scholarly journals The energy calibration of the IFIN-HH 3 MV Tandetron accelerator for alpha particles

AIP Advances ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 085307
Author(s):  
D. Pantelica ◽  
C. R. Nita ◽  
R. A. Ionescu ◽  
M. D. Mihai ◽  
P. Ionescu
2017 ◽  
Author(s):  
◽  
Haruetai Kasiwattanawut

In this work, the single crystal Chemical Vapor Deposition (CVD) diamond detectors were designed and fabricated to investigate and detect any possible charged particle and neutron emissions from gas-phase Low Energy Nuclear Reaction (LENR) experiments at room temperature. The diamond detectors were used in two experimental gas loading systems, palladium-deuterium, and nickel hydrogen. Palladium and nickel were used as host materials. Thin film layers of Ti/Pd and Ti/Pt/Au/Ni were deposited on the CVD diamond plates by evaporation techniques to create an Ohmic contact. Electronic characterizations of the detectors were completed by current-voltage measurements and energy calibration with alpha particles. The simulation and experimental run of the diamond detector with alpha and beta radiations exposures were done to determine the response of the detector to charged particles. The experimental results show that the diamond detectors observed and detected significant signal bursts from the gas loading experiments. The results from this work demonstrate that diamond detectors are suitable for alpha and beta radiation detection.


1917 ◽  
Vol s4-44 (259) ◽  
pp. 69-72 ◽  
Author(s):  
H. J. Vennes
Keyword(s):  

Author(s):  
E. L. Wolf

Protons in the Sun’s core are a dense plasma allowing fusion events where two protons initially join to produce a deuteron. Eventually this leads to alpha particles, the mass-four nucleus of helium, releasing kinetic energy. Schrodinger’s equation allows particles to penetrate classically forbidden Coulomb barriers with small but important probabilities. The approximation known as Wentzel–Kramers–Brillouin (WKB) is used by Gamow to predict the rate of proton–proton fusion in the Sun, shown to be in agreement with measurements. A simplified formula is given for the power density due to fusion in the plasma constituting the Sun’s core. The properties of atomic nuclei are briefly summarized.


Author(s):  
Frank S. Levin

Quantum tunneling, wherein a quanject has a non-zero probability of tunneling into and then exiting a barrier of finite width and height, is the subject of Chapter 13. The description for the one-dimensional case is extended to the barrier being inverted, which forms an attractive potential well. The first application of this analysis is to the emission of alpha particles from the decay of radioactive nuclei, where the alpha-nucleus attraction is modeled by a potential well and the barrier is the repulsive Coulomb potential. Excellent results are obtained. Ditto for the similar analysis of proton burning in stars and yet a different analysis that explains tunneling through a Josephson junction, the connector between two superconductors. The final application is to the scanning tunneling microscope, a device that allows the microscopic surfaces of solids to be mapped via electrons from the surface molecules tunneling into the tip of the STM probe.


Author(s):  
Roger H. Stuewer

Frédéric Joliot discovered artificial radioactivity on January 11, 1934, when he bombarded aluminum with polonium alpha particles and produced a radioactive isotope of phosphorus that decayed by emitting a positron. He detected it with a Geiger–Müller counter that Wolfgang Gentner had constructed for him. Two months later, Enrico Fermi, motivated in part by an insight of his first assistant, Gian Carlo Wick, decided to see if neutrons also could produce artificial radioactivity. The transformation of a neutron into a proton in a nucleus should create an electron, so to increase their number and hence the probability of creating an electron, he bombarded various elements with intense sources of neutrons, and on March 20, 1934, with aluminum he observed the created electrons and thereby discovered neutron-induced artificial radioactivity. Less than four months later, Marie Curie died on July 4, 1934, at age sixty-six.


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.


Author(s):  
Roger H. Stuewer

Serious contradictions to the existence of electrons in nuclei impinged in one way or another on the theory of beta decay and became acute when Charles Ellis and William Wooster proved, in an experimental tour de force in 1927, that beta particles are emitted from a radioactive nucleus with a continuous distribution of energies. Bohr concluded that energy is not conserved in the nucleus, an idea that Wolfgang Pauli vigorously opposed. Another puzzle arose in alpha-particle experiments. Walther Bothe and his co-workers used his coincidence method in 1928–30 and concluded that energetic gamma rays are produced when polonium alpha particles bombard beryllium and other light nuclei. That stimulated Frédéric Joliot and Irène Curie to carry out related experiments. These experimental results were thoroughly discussed at a conference that Enrico Fermi organized in Rome in October 1931, whose proceedings included the first publication of Pauli’s neutrino hypothesis.


2020 ◽  
Vol 86 (5) ◽  
Author(s):  
Y. Lin ◽  
J. C. Wright ◽  
S. J. Wukitch

Ion cyclotron range of frequencies (ICRF) heating will be the sole auxiliary heating method on SPARC for both full-field (Bt0 ~ 12 T) D–T operation and reduced field (Bt0 ~ 8 T) D–D operation. Using the fast wave at ~120 MHz, good wave penetration and strong single-pass absorption is expected for D–T(3He), D(3He), D(H) and 4He(H) heating scenarios. The dependences of wave absorption on ${k_\parallel }$ , 3He concentration, resonance location, antenna poloidal location and losses on alpha particles and ash have been studied. The antenna loading has been assessed by comparison with the Alcator C-Mod antennae. An antenna spectrum of ${k_\parallel }\sim 15\text{--}18\,{\textrm{m}^{ - 1}}$ is shown to be good for both core absorption and edge coupling. For the control of impurity sources, the antenna straps are rotated ~10° to be perpendicular to the B field and the straps can run with different power levels in order to optimize the antenna spectrum and to minimize the image current on the antenna frame. Combining the physics constraints with the SPARC port design, maintenance requirement and contingency against antenna failure during D–T operation, we plan to mount on the inner wall of the vacuum vessel a total of 12 4-strap antennae in 6 ports while keeping 3-strap antennae that are insertable and removable on port plugs as the backup option.


Sign in / Sign up

Export Citation Format

Share Document