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Stellar surface fusion

Main articles: Stars/Surface fusion and Stellar surface fusion

RHESSI observes high-energy phenomena from a solar flare. Credit: NASA/Goddard Space Flight Center Scientific Visualization Studio.

Stellar surface fusion occurs above a star's photosphere to a limited extent as found in studies of near coronal cloud activity.

Surface fusion is produced by reactions during or preceding a stellar flare and at much lower levels elsewhere above the photosphere of a star.

"Nuclear interactions of ions accelerated at the surface of flaring stars can produce fresh isotopes in stellar atmospheres."

"This energy [10³² to 10³³ ergs] appears in the form of electromagnetic radiation over the entire spectrum from γ-rays to radio burst, in fast electrons and nuclei up to relativistic energies, in the creation of a hot coronal cloud, and in large-scale mass motions including the ejections of material from the Sun."

"The new reaction ²⁰⁸Pb(⁵⁹Co,n)²⁶⁶Mt was studied using the Berkeley Gas-filled Separator [BGS] at the Lawrence Berkeley National Laboratory [LBNL] 88-Inch Cyclotron."

²⁶⁶Mt has been produced using the ²⁰⁹Bi(⁵⁸Fe,n)²⁶⁶Mt reaction.

"Reactions with various medium-mass projectiles on nearly spherical, shell-stabilized ²⁰⁸Pb or ²⁰⁹Bi targets have been used in the investigations of transactinide (TAN) elements and their decay properties for many years. These so-called “cold fusion” reactions produce weakly excited (10-15 MeV) [1] compound nuclei (CNs) at bombarding energies at or near the Coulomb barrier that de-excite by the emission of one to two neutrons."

"The laboratory-frame, center-of-target energy used was 291.5 MeV, corresponding to a CN excitation energy of 14.9 MeV."

"At the start of the experiment the BGS magnet settings were chosen to guide products with a magnetic rigidity of 2.143 T·m to the center of the [focal plane detector] FPD. After the first event of ²⁶⁶Mt was detected in strip 45 (near one edge of the FPD), the magnetic field strength was decreased to 2.098 T·m in an effort to shift the distribution of products toward the center of the detector."

"²⁵⁸Db [has been produced] via the ²⁰⁹Bi(⁵⁰Ti,n) and ²⁰⁸Pb(⁵¹V,n) reactions [15], and ²⁶²Bh via the ²⁰⁹Bi(⁵⁴Cr,n) and ²⁰⁸Pb(⁵⁵Mn,n) reactions [13, 16]."

"Hofmann et al. at Gesellschaft für Schwerionenforschung (GSI) in Darmstadt, Germany, and Morita et al., at the Institute of Physical and Chemical Research (RIKEN) in Saitama, Japan, have studied the ²⁰⁹Bi(⁶⁴Ni,n)²⁷²Rg reaction [7, 17, 18]. The complementary ²⁰⁸Pb(⁶⁵Cu,n)²⁷²Rg reaction was studied by Folden et al. at the Lawrence Berkeley National Laboratory (LBNL) [19]."

"Based on the observation of the long-lived isotopes of roentgenium, ²⁶¹Rg and ²⁶⁵Rg (Z = 111, t_1/2 ≥ 10⁸ y) in natural Au, an experiment was performed to enrich Rg in 99.999% Au. 16 mg of Au were heated in vacuum for two weeks at a temperature of 1127°C (63°C above the melting point of Au). The content of ¹⁹⁷Au and ²⁶¹Rg in the residue was studied with high resolution inductively coupled plasma-sector field mass spectrometry (ICP-SFMS). The residue of Au was 3 × 10⁻⁶ of its original quantity. The recovery of Rg was a few percent. The abundance of Rg compared to Au in the enriched solution was about 2 × 10⁻⁶, which is a three to four orders of magnitude enrichment."