Document text
Machine-read from the scan, so expect some errors. Lines that couldn’t be read are left out.
Page 1
Positron emitting isotopes are obtained by irradiating stable elements target nuclei undergo photonuclear reactions with photons above the (y,d reaction threshold. The (y,n) cross section for the el em nts of priw interest, n m l y l6O, 1 4 N and I 2 C are sham in the figure below. Saturation activities for the 150-isotope are about .2 micro-curiedcc at S.T.P. at f u l l accelerator power with O2 as a target gas. and Ozone f o m readily and the resulting gas i s a mixture of 02,02', O3 and 03" is no way t o identify the annihilation gamrras as t o whether they originate Erom 02" or 03",the active W g e n , 02; must therefore be remved from the target gas before the Ozone containing breathing gas can be used. mre, a certain amount of ',IC is produced v i a the reaction 160(y,na) and C"02 results i n turn which also must be removed f r o m the gas. typical exposure of 'L 6 minutes the fraction of the total activity due t o Sow of the When Oxygen is exposed t o the bremsstrahlung X-rays,ionization occurs .'. This fraction increases exponentially with longer
Page 2
17ie total. integrated dose t o the lung from 364 pCi of retained ''0 would be about 35 mm. The dose i n the first minute would be 2.11 ti in z s, the dose to the lung would be about 1 0 percent of that allowed by AEC Appendix 0524. (15 EYper vear, 5REM per calendar quarter.) If small concentrations t h e lung air and would be exhaled. breaths would be negligible. This assms a conservatj-ve de1 with the oxygen d is tri - I f the experirrlc_nt were repcdted Standards for Radiation Proeection. w e R present as a contaminant it would fix with the cc)2 in The concentration after afew
Page 3
It is measured with implanted pressure transducers. This pertains t o t h e blocking of airways and is measured by observing t h e emptying of the lung as a function of breathing Is measured by mixing helium with t h e breathing air and observing how fast it comes out of the lung. 4) Resting ventilation is the n o m 1 breathing frequency. 5) Hyperpnea is t h e deep breathing action during exercise.
The text continues in the original scan (5 pages).