Lonely Planet's Experience Portugal travel guide reveals exciting new ways to explore this iconic destination with one-of-a-kind adventures at every turn. Feast on fresh fish in the Algarve, enjoy a yoga class with wine, island-hop the white sand banks of the Ria Formosa - using our local experts and planning tools to create your own unique trip. Inside Lonely Planet's Experience Portugal: Local experts share their love for the real Portugal, offering fresh perspectives into the country's traditions, values and modern trends to make your travel experience even more meaningful In the know tips to help you build on your experiences when visiting well-known sights and landmarks Fun insights that will pique your curiosity and take you to the heart of the place - embrace Alentejo's slow paced vibe with olive harvesting and horse riding; discover riverside Porto by bike and stop for freshly grilled seafood in Afurada; dive in the crisp waters of the human-made Azibo reservoir Insider scoop on the best festivals, secret hangouts, hidden locations, tantalising local food scene and photo-worthy views Handy seasonal trip planner to guide you on where to go, when to travel and what to pack Practical information on money, getting around, unique and local ways to stay, and responsible travel Comprehensive selection of maps throughout and beautiful full-colour photography to inspire you as you plan your unforgettable journey Covers Lisbon, Alentejo, The Algarve, Porto, Douro Valley, Tras-os-Montes Lonely Planet's Experience Portugal is an essential travel guide for all explorers looking to immerse themselves in the Portuguese way of life. Each book within the Experience series contains handy trip building tools so that you can take your pick of the must-see attractions and activities as suggested by our local experts - and create your own dream travel itinerary to get away from the everyday. Unlock even more travel secrets using the QR codes throughout each guide and discover story-worthy travel moments that you'll never forget. About Lonely Planet: Lonely Planet, a Red Ventures Company, is the world's number one travel guidebook brand. Providing both inspiring and trustworthy information for every kind of traveller since 1973, Lonely Planet reaches hundreds of millions of travellers each year online and in print and helps them unlock amazing experiences. Visit us at lonelyplanet.com and join our community of followers on Facebook (facebook.com/lonelyplanet), Twitter (@lonelyplanet), Instagram (instagram.com/lonelyplanet), and TikTok (@lonelyplanet). "...these new Experience guides from Lonely Planet are irresistibly attractive." - The Washington Post Book Club "Lonely Planet. It's on everyone's bookshelves; it's in every traveller's hands. It's on mobile phones. It's on the Internet. It's everywhere, and it's telling entire generations of people how to travel the world." - Fairfax Media (Australia)

IONIZATION CHAMBERS AND COUNTERS Experimental Techniques by BRUNO B. ROSSI Professor of Physics, Massachusetts Institute of Technology and HANS H. STAUB Professor of Physics, Stanford University First Edition New York Toronto London McGRAW-HILL BOOK COMPANY, INC. 1949 IONIZATION CHAMBERS AND COUNTERS Experimental Techniques Copyright, 1949, by the McGraw-Hill Book Company, Inc. Printed in the United States of America Copyright assigned, 1949, to the General Manager of the United States Atomic Energy Commission. All rights reserved. This book, or parts thereof, may not be reproduced in any form without per mission of the Atomic Energy Commission. Lithoprinted by Edwards Brothers, Incorporated Ann Arbor, Michigan FOREWORD The United States program of development of atomic energy has been described by Major General L. R. Groves, who, as Commanding General of the War Departments Manhattan Project, directed the program from mid-1942 until December 31, 1946, as a generation of scientific development compressed into three years. The tremen dous scope of the Manhattan Project Technical Section of the National Nuclear Energy Series, which has been in preparation since 1944, is a tribute to the unprecedented accomplishments of science, industry, government, labor, and the Army and Navy working together as a team. These volumes can be a firm foundation for the United States atomic energy program which, in the words of the Atomic Energy Act of 1946, is . . . directed toward improving the public welfare, in creasing the standard of living, strengthening free competition in private enterprise, and promoting world peace. David E. Lilienthal, Chairman U. S. Atomic Energy Commission ACKNOWLEDGMENT TheManhattan Project Technical Section of the National Nuclear Energy Series embodies results of work done in the nations wartime atomic energy program by numerous contractors, including Columbia University. The arrangements for publication of the series volumes were effected by Columbia University, under a contract with the United States Atomic Energy Commission. The Commission, for itself and for the other contractors who contributed to this series, wishes to record here its appreciation of this service of Columbia University in support of the national nuclear energy program. PREFACE This volume is one of a series which has been prepared as a record of the research work done under the Manhattan Project and the Atomic Energy Commission. The name Manhattan Project was assigned by the Corps of Engineers, War Department, to the far-flung scientific and engineering activities which had as their objective the utilization of atomic energy for military purposes. In the attainment of this objec tive, there were many developments in scientific and technical fields which are of general interest. The National Nuclear Energy Series Manhattan Project Technical Section is a record of these scientific and technical contributions, as well as of the developments in these fields which are being sponsored by the Atomic Energy Commission. The declassified portion of the National Nuclear Energy Series, when completed, is expected to consist of some 60 volumes. These will be grouped into eight divisions, as follows Division I Electromagnetic Separation Project Division II Gaseous Diffusion Project Division III Special Separations Project Division IV Plutonium Project Division V Los Alamos Project Division VIUniversity of Rochester Project Division VII Materials Procurement Project Division VIII Manhattan Project Soon after the close of the war the Manhattan Project was able to give its attention to the preparation of a complete record of the research work accomplished under Project contracts. Writing pro grams were authorized at all laboratories, with the object of obtaining complete coverage of Project results...