CONTENTS ~ ABSTRACT - - ---- 77 oo or rere ore sees ewes ee ccoor sess sssssssss 5 FOREWORD: ewer rer rr rrr crreerrr errs rrsr ese cers crrers tose ence 6 ce cnn PREFACE------- orc errr rene ccrccr crass esc 6 CHAPTER 1 INTRODUCTION ---------0---r remem nen n nen n nen e nen nnn 1 1.1 Objectives------- ort rrr rer terete cer rent nn cnn een nne 11 1.2 Background and Theory ------- wert tte rece err ert cen ec enne 11 1.2.1 Formation and Nature of Fallout Particles ---------------------- 12 1.2.2 Cloud Development- - ------------------ 22-27 rr rere eee enn 14 1.2.3 Transport and Distribution ---------------------+-------+--- 14 1.2.4 Procedures for the Determination of Fallout Partition -------------- 15 1.2.5 Prior Estimates of Local Fallout ------+------------+----+------ 16 1.2.6 Worldwide Fallout ------------------+----------+--------- 18 1.2.7 Fractionation Effects-—— Observations at Other Tests --------------- 17 1.2.8 Fractionation Effects— Relations among the R-Values for Several Radionuclides ----------+-+-------------++------+-s- 18 1.8 Experimental Program -- ------ 22-2 enter wee eee meer een ee ee nee 18 1.3.1 Outline of the Program ----------2-2 2-2 eee een ee ene een ee een 18 1.3.2 Rocket Sampling of Clouds -~-------------------------+-----+- 19 1.3.3 Aircraft Sampling of Clouds -----------------+---+----+------ 20 1.3.4 Aircraft Sampling of Fallout ---------------22--------e2--e-- 20 1.3.5 Selection of Radionuclides --------------------------e------ 21 CHAPTER 2 PROCEDURE ----------------- eens cen r nn nr een ee en nee 22 2.1 Shot Participation -----------+--------- +--+ - se ee nee ee eee eee 22 2.2 Instrumentation - --------- 222-2 ee ee ee ee ee ee et ee ee eee ee ee ee 22 2.3 Field Operations --------------------+------- +22 - ee eee eee ee 24 2.3.3 Shot Walnut --------------------- + - 2 eee ee ee eee 2.3.4 Shot Oak -------------- 2-2 ee ee ee ee ee ee ee ee ee ee eee 25 25 2.4 Particle Work -----------2- ee - ene een ee ee ee ee ee ee ee ee ee 27 2.6 Data Reduction -------------c- ene eee ee ne ene ee ee ee ee eee eee 28 RESULTS AND DISCUSSION -----------------------+------ 37 3.1 Discussion and Interpretation of the Data ----------------+---------- 37 3.1.2 Fallout Data -----------~--------------- ee ee ee eee eee eee 38 2.2.1 Rocketborne Cloud Sampler - ----------------+---+-+---------- 22 2.2.2 Aircraftborne Samplers -----------------------+-+---------- 23 2.2.3 Possible Errors in Sampling -----------------------------+-- 23 2.3.1 Meteorology ------------+------------+--2-- 22 -- +--+ eee 24 2.3.2 Shot Koa ~-------- cen evn ne cee ene ne eee ee ee wee eee ewan 24 2.3.5 Rocket Development - ------------------------------------ 26 2.3.6 Aircraft Samples --------~--------------------+---------- 26 2.5 Sample Analysis and Radlochemical Procedures --------------------- 27 CHAPTER 3 3.1.1 Cloud Data ------------~-----+------------+--------+--- +e 37