Internal bremsstrahlung from²⁰⁴Tl and⁹¹Yt

Internal bremsstrahlung from Pr-143

“…Concerning the results of IB due to Berenyi et al which were found to agree closely with the KUBN theory and thus being different from the results of Cederlund and Starfelt, Langevin-Joliot and also from the present results, it may be stated that it is hard to accept the explanation offered by them for the experimental surplus of IB over theory in the earlier studies as of instrumental origin since their same type of differential measurements of IB from 2~ were seen to agree qualitatively with those of single counter measurements of Ricci [21] and Narasimha Murty [20] where also such experimental inadequacies are likely to be present. The total yields of intensity and of energy of IB from this isotope in the investigated energy region of 40 to 830 keV is determined to be 1.591 x 10-3 (1.267 x 10-3; 1.639 x 10 -3) and 0.723 x 10 .3 (0.519 x 10 3; 0.687 x 10 -3) respectively.…”

“…The IB spectra were recorded with a multichannel-NaI(T1) scintillation spectrometer consisting of a sealed NaI(T1) Harshaw crystal of 1• in diameter ~2 and 1" thick optically coupled to a Dumont 6292 photomultiplier, a non-over loading linear pulse amplifier and a multichannel pulseheight analyser of ND 1100 system along with a standard geometrical set up. The experimental arrangement except for some minor modifications is essentially the same as that mentioned in one of our earlier publications [20]. To eliminate air disturbances, the source and the detector were kept in vacuum which is maintained at less than 1 mm pressure.…”

“…In order to obtain the true IB photon distribution, the measured IB pulseheight distributions are corrected for energy resolution, backscattering, geometrical and gamma detection efficiencies of the crystal, iodine K x-ray escape, Compton electron distribution, background, dead time of the electronic assembly and absorption of the radiation in the beta stopper and in the aluminium can of the crystal. In the present investigation the procedure adopted for these correctins and the way of estimation of various possible errors in the measurements as well as in the calculation of various correction factors are similar to that employed by Narasimha Murty and Jnanananda [20]. The different errors are given in percentages ha the Table 1, in which the error in the determination of the total activity of the source is not included because D.G.S.…”

Internal Bremsstrahlung from14C and36Cl

“…Under these conditions no satisfactory explanation can be given to the observed experimental excess over theory in this case except concluding that its nature is but like that. In this context it may be noted that this kind of trend of the IB experimental results relative to the theory (KUB) was observed for some of the cases [8,[12][13][14][15][16] investigated earlier such as P-32, Y-91, Pr-143, Y-90 and S-35 where also no satisfactory explanation for the trend could be given. It is interesting to state that no earlier punished work on IB from 14C has been found in the literature available here.…”

“…As mentioned in the case of 14C, here also the contribution to IB from the EB in the source as well as in the perspex beta stopper cannot be considered so much as to give rise to the large observed IB excess over theory in the low energy region below 140 keV. Under these circumstances it is hard indeed to understand the real cause for the observed experimental IB excess over theory except to make a reference [12] to a similar situation that was found in the case of IB from 2~ which was studied earlier a number of times.…”