Leslie Hodson: Particle physicist and pioneer in the study of cosmic rays

Leslie Hodson was an experimental particle physicist who developed cloud- and spark-chamber techniques in the study of cosmic rays.

Yet despite his achievements in the field, he believed that the most useful thing he did was prevent asbestos from being used in the construction of the new campus at Leeds University in the 1960s.

Albert Leslie Hodson was born an only child in 1925 to tenant farmer parents at Fishlake, north-east of Doncaster. He first attended Fishlake Endowed School, a two-room school where children of all levels were taught together. He failed his 11-plus but despite this, his father found him a place at Thorne grammar school, at a cost of three guineas a term, and his parents managed to scrimp enough to pay for it.

In 1943, Hodson's higher school certificate results were good enough for a county scholarship. He decided to study physics at Manchester University, having heard from a cousin that Professor P.M. Blackett was working there. Leslie had never heard of Blackett, but what had impressed his cousin was good enough for him. After two years he was recruited to the Royal Aircraft Establishment at Farnborough, but the week he was due to report he developed mumps. The war ended, and instead of going to Farnborough he completed his third year at Manchester.

During this year he devised his own project on the optics of sodium vapour using equipment of his own construction. Blackett immediately offered him a PhD researching cosmic rays.

He studied altitude effects in cosmic ray air-showers. This involved building his own instruments, including making Geiger counters from glass tubing and fitting them into bomb casing. This instrument package was loaded into the bomb bay of a Mosquito and flown to over 30,000ft. The solution to a problem in the use of Geiger tubes led to his first scientific paper at only 23.

The mainstay of Blackett's cosmic-ray research was the cloud chamber. He had received the Nobel Prize in 1948 for his work on triggering chambers using external Geiger counters and the subsequent discovery of the positron. In a flash of inspiration, Hodson realised that the trigger could be generated from the gas within the chamber itself. Despite others' doubts, he persuaded Blackett to support him. He also built the electronics to control the chamber, secretly automatically, out of hours, hiding his prototype from Blackett under a cover and only revealing it when it was fully working. As a result, Manchester appointed him assistant lecturer.

In 1951 he became a research associate at Princeton. The Princeton cosmic-ray group was running cloud chambers at Echo Lake in the Rockies at an altitude of 3,230m. They were studying the so-called V-particles, recently discovered at Manchester. All the images were photographed and, on the last reel of film they discovered a new particle, now known as the K+, one of the kaons. Their measurement of the particle's rest mass was within two per cent of the currently accepted figure.

Hodson returned to Britain in 1954 to take up a lectureship at Leeds University. He designed and built the world's largest cloud chamber, having taught himself the required skills, and made deft use of local industry in its construction.

The mid-Sixties were a period of expansion in the universities, and Leeds had chosen Chamberlin, Powell and Bon to design a new campus. Leslie worked with them, providing a link between the architectural vision and the scientists and educators who were to use the buildings. The design called for asbestos cement panels as duct covers; Hodson had read in the scientific press that asbestos was hazardous and fought against its use. The University banned the use of asbestos in all future buildings, probably the first time this was done in Britain.

By the end of the 1960s the physics department was installed in its elegant modernist buildings and Hodson could turn once again to research. The quark model had been proposed by Murray Gell-Mann and George Zweig in 1964 and physicists were looking for evidence of them. Using the Leeds cloud chamber, he and his team searched for free quarks in the cores of cosmic ray air-showers. Quarks were predicted to have one-third or two-thirds the charge of an electron and this would give rise to one-ninth or four-ninths the ionisation along their path. This would be clearly visible by the thickness of the tracks produced in a cloud chamber. However, the cores of cosmic ray air-showers have vast numbers of particle tracks, all of which had to be examined in detail. It was painstaking work and at the end of it Hodson and his team came to the conclusion that there was no evidence that free quarks existed.

The visual and photographic techniques Hodson used were labour-intensive and expensive; towards the end of his career this became a seriously limiting factor. Recent experiments replaced the cameras with electronic techniques using charge read-out from vast numbers of wires and strips. However, now in an era where high-resolution digital photography is cheap and the computer power to process it ubiquitous, a return to visual and photographic techniques offers simplicity and elegance, and a further reduction in cost.

Hodson was a Methodist and a teetotaller. He had a huge range of interests, including philosophy, genealogy, planning, architecture, music, education and modern art. He was a founder member of his local residents' association and fought inappropriate developments. He was also a keen gardener, winning prizes at his local horticultural society for fruit and vegetables, including greenhouse-grown peaches.

John McMillan

Albert Leslie Hodson, scientist: born Fishlake, South Yorkshire 15 July 1925; married 1958 Joyce Wicks (three sons); died Leeds 1 March 2010.

Start your day with The Independent, sign up for daily news emails
Latest stories from i100
Have you tried new the Independent Digital Edition apps?
Independent Dating

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

iJobs Job Widget
iJobs General

Recruitment Genius: Senior Environmental Adviser - Maternity Cover

£37040 - £43600 per annum: Recruitment Genius: The UK's export credit agency a...

Recruitment Genius: CBM & Lubrication Technician

£25000 - £27500 per annum: Recruitment Genius: This company provides a compreh...

Recruitment Genius: Care Worker - Residential Emergency Service

£16800 - £19500 per annum: Recruitment Genius: Would you like to join an organ...

Recruitment Genius: Senior Landscaper

£25000 - £28000 per annum: Recruitment Genius: In the last five years this com...

Day In a Page

The long walk west: they fled war in Syria, only to get held up in Hungary – now hundreds of refugees have set off on foot for Austria

They fled war in Syria...

...only to get stuck and sidetracked in Hungary
From The Prisoner to Mad Men, elaborate title sequences are one of the keys to a great TV series

Title sequences: From The Prisoner to Mad Men

Elaborate title sequences are one of the keys to a great TV series. But why does the art form have such a chequered history?
Giorgio Armani Beauty's fabric-inspired foundations: Get back to basics this autumn

Giorgio Armani Beauty's foundations

Sumptuous fabrics meet luscious cosmetics for this elegant look
From stowaways to Operation Stack: Life in a transcontinental lorry cab

Life from the inside of a trucker's cab

From stowaways to Operation Stack, it's a challenging time to be a trucker heading to and from the Continent
Kelis interview: The songwriter and sauce-maker on cooking for Pharrell and crying over potatoes

Kelis interview

The singer and sauce-maker on cooking for Pharrell
Refugee crisis: David Cameron lowered the flag for the dead king of Saudi Arabia - will he do the same honour for little Aylan Kurdi?

Cameron lowered the flag for the dead king of Saudi Arabia...

But will he do the same honour for little Aylan Kurdi, asks Robert Fisk
Our leaders lack courage in this refugee crisis. We are shamed by our European neighbours

Our leaders lack courage in this refugee crisis. We are shamed by our European neighbours

Humanity must be at the heart of politics, says Jeremy Corbyn
Joe Biden's 'tease tour': Could the US Vice-President be testing the water for a presidential run?

Joe Biden's 'tease tour'

Could the US Vice-President be testing the water for a presidential run?
Britain's 24-hour culture: With the 'leisured society' a distant dream we're working longer and less regular hours than ever

Britain's 24-hour culture

With the 'leisured society' a distant dream we're working longer and less regular hours than ever
Diplomacy board game: Treachery is the way to win - which makes it just like the real thing

The addictive nature of Diplomacy

Bullying, betrayal, aggression – it may be just a board game, but the family that plays Diplomacy may never look at each other in the same way again
Lady Chatterley's Lover: Racy underwear for fans of DH Lawrence's equally racy tome

Fashion: Ooh, Lady Chatterley!

Take inspiration from DH Lawrence's racy tome with equally racy underwear
8 best children's clocks

Tick-tock: 8 best children's clocks

Whether you’re teaching them to tell the time or putting the finishing touches to a nursery, there’s a ticker for that
Charlie Austin: Queens Park Rangers striker says ‘If the move is not right, I’m not going’

Charlie Austin: ‘If the move is not right, I’m not going’

After hitting 18 goals in the Premier League last season, the QPR striker was the great non-deal of transfer deadline day. But he says he'd preferred another shot at promotion
Isis profits from destruction of antiquities by selling relics to dealers - and then blowing up the buildings they come from to conceal the evidence of looting

How Isis profits from destruction of antiquities

Robert Fisk on the terrorist group's manipulation of the market to increase the price of artefacts
Labour leadership: Andy Burnham urges Jeremy Corbyn voters to think again in last-minute plea

'If we lose touch we’ll end up with two decades of the Tories'

In an exclusive interview, Andy Burnham urges Jeremy Corbyn voters to think again in last-minute plea