Mass Measurement of Upper fp-Shell N=Z-2 and N=Z-1 Nuclei and the Importance of Three-Nucleon Force along the N=Z Line

Using a novel method of isochronous mass spectrometry, the masses of ^{62}Ge, ^{64}As, ^{66}Se, and ^{70}Kr are measured for the first time, and the masses of ^{58}Zn, ^{61}Ga, ^{63}Ge, ^{65}As, ^{67}Se, ^{71}Kr, and ^{75}Sr are redetermined with improved accuracy. The new masses allow us to derive residual proton-neutron interactions (δV_{pn}) in the N=Z nuclei, which are found to decrease (increase) with increasing mass A for even-even (odd-odd) nuclei beyond Z=28. This bifurcation of δV_{pn} cannot be reproduced by the available mass models, nor is it consistent with expectations of a pseudo-SU(4) symmetry restoration in the fp shell. We performed ab initio calculations with a chiral three-nucleon force (3NF) included, which indicate the enhancement of the T=1 pn pairing over the T=0 pn pairing in this mass region, leading to the opposite evolving trends of δV_{pn} in even-even and odd-odd nuclei.

A 410 MHz resonant cavity pickup for heavy ion storage rings

An improved design of a longitudinally sensitive resonant Schottky cavity pickup for the heavy ion storage rings of the Facility for Antiproton and Ion Research in Europe (FAIR) project is reported. The new detector has a higher measured Q value of ∼3000 and a higher simulated shunt impedance of 473.3 kΩ. It is possible to vary the sensitivity of the cavity with a motorized mechanism by inserting a dissipative blade during the operation based on experimental needs. Apart from a lower price tag, the new design features a more robust and production-friendly mechanical structure suitable for a series production in the future FAIR project. The manufactured cavity was built temporarily into the experimental storage ring and had delivered its first results using stored heavy ion beams. The structure, simulation results, and performance of this cavity are presented in this work.

Direct observation of long-lived isomers in 212Bi

Long-lived isomers in (212)Bi have been studied following (238)U projectile fragmentation at 670 MeV per nucleon. The fragmentation products were injected as highly charged ions into a storage ring, giving access to masses and half-lives. While the excitation energy of the first isomer of (212)Bi was confirmed, the second isomer was observed at 1478(30) keV, in contrast to the previously accepted value of >1910 keV. It was also found to have an extended Lorentz-corrected in-ring half-life >30 min, compared to 7.0(3) min for the neutral atom. Both the energy and half-life differences can be understood as being due a substantial, though previously unrecognized, internal decay branch for neutral atoms. Earlier shell-model calculations are now found to give good agreement with the isomer excitation energy. Furthermore, these and new calculations predict the existence of states at slightly higher energy that could facilitate isomer deexcitation studies.

Study of Monarda fistulosa essential oil as a prospective antiseborrheic agent

Monarda fistulosa essential oil characterized by pronounced therapeutic effects is proposed for the treatment of seborrhea. Studies of its antibacterial, antimycotic, and antiinflammatory activities showed that it inhibits microorganism growth and is superior to hydrocortisone in combination with vitamin B6 by its antiinflammatory activity.

Schottky mass measurement of the 208Hg isotope: implication for the proton-neutron interaction strength around doubly magic 208Pb

Time-resolved Schottky mass spectrometry has been applied to uranium projectile fragments which yielded the mass value for the 208Hg (Z=80, N=128) isotope. The mass excess value of ME=-13 265(31) keV has been obtained, which has been used to determine the proton-neutron interaction strength in 210Pb, as a double difference of atomic masses. The results show a dramatic variation of the strength for lead isotopes when crossing the N=126 neutron shell closure, thus confirming the empirical predictions that this interaction strength is sensitive to the overlap of the wave functions of the last valence neutrons and protons.

Measurement of the beta+ and orbital electron-capture decay rates in fully ionized, hydrogenlike, and heliumlike 140Pr ions

We report on the first measurement of the beta+ and orbital electron-capture decay rates of 140Pr nuclei with the simplest electron configurations: bare nuclei, hydrogenlike, and heliumlike ions. The measured electron-capture decay constant of hydrogenlike 140Pr58+ ions is about 50% larger than that of heliumlike 140Pr57+ ions. Moreover, 140Pr ions with one bound electron decay faster than neutral 140Pr0+ atoms with 59 electrons. To explain this peculiar observation one has to take into account the conservation of the total angular momentum, since only particular spin orientations of the nucleus and of the captured electron can contribute to the allowed decay.

[Effect of acetylcholine and histamine on electrolyte and catecholamine content of vessel walls exposed to x-rays and cystamine]

Experiments on adult rats have shown that a single rectal x-ray irradiation is accompanied by a decrease in the content of adrenaline, noradrenaline and potassium and by a increase in sodium and calcium concentration in vascular tissue. The degree of these shifts depends on the time elapsed after exposure to x-rays. X-Ray injury produces specific changes in the biochemical response of the vascular wall to different doses of acetylcholine and histamine during varying times of x-ray-induced pathology. Pretreatment (before irradiation) with radioprotectors (cistamine) lowers the damaging effect of radiation and promotes the normalization of the vascular tissue response to the administration of mediator agents.

[Catecholamine and electrolyte content in the vascular wall of animals with radiation sickness and administered radioprotectors]

Experiments on adult cats have shown that total x-ray irradiation in a single dose of 400 Gy produces different changes in electrolyte and catecholamine metabolism in the aortal wall in response to the injection of varying doses of adrenaline (1.5, 15, 150 mg/kg). Premedication with cystamine (75 mg/kg) lowers the degree and frequency of inadequate changes in the biochemical response of vascular tissue to adrenaline injection in a dose of 15 mg/kg.