摘要:

This article is intended to give the reader some understanding of why masers have suddenly become of such great interest. It begins with an account of the background to the problem of microwave amplification and then passes to a description of the properties of the populations of energy levels in thermal and other kinds of equilibrium. Particular attention is paid to the way in which a population reversal can be used for amplification, the basis of the maser. The next considerations are related to the performance characteristics to be anticipated and the article ends with descriptions of the ammonia maser, the ruby 3-level maser and a brief mention of the 2-level maser work. In having to choose between describing the technological and physical problems which are involved the basic physics has seemed of more importance and has been stressed.

ISSN:0010-7514    

DOI:10.1080/00107516008202622

出版商:Taylor & Francis Group    

年代:1960

数据来源: Taylor

摘要:

Dr. Reginald Smith-Rose, C.B.E., D.Sc., Ph.D., F.C.G.I., M.I.E.E., F.I.R.E., has been elected to succeed Dr. Lloyd Berkner of the U.S.A. as President of the International Scientific Radio Union (URSI). Previous holders of the office include the late Father Lejay of France and another British scientist, Sir Edward Appleton.

ISSN:0010-7514    

DOI:10.1080/00107516008202624

出版商:Taylor & Francis Group    

年代:1960

数据来源: Taylor

摘要:

A sub-critical assembly of U235has been used to increase by a factor of ten the neutron output of the pulsed source used for neutron time-of-flight measurements. This source consists of an electron linear accelerator producing a pulsed beam of high energy electrons which are then used to generate neutrons by x-ray production followed by photonuclear processes in a heavy element target. This paper describes some of the physics and engineering problems that had to be solved before a practical multiplying assembly could be built.

ISSN:0010-7514    

DOI:10.1080/00107516008202625

出版商:Taylor & Francis Group    

年代:1960

数据来源: Taylor

摘要:

Science teaching, both in school and university, is geared very closely to utilitarian aims. Has it also an important contribution to make to a liberal education? This article argues that it has, but that its opportunities are not being seized. Various ways of improving on the present state of affairs are discussed.

ISSN:0010-7514    

DOI:10.1080/00107516008202626

出版商:Taylor & Francis Group    

年代:1960

数据来源: Taylor

摘要:

A brief description is given of the development of the electrostatic generator from the single-ended machine to the double-ended, or tandem generator. The performance of the tandem machines is illustrated with reference to the U.K.A.E.A. tandems.

ISSN:0010-7514    

DOI:10.1080/00107516008202627

出版商:Taylor & Francis Group    

年代:1960

数据来源: Taylor

ISSN:0010-7514    

DOI:10.1080/00107516008202628

出版商:Taylor & Francis Group    

年代:1960

数据来源: Taylor

摘要:

The high-light of the British Association Meeting at Cardiff was the Symposium on World Food and Population. This was remarkable because the several sections of the Association suspended their separate activities for the day, on September Sth, to assemble in the large Sophia Gardens Pavilion. The proceedings were extremely interesting to all scientists but, as they were not especially concerned with physics, they will only be briefly noted here. Physicists were, however, prominent in the symposium. Sir George Thomson took the chair at the morning session, and Professor P. M. S. Blackett summed up at the close of the afternoon session. It was clear that the members of the B.A. faced up to the fact that the present rate of growth of world population is dangerously large, and that even if tremendous advances take place in the use of land and even if the rate of production of food is enormously increased in the not too distant future, that growth is likely to lead to catastrophe. The position was ably presented in a nutshell by an eminent physicist who, in private conversation, commented that if a nuclear war broke out tomorrow and 200 million people were wiped out, then if the present rate of growth of population persisted, we should be back where we were within five years.

ISSN:0010-7514    

DOI:10.1080/00107516008202629

出版商:Taylor & Francis Group    

年代:1960

数据来源: Taylor

ISSN:0010-7514    

DOI:10.1080/00107516008202630

出版商:Taylor & Francis Group    

年代:1960

数据来源: Taylor

摘要:

On Friday 16th September 1960, The Atomic Energy Establishment at Winfrith, Dorset, was officially opened by the Rt. Hon. Viscount Chandos, P.C., M.C; it had, in fact, been in operation for more than a year.

ISSN:0010-7514    

DOI:10.1080/00107516008202631

出版商:Taylor & Francis Group    

年代:1960

数据来源: Taylor

摘要:

This Conference, under the auspices of OEEC and the International Union of Pure and Applied Physics, was attended by more than a hundred delegates, representing some twenty-six nations. The Conference Chairman was Professor Sanborn C. Brown (U.S.A.), and the Conference Secretary Mr. Norman Clarke. The forty papers to be discused had been circulated to delegates well before the Conference, and the actual sessions were devoted to general discussions based on groups of papers which formed a unifying theme. Immediately after the close of the Conference, Prof. Brown and Mr. Clarke began the preparation of a full report of the proceedings, which will make a substantial volume. Among the general topics discussed were the place of physics in general education (opened by Mr. Clarke); the selection of university entrants for physics courses (Prof. G. K. T. Conn); examinations in physics (Dr. H. F. Boulind); the use of films and television in physics teaching (Dr. Harvey White, U.S.A.); and the Physical Science Study Committee's syllabus and programme (Prof. J. R. Zacharias, U.S.A.).

ISSN:0010-7514    

DOI:10.1080/00107516008202632

出版商:Taylor & Francis Group    

年代:1960

数据来源: Taylor