Large Particle Accelerators Research Articles

Degradation of the lunar vacuum by a moon base

High vacuum is required for many industrial processes which might be accomplished on the moon, such as electronic component and solar cell manufacturing or a large particle accelerator. Ambient pressure on the moon is in the range of 10 −12 torr (night) to 10 −10 torr (day). The effects of a 20 person base and a 250 person industrial facility on this vacuum are discussed. Exhaust from the transport spacecraft and leakage from the habitat will be roughly comparable to the daytime gas pressure for the 20 person base, and will degrade the vacuum to the range of 2 × 10 −9 torr for the 250 person facility. This is higher than the desired pressures for some semiconductor manufacture processes or for a lunar-based particle accelerator.

New Machine Sparks Rivalries at CERN

New Machine Sparks Rivalries at CERN

Development of a large graphics-based application package

CERN, the European Laboratory for Particle Physics, is one of the largest scientific research laboratories in the world. Most of the research work carried out in the Laboratory is not only strongly dependent upon the large particle accelerators in operation, but it also relies heavily on the use of computer systems of which several hundreds, of various types, are presently installed. During the last 20 years, CERN has played a leading role as the focus for development of packages and software libraries to solve problems related to High Energy Physics (HEP). The results of the integration of resources from many different Laboratories can be expressed in several millions lines of code written at CERN during this period of time, used at CERN and distributed to collaborating Laboratories. Nowadays, this role of software developer is considered very important by the entire HEP community. This paper reports the development of a large application package. The paper is divided into two parts. Firstly, a large software package where graphics play a key role (PAW—Physics Analysis Workstation) is taken as a case study, and its origin and main characteristics are presented in detail. PAW is essentially an interactive system which includes many different software tools, strongly oriented towards data analysis and data presentation. Secondly, the criteria and rules to be obeyed for the development of a large package in the environment of a large international collaboration are outlined. Then, the development process of the package is described and some of the problems encountered and the solutions adopted are discussed.

Budget Crunch Stalls Super Collider

Budget Crunch Stalls Super Collider

Demands on advanced superconductors by large projects in fusion and particle accelerators

A review is presented of the needs of large fusion and particle accelerator projects for advanced superconductors. The amounts of superconductors required and the materials are discussed.

A Bilateral Power Supply with Energy Storage Buffer for the Superconductive Coils of Large Particle Accelerators

Considerable development and testing on the active control of current in superconducting coils using DC-AC-DC thyristor convertor networks with superconductive magnetic energy storage has been completed. The charging and discharging cycles of the magnet are decoupled from the power grid, and since these networks are asynchronous with the line. operation at any practical frequency for the switching devices is possible. These systems. avoid putting large lpower bhumps on the utility grid during charging and discharging. eliminate phase related noise on other 60 Hz converter systems. and reduce the size of magnet ripple. Operation and design of thyrist, or networks in closed-loop feedback with varriable phase and frequency modes are discussed. Techniques for switching operation at one phase and frequency to another are described. Operating data on a bang-bang controller for 100 A.. 4 Hy. load and storage coils is given.

The design and commissioning of large particle accelerators

Abstract This paper is concerned with the synchrotrons and storage rings which accelerate protons and electrons for high energy physics. First we trace the development of these machines from early cyclotrons, pausing to describe the main principles of their operation as they emerge. After briefly introducing the reader to the present generation of synchrotrons, we explain in more detail how such large machines are designed, drawing together a consistent whole from a diversity of technical components. We make no attempt to describe the construction phase but move to the running in where component systems must be made to work together and design principles are put to the test.

Three-Phase Energy Transfer Circuit with Superconducting Energy Storage Coils

The operation and circuit analysis of a three-phase inductor converter bridge (ICB) is described. The ICB is used to transfer energy between two superconducting coils and may find application in future tokamak fusion power reactors and large particle accelerators. This circuit provides an efficient, controllable, and reversible means for energy transfer.

How to Mass Produce Reliable Cryostats for Large Particle Accelerators

Accelerators such as the Fermilab Energy Doubler/ Saver require large numbers of reliable cryostats which can be mass produced. Successful production of these devices is an extremely exacting business, requiring great attention to detail. A method has been developed and adopted at Fermilab which provides the precise control of the manufacturing process, necessary whether the cryostats are manufactured in-house or purchased from industry. This paper describes the system in detail, showing the integration of the engineering specifications, the quality assurance program including the high vacuum leak testing methods, and the manufacturing and materials specifications. To date over one hundred reliable cryostats have been produced using this method; experience and results are discussed.

Superconducting magnetic energy storage

An investigation into the application of superconducting magnetic energy storage for large particle accelerators, and to peak shaving in a power network, where efficiency is improved over the hydro-pumped storage stations already widely used.

Dosimetry and instrumentation for helium and heavy ions

The use of large particle accelerators for biological experiments and medical procedures requires a very reliable and accurate beam-monitoring system. The instrumentation at the 184-in. cyclotron medical facility and the Bevalac biomedical facility includes beam-monitoring devices and instruments used in their calibration. The variables involved in hellum- and heavy-ion dosimetry will be discussed.

The Feasibility and Advantages of Commercial Process I/O Systems for Accelerator Control

Control systems for large particle accelerators must be able to handle analog and digital signals and timing coordination for devices which are spread over a large physical area. Many signals must be converted and transmitted to and from a central control area during each accelerator cycle. Digital transmission is often used to combat common mode and RF interference. Most accelerators in use today have met these requirements with custom process I/O hardware, data transmission systems, and computer interfaces. In-house development of hardware and software has been a very costly and time consuming process, but due to the lack of available commercial equipment, there was often no other alternative. Today, a large portion of these development costs can be avoided. Small control computers are now available off the shelf which have extensive process control I/O hardware and software capability. Computer control should be designed into accelerator systems from the beginning, using operating systems available from manufacturer. With most of the systems programming done, the designers can begin immediately on the applications software.

Geodesy and Large Particle Accelerators

Geodesy and Large Particle Accelerators

Primary Hazards of Particle Accelerators

Particle accelerator safety problems are primarily those of activation and shielding. The phenomena of activations from various nuclear particles and from photons is relatively well known. Use of low activation materials at exposed locations and of adequate shielding at all locations is basic to the art of constructing an accelerator facility that will be safe in operation and require minimum cooling time. Side effects must also be considered relative to safety. These may include fire, heat, noxious gas, electricity and possibly sound, each of which may prove hazardous to personnel and may interfere with successful experimentation. The know-how and the materials existing today make possible the design and construction of large and small particle accelerators of various types that are radiologically safe both in operation and after shutdown. Good design and construction, followed by routine safety procedures associated with such facilities, will accomplish this objective.

A Visit to the Serpukhov 76‐GeV Synchrotron

The world's largest particle accelerator, the 76‐GeV synchrotron at Serpukhov, is now producing 2×1011 protons/pulse and is expected to be doing experiments shortly. Groups from CERN and France are collaborating with Serpukhov scientists, and there is some hope for American participation, too. (Such international coöperation may, of course, be influenced by the Czechoslovakian situation.)

A vidicon system for spark chambers

Abstract In order to cut down the time required to scan and measure spark chamber systems an automatic system has been developed. The system uses vidicon cameras and can digitize and record the positions of up to 4 sparks per gap. Scanning accuracy is 0.1% of full scan. During a beam pulse from a large particle accelerator up to 5 events can be recorded in a core store. During intervals between beam pulses the core store is read out on to I.C.T. compatible magnetic tape.

The Klystron - An Ultra High Power RF Energy Source

Each large particle accelerator which has been developed over the past years has been designed to yield information which was previously unavailable. Much of the design criteria depended upon the r.f. energy source available. This paper discusses the r.f. energy sources preserntly available. An extension is made to higher power tubes and the associated problems are discussed in detail.

Design of high-power modulator tubes

Grid-controlled high-vacuum tubes can be used advantageously to generate the pulse modulation of large radars and particle accelerators. Factors considered in designing high-power tubes which will meet the exacting requirements of switch-tube service are discussed as are structural details of a superpower beam-forming shielded-grid triode. Included are such features as the unit-cathode design and special processing, beam-forming structures, high-dissipation plate, high-conductivity seals, and special high-voltage considerations which make this tube superior in pulse-modulator service. Other types of superpower tubes and their adaptability to switch-tube service, as well as future trends in very-high-power switch-tube designs, also are considered.

Progress in cosmic ray research since 1947

Cosmic ray physics, which ten years ago was a fairly specialized branch of science, has in the course of its recent development become closely linked with many other fields of research. It has become an integral part of astrophysics, radioastronomy, and solar physics; it has made important contributions to such diverse fields as geomagnetism, hydrology, and archeology, and has begun to gain some importance in the study of meteorites and of oceanography and meteorology. It has also given rise to one of the newest and most active branches of physics, ‘particle physics,’ and has thereby provided the impetus for designing the large and powerful particle accelerators which are now in operation or under construction in various parts of the world. This paper is a survey of the most important developments which have taken place in cosmic ray physics during the last decade. The principal technical advances which have exerted decisive influence on cosmic ray research are the development of large stratosphere balloons, of nuclear emulsions, and of radio telescopes, as well as the great progress made since the war in radio chemistry and in low level beta- and gamma-ray counting. The three sections following the introduction discuss how, with the help of these and other techniques, the nature of the primary cosmic ray particles was determined and how a connection was established between cosmic ray effects and astrophysical and solar phenomena. The next section deals with largely successful efforts which have been made to understand the complicated chain of processes by which the energy carried by primary cosmic ray particles entering from outer space is first distributed over a great variety of new stable and unstable particles and finally is dissipated within the atmosphere. The two following sections treat the discovery of stable and radioactive isotopes which are produced during the passage of cosmic radiation through the atmosphere and contain a short review of the application which these isotopes have found in other branches of science. The last section contains a brief discussion of still unsolved problems which have now become accessible because of more recent technical advances such as satellites, permanent polar stations, and synoptic cosmic ray observations during the International Geophysical Year.