OBITUARY: Isobel Powell

Isobel Powell was responsible for identifying one of the double mesons (subatomic particles) which led to the award of the 1950 Nobel Prize for Physics to her husband Cecil Powell. She was closely involved with her husband's work throughout his distinguished career at Bristol University and his work with the Pugwash organisation.

She was born Isobel Artner in Hamburg in 1907. Her mother was the daughter of a Scottish minister from Dornoch, on the north-east Scottish coast, and her father was an Austrian Jew. She was brought up chiefly in Vienna, but spent three years with friends in Denmark - she maintained an interest in languages all her life.

In her early twenties Isobel went to Paris, where she worked for a time as the composer Sergei Prokofiev's secretary - Peter and the Wolf was later a favourite record in her household. Through a mutual friend, Max Delbruck, she met Cecil Powell. Delbruck was a Research Fellow at Bristol University, sharing rooms with Powell, then a Research Assistant. In 1932 Isobel came to Bristol to be married to Cecil; shortly afterwards she started work in the Physics Department as his secretary and later, in addition, as a microscope observer or scanner. Remarkably, both Powell and Delbruck were, in due course, awarded Nobel Prizes for their work, Powell the prize for Physics in 1950, Delbruck that for Medicine and Physiology in 1969.

At Bristol, Cecil Powell with his chief collaborator G.P.S. Occhialini transformed the use of photographic emulsions for recording the tracks of subatomic particles into a powerful new technique. From the track of the particle one could, in favourable cases, determine both its energy and its mass - and see its behaviour. At that time Isobel Powell was a member of a small group of microscope observers employed to scan the processed emulsion plates that had been exposed either to the Cosmic Radiation at Mountain Observatories (for example, at Pic-du-Midi, and Jungfraujoch), or to laboratory sources of particles. These emulsions were mounted on glass plates and the task of the scanners was to search the whole plate area and thickness under a magnification of about 100 times, to locate and record tracks for further measurement by physicists.

The discovery of the p-meson in 1946, using the new technique, was a milestone for Bristol physics and the university. The parent p-meson comes to rest within the emulsion and gives rise to a second meson, always with the same energy and track length; careful measurement showed the parent to be a new particle and the daughter to be a m-meson, a particle whose existence was already known. The first two of these double mesons were decisive in their information, and Isobel found one of these in the course of her scanning. For his work Cecil Powell was awarded the Nobel Prize for Physics in 1950. Isobel Powell recorded in her diary of the award in Stockholm, "It was a very curious sensation when you suddenly see yourself on the screen. It was the first time that television had been used in Sweden for the Nobel Prize-giving ceremony."

After the p-meson discovery, there was a rapid growth in the size of the team at Bristol; the number of scanners rose to more than 20, many of them straight from school, and as chief scanner Isobel Powell was in charge of the team known affectionately as "Cecil's Beauty Chorus". There was a large throughput of postgraduates and scientists of many nationalities who came to join the exciting research. Morale was very high, and work continued at a great pace for many years.

Isobel also strongly supported the second strand of Cecil Powell's scientific career - his involvement with Joseph Rotblat in the politics of science. Powell was a scientific adviser to Bertrand Russell in his attempts, with Albert Einstein, to influence nuclear powers to consider the serious issues arising from modern weapon systems, and was one of the 11 signatories of the Russell- Einstein manifesto of 1955. These efforts became focused in 1957 in the Pugwash Organisation, with Powell as Deputy Chairman, and Rotblat as Secretary. Pugwash acted as a gadfly to prod governments into action in the Cold War period. After Russell's death in 1967, Cecil Powell was elected Chairman, a post he held briefly until his death in 1969. Just a few weeks ago it was announced that Joseph Rotblat and the Pugwash Organisation were to share the 1995 Nobel Peace Prize for their 40-year-long efforts. Cecil and Isobel Powell would have been very pleased.

After Cecil's death, Isobel Powell stayed in Bristol, and maintained her connections with the university. She continued her interest in languages, and took a diploma in Spanish. For as long as possible, she continued her weekly involvement with the university "Wives' International Group", which helped the families of overseas students and staff - she could speak to nearly all in their own home tongue. In 1987 there was a celebration of "Forty Years of Particle Physics" held in Bristol, attended by many from all over the world. Isobel much enjoyed meeting old friends.

Peter Fowler

Isobel Therese Artner, microscope scanner: born Hamburg 12 September 1907; married 1932 Cecil Powell (died 1969; two daughters); died 15 October 1995.

Latest stories from i100
Have you tried new the Independent Digital Edition apps?
Independent Dating
and  

By clicking 'Search' you
are agreeing to our
Terms of Use.

iJobs Job Widget
iJobs People

Project Manager (HR)- Bristol - Upto £400 p/day

£350 - £400 per annum + competitive: Orgtel: Project Manager (specializing in ...

HR Business Partner (Maternity Cover 12 Months)

£30000 - £34000 Per Annum 25 days holiday, Private healthcare: Clearwater Peop...

Project Manager (Procurement & Human Resources)

Unpaid: Cancer Research UK: If you’re a professional in project management, lo...

Geography Teacher

£85 - £140 per day: Randstad Education Cheshire: We require a teacher of Geogr...

Day In a Page

Dress the Gaza situation up all you like, but the truth hurts

Robert Fisk on Gaza conflict

Dress the situation up all you like, but the truth hurts
Save the tiger: Tiger, tiger burning less brightly as numbers plummet

Tiger, tiger burning less brightly

When William Blake wrote his famous poem there were probably more than 100,000 tigers in the wild. These days they probably number around 3,200
5 News's Andy Bell retraces his grandfather's steps on the First World War battlefields

In grandfather's footsteps

5 News's political editor Andy Bell only knows his grandfather from the compelling diary he kept during WWI. But when he returned to the killing fields where Edwin Vaughan suffered so much, his ancestor came to life
Lifestyle guru Martha Stewart reveals she has flying robot ... to take photos of her farm

Martha Stewart has flying robot

The lifestyle guru used the drone to get a bird's eye view her 153-acre farm in Bedford, New York
Former Labour minister Meg Hillier has demanded 'pootling lanes' for women cyclists

Do women cyclists need 'pootling lanes'?

Simon Usborne (who's more of a hurtler) explains why winning the space race is key to happy riding
A tale of two presidents: George W Bush downs his paintbrush to pen father’s life story

A tale of two presidents

George W Bush downs his paintbrush to pen father’s life story
Restaurateur Mitch Tonks has given the Great Western Pullman dining car a makeover

The dining car makes a comeback

Restaurateur Mitch Tonks has given the Great Western Pullman dining car a makeover
Gallery rage: How are institutions tackling the discomfort of overcrowding this summer?

Gallery rage

How are institutions tackling the discomfort of overcrowding this summer?
Louis van Gaal has £500,000 video surveillance system installed to monitor Manchester United players

Eye on the prize

Louis van Gaal has £500,000 video surveillance system installed to monitor Manchester United players
Women's rugby: Tamara Taylor adds fuel to the ire in quest to land World Cup

Women's rugby

Tamara Taylor adds fuel to the ire in quest to land World Cup
Save the tiger: The day America’s love of backyard tigers led to a horrific bloodbath

The day America’s love of backyard tigers led to a horrific bloodbath

With only six per cent of the US population of these amazing big cats held in zoos, the Zanesville incident in 2011 was inevitable
Samuel Beckett's biographer reveals secrets of the writer's time as a French Resistance spy

How Samuel Beckett became a French Resistance spy

As this year's Samuel Beckett festival opens in Enniskillen, James Knowlson, recalls how the Irish writer risked his life for liberty and narrowly escaped capture by the Gestapo
We will remember them: relatives still honour those who fought in the Great War

We will remember them

Relatives still honour those who fought in the Great War
Star Wars Episode VII is being shot on film - and now Kodak is launching a last-ditch bid to keep celluloid alive

Kodak's last-ditch bid to keep celluloid alive

Director J J Abrams and a few digital refuseniks shoot movies on film. Simon Usborne wonders what the fuss is about
Once stilted and melodramatic, Hollywood is giving acting in video games a makeover

Acting in video games gets a makeover

David Crookes meets two of the genre's most popular voices