P.I.P. Kalmus

Central Hadron Calorimeter of UA1

Abstract An iron—scintillator sampling calorimeter is described, which measures hadronic energy in proton-antiproton interactions at the CERN 540 GeV SPS collider. Construction details are given of the instrumentation of the magnet pieces of the UA1 experiment and of the methods used to measure the calorimeter response and resolution. The system of lasers and quartz fibres, which allows long term monitoring of the calorimeter response, is also described.

Empty matter and the full physical vacuum

Experiments with elementary particles have shown that much of matter is made up of empty space, but this vacuum is not really empty. The uncertainty principle allows the temporary existence of virtual particles, and these have been shown experimentally to have measurable effects.

Experimental techniques in particle physics

Abstract The great majority of experiments in particle physics use beams of particles from accelerators. Individual interactions of these with other particles are observed by detector systems. Fixed target and colliding beam experiments are contrasted, and non-accelerator experiments mentioned briefly. An account is given of the principles of the various detectors. These include scintillation and Cerenkov counters and the various tracking devices such as bubble chambers, proportional and drift chambers. Calorimeters have emerged recently as important detectors at the highest energies. Electronic logic modules are mentioned and the main steps in data acquisition and analysis are described. Finally an example is given of a large detector system.

Neutrino, by Frank Close

who read books rather than rely entirely on the internet) the layout and general attractiveness of a volume are of great importance, and this book (published by Cambridge but designed by the Open University) is an attractive production, with nice clear diagrams, good use of colour, and photographs and thumb-nail sketches of the major contributors to the field. Lambourne’s book really scores, however, in its careful, thorough and well thought-out presentation of the subject. It bears all the hall-marks of the Open University publications, combining expertise with a real understanding – almost intuition – of the best way to introduce a difficult subject to beginning students. The text reads very comfortably and creates a sense that one is being guided by experienced and knowledgeable authors (Lambourne is the chief author but the text is a collaborative effort). Very many of the equations are derived and explained properly, but sometimes it is judged appropriate simply to quote an equation in order to discuss its physical import. The topics covered are fairly standard: special relativity, geometry and curvature, general relativity (GR), Schwarzschild solution, black holes, tests of GR (including satellite tests and gravitational waves) and cosmology. There is no skimping on the treatment of geometry, which covers parallel transport, connection coefficients, the Riemann curvature tensor and the geodesic equation, in a complete and admirably lucid way. (Differential forms and intrinsic vector notation are not used.) It is good to find a book where the Einstein summation convention is not used; this surely makes it less confusing for students. Additional interesting topics include the Penrose process, the Lense–Thirring effect and Hawking radiation, though a minor quibble is that the thermodynamic analogy with black holes receives no mention. This is an excellent volume which can be highly recommended for an introductory course on general relativity and I hope will have the effect of increasing understanding of this most beautiful and striking creation of twentieth century physics.

Playing with Planets, by Gerard 't Hooft

It is undoubtedly a challenging task to comprehensively cover even a relatively focused topic of a modern science in one book. If a multi-volume handbook series is not an option, such a book often gets compressed in a single volume handbook that at most can provide an overview of the topic for the new reader and a few key reminder formulas for those familiar to the field. In a less favourable case (fortunately, less frequently encountered) such a book can result in a disjointed collection of narrow specialist papers. Fortunately, Biophotonics, edited by Lorentzo Pavesi and Philippe M. Fauchet, is neither of those. It is produced as a result of a fourth successful winter school on Biophotonics and its crisp and efficient style seems to convey a spirit of a wintry air from the northern Italian mountains where the school was held. Seventeen chapters of the book written by the leading experts in the field uncover four major areas of biophotonics – photosynthesis, modern bio-microscopy that uses light coherence and nonlinear effects, biosensors and biochips, and, finally, optical cell manipulation and therapies involving light sources. The overall style of the book is more of a textbook rather than a handbook – all ideas are introduced on a level that can be easily grasped by either a physicist or a biologist – starting from advanced undergraduates through to post-doctoral researchers. While the book does not include extensive mathematical formulae associated with the topic, it does provide where necessary fundamental relationships for understanding the performance of a biophotonic system (e.g. relationships for the point-spread-function in confocal microscopy, forces acting on a cell in the optical trap, and reflection coefficients for resonant cavity sensors). The relative absence of formulae (that probably will be quite welcome by biologists) is well compensated by the extensive bibliographies placed at the end of individual chapters, which promptly include both books on the specific subject as well as periodic journal references. There is a relatively short index that nevertheless covers all chapters through the book. Illustrations including schematic diagrams, graphs, microscopy images and tables are plentiful and there are rarely two consecutive pages without one of these. The book opens with the chapters on photosynthesis that spans topics from light conversion in organisms to biofuel production to photoprotection. It then moves onto advanced optical microscopy and micro-scale optical measurements of biomedical objects that utilise light coherence (optical coherence tomography (OCT), electronic speckle pattern interferometry (ESPI) and optical micro-cavities), nonlinear second harmonic generation (SHG) imaging, as well as ultimate performance of CMOS detectors in such applications. Biosensors – the major area of biophotonics, is also a significant part of this book. The book has dedicated chapters on fluorescence biomarkers, biosensors and biochips in genomics. Finally, the book moves from the topics of detection and measurements in bio-systems to how light can affect and treat cells and tissues – the last four chapters of the book cover optical trapping and manipulation of cells, photobiology of the skin, laser microsurgery and a photodynamic therapy. Overall, a chosen textbook style is seamlessly implemented by the editors and well adhered to by the authors of individual chapters. Biophotonics is highly recommended to anyone from graduate students in their final years at university to academics, providing a detailed introduction to the new research topics in key areas of biophotonics. This book can also provide a solid base for building up a curriculum for a course in biophotonics, biophysics or related subjects and to provide a key reading material for such subjects.

PARTICLES AND THE UNIVERSE

Physics Education is pleased to publish the written version of the 1998/9 Institute of Physics Schools and Colleges lecture given by Professor Peter Kalmus. This lecture is currently touring around the UK. Professor Kalmus was featured in our `People in physics columns in the July 1998 issue of the journal (page 266) and a list of the venues for the event appeared in the News section of the November issue (page 339).

THE STANDARD MODEL TRIUMPHS AGAIN

Results presented at the International Conference on High Energy Physics – hosted by the TRIUMF laboratory in Vancouver, Canada at the end of July – have confirmed the remarkable success of the Standard Model of particle physics. This model incorporates the electroweak theory, which describes how particles respond to the electromagnetic and weak forces, and quantum chromodynamics (QCD), which covers the strong interactions of quarks and the gluons through which they interact.

Quarks amongst the dinosaurs

Dinosaurs were described and named just 150 years ago in Plymouth at the 1841 annual meeting of the British Association for the Advancement of Science. The aims of the association are to enhance the public understanding and awareness of science and technology. During the last week of August 1991, the British Association (BA) again met in Plymouth, and dinosaurs were very much on the agenda. Out of more than 300 talks given during the week, usually in parallel, by 18 subject sections covering the whole of science, about 15 were on dinosaurs. Dinosaurs have captured the public imagination for 150 years, and have helped to popularise science in a way that might be envied by some physicists.

Test Your Own Eyesight

Perhaps readers of Physics World can help to explain an intriguing device which rapidly allows individuals to check their own eyesight for the common defects of long-and short-sighted and astigmatism. We have used this at Queen Mary College to illustrate various aspects of our elementary optics course: namely the optical properties of the human eye, the use of lasers, coherence and speckle.