From cover page: This document has been assigned the above MDDC (Manhattan District Declassification) number, as given in the List of Declassified Documents issued semi-monthly by the Research Division, Manhattan District. In the case of Los Alapnos reports, LADC (Los Alamos Declassification) numbers are listed on the title page if known. This declassified document may differ materially from the original classified document by reason of deletions necessary to accomplish declassification. Hence, this copy of a declassified document does not constitute authority for declassification of classified copies of a similar document which may bear the same title and authors. Reference is made to District Circular Letter (Research Control 47-3) dated 31 October 1946, subject: "Instructions for Use of List of Declassified Documents," which outlines the procedure by means of which declassification of classified copies may be effected. Every effort has been made to reproduce with accuracy of detail the declassified document as certified for declassification. No corrections or changes have been made in the content of the document.
From foreword: "Construction of some typical ionization detectors and their operation, with most developed at the Los Alamos Laboratory and a few at other projects connected with the development of the atomic bomb." This report includes chapters 8-16 and an appendix to the second part.
From introduction: "Discussion of alternate processes for manufacture of perfluoroxylene as insurance against any eventuality, e.g. disaster, poor quality, required amount of elemental fluorine not obtainable, necessity for further expansion at some future date, or decreasing cost."