47 



with X and alpha rays. These results have been considered in the interpreta- 

 tion of temperature effects in certain biological systems. 



HOCHANADEL: One reason for our initiating a study of the radiation chem- 

 istry of ice was the observation of Bonet- Maury that no hydrogen peroxide was 

 produced in ice irradiated with X rays at temperatures below -116°C. In con- 

 trast to this, Ghormley and Allen had found considerable gas production by self 

 radiation in tritium ice at -196°C. In the present work, Ghormley and Stewart 

 find peroxide in ice irradiated with gamma rays at all temperatures from 4° K 

 to 273° K. 



ALLEN: If you freeze de-aerated water and obtain ice as pure as possible, 

 and you irradiate it with gamma rays while it is very cold, and then you warm 

 it up, you say you do find peroxide, whereas if you irradiate when it is not fro- 

 zen you do not find peroxide? 



HOCHANADEL: In a sample tube containing no gas space, a low steady 

 state concentration of peroxide is produced by gamma rays in liquid water near 

 0°C ; however, this concentration is somewhat smaller than the steady state 

 concentration in ice near 0°C. Both the yield of peroxide production and the 

 yield of back reaction are probably larger in the liquid than in the solid near 

 0°C, however, the steady state concentration is lower in the liquid. 



PLATZMAN: Does the yield decrease as the temperature declines? 



HOCHANADEL: The yield for peroxide formation decreases continually 

 with temperature from zero down to liquid nitrogen temperature below which the 

 yield is nearly constant down to liquid helium temperature. 



ALLEN: Right near the melting point you still get a big yield of peroxide? 



HOCHANADEL: That is right. 



ALLEN: Even though just above the melting point you would not find it? 



HOCHANADEL: Near the melting point the steady state concentration is 

 lower in the liquid than in the solid. 



BURTON: The rate at which you come up from the low temperature will have 

 a great bearing upon the results that are observed because you observe your 

 results only in liquid water. 



HOCHANADEL: A study of the effect of rate of warming of the irradiated ice 

 has not been made, although no appreciable effect is expected. 



ZIRKLE: Is this work in report form anywhere? 



HOCHANADEL: This work is published in Oak Ridge National Laboratory, 

 Chemistry Division quarterly reports. Papers will be presented both at the 

 Radiation Research Society meeting and at the Gordon Research Conference in 

 June. A paper will also be submitted for publication in the open literature very 

 soon. 



POLLARD: There is a way by which you can use all cosmic ray data without 

 changing the data to tell you the average of primary ionization. It does tell the 

 number of places where events will happen. This works out from data purely 

 taken from electrons, which is rather unfortunate, to be 110 volts per primary 



