didn't get to see much of it this time.  The meeting was in the King's Manor, an old mansion in the centre of town that now belongs to the University of York, and I stayed very close, between there and the Minster, so I did get a little bit of vicarious tourism in.  The picture is of King's Manor.  

The lithium-beryllium wars, continued

In May I posted about a public spat playing out on the arXiv between one member of a (former) collaboration, M. Gai of UConn, and other members, led by D Schumann of PSI.

My previous post was prompted by a lengthy note submitted to the arXiv by Gai (1905.06999) in response to a brief note by Schumann et al. (1904.03023v1).  

Earlier this week Schumann et al. superseded their note with version 2 (1904.03023v2), which is a substantially different document, going in to detail with an analysis of the history of the project and where they contend there are scientific errors.  Alongside this is some general statements about scientific research (e.g "It  is  the  dream  of  every  serious  researcher  to  contribute  with something  essential to the progress in  his/her  field  of  science.") as prelude to a continuation of the personal argument against Gai in terms of appropriate scientific and collaborative behaviour – so we may well see a response from Gai in due course. 

I find it tempting to read all this stuff slightly hiding my eyes behind my fingers, to avoid seeing things that make me cringe too much.  In the concluding section, Schumann writes "We have also to admit, that, making the entire quarrel public by posting comments and reply to comments further and further on, is not the way one should handle friction in a collaboration. These problems should have been solved internally before publishing anything."   Well, quite.

Proceedings of the EFB conference - open refereeing is go

I'm enjoying my temporary role as guest editor of the proceedings of the European Few Body Conference that we organised here at Surrey last month.  Because we are publishing the proceedings in SciPostProceedings, using their open refereeing model, the submitted papers are there for anyone to comment on. 

I'm expecting most of the submissions to be made closer to the deadline, but if you want to, feel free to look at the following and make comments online:

• Roy Glauber and Asymptotic Diffraction Theory by Per Ostlund, is a mini review of one of Roy Glauber's achievements along with some biographical reminiscences.

• Properties of heavy mesons at finite temperature by Gloria Montaña, Angels Ramos, and Laura Tolos, describes the authors' effective hadronic theory as applied to heavy (charmed) mesons

• Study of deuteron-proton backward elastic scattering at intermediate energies by Nadezhda Ladygina discusses d-p elastic scattering using a relativistic multiple scattering framework, and

• A time-dependent Hartree-Fock study of triple-alpha dynamics by P. D. Stevenson and J. L. Willerton uses a mean field dynamic approach to study the fusion of helium to form carbon.

If you feel qualified to comment on any of these, please go ahead.  They are all sent to a nominated referee, too, but open refereeing means that anyone can contribute. 

 The picture attached to this post is from the first paper listed, and shows Roy Glauber (winner of 2005 Nobel Prize in Physics) from the collection of the author of the proceeding article, Per Ostlund, as featured in the article.

Dr Lennard-Jones

I was attending an appointment at the local hospital earlier this week, and one of the doctors present was called Dr Lennard-Jones.  I immediately thought of the Lennard-Jones potential, such a standard part of physics and chemistry that we teach it to our undergraduates, and named after Sir John Lennard-Jones (d.1954), who was a professor of physics at Bristol and Cambridge.

I wasn't sure if it was okay to ask if she (the doctor) was any relation, but during some small talk it came up what I did for a living, which was a way in for me to ask if she was any relation of the famous physicist.  The answer was yes, unsurprisingly (since presumably this particular combination of names has only been double-barrelled once).  If I remember what she said rightly, he was her great-grandfather.   She said it had been a while since anyone had asked and it was always nice when they did.  

I thought it was nice, too, to make that link, and to meet a real-life Lennard-Jones.  The picture is the famous 6-12 Lennard-Jones potential, courtesy of Wikipedia.

It was 20 years ago today...

More or less twenty years ago today (I can't remember the exact date) I finished writing, and submitted my D.Phil. dissertation.  I was a graduate student at the University of Oxford though I was working on a project co-supervised at Oak Ridge National Lab in Tennessee, and I spent most of the last year of my studies out there.  I had to be back in Oxford to submit the right kind of hard-bound copies in the right place at the right time, which I duly did.  

It was a busy month-long trip back to the UK:  After submitting my D.Phil. I had the viva exam, then I got married, went on honeymoon, and then went back to the US to start a postdoctoral position at the University of Tennessee in Knoxville.   It seems like such a long time ago.  I suppose it is a long time ago.  This week is freshers' week on campus here at the University of Surrey.  Most of the arriving students were born after the events described above. My youngest son is a toddler; no longer a baby, and increasing competent with language and reasoning.  He was born after the referendum on leaving the EU, and knows nothing of the halcyon time before the vote.  I wonder how old he will be by the time the situation is resolved.

Last night I came across an old photo of me from when I was a PhD student, and I attach it here.  This is probably about mid-way through, so more like 1997 than 1999, and shows me dressed in a Tennessee T-shirt in proper school colours.

Semi-empirical mass formula on the plane

I've just returned from a long trip away, to visit students on MPhys placement, attend a conference and discuss work with some people I am collaborating with (a phrase I still think of as meaning something sinister).  On the plane I watched a terrible film called Red Joan.  It sounded like it might be a decent enough spy thriller and Judy Dench's name lent it some respectability.  On-topic for me is that it featured someone (the eponymous hero, or antihero, Joan) who passed secrets about the UK's wartime and post-war atomic weapon secrets to the Russians.  There was one scene, supposedly dramatically showing people thinking about a physics problem, in which the camera focused on the pencil-and-paper working of one of the scientists, which showed the semi-empirical mass formula (see attached photo).  This is certainly something that was known in the late 40s, and the kind of thing that would have been used to give an idea of the energy release from nuclear fission, so credit to them for doing that research.  Given that I was on my way to a conference where I talked about the semi-empirical mass formula, it was a nice coincidence, and I took the photo of the screen on the back of the seat in front and used it in my talk, and here in this post.

HIAS conference photo

It's the last (half) day at the HIAS2019 conference today.  Just before the first session started (with some oldish results from RIKEN around the tin-132 isotope, they presented the obligatory group photo which was taken on Tuesday.  Here it is.  I'm in the back (as ever, being quite tall), wearing a blue hoodie, and a beard.  Next to me is ex-Surrey student Ed Simpson who laughed at me when I called my hoodie a "cardigan".  The photo can be clicked on to get a high resolution version.

HIAS-19

I'm in Canberra visiting some students on their MPhys Research Year placement, and also attending the HIAS-2019 conference (HIAS = Heavy-ion Accelerator Symposium).  The scientific topics cover any of the things that one can do at a heavy-ion accelerator which include the kind of reactions that I am interested in calculating, but also things like accelerator mass spectroscopy.  This is a very sensitive way of measuring the masses of individual isotopes in a sample of material.  One such application was presented by Dominik Koll who showed how to measure the abundance of Iron-60 which is a long-lived radioactive isotope generated in supernova explosions, and shot out into interstellar space, some of which then arrives on the Earth.  It turns out that it is currently raining down on Earth to the extent of a couple of atoms per square centimetre per year. 

European Few Body Conference

At The Univerity of Surrey we are hosting (and organising) the 24th European Few-Body Conference.  Its topics cross nuclear, atomic, and solid state physics;  any place where a many-body problem can be considered a few-body problem, with the resulting related set of mathematical techniques for solving them across the physics sub-fields.

Running a conference in ones own institution means competing with other day-job activities.  I have four MSc projects doing projects this summer who need meeting, and I only work on 4 weekdays, having a day with my children on Mondays.  So today is the first day I'll be able to attend all the sessions, and we've started with a talk on hyperons -- protons or neutrons in which one (or more) quarks have been replaced by strange quarks. 

On Monday, I thought I'd bring the kids along for the coffee break to see the conference.  They quite liked the lecture theatre chairs with the little desktops fitted into the armrests, though they do look a little bored in the picture I took that I've put in this post.  I'm presenting a poster tomorrow on the triple-alpha reaction -- work started by a BSc project student last year.

By the way; when I say above "we are [...] organising" I really mean that Natasha Timofeyuk is organising, and the rest of the committee are playing bit parts.  My bit is mainly sorting out the proceedings;  a job which is about to start getting busy, assuming anyone submits their papers.

The Thermal Syndicate Ltd

I'm on holiday this week in Deal, Kent, where I have been coming with my partner and kids, my brother's family, and my parents for the past few years for a week-long holiday in August.  We stat at a house belonging to a friend of my parents who is also a descendant of William Thomson, Lord Kelvin.  There's a lot of interesting reading matter in the house.  This year I've started with a history of a company called The Thermal Syndicate Ltd., erstwhile makers of fused quartz ware which was used for, amongst other things, chemical apparatus. 

The book was written for the company's 1956 50th Jubilee, and is clearly a corporate exercise, with no author mentioned.  It is a fairly sober retelling of the company's history.  It's sort-of interesting to read about how the company was founded, with a combination of money and connections being the key features.  The scientific aspects of it were interesting -- not just the techniques developed to make the very high-temperature-resistant glass, but also the scientific culture of the time married with the commercial aspects.  

The sober account of the company contains what pass for a couple of anecdotes, including an "imagined conversation" in local (Newcastle) dialect of the speculation of what took place in the Wallsend factory, as in the attached picture, which reads

   'Whaat d'them blokes dee at Waalsend Laboratories?

    They analiise things for Thormal Synnicate.

    What d' the Synnicate myek?

    They myek things for Waalsend Laboratories t' analiise!'

Aside from that, I also enjoyed some of the pictures of industrialists of Edwardian industrialists, which I have added at the top of this post.

Happy 100th Birthday Margaret Burbridge!

Today, 12th August 2019, is the 100th birthday of Margaret Burbridge.  She is a British-American astrophysicist who is jointly responsible for the idea that stars are giant nuclear fusion reactors.  This started the whole field of nuclear astrophysics, and is canonical enough to be taught to undergraduates.  In fact, we (at Surrey) have a degree programme called Physics with Nuclear Astrophysics, which we wouldn't have if not for Prof (emeritus) Burbridge.  Happy Birthday!

The picture is from the Wikipedia article about her, and shows her in 1976 winning a Woman of the Year award.

Thursday at #UNTF2019

#UNTF2019 continues today after yesterday's talks, poster session, and conference dinner, with two sessions in the morning, followed by the end of the conference and lunch.  Here's a summary of the first session's first two talks (with the third being designated for attendees-eyes only)

Toby Wright from Manchester started the morning with a comprehensive survey of all kinds of nuclear data being collected at the n_TOF (neutron time-of-flight) facility at CERN.  This includes things like neutron absorption cross sections and fission data, which provide useful input for applications - particularly nuclear reactors. Toby presented a lot of results of data, improving on older measurements and evaluations

The second talk had the title "Robots used to mitigate nuclear disasters", with a discussion of exactly that -- how robots can be made and used in nuclear disasters.  They need to be very radiation-resistant, for examples, which has consequences for the design.  Also, you can't go in and fix it if it has a small problem, so it has to be very reliable.  Ideally you'd like to communicate with it wirelessly, but nuclear reactors tend to be heavily shielded.  The environment (radiation aside) can be pretty hazardous; flooding, fallen masonry etc.  All-in-all, quite a challenge to the robot builder. We had
The talk covers robots used historically;  the "RadRobot", "RedBot", and "WorkHorse" used at Three Mile Island; At Chernobyl there is a museum dedicated to the robots used there, though full details of the ~60 robots used there have been lost.  The most succssful robot used there, "MoBot" was destroyed when a helicopter accidentally dropped it.  Some robots used, such as converted tanks and bulldozers, broke down very quickly due to the environmental hazards.   Some years after the initial disaster further more advanced robots were sent in to assess the continuing status of the ruined reactor;   The robots used at Three Mile Island and Chernobyl were built reactively after the disasters, while in Fukushima there were a number of robots built in advance to be used in case of problems (as well as to routinely monitor).  Unfortunately, they were not very usable in Fukushima because the robot projects had been defunded and the robots left in cupboards, lacking maintenance, and lacking expertise of the staff who had left or moved on to other projects.  Instead, "Packbots" and "Warrier" robots were bought off the shelf from the US and deployed.  They weren't radiation-hardened but were well-developed in other technological areas.  Many other robots were then deployed -- e.g. the "quince" which could go up stairs and over rubble, the "RaBot", a radiation-hardened robot which could handle very high radiation doses (10,000 Sv per hour).

The talk ended with a couple of robots designed for the future;  Honda's E2-DR and the Centauro from Italy.  We were treated to a video of the E2-DR which looks a little like it's trying to get back from a conference dinner after one too many drinks:

Conrerence photo from UNTF

Today, as #UNTF2019 continues, we had our conference photo.  Here it is.  If you click on it, it should come up larger. I'm the one nearest the top border of the image file.

Session 1 at #UNTF2019

It's a busy time conference-wise in the UK.  The week after next sees the world's largest periodic nuclear physics conference, INPC, taking place in Glasgow.  Next week I'll be at a conference organised here at Surrey on ab initio methods, designed to attract delegates attending INPC the following week.  That clashes with a workshop on octupole shapes in nuclei, taking place even more conveniently for INPC attendees, in Paisley.

This week there is a workshop at the University of York to celebrate the conferring of an honorary degree on Witek Nazarewicz, which would have been nice to attend, but I am staying in Surrey this week to attend our graduation ceremony (on Friday) and the Universities Nuclear Technology Forum (UNTF2019) today to Thursday.

The topics of #UNTF2019 cover a wide range of nuclear science and engineering, so I hope to learn a lot of things that are not so close to my own area.  

Here is a live-blog summary of the first session:

First up is Sam Bennett (Manchester) who has performed new measurements on the capture of neutrons on C–13 in order to help understand how the long-lived radioactive contaminant C–14 is generated in graphite-moderated reactors.  The cross section for this reaction has been measured a few times historically, going back around 60 years, but there is inconsistency in the data.  Sam's work uses a method different to the past measurements -- irradiating a sample of carbon and using atomic mass spectroscopy to anaylse the results.  He discussed in some detail how to counter the problem of N–14 contamination in the samples.   The conclusion:  Good agreement with the most recent calculation which has been taken as the adopted value.  

Second, Emma Braysher (Surrey/NPL), talks about the need to improve measurements of half-lives of long-lived isotopes for their use in things like radio-dating.  Surprising (to me) is that Uranium-238 has only had its mass measured once before (until very recently) and that the experimental uncertainty is a million years.  Emma talks about using mass spectroscopy to measure half-lives;  either one can use isotope dilution in which the isotope which one wants to measure is diluted with (preferably a stable) isotope of the same element as a reference and mass spectrometry is used to measure the ratio of the isotopes;  or one uses the in-growth method in which ones looks at the build-up over time of the daughter produces of the decay of the isotope in question.  The work presented showed the speaker's theoretical studied so far, with the experimental realisation the next stage in her project.

The third speaker is Rhiann Canavan (Surrey/NPL) who begins by asking what can be done with the large amount of U–238 waste from our standard nuclear reactors.  U–238 is not fissile, but is fertile so can be turned into a fissile material (in this case, isotopes of plutonium) by reaction with fast neutrons.  The fissile material can then be used as commercial fission reactor fuel.  The goal of Rhiann's work is to better understand the fast-breeding reactions which convert U–238 in to a fissile material and the resulting range of fission fragments.  In Orsay, near Paris, Rhiann and co-workers used an intense neutron source, LICORNE, to breed U–238 into fissile isotopes, and then a gamma-ray detector, NuBall, to look at the decay of the hot fission fragments.  A phenomenal amount of data is collected from the reactions, which then has to be painstakingly analysed, both for the fission decay products of interest, and also to avoid the background signal (e.g. from decay of germanium isotopes in the gamma-ray detector itself).  It's the first time I've seen a description of gamma-ray gating in spectroscopic analysis in terms of selecting coloured jelly-babies from a pile of sweets.

The final speaker is Thomas Fried (Lancaster).  As well as his affiliation to Lancaster Uni, Thomas works at Sellafield and is concerned with long-term decommissioning of the site.  This includes, in particular, older waste that has been processed for storage.  Some of it is known as "heat-generating sludge" and Thomas's project aims to develop a mechanism for assessing the properties (mechanical, thermodynamic) properties of the stored sludge.  The slide shows a schematic of the prototype mechanism.

I don't think I'll live-blog the whole thing, but I hope this gives you a flavour of the conference.  Next up: Coffee break :-D

Rutherford Medal Winner Prof Phil Walker

The Institute of Physics have just announced that the 2019 winner of their Rutherford Medal is Prof Phil Walker.  

Phil is an emeritus professor here at the University of Surrey who straddles the experimental–theoretical divide and specialises in understanding metastable isomeric states in nuclei;  excited states that decay much more slowly that you'd expect for such an excitation.  The full citation is on the IoP's new story, as linked above. 

Phil has been a good friend and colleague to me during my time at Surrey.  It was thanks to him that I got my first post-doctoral position here, joining the reaction-theory dominated theoretical group, though my specialty is in nuclear structure.  We have since worked together on various project together over the years, writing 14 co-authored papers together, which for me is one short of my record of 15 (with one of my two PhD co-supervisors, Irena Stone).  I've always found his way of thinking very clear, grasping the context of a problem and the bigger picture.  Hopefully I can up this figure of 14 with him.

My opinion may be biased, but I think his prize is very well deserved, and overdue. Cheers, Phil!

I attach to this post a rather blurry photo of Phil that I happen to have in my collection, from a meeting in Krakow a few years ago.

Publishing proceedings in SciPost

In September, we (the Surrey nuclear theory group) are hosting the 24th European Few-Body Physics Conference.  One of my main roles on the local organising committee is to arrange publication of the proceedings, and I'm pleased to have organised this with the journal SciPost Proceedings.  Unlike most (all?) of the other regular journal options, SciPost proceedings are free to publish in and free to read.  The costs involved in the whole publication process are pretty modest, being the web–hosting of the papers, and the provision of a doi for each paper.  All other tasks, such as managing and implementing the refereeing and editing process is done, as usual, free of charge by academics, who are paid a full time salary to be academics. 

Those low costs of running the journal are provided by sponsors, and I'm happy to see, from attending a presentation about Plan S last week, that the University of Surrey are sponsoring SciPost.  The amount paid by the University is minuscule compared to traditional journal subscription costs, and amounts to the cost of paying for a couple of Article Processing Charges to a regular journal.

I'm excited to go through the process of editing the proceedings (i say now, before the real work starts in earnest), and I'll report back here how it goes later in the year.

Advances in Time-Dependent Methods for Nuclear Structure and Dynamics

Together with some co-editors, I've started up a Research Topic in the journal Frontiers in Physics.  It's called Advances in Time-Dependent Methods for Nuclear Structure and Dynamics, which I hope is a reasonably self-descriptive title for the kinds of articles we are looking for for the special issue.  

There's a little picture of me on the topic web page among the list of editors.  Fame at last.  If you want to submit an original research article, a review, or a perspective piece on future research areas, please get in touch.  We (the other editors and me) hope it will be a thorough snapshot of time-dependent methods being used today in nuclear physics research.

Student placement in Beijing

Marko, at the entrance to the nuclear physics building

I'm heading home from my last trip of the season to visit students on their MPhys Research Year placement.  This time it's been to Beijing where we have a student, Marko, working on some calculations of nuclear fission.  He is being hosted by Peking University, working in the group of Junchen Pei.  Usually on these trips, I am visiting a student working in an area not exactly the same as my own.  In this case, Marko, together with Pei, is building on some work that I did with a PhD student a few years ago, and it's exciting for me to see this work being continued.  

I now have a relatively quiet summer (travel-wise, at least).  According to the rules for the MPhys Research Year, our students get visited twice by a member of academic staff, and I will make a second round of trips in September.

Visiting students in Canberra

This year, we (University of Surrey Physics Department) have sent two of our undergraduate masters students out to the Australian National University in Canberra for a paid work placement in the nuclear physics department.  In the last few days I've been visiting them to find out what they've been up to, to check on progress, conduct an assessment and to make sure everything is generally okay.

The two students are working on reaction mechanisms, trying to understand the process of fusion better, particularly as fusion processes compete with reaction mechanism that lead to the combined nucleus, formed when two nuclei react, not sticking together.  This is especially important in understanding the reactions that lead to making new superheavy elements, where the competing processes dominate.

I'm happy to report that the students are enjoying life in Canberra and at ANU in particular, and I've enjoyed learning about the work they are doing.  I should be back for a second visit in September, which will coincide with a workshop taking place here (HIAS 2019).

Last night, as part of the visit, I took the students and two of the supervisory team out to dinner.   From left to right in the picture we are Prof Mahananda Dasgupta, Dr Ed Simpson, Stefan Parker-Steele, Wiktoria Wojtaczka, and me, Dr Paul Stevenson.

Re-writing nuclear physics textbooks

Following a Summer School in Pisa in 2017 with the ambitious title "Re-writing Nuclear Physics textbooks: Basic Nuclear Interactions and Their Link to Nuclear Processes in the Cosmos and on Earth" the notes from the lecturers have been written up and published in a special collection (a "focus point", so they call it) across several issues of the EPJplus journal.  They are freely available until 20th July 2019 here.  Seems like a useful resource to point students at and, indeed, to read oneself.

The early-universe lithium-beryllium wars

There's a spat playing out on the nucl-ex (nuclear experimental) part of the arXiv preprint server.  I have no special knowledge of what's going on, but the timeline of the papers on arXiv is:

1. Moshe Gai of UConn sent a paper to the arXiv "The Interaction of Neutrons With 7Be: Lack of Standard Nuclear Physics Solution to the "Primordial 7Li Problem"."  The paper describes an experiment to look at the capture of neutrons by beryllium–7 nuclei at energies similar to the conditions of the early universe, in order to try to understand if this reaction can account for the disagreement between the observed amount of lithium–7 in the universe compared to models of the big bang in which the lightest few elements were formed.  The paper appeared on 24th Dec 2018 and in the submission comments, Prof Gai says

Talk presented on behalf of the SARAF US-Israel, Switzerland Collaboration at Nuclear Physics in Astrophysics (NPA8), 18-23 June 2017, Catania, Italy, that was reviewed by two referees and accepted for publication in NPA6, EPJA, 2017

So it appears to be a paper written for and accepted for a conference proceedings, but that did not appear in the proceedings.  The preprint gives results from the experiment in a summarised list, promising that a full paper is planned for publication.

2. On 3rd April 2019 Dorothea Schumann submitted at "Comment to "The Interaction of Neutrons With 7Be: Lack of Standard Nuclear Physics Solution to the Primordial 7Li Problem", published by M. Gai in arXiv 1812.09914v1".  Dr Schumann is one of the authors listed as being in the collaboration on behalf of which the original Gai paper was claimed to be written and the comment is also coauthored by 5 other members of the original collaboration list.  The comment says that "The Hebrew University PI of this collaboration has dissociated himself together with his team from this experiment and from the collaboration in Fall 2016" though which members of the list given by Gai are from the Hebrew University is not obvious.

Moreover, the comment goes on to say that Gai had no permission from the collaboration to publish the experimental data, and that the cross sections given by Gai as deduced from the experimental data are unreliable for reasons that Dr Schumann will provide "on request".   The comment finished with the strongly worded statement

We  consider  unauthorized  release  of  questionable  data  an  intolerable  damage  of  the  scientific reputation  of  the  collaborators  personally,  the  involved  research  institutions  in  general  and  the trustworthiness of published data in the entire scientific field. We fully dissociate ourselves from any scientific content published by M. Gai on the project “The Interaction of Neutrons With 7Be: Lack of Standard Nuclear Physics Solution to the Primordial 7Li Problem" and request the paper currently posted on arXiv immediately to be retracted.

3. Today (why I am now noticing the conversation) Prof. Gai has posted, on the arXiv, "Gai Reply to Comment by Schumann et al. [arXiv:1904.03023]".  This is quite lengthy, but the gist of it is given in the abstract:

Statements included   in   the   comment   published   by   Schumann et al.(arXiv:1904.03023) are contradicted by documents that were communicated to one of the co-authors of the comment (Dr. Koester). These documents are reviewed but cannot be disclosed here due to copyright (they are available on request). A summary of the scientific dispute between the collaboration and Dr. Schumann,was submitted on September 24, 2018, to the Directorate Support of the Paul Scherrer Institute (PSI) and can be provided on request.

Here the disagreement is characterised as being between Schumann and "the collaboration".  Gai goes on to elaborate on his side of the story, though clearly there is more information that the authors have not disclosed (and I have not taken them up on their request, since I don't imagine that I am exactly going to arbitrate on this), but it's rather unfortunate that it is playing out in the arXiv.

I suppose next that either there will be a response on the arXiv from Dr. Schumann or another co-author, or perhaps better, that the institutes involved will convene a panel, if they haven't already, to adjudicate.

[N.B. I've used the titles Prof for Gai as per his institution' website, and Dr for Schumann as for hers.  Apologies to either if that is an incorrect title.]

Well hello neptunium-220

The discovery has been announced, in Physical Review Letters (here, but paywalled) of a new isotope of element number 93, Neptunium (Np).  It's Np–220, with 93 protons and 127 neutrons.  

This isotope is a long way from the nearest stable isotope, as can be seen on this section of the nuclear chart, with proton number Z increasing along the vertical axis and neutron number N along the horizontal axis:

Np–220 is at the top left of the chart.  The stable isotopes are the black ones, with the nearest either involving losing many protons to go towards bismuth and lead, or to gain many neutrons to get towards the stable uranium isotopes. 

It's possible to make these very far-from-stability isotopes by reacting together two lighter nuclei, in which the stable isotopes tend to have a N:Z ratio which is close to that of Np–220.  The actual reaction used was to fuse argon–40 with rhenium–185, making a very excited Np–225 nucleus, and then looking for decays in which 5 neutrons are emitted. 

The experiments were performed in Lanzhou, China, and the resulting observation of alpha decay of Np–220 led to the conclusion that the extra stability conferred by the N=126 magic number survives into this far-from-stability region.

Thanks, as ever, to Ed Simpson, for providing the #1 online chart of the isotopes at http://people.physics.anu.edu.au/~ecs103/chart/index.php

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.

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!

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.
 

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.