Introductory Nuclear Physics. David Halliday. New York: Wiley; London: Chapman & Hall, 1950. 558 pp. $6.50

Atomic physics techniques for the determination of ground-state properties of radioactive isotopes are very sensitive and provide accurate masses, binding energies, Q-values, charge radii, spins and electromagnetic moments. Many fields in nuclear physics benefit from these highly accurate numbers. They give insight into details of the nuclear structure for a better understanding of the underlying effective interactions, provide important input for studies of fundamental symmetries in physics, and help to understand the nucleosynthesis processes that are responsible for the observed chemical abundances in the Universe. Penning-trap and storage-ring mass spectrometry as well as laser spectroscopy of radioactive nuclei have now been used for a long time but significant progress has been achieved in these fields within the last decade. The basic principles of laser spectroscopic investigations, Penning-trap and storage-ring mass measurements of short-lived nuclei are summarized and selected physics results are discussed.

https://iopscience.iop.org/article/10.1088/0031-8949/2013/T152/014017/pdf

Precision Atomic Physics Techniques for Nuclear Physics with Radioactive Beams

The strongly spin dependent absorption of neutrons in nuclear spin polarized 3He opens the possibility to polarize beams of thermal and epithermal neutrons. An effective 3He neutron spin filter (NSF) requires high 3He nuclear polarization as well as a filter thickness corresponding to a gas amount of the order of 1 barl. We realized such a filter using direct optical pumping of metastable 3He∗ atoms in a 3He plasma at 1 mbar. Metastable exchange scattering transfers the angular momentum to the whole ensemble of 3He atoms. At present 3 × 1018 3He-atoms/s are polarized up to 64%. Subsequent polarization preserving compression by a two stage compressor system enables to prepare NSF cells of about 300 cm3 volume with 3 bar of polarized 3He within 2 h. 3He polarizations up to 53% were measured in a cell with a filter length of about 15 cm. By this cell a thermal neutron beam from the Mainz TRIGA reactor was polarized. A wavelength selective polarization analysis by means of Bragg scattering revealed a neutron polarization of 84% at a total transmission of 12% for a neutron wavelength of 1 A.

Realization of a broad band neutron spin filter with compressed, polarized 3He gas☆

A precision mass investigation of the neutron-rich titanium isotopes 
51
−
55
Ti
 was performed at TRIUMF’s Ion Trap for Atomic and Nuclear science (TITAN). The range of the measurements covers the 
N
=
32
 shell closure, and the overall uncertainties of the 
52
−
55
Ti
 mass values were significantly reduced. Our results conclusively establish the existence of the weak shell effect at 
N
=
32
, narrowing down the abrupt onset of this shell closure. Our data were compared with state-of-the-art ab initio shell model calculations which, despite very successfully describing where the 
N
=
32
 shell gap is strong, overpredict its strength and extent in titanium and heavier isotones. These measurements also represent the first scientific results of TITAN using the newly commissioned multiple-reflection time-of-flight mass spectrometer, substantiated by independent measurements from TITAN’s Penning trap mass spectrometer.

/pdf/dawning-of-the-n-32-shell-closure-seen-through-precision-frs3mctds9.pdf

Dawning of the N=32 shell closure seen through precision mass measurements of neutron-rich titanium isotopes

The Phase-Imaging Ion-Cyclotron-Resonance (PI-ICR) technique has been commissioned at the JYFLTRAP double Penning trap mass spectrometer This technique is based on projecting the ion motion in the Penning trap onto a position-sensitive multichannel-plate ion detector Mass measurements of stable 85 Rb $ ^{+}$
 and 87 Rb $ ^{+}$
 ions with well-known mass values show that relative uncertainties $ \Delta m/m \leq 7\cdot 10^{-10}$
 are possible to reach with the PI-ICR technique at JYFLTRAP The significant improvement both in resolving power and in precision compared to the conventional Time-of-Flight Ion Cyclotron Resonance technique will enable measurements of close-lying isomeric states and of more exotic isotopes as well as ultra-high precision measurements required, eg, for neutrino physics In addition, a new phase-dependent cleaning method based on the differences in the accumulated cyclotron motion phases has been demonstrated with short-lived 127 In $ ^{+}$
 and 127m In $ ^{+}$
 ions

/pdf/phase-imaging-ion-cyclotron-resonance-technique-at-the-1xbo7x2yz1.pdf

Phase-Imaging Ion-Cyclotron-Resonance technique at the JYFLTRAP double Penning trap mass spectrometer

We present a description of the Radio Frequency Quadrupole (RFQ) ion trap built as part of the TITAN facility. It consists of a gas-filled, segmented, linear Paul trap and is the first stage of the TITAN setup with the purpose of cooling and bunching radioactive ion beams delivered from ISAC-TRIUMF. This is the first such device to be driven digitally, i.e., using a high voltage ( V pp = 400 V ), wide bandwidth ( 0.2 f 1.2 MHz ) square-wave as compared to the typical sinusoidal wave form. Results from the commissioning of the device as well as systematic studies with stable and radioactive ions are presented including efficiency measurements with stable 133Cs and radioactive 124,126Cs. A novel and unique mode of operation of this device is also demonstrated where the cooled ion bunches are extracted in reverse mode, i.e., in the same direction as previously injected.

http://inspirehep.net/record/918016/files/arXiv:1107.2187.pdf

TITAN's Digital RFQ Ion Beam Cooler and Buncher, Operation and Performance

A new dynamically polarized proton target at LANL polarizes an epithermal neutron beam in the energy range from 01 eV to 50 keV In a 4He bath at a temperature of 11 K, irradiation doped ammonia is polarized longitudinally in a magnetic field of 5 T The sample has a diameter of 80 mm and is 13 mm thick The typical proton polarization is 085 giving a neutron polarization of 075 With the polarized neutron beam parity violation has been studied in many samples with a high degree of sensitivity

P.P.J. Delheij

Papers

TITAN's Digital RFQ Ion Beam Cooler and Buncher, Operation and Performance

The TRIPLE spin filter