B. S. Cooper, H. A. Perrett, C. Ricketts, K. T Flanagan and the CRIS collaboration.
The CRIS technique (Collinear Resonance Ionisation Spectroscopy) has been shown to be an efficient method for accessing fundamental nuclear properties of exotic isotopes [1]. Currently, radioactive ion beams are produced via proton impact with a suitable target at the ISOLDE (Ion separator On-line) facility at...
The RadioFrequency Quadrupole cooler buncher (RFQcb or ISCOOL) is a permanent beam cooling installation on the High Resolution Separator (HRS) at ISOLDE. It is extensively used by many of the downstream experiments for beam preparation by reducing the transverse emittance and converting a DC beam into pulsed bunches.
An extensive investigation into the RFQcb bunching properties was carried...
Collinear resonant laser ionization spectroscopy is a powerful technique which can provide a unique insight in nuclear properties such as spin, electromagnetic moments and changes in mean-square charge radii from near doppler-free measurement of the hyperfine structure of exotic isotopes. This technique was recently used at the collinear resonant ionization spectroscopy (CRIS) beam line at...
The radiative capture reaction $^{13}$N(p,$\gamma$)$^{14}$O is an important reaction determining the transit from the Carbon-Nitrogen-Oxygen (CNO) cycle to the hot CNO cycle occurring in several astrophysical situations such as super-massive stars, novae etc. Since the direct measurement is difficult due to low cross section, Coulomb dissociation of $^{14}$O in the presence of a heavy target...
This work pertains to determining the spectroscopic quadrupole moment for the first 2+ state in 66Ge using “safe” Coulomb excitation measurements. Motivation to study 66Ge arises from the anomalous rotational behaviour of the high-lying first 2+ state observed in even-even isotopes in the A ~ 70 region [1]. Low-lying 0+ excited states have been suggested for even-even neutron-deficient nuclei...
In this talk, I will present the study of the decay of 8B into highly excited states of 8Be with the aim of determining the branching ratios. Our interest lies in the 2+ doublet at 16.6 and 16.9 MeV populated via β+ and electron capture (EC) respectively and also the so far unobserved EC-delayed proton emission via the 17.640 MeV state, that has a theoretical branching ratio of 2.3·10-8. The...
The experiments at the SEC and IDS with segmented silicon detectors utilize a VME-based DAQ with between 100 and 300 channels, typically. The achievable acquisition rates of modern triggered nuclear physics experiments are heavily dependent on the readout software. This contribution presents a novel readout scheme that minimizes the deadtime associated with data readout, thus lowering the...
The interest in Be in GaN stems from the challenge to understand why it is technologically feasible to dope this wide band gap semiconductor p-type with Mg, while this does not work for Be. While theory has actually predicted an acceptor level for Be that is shallower than Mg [1,2], it was also argued that Be would not be a suitable acceptor because its amphoteric nature, i.e. its tendency...
Collinear laser spectroscopy (CLS) is a powerful technique to probe the structure information of the ground and long-lived isomeric states by measuring their nuclear spins, moments and charge radii [1, 2, 3]. Over the last decade, this technique has been intensively employed for the study of the exotic isotopes of the Ni region, namely around the major proton shell closure at Z = 28 and...
Fusion reactions can play an important role in the dynamics of weakly-bound exotic nuclei at sub-Coulomb energies.
However, these measurements are usually difficult to perform due to the low value of cross sections and beam intensities.
In this contribution we discuss the advantages and limitations of applying radiochemical techniques using recent data
on the sub-barrier fusion of the...
The IS559 experiment is the first ever attempt of utilising the Oslo Method with a radioactive beam in inverse kinematics reactions. A $^{66}\mathrm{Ni}$ beam with 4.5 MeV/u hit a deuterated polyethylene target for a total of ≈ 10 days. The ultimate goal of the experiment is to look for particle-gamma coincidences from the d($^{66}\mathrm{Ni}$,p)$^{67}\mathrm{Ni}$ reaction, reconstructing the...
L. Barber [1], D. M. Cullen [1], B. S. Nara Singh [1], M. Giles [1], M. J. Taylor [1], P. Papadakis [2], E. Parr [2], J. Heery [2], T. Grahn [3], P. T. Greenlees [3], H. Badran [3], R. Julin [3], S. Juutinen [3], J. Konki [3], M. Leino [3], J. J. Pakarinen [3], J. Partanen [3], P. Rahkila [3], M. Sandzelius [3], J. Saren [3], J. Sorri [3] and J. Uusitalo [3].
[1] University of Manchester,...
11-Be is the neutron - rich nucleus expected to be a β-delayed proton emitter. The (very mall) branching ratio for this exotic decay mode (∼ 10e−6 ) was obtained through indirect
observations based on accelerator mass spectrometry [1, 2] and resulted to be about two
orders of magnitude larger than predicted by theory [3]. The direct measurement of the
delayed proton emission probability and...
Due to its high precision, accuracy, and resolution, Collinear Laser Spectroscopy (CLS) is an important experimental technique to access nuclear spins, electromagnetic moments, and mean square charge radii of short-lived radionuclides and hence provides insight into the nuclear shell structure [1]. However, to experimentally probe the most exotic nuclides, which can only be produced with low...
High entropy alloys are multicomponent alloys, which consist of four or more elements in equiatomic or nearly equiatomic concentrations. These materials are hypothesized to show significantly decreased self-diffusivities. The understanding of the diffusion kinetics in HEAs is of fundamental significance, however the present knowledge is limited to several interdiffusion investigations on the...
The strength function $ S_{\beta}(E) $ governs [1,2] the nuclear energy distribution of elementary charge-exchange excitations and their combinations like proton particle $({\pi}p)$-neutron hole $({\nu}h)$ coupled into a spin-parity $I^{\pi}$ : $[{\pi}p \otimes {\nu}h]I^{\pi}$ and neutron particle $({\nu}p)$-proton hole $({\pi}h)$ coupled into a spin-parity $I^{\pi} : [{\nu}p \otimes...
For certain combination of protons and neutrons an appearance of reflection asymmetry is expected. In particular, the experimentally determined E3 strengths as a function of the neutron number are peaked around N~88 and N~134. Many theoretical approaches have been applied to describe the regions of enhanced octupole collectivity and its experimental signatures, such as parity doublets in...
Over the last years the advance in experimental techniques allowed to refine the experimental knowledge on $^{133}$Sn, which is a key nucleus to deduce neutron single-particle (SP) energies above the doubly magic $^{132}$Sn core. The different adopted techniques allowed to obtain mutually consistent information about SP energies for $\nu p_{3/2}$, $\nu p_{1/2}$, $\nu h_{9/2}$ and $\nu f_{5/2}$...
Targeted Radionuclide Therapy (TRT) and diagnostics are currently the most intensively developing fields of nuclear medicine as they allow the very precise imaging of tumors (or other targeted tissues), and the minimization of healthy tissue damage during medical therapy. TRT relies on the labeling of a radionuclide to a targeting vector – a biomolecule that has a high affinity to...
In the atomic nucleus, the interplay between single-particle motion, collectivity and
pairing is seen as a rich tapestry of shape coexisting states and exotic excitations, often associated with so called intruder states. One region where this shape coexistence phenomenon is especially prevalent is in the very neutron-deficient nuclei close to Z=82 with a neutron number close to the mid-shell...
In December 2017 we recorded the first beta-NMR signals of 26Na in liquid samples [Kow18]using the Bio Beta-NMR setup at the VITO beamline [Kow17, Gin18]. 2018 has seen many beamline upgrades including a new charge exchange cell [Gin18], a home-build vacuum-compatible NMR magnetometer, a new magnet giving better homogeneity and higher field strength, a new measurement chamber and a temporal...
It is well known that there is a serious anomaly between the observed and Big Bang Nucleosythesis predicted abundance of $^{7}$Li. Since the $^{7}$Li abundance is known to be intimately related to the production and destruction of $^{7}$Be, it is pertinent to study reactions involving $^{7}$Be. An experiment measuring the transfer reaction $^7$Be(d,p)$^8$Be* at E = 5 MeV/A (IS 554) at...
Dielectronic Recombination (DR) is a resonant process that describes the capture of an electron by a (highly charged) ion, occurring at sharply defined collision energies. In an electron beam ion source, where charge breeding is achieved through successive electron impact ionisation, DR transitions can be selectively driven by adjusting the electron beam energy. The increased recombination...
Molecular beams injected into the ISOLDE Radio-Frequency Quadrupole cooler and buncher (RFQcb), ISCOOL, have been studied under varying conditions using the new Time-of-Flight detector at ISOLDE.
When a beam of molecules is injected into the RFQcb and the molecules interact with the buffer gas collisional dissociation processes may occur. In this study, two different beams of molecules,...
The WISArD (Weak Interaction Studies with Argon Decay) experiment aims to determine the beta-neutrino angular correlation (a$_{\beta\nu}$) in the super-allowed Fermi decay of $^{32}$Ar. The latter decays are sensitive probes to a possible scalar contribution in the weak interaction model. Deviation from the expected theoretical value will point to physics beyond the standard model.
The...
The structure of the odd-odd 232Ac nucleus, produced in the β– decay of 232Ra, was investigated through γ-ray spectroscopy at the ISOLDE Decay Station at ISOLDE, CERN. A radioactive beam of 232Fr was implanted in the IDS. The γ-rays originating from the β – decay chain 232Fr - 232Ra - 232Ac - 232Th were registered using a mixed array consisting of 4 HPGe Clover and 2 LaBr3(Ce) detectors...
