Book contents
- Frontmatter
- Contents
- List of Illustrations
- Preface
- 1 Introduction
- 2 Early Research on Fission: 1933–1943
- 3 The Early Materials Program: 1933–1943
- 4 Setting Up Project Y: June 1942 to March 1943
- 5 Research in the First Months of Project Y: April to September 1943
- 6 Creating a Wartime Community: September 1943 to August 1944
- 7 The Gun Weapon: September 1943 to August 1944
- 8 The Implosion Program Accelerates: September 1943 to July 1944
- 9 New Hopes for the Implosion Weapon: September 1943 to July 1944
- 10 The Nuclear Properties of a Fission Weapon: September 1943 to July 1944
- 11 Uranium and Plutonium: Early 1943 to August 1944
- 12 The Discovery of Spontaneous Fission in Plutonium and the Reorganization of Los Alamos
- 13 Building the Uranium Bomb: August 1944 to July 1945
- 14 Exploring the Plutonium Implosion Weapon: August 1944 to February 1945
- 15 Finding the Implosion Design: August 1944 to February 1945
- 16 Building the Implosion Gadget: March 1945 to July 1945
- 17 Critical Assemblies and Nuclear Physics: August 1944 to July 1945
- 18 The Test at Trinity: January 1944 to July 1945
- 19 Delivery: June 1943 to August 1945
- Epilogue
- 20 The Legacy of Los Alamos
- Notes
- Name Index
- Subject Index
7 - The Gun Weapon: September 1943 to August 1944
Published online by Cambridge University Press: 31 March 2010
- Frontmatter
- Contents
- List of Illustrations
- Preface
- 1 Introduction
- 2 Early Research on Fission: 1933–1943
- 3 The Early Materials Program: 1933–1943
- 4 Setting Up Project Y: June 1942 to March 1943
- 5 Research in the First Months of Project Y: April to September 1943
- 6 Creating a Wartime Community: September 1943 to August 1944
- 7 The Gun Weapon: September 1943 to August 1944
- 8 The Implosion Program Accelerates: September 1943 to July 1944
- 9 New Hopes for the Implosion Weapon: September 1943 to July 1944
- 10 The Nuclear Properties of a Fission Weapon: September 1943 to July 1944
- 11 Uranium and Plutonium: Early 1943 to August 1944
- 12 The Discovery of Spontaneous Fission in Plutonium and the Reorganization of Los Alamos
- 13 Building the Uranium Bomb: August 1944 to July 1945
- 14 Exploring the Plutonium Implosion Weapon: August 1944 to February 1945
- 15 Finding the Implosion Design: August 1944 to February 1945
- 16 Building the Implosion Gadget: March 1945 to July 1945
- 17 Critical Assemblies and Nuclear Physics: August 1944 to July 1945
- 18 The Test at Trinity: January 1944 to July 1945
- 19 Delivery: June 1943 to August 1945
- Epilogue
- 20 The Legacy of Los Alamos
- Notes
- Name Index
- Subject Index
Summary
Although the problem of producing a gun weapon seemed relatively simple as the laboratory entered the summer of 1943, William Parsons and Charles Critchfield soon recognized that the guns needed to assemble uranium and plutonium would be very different from the ordinary ones that shot high-explosive projectiles at targets. The Ordnance and Engineering Division (E) did not know enough about the critical masses of plutonium and uranium, their metallurgical properties, or the speed required by nuclear constraints to assemble an effective plutonium weapon. Three points were clear: the guns would have to be designed from scratch – standard ordnance cannon could not be adapted to this use; extensive testing of both the plutonium and uranium guns and their mockup target and projectile components would be required; and targets and projectiles of active material would have to be designed. No one had yet tried to create an explosion using two or more pieces of fissionable material. Work on the gun gadget proceeded along three paths – interior ballistics research, experimental testing of designs, and target-projectile-initiator development. Each proceeded more or less independently until the reorganization of the laboratory in August 1944 consolidated all gun work.
Between April 1943 and August 1944, Parsons, Critchfield, Edwin McMillan, and Joseph Hirschfelder designed, created, and tested all the principal components of the gun gadget, including the gun mechanism, target and projectile geometries, and initiators.
- Type
- Chapter
- Information
- Critical AssemblyA Technical History of Los Alamos during the Oppenheimer Years, 1943–1945, pp. 111 - 128Publisher: Cambridge University PressPrint publication year: 1993