William Henry Bragg

Sir William Henry Bragg OM KBE PRS[1] (2 July 1862 – 12 March 1942) was a British physicist, chemist, mathematician, and active sportsman who uniquely[2] shared a Nobel Prize with his son Lawrence Bragg – the 1915 Nobel Prize in Physics: "for their services in the analysis of crystal structure by means of X-rays".[3] The mineral Braggite is named after him and his son. He was knighted in 1920.

Sir William Henry Bragg

William Henry Bragg Nobel bw
Born2 July 1862
Wigton, Cumberland, United Kingdom
Died12 March 1942 (aged 79)
London, United Kingdom
ResidenceEngland
NationalityBritish
Alma materTrinity College, Cambridge
Known forX-ray diffraction
Bragg peak
AwardsNobel Prize in Physics (1915)
Barnard Medal (1915)
Matteucci Medal (1915)
Rumford Medal (1916)
Copley Medal (1930)
Faraday Medal (1936)
John J. Carty Award (1939)
Scientific career
FieldsPhysics
InstitutionsUniversity of Adelaide
University of Leeds
University College London
Royal Institution
Academic advisorsJ. J. Thomson
Notable studentsW. L. Bragg
Kathleen Lonsdale
William Thomas Astbury
John Desmond Bernal
John Burton Cleland
Notes
He is the father of Lawrence Bragg. Father and son jointly won the Nobel Prize.

Biography

Market Harborough Grammar School
The Old Grammar School, Market Harborough, which has a plaque inside noting Bragg's attendance.

Early years

Bragg was born at Westward, England, near Wigton, Cumberland, the son of Robert John Bragg, a merchant marine officer and farmer, and his wife Mary née Wood, a clergyman's daughter. When Bragg was seven years old, his mother died, and he was raised by his uncle, also named William Bragg, at Market Harborough, Leicestershire. He was educated at the Grammar School there, at King William's College on the Isle of Man and, having won an exhibition (scholarship), at Trinity College, Cambridge. He graduated in 1884 as third wrangler, and in 1885 was awarded a first class honours in the mathematical tripos.[4][5][6]

University of Adelaide

In 1885,[7] at the age of 23, Bragg was appointed (Sir Thomas) Elder Professor of Mathematics and Experimental Physics in the University of Adelaide,[8] Australia, and started work there early in 1886.[9] Being a skilled mathematician, at that time he had limited knowledge of physics, most of which was in the form of applied mathematics he had learnt at Trinity. Also at that time, there were only about a hundred students doing full courses at Adelaide, of whom less than a handful belonged to the science school, whose deficient teaching facilities Bragg improved by apprenticing himself to a firm of instrument makers. Bragg was an able and popular lecturer; he encouraged the formation of the student union, and the attendance, free of charge, of science teachers at his lectures.[5][6]

Bragg's interest in physics developed, particularly in the field of electromagnetism. In 1895, he was visited by Ernest Rutherford, en route from New Zealand to Cambridge; this was the commencement of a lifelong friendship. Bragg had a keen interest in the new discovery of Wilhelm Röntgen. On 29 May 1896 at Adelaide, Bragg demonstrated before a meeting of local doctors the application of "X-rays to reveal structures that were otherwise invisible". Samuel Barbour, senior chemist of F. H. Faulding & Co., an Adelaide pharmaceutical manufacturer, supplied the necessary apparatus in the form of a Crookes tube, a glass discharge tube. The tube had been obtained at Leeds, England, where Barbour visited the firm of Reynolds and Branson, a manufacturer of photographic and laboratory equipment. Barbour returned to Adelaide in April 1896. Barbour had conducted his own experiments shortly after return to Australia, but results were limited due to limited battery power.[10] At the University, the tube was attached to an induction coil and a battery borrowed from Sir Charles Todd, Bragg's father-in-law. The induction coil was utilized to produce the electric spark necessary for Bragg and Barbour to "generate short bursts of X-rays". The audience was favorably impressed. Bragg availed himself as a test subject, in the manner of Röntgen and allowed an X-ray photograph to be taken of his hand. The image of the fingers in his hand revealed "an old injury to one of his fingers sustained when using the turnip chopping machine on his father's farm in Cumbria".[11][12]

As early as 1895, Professor William H. (later Sir William) Bragg was working on wireless telegraphy, though public lectures and demonstrations focussed on his X-ray research which would later lead to his Nobel Prize. In a hurried visit by Rutherford, he was reported as working on a Hertzian oscillator. There were many common practical threads to the two technologies and he was ably assisted in the laboratory by Arthur Lionel Rogers who manufactured much of the equipment. On 21 September 1897 Bragg gave the first recorded public demonstration of the working of wireless telegraphy in Australia during a lecture meeting at the University of Adelaide as part of the Public Teachers' Union conference.[13][14] Bragg departed Adelaide in December 1897,[15] and spent all of 1898 on a 12-month leave of absence, touring Great Britain and Europe and during this time visited Marconi and inspected his wireless facilities.[16][17] He returned to Adelaide in early March 1899,[18] and already on 13 May 1899, Bragg and his father-in-law, Sir Charles Todd, were conducting preliminary tests of wireless telegraphy with a transmitter at the Observatory and a receiver on the South Road (about 200 metres).[19] Experiments continued throughout the southern winter of 1899 and the range was progressively extended to Henley Beach. In September the work was extended to two way transmissions with the addition of a second induction coil loaned by Mr. Oddie of Ballarat.[20] It was desired to extend the experiments cross a sea path and Todd was interested in connecting Cape Spencer and Althorpe Island, but local costs were considered prohibitive while the charges for patented equipment from the Marconi Company were exorbitant. At the same time Bragg's interests were leaning towards X-rays and practical work in wireless in South Australia was largely dormant for the next decade.

The turning-point in Bragg's career came in 1904 when he gave the presidential address to section A of the Australasian Association for the Advancement of Science at Dunedin, New Zealand,[6] on "Some Recent Advances in the Theory of the Ionization of Gases". This idea was followed up "in a brilliant series of researches"[6] which, within three years, earned him a fellowship of the Royal Society of London. This paper was also the origin of his first book Studies in Radioactivity (1912). Soon after the delivery of his 1904 address, some radium bromide was made available to Bragg for experimentation. In December 1904 his paper "On the Absorption of α Rays and on the Classification of the α Rays from Radium" appeared in the Philosophical Magazine, and in the same issue a paper "On the Ionization Curves of Radium", written in collaboration with his student Richard Kleeman, also appeared.[5][6]

At the end of 1908, Bragg returned to England. During his 23 years in Australia "he had seen the number of students at the University of Adelaide almost quadruple, and had a full share in the development of its excellent science school."[5] He had returned to England on the maiden voyage of the SS Waratah, a ship which vanished at sea on its second voyage the next year. He had been alarmed at the ship's tendency to list during his voyage, and had concluded that the ship's metacentre was just below her centre of gravity. In 1911, he testified his belief that the Waratah was unstable at the Inquiry into the ship's disappearance.[21]

University of Leeds

Bragg plaque leeds
Commemorative plaque on the Parkinson Building, University of Leeds
X-ray spectrometer, 1912. (9660569929)
X-ray spectrometer developed by Bragg

Bragg occupied the Cavendish chair of physics in the University of Leeds from 1909. He continued his work on X-rays with much success. He invented the X-ray spectrometer and with his son, Lawrence Bragg, then a research student at Cambridge, founded the new science of X-ray crystallography, the analysis of crystal structure using X-ray diffraction.

World War I

Both of his sons were called into the army after war broke out in 1914 .[22] The following year he was appointed Quain Professor of physics at University College London.[5] He had to wait for almost a year to contribute to the war effort: finally, in July 1915, he was appointed to the Board of Invention and Research set up by the Admiralty.[5] In September, his younger son Robert died of wounds at Gallipoli. In November, he shared the Nobel Prize in Physics with elder son William Lawrence. The Navy was struggling to prevent sinkings by unseen, submerged U boats. The scientists recommended that the best tactic was to listen for the submarines. The Navy had a hydrophone research establishment at Aberdour Scotland, staffed with navy men. In November 1915, two young physicists were added to its staff. Bowing to outside pressure for using science, in July 1916, the Admiralty appointed Bragg as scientific director at Aberdour, assisted by three additional young physicists. They developed an improved directional hydrophone, which convinced the Admiralty of their usefulness. Late in 1916, Bragg with his small group moved to Harwich, where the staff was enlarged and they had access to a submarine for tests. In France, where scientists had been mobilized since the beginning of the war, the physicist Paul Langevin made a major stride with echolocation, generating intense sound pulses with quartz sheets oscillated at high frequency, which were then used as microphones to listen for echoes. Quartz was usable when vacuum tubes became available at the end of 1917 to amplify the faint signals. The British made sonar practicable by using mosaics of small quartz bits rather than slices from a large crystal. In January 1918, Bragg moved into the Admiralty as head of scientific research in the anti-submarine division. By war's end British vessels were being equipped with sonar manned by trained listeners.

Inspired by William Lawrence's methods for locating enemy guns by the sound of their firing, the output from six microphones miles apart along the coast were recorded on moving photographic film. Sound ranging is much more accurate in the sea than in the turbulent atmosphere. They were able to localize the sites of distant explosions, which were used to obtain the precise positions of British warships and of minefields.

University College London

After the war he returned to University College London, where he continued to work on crystal analysis.[5]

Royal Institution

From 1923, he was Fullerian Professor of Chemistry at the Royal Institution and director of the Davy Faraday Research Laboratory.[23] This institution was practically rebuilt in 1929–30 and, under Bragg's directorship many valuable papers were issued from the laboratory.[5] In 1919, 1923 and 1925, he was invited to deliver the Royal Institution Christmas Lecture on The World of Sound; Concerning the Nature of Things and Old Trades and New Knowledge respectively.

The Royal Society and the coming war

Bragg was elected President of the Royal Society in 1935. The physiologist AV Hill was Biological Secretary and soon ACG Egerton became Physical Secretary.[24] During World War I all three had stood by for frustrating months before their skills were employed for the war effort. Now the cause of science was strengthened by the report of a high level Army committee on lessons learned in the last war; their first recommendation was to "keep abreast of modern scientific developments".[25] Anticipating another war, the Ministry of Labour was persuaded to accept Hill as a consultant on scientific manpower. The Royal Society compiled a register of qualified men. They proposed a small committee on science to advise the Committee on Imperial Defence, but this was rejected. Finally in 1940, as Bragg's term ended, a Scientific Advisory Committee to the War Cabinet was appointed. Bragg died in 1942.

Honours and awards

Bragg was joint winner (with his son, Lawrence Bragg) of the Nobel Prize in Physics in 1915: "For their services in the analysis of crystal structure by means of X-ray".[26]

Bragg was elected Fellow of the Royal Society in 1907, vice-president in 1920, and served as President of the Royal Society from 1935 to 1940. Elected member of the Royal Academy of Science, Letters and Fine Arts of Belgium on 1 June 1946.

He was appointed Commander of the Order of the British Empire (CBE) in 1917 and Knight Commander (KBE) in the 1920 civilian war honours.[27] He was admitted to the Order of Merit in 1931.[5]

Private life

In 1889, in Adelaide, W.H. Bragg married Gwendoline Todd, a skilled water-colour painter, and daughter of astronomer, meteorologist and electrical engineer Sir Charles Todd.[5][6] They had three children, a daughter, Gwendolen and two sons, (William) Lawrence (W.L.), born in 1890 in North Adelaide, and Robert. Bragg taught William at the University of Adelaide. Robert was killed in the Battle of Gallipoli.

Bragg played tennis and golf, and as a founding member of the North Adelaide and Adelaide University Lacrosse Clubs, contributed to the introduction of lacrosse to South Australia and was also the secretary of the Adelaide University Chess Association.[29] W.H.'s wife Gwendoline died in 1929. W.H. Bragg died in 1942 in England and was survived by his daughter Gwendolen (Mrs. Alban Caroe) and his son, Lawrence.

Legacy

The lecture theatre of King William's College (KWC) is named in memory of Bragg; the Sixth-Form invitational literary debating society at KWC, the Bragg Society, is also named in his memory. One of the school "Houses" at Robert Smyth School, Market Harborough, Leicester, is named "Bragg" in memory of him being a student there. Since 1992, the Australian Institute of Physics has awarded The Bragg Gold Medal for Excellence in Physics for the best PhD thesis by a student at an Australian university. The two sides of the medal contain the images of Sir William Henry and his son Sir Lawrence Bragg.[30]

The Experimental Technique Centre at Brunel University is named the Bragg Building.

In 1962, the Bragg Laboratories were constructed at the University of Adelaide to commemorate 100 years since the birth of Sir William H. Bragg.[5]

Publications

  • William Henry Bragg, William Lawrence Bragg, "X Rays and Crystal Structure", G. Bell & Son, London, 1915.
  • William Henry Bragg, The World of Sound (1920)
  • William Henry Bragg, The Crystalline State – The Romanes Lecture for 1925. Oxford, 1925.
  • William Henry Bragg, Concerning the Nature of Things (1925)
  • William Henry Bragg, Old Trades and New Knowledge (1926)
  • William Henry Bragg, An Introduction to Crystal Analysis (1928)
  • William Henry Bragg, The Universe of Light (1933)

See also

References

  1. ^ Da c. Andrade, E. N.; Lonsdale, K. (1943). "William Henry Bragg. 1862-1942". Obituary Notices of Fellows of the Royal Society. 4 (12): 276. doi:10.1098/rsbm.1943.0003. JSTOR 769040.
  2. ^ This is still a unique accomplishment, because no other parent-child combination has yet shared a Nobel Prize (in any field). In several cases, a parent has won a Nobel Prize, and then years later, the child has won the Nobel Prize for separate research. An example of this is with Marie Curie and her daughter Irène Joliot-Curie, who are the only mother-daughter pair. Several father-son pairs have won two separate Nobel Prizes.
  3. ^ "The Nobel Prize in Physics 1915". Nobel Foundation. Retrieved 9 October 2008.
  4. ^ "Bragg, William Henry (BRG880WH)". A Cambridge Alumni Database. University of Cambridge.
  5. ^ a b c d e f g h i j k Serle, Percival (1949). "Bragg, William Henry". Dictionary of Australian Biography. Sydney: Angus and Robertson. Retrieved 7 October 2008.
  6. ^ a b c d e f Tomlin, S. G. (1979). "Bragg, Sir William Henry (1862–1942)". Australian Dictionary of Biography. Canberra: Australian National University. Retrieved 7 October 2008.
  7. ^ "The New Elder Professor of Mathematics". The Express and Telegraph. XXIII (6, 596). South Australia. 18 December 1885. p. 2 (Afternoon Edition.). Retrieved 11 February 2018 – via National Library of Australia.
  8. ^ Bragg Centenary, 1886–1986, University of Adelaide, Pages 3 & 4. Proof of advertisement in the Oxford University Gazette of 16 October 1885, and the Cambridge University Reporter of 13 October 1885. The advertisements read:
    THE UNIVERSITY OF ADELAIDE
    ELDER PROFESSOR OF MATHEMATICS AND EXPERIMENTAL PHYSICS
    The Council invite applications for the above Professorship. Salary £800 per annum. The appointment will be for a term of five years, subject to renewal at the discretion of the Council. Salary will date from March 1, 1886, and the Professor will be expected to enter on his duties on that date. An allowance will be made for travelling expenses. Applications with testimonials should reach ... not later than December 1, 1885.
    Bragg was informed of his appointment by a letter dated 17 December 1885.
  9. ^ "THE ADELAIDE UNIVERSITY". The South Australian Advertiser. XXVIII (8500). 15 January 1886. p. 5. Retrieved 11 February 2018 – via National Library of Australia.
  10. ^ "RONTGEN PHOTOGRAPHY UNSUSPECTED". Evening Journal. XXVIII (7976). Adelaide. 30 May 1896. p. 7. Retrieved 11 February 2018 – via National Library of Australia.
  11. ^ George, Robert. (1996). 100 Years of X-Rays – the South Australian Connection. The Journal of the Radiology History & Heritage Charitable Trust. 12(Autumn/Winter): 3.
  12. ^ Hall, Kersten T. (2014). The Man in the Monkeynut Coat: William Astbury and the Forgotten Road to the Double-Helix. Oxford University Press. Oxford. Page 26.
  13. ^ "PUBLIC TEACHERS' UNION". South Australian Register. LXII (15, 869). 22 September 1897. p. 6. Retrieved 8 February 2018 – via National Library of Australia.
  14. ^ "SECOND DAY". Adelaide Observer. LIV (2, 921). 25 September 1897. p. 14. Retrieved 8 February 2018 – via National Library of Australia.
  15. ^ "THE LATE MR. MCPHERSON". The Express and Telegraph. XXXV (10, 241) (ONE O'CLOCK ed.). South Australia. 15 December 1897. p. 2. Retrieved 11 February 2018 – via National Library of Australia.
  16. ^ "THE LATE MR. MCPHERSON". The Express and Telegraph. XXXV (10, 241) (ONE O'CLOCK ed.). South Australia. 15 December 1897. p. 2. Retrieved 8 February 2018 – via National Library of Australia.
  17. ^ "ASTRONOMICAL SOCIETY". The Advertiser. Adelaide. 11 May 1899. p. 3. Retrieved 8 February 2018 – via National Library of Australia.
  18. ^ "RETURN OF PROFESSOR BRAGG". Evening Journal. XXXI (8817) (ONE O'CLOCK ed.). Adelaide. 6 March 1899. p. 2. Retrieved 11 February 2018 – via National Library of Australia.
  19. ^ "WIRELESS TELEGRAPHY". South Australian Register. LXIV (16, 381). 15 May 1899. p. 4. Retrieved 8 February 2018 – via National Library of Australia.
  20. ^ "WIRELESS TELEGRAPHY". Evening Journal. XXXI (8989) (ONE O'CLOCK ed.). Adelaide. 28 September 1899. p. 2. Retrieved 11 February 2018 – via National Library of Australia.
  21. ^ "THE WARATAH. A PROFESSOR'S ALARM: SAVED BY A VISION. MISS HAY WARNED". The Advertiser. LIII, (16, 306). South Australia. 20 January 1911. p. 7. Retrieved 2 September 2018 – via National Library of Australia.
  22. ^ Van der Kloot, William (2014). Great Scientists wage the Great War. Stroud: Fonthill. pp. 93–128.
  23. ^ William Henry Bragg (1862–1942). The Davy Faraday Research Laboratory
  24. ^ Van der Kloot 2014, pp. 201-207
  25. ^ Van der Kloot 2014, p. 202.
  26. ^ "The Nobel Prize in Physics 1915". Nobel Foundation. Retrieved 26 April 2018.
  27. ^ "No. 31840". The London Gazette (Supplement). 30 March 1920. p. 3758.
  28. ^ "John J. Carty Award for the Advancement of Science". National Academy of Sciences. Archived from the original on 29 December 2010. Retrieved 25 February 2011.
  29. ^ Bragg Centenary, 1886–1986, University of Adelaide, page 43.
  30. ^ "Bragg Gold Medal for Excellence in Physics". Australian Institute of Physics. 2009. Retrieved 11 January 2009.

Further reading

  • "[a] most valuable record of his work and picture of his personality is the excellent obituary written by Professor Andrade of London University for the Royal Society of London." Statement made by Sir Kerr Grant, in:
  • "The Life and work of Sir William Bragg", the John Murtagh Macrossan Memorial Lecture for 1950, University of Queensland. Written and presented by Sir Kerr Grant, Emeritus Professor of Physics, University of Adelaide. Reproduced as pages 5–37 of Bragg Centenary, 1886–1986, University of Adelaide.
  • "William and Lawrence Bragg, Father and Son: The Most Extraordinary Collaboration in Science", John Jenkin, Oxford University Press 2008.
  • Ross, John F. A History of Radio in South Australia 1897–1977 (J. F. Ross, 1978) [1]

External links

Adelaide University Lacrosse Club

The Adelaide University Lacrosse Club (AULC) is an Australian-based lacrosse club founded in 1889 by Nobel Prize winning Professor William Henry Bragg. It is one of the oldest lacrosse clubs in Australia and is a founding member of the Adelaide University Sports Association. The AULC takes part in an annual competition against the Melbourne University Lacrosse Club that was first contested in 1905 and competes locally in the Lacrosse South Australia competition. Club membership is focused on University of Adelaide students and graduates. Other non students are also members. The AULC trains on the University of Adelaide's Park 10 sports fields in the park lands between the University campus and North Adelaide.

Alban Caroe

Alban Douglas Rendall Caroe OBE FSA FRIBA (17 April 1904 − 11 December 1991) was a British architect.

He was the son of W. D. Caroe and brother of Sir Olaf Caroe. He married Gwendolen Mary Bragg (1907-1982), daughter of William Henry Bragg. His son, with whom he worked, was Martin Caroe. His daughter, Lucy Caroe, historical geographer, married Richard Adrian, 2nd Baron Adrian. He was awarded an OBE in the 1987 Birthday Honours.

Anti-submarine indicator loop

In the first years of World War I submarines were fearful, one-sided weapons because they were invisible. In July 1915 Arthur Balfour replaced Winston Churchill as First Lord of the Admiralty. Balfour appreciated the importance of science, so he set up a Board of Invention and Research (BIR), made up of a three-man central committee supported by an eminent consulting panel.  The remits of Section II of the panel included submarines, its members included the eminent physicists Ernest Rutherford and William Henry Bragg.

  The panel concluded that the most promising approach was to listen for submarines, so they pushed work to improve hydrophones. Soon Bragg moved to the hydrophone research center HMS Tarlair at Aberdour on the Firth of Forth (which later relocated to Harwich in Essex).

Independently from the BIR, in August 1915, a submerged cable was laid on the seabed of the Firth of Forth. The idea originated with the Scottish physicist Alexander Crichton Mitchell, who was helped by the Royal Navy at HMS Tarlair.  He had shown that the passage of a submarine past a cable formed an induction loop which induced a voltage of a millivolt or so that could be detected by a sensitive galvanometer. However, voltages were also induced in the cable by random fluctuations in the earth's magnetic field and electrical noise from the Glasgow tram lines, so Mitchell installed an identical loop outside of the channel for vessels, the two loops were connected so that the random fluctuations canceled each other out. A rheostat was used to give the two loops identical resistances, so that no current flowed until a vessel approached. Unfortunately his report to the BIR was misunderstood and his findings rejected as of no value.  Consequently, there was a hiatus in the installation of loops until their utility was demonstrated beyond question; then with Bragg's leadership a number were installed.  Later in World War I the tiny induced voltages were amplified by vacuum tube amplifiers. Even with this assistance a long loop installed to monitor traffic in the English Channel proved impractical.

The "Liverpool Cable" used for the loops consisted of four core, single strand 1.23 mm copper wire sheathed in 2-layer rubber insulation of diameter 3.7 mm that was wrapped in jute identification tape. The cores are separated by five strands of 36-thread cotton serving, wrapped in two layers of linen identification tape, all encased in a 12.8 mm diameter lead sheath that was wrapped in 18 strands of tarred hemp serving and armoured with 26 strand 2.0 mm steel wire to a final diameter of 18.8 mm.   The cores were wired together when the cable was used for a loop.

A notable operational use of a loop was at the Grand Fleet's anchorage at Scapa Flow.  The German submarine UB-116 captained by Lieutenant JJ Emsmann — who along with his crew had volunteered for a suicide mission — was detected by hydrophones at 21:21 on 28 October 1918 while entering the harbour via Hoxa Sound. There were no allied vessels in the harbour, therefore the indicator loops on the minefields were activated. Two hours later (at 23:32) current was detected in an indicator loop laid in a remotely controlled minefield, induced by the submarine as it passed over the cable. Activation of the loop detonated mines in the field, which sank the submarine.  It was the last U-boat destroyed by enemy action before the Armistice, ironically when it had no prey. The wreck of UB-116 was raised in 1919 but floundered while being towed and its broken-up scraps fell back onto the seabed, where now they are popular viewing for scuba divers. After the First World War, indicator loop devices were further developed by the Admiralty's research divisions at HMS Vernon and HMS Osprey (Portland Naval Base). In WWII indicator loops were used by the Allies for harbour defence in the UK and its dominions and protectorates, as well as by the US Navy.   For example, the Hoxa channel into Scapa Flow was provided with two guard loops followed by eight mine loops in echelon.

Bragg-Paul Pulsator

The Bragg-Paul Pulsator, also known as the Bragg-Paul respirator, was a non-invasive medical ventilator invented by William Henry Bragg and designed by Robert W. Paul in 1933 for patients unable to breathe for themselves due to illness.It was the first 'Intermittent Abdominal Pressure Ventilator' (IAPV).

Bragg Institute

The Australian Centre for Neutron Scattering (ACNS), formerly the Bragg Institute, is a landmark neutron and X-ray scattering facility in Australia. It is located at the Australian Nuclear Science and Technology Organisation's (ANSTO) Lucas Heights site, 40 km south west of Sydney, in New South Wales, Australia.

The Institute was formed in December 2002 in preparation for the start-up of the Open-pool Australian lightwater reactor in 2006, and named as a tribute to the father-and-son team Sir William Henry Bragg and son William Lawrence Bragg, who were jointly awarded the Nobel Prize for Physics in 1915 for pioneering the analysis of crystal structures by means of X-rays. Following a restructure of scientific operations in 2016, the Institute was split to form two distinct research platforms, ACNS and the National Deuteration Facility.ACNS operates the cold- and thermal-neutron scattering facility associated with the OPAL research reactor, including 14 operational neutron beam instruments, and one instrument in transfer from the BER-II Research Reactor at the Helmholtz-Zentrum Berlin. It houses a helium-3 polarisation system to enable polarised-neutron experiments, two small-angle X-ray scattering instruments, an X-ray reflectometer and Physical Properties Measurement System.

Neutron scattering covers an extremely wide range of disciplines from fundamental physics, through chemistry, materials, and biology, right through to interdisciplinary areas such as engineering and archaeology. Science at the Australian Centre for Neutron Scattering covers many of these areas, usually in collaboration with other groups, with a focus on the application of neutron scattering to crystallography, soft condensed matter, solid-state physics, physical chemistry and increasingly biology. The ACNS identifies 6 key scientific projects: The Food Science Project, Thermo-Mechanical Processes, Energy Materials, Magnetism, Cultural Heritage and Planetary Materials.From its inception until 2016, the Institute was led by Robert Robinson. In 2016 Jamie Schulz became leader of the ACNS. ACNS currently employs approximately 100 staff.

Access to the neutron instrumentation at the ACNS is available to all qualified applications through either proprietary fee-for-service research, non-proprietary peer reviewed merit access, non-proprietary peer reviewed research program process for 3-year programs, or fast-turnaround experiments. Research proposals are accepted and reviewed twice yearly via the ACNS Customer Portal.

Bragg peak

The Bragg peak is a pronounced peak on the Bragg curve which plots the energy loss of ionizing radiation during its travel through matter. For protons, α-rays, and other ion rays, the peak occurs immediately before the particles come to rest. This is called Bragg peak, after William Henry Bragg who discovered it in 1903.When a fast charged particle moves through matter, it ionizes atoms of the material and deposits a dose along its path. A peak occurs because the interaction cross section increases as the charged particle's energy decreases. Energy lost by charged particles is inversely proportional to the square of their velocity, which explains the peak occurring just before the particle comes to a complete stop. In the upper figure, it is the peak for alpha particles of 5.49 MeV moving through air. In the lower figure, it is the narrow peak of the "native" proton beam curve which is produced by a particle accelerator of 250 MeV. The figure also shows the absorption of a beam of energetic photons (X-rays) which is entirely different in nature; the curve is mainly exponential.

The phenomenon is exploited in particle therapy of cancer, to concentrate the effect of light ion beams on the tumor being treated while minimizing the effect on the surrounding healthy tissue.The blue curve in the figure ("modified proton beam") shows how the originally monoenergetic proton beam with the sharp peak is widened by increasing the range of energies, so that a larger tumor volume can be treated. This can be achieved by using variable thickness attenuators like spinning wedges.

Braggite

Braggite is a sulfide mineral of platinum, palladium and nickel with chemical formula: (Pt, Pd, Ni)S. It is a dense (specific gravity of 10), steel grey, opaque mineral which crystallizes in the tetragonal crystal system. It is the central member in the platinum group end-members cooperite and vysotskite.

It was first described in 1932 for an occurrence in the Bushveld Igneous Complex of South Africa. Its name came from William Henry Bragg (1862–1942) and his son, William Lawrence Bragg (1890–1971). It was the first mineral that was discovered with the assistance of X rays.It occurs as magmatic segregations in layered igneous intrusions such as Bushveld, the Stillwater igneous complex, the Lac des Îles igneous complex, the Isle of Rum intrusive, the Great Dyke and many others. It is one of the most common platinum group minerals.

Bragg–Gray cavity theory

Bragg-Gray cavity theory relates the radiation dose in a cavity volume of material to the dose that would exist in a surrounding medium in the absence of the cavity volume. It was developed in 1936 by British scientists Louis Harold Gray, William Henry Bragg, and William Lawrence Bragg.

Most often, material is assumed to be a gas, however Bragg-Gray cavity theory applies to any cavity volume (gas, liquid, or solid) that meets the following Bragg-Gray conditions.

When the Bragg-Gray conditions are met, then

,

where

is the dose to material (SI unit Gray)
is the dose to the cavity material (SI unit Gray)
is the ratio of the mass-electronic stopping powers of and averaged over the charged particle fluence crossing the cavity. (mass-electronic stopping powers are also known as mass-collision stopping powers)

In an ionization chamber,the dose to material (typically a gas) is

where

is the ionization per unit volume produced in the (SI unit Coulomb)
is the mass of the gas (SI unit kg)
is the mean energy required to produce an ion pair in divided by the charge of an electron (SI units Joules/Coulomb)
Kedareswar Banerjee

Kedareswar Banerjee (15 September 1900 – 30 April 1975) was an X-ray crystallographer and director of the Indian Association for the Cultivation of Science, Kolkata. Early in his career he determined the structures of naphthalene and anthracene. In 1931, he worked with Sir William Henry Bragg and developed one of the first direct methods of crystal structure determination. He was Professor of Physics at the Indian Association for the Cultivation of Science from 1943 to 1952 and Director of the Association from 1959 until his retirement in 1965. Between 1952 and 1959 he was Head of the Department of Physics at Allahabad University. His interests in crystallography were widespread and, with his death, India has lost a renowned teacher. K. Banerjee joined the research group of Sir C. V. Raman at the Indian Association for the Cultivation of Science (IACS), Calcutta, a premier Indian research institute of India. He worked in various institutions including IACS, the India Meteorological Department, University of Dhaka and Allahabad University and finally retired as the Director of IACS, Calcutta in 1965. Prof. Banerjee explained some points of crystal research to Homi J. Bhabha (21 Dec 1956) also .

Lawrence Bragg

Sir William Lawrence Bragg, (31 March 1890 – 1 July 1971) was an Australian-born British physicist and X-ray crystallographer, discoverer (1912) of Bragg's law of X-ray diffraction, which is basic for the determination of crystal structure. He was joint winner (with his father, William Henry Bragg) of the Nobel Prize in Physics in 1915: "For their services in the analysis of crystal structure by means of X-ray", an important step in the development of X-ray crystallography.

Bragg was knighted in 1941. As of 2018, he is the youngest ever Nobel laureate in physics, having received the award at the age of 25 years. Bragg was the director of the Cavendish Laboratory, Cambridge, when the discovery of the structure of DNA was reported by James D. Watson and Francis Crick in February 1953.

List of Fellows of the Royal Society elected in 1907

This is a list of Fellows of the Royal Society elected in 1907.

Martin Caroe

Martin Bragg Caroe FSA (15 November 1933 − 19 November 1999) was a British conservation architect, and partner in Caroe & Partners from 1963 until his death.

He was the son of Alban Caroe and his wife Gwendolen Mary (née Bragg), daughter of Sir William Henry Bragg OM KBE. He was educated at Amesbury School, Winchester College and Trinity College, Cambridge (BA, 1957). He married Mary Elizabeth Roskill in 1962; they had the following children:

Rebecca Elizabeth Caroe (born 14 July 1965, in Camberwell)

William Desborough Caroe (6 May 1967, in Camberwell − 17 September 1974, in Surrey (road traffic accident))

Oliver Bragg Caroe (born 24 August 1968, in Vann, Hambledon

Ruth Gwendolen Caroe (born 20 September 1972, in Vann, Hambledon)

Emily Grace Mary Caroe (born 24 August 1976, in Vann, Hambledon)

Matteucci Medal

The Matteucci Medal is an Italian award for physicists, named after Carlo Matteucci. It was established to award physicists for their fundamental contributions. Under an Italian Royal Decree dated July 10, 1870, the Italian Society of Sciences was authorized to receive a donation from Carlo Matteucci for the establishment of the Prize.

Matteucci MedalistsSource: Italian Society of Sciences

North Adelaide Lacrosse Club

The North Adelaide Lacrosse Club was founded on 22 March 1887, and is the oldest continually existing lacrosse club in South Australia. Nobel Laureate Sir William Henry Bragg, previously a member of the Adelaide Lacrosse Club, was a founding member of North Adelaide as well as the Adelaide University Lacrosse Club later in 1889. NALC are currently located in the suburb of Gepps Cross.

Quain Professor

Quain Professor is the professorship title for certain disciplines at University College London, England. The title is derived from Richard Quain (1800-1887) who became professor of anatomy in 1832 at what was to become UCL. He made a provision in his will to the University that endowed professorships for four subjects; intending that funding gave recognition to his brother, John Richard Quain, as well as his own.

The Burhop prize for Physics, Applied Physics or Mathematics/Physics is also drawn from these funds.The Quain professorships are of Botany, English language and literature, Jurisprudence, and Physics.

Royal Institution of Australia

The Royal Institution of Australia (RiAus) is a national scientific not-for-profit organisation with a mission to 'bring science to people and people to science'. It opened in October 2009.

Stephen Bragg

Stephen Lawrence Bragg (1923–2014) was a British engineer who was Vice Chancellor of Brunel University from 1971-81. He was the son of Lawrence Bragg and grandson of William Henry Bragg.

The Bragg UNSW Press Prize for Science Writing

The Bragg UNSW Press Prize for Science Writing was established in 2012 to recognise excellence in Australian science writing. The annual prize of A$7,000 is awarded to the best short non-fiction piece of science fiction with the aim of a general audience. Two runners up are awarded $1,500 each.

The prize is named in honour of Australia’s first Nobel Laureates, father and son team William Henry Bragg and William Lawrence Bragg. The prize is supported by the Copyright Agency Cultural Fund and the UNSW Faculty of Science.

An associated anthology, The Best Australian Science Writing (NewSouth Publishing) collects the best of the year’s science writing.

Westward, Cumbria

Westward is a small village and civil parish in the English county of Cumbria. It had a population of 814, at the 2001 census, increasing slightly to 838 at the 2011 Census. Westward is located on the south side of the Wiza Beck. It is 3.3 miles (5.3km) to the south of the town of Wigton. Administratively it forms part of the district of Allerdale.

The Nobel prize winner William Henry Bragg was born in Westward in 1862.

Recipients of the Copley Medal (1901–1950)
1901–1925
1926–1950
1951–1975
1976–2000
2001–
present
17th century
18th century
19th century
20th century
21st century

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