Determination of the Ranges and Straggling of Low-Energy Alpha Particles in a Cloud Chamber

1954 ◽  
Vol 96 (3) ◽  
pp. 673-678 ◽  
Author(s):  
S. Barile ◽  
R. Webeler ◽  
G. Allen
Author(s):  
Roger H. Stuewer

In December 1931, Harold Urey discovered deuterium (and its nucleus, the deuteron) by spectroscopically detecting the faint companion lines in the Balmer spectrum of atomic hydrogen that were produced by the heavy hydrogen isotope. In February 1932, James Chadwick, stimulated by the claim of the wife-and-husband team of Irène Curie and Frédéric Joliot that polonium alpha particles cause the emission of energetic gamma rays from beryllium, proved experimentally that not gamma rays but neutrons are emitted, thereby discovering the particle whose existence had been predicted a dozen years earlier by Chadwick’s mentor, Ernest Rutherford. In August 1932, Carl Anderson took a cloud-chamber photograph of a positron traversing a lead plate, unaware that Paul Dirac had predicted the existence of the anti-electron in 1931. These three new particles, the deuteron, neutron, and positron, were immediately incorporated into the experimental and theoretical foundations of nuclear physics.


2018 ◽  
Vol 189 ◽  
pp. 227-235 ◽  
Author(s):  
S. Padilla ◽  
J.M. López-Gutiérrez ◽  
D.M.R. Sampath ◽  
T. Boski ◽  
J.M. Nieto ◽  
...  

1948 ◽  
Vol 74 (6) ◽  
pp. 699-700 ◽  
Author(s):  
Arthur Waltner ◽  
F. T. Rogers
Keyword(s):  

1995 ◽  
Vol 74 (16) ◽  
pp. 3169-3172 ◽  
Author(s):  
S. R. Bandler ◽  
S. M. Brouër ◽  
C. Enss ◽  
R. E. Lanou ◽  
H. J. Maris ◽  
...  

1997 ◽  
Vol 44 (6) ◽  
pp. 2065-2070 ◽  
Author(s):  
J.R. Turinetti ◽  
K.L. Critchfield ◽  
J.R. Chavez ◽  
W.T. Kemp ◽  
R.D. Bellem ◽  
...  
Keyword(s):  

The 90° cross-section of the reaction 3 1 H( d , n ) 4 2 He has been investigated over the energy range 100 to 200 keV (energy of bombarding triton) using the 200 keV accelerating set of the establishment. Two methods have been used. As a preliminary experiment the yield of alpha-particles from a thick heavy-ice target was measured per unit charge of incident beam, as a function of deuteron energy, and the variation of cross-section deduced from the gradient of this excitation curve and the range energy relation for tritons in heavy water. Secondly, a comparison was made between the yield of alpha-particles from the D-T reaction and the yield of protons from the D-D reaction when a beam containing both deuterons and tritons was passed through a heavy-water vapour target. (The energy loss in this target was calculated as only a few hundred electron volts.) To do this a simultaneous observation was made of the protons and alpha-particles using the same counter. The values obtained for the cross-section have been compared with the resonance formulae given by Bretscher & French (1949) and by Tascbek, Everhart, Gittings, Hemmendinger & Jarvis (1948) and have been found to be in disagreement with formulae of this type. From considerations of the absolute magnitude of the cross-section it has been deduced that no conventional theory postulating reaction at a distance equal to the sum of the nuclear radii (cf. Konopinski & Teller 1948) will be able to explain this reaction. The evidence for a low-energy resonance (Allan & Poole 1949) is thought to be inconclusive.


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