Advances at TRIUMF-ISAC and decay of neutron-rich Cd studied with GRIFFIN

P E Garrett ,C Burbadge,O Paetkau,S Hallam,V Bildstein,H Bidaman,P Boubel,K Ortner,T Zidar,B Olaizola,G Hackman,A Jungclaus,R Dunlop,M Moukaddam,J Turko,A Teigelhöfer,K Whitmore,R Krücken,R Caballero-Folch,C E Svensson ,E Macconnachie ,A D Maclean ,I Dillmann ,F H Garcia ,J R Henderson ,J L Pore ,J K Smith ,J Lassen ,M R Dunlop ,E Padilla‐Rodal ,N Bernier ,D Kisliuk ,J Park ,A B Garnsworthy ,P Ruotsalainen ,A J Radich ,C M Petrache ,S Ilyushkin ,J Smallcombe ,R Li ,C Andreoiu ,Erin Mcgee ,S L Tabor ,G C Ball ,L J Evitts

doi:10.1051/epjconf/201819304011

Abstract

The β-decay half lives of nuclei near the r-process path are critical information required for abundance calculations, especially those near neutron number N = 82. Specifically, the nuclei below doubly-magic 132Sn are key, and play an important role in the formation and shape of the second r-process abundance peak. The half lives in this region are challenging to measure due to the significant β-delayed neutron decay branches and the population of isomeric states with half lives comparable to the ground states. However, by measuring the time distribution of γ rays, these complications can be eliminated. This requires, however, a very effcient γ-ray spectrometer since the production of isotopes in this region is very limited. The new GRIFFIN array at TRIUMF-ISAC provides the high effciency required for these measurements. Recent improvements in the quality of the beams produced at TRIUMF, employing the IG-LIS device, are outlined, as well as the current status of the ARIEL facility. The GRIFFIN spectrometer and its use are briefly described. The experiment to measure the half lives of 128-130Cd is outlined and the results given, and some examples of the power of GRIFFIN to expand decay schemes, specifically for the decay of 128Cd to 128In, are given.

Highlights

Advancements in the production, separation, and re-acceleration of unstable nuclei has propelled nuclear physics into a new era
We focus on the Isotope Separator And Accelerator (ISAC) at TRIUMF – an Isotope Separator On-Line (ISOL) facility that produces some of the most intense radioactive beams in the world
Thick high-resolution Si(Li) detectors; and the Moving Tape Collector (MTC) – a device that consists of a continuous loop of tape on which beam can be deposited at the centre of the array and transported outside of the focal volume once the counting period is completed

Summary

Introduction

Advancements in the production, separation, and re-acceleration of unstable nuclei has propelled nuclear physics into a new era. Many laboratories around the world are dedicated to the development and use of unstable isotopes In this contribution, we focus on the Isotope Separator And Accelerator (ISAC) at TRIUMF – an Isotope Separator On-Line (ISOL) facility that produces some of the most intense radioactive beams in the world. One of the flagship facilities that makes use of the beams from ISAC, and those of the future ARIEL, is the Gamma-Ray Infrastructure For Fundamental Investigations of Nuclei (GRIFFIN). This new spectrometer offers unprecedented sensitivity for β-decay measurements of radioactive nuclei that are produced in copious amounts, typically in the region of stable nuclei, as well as those produced at very low intensities at the extremes of existence

TRIUMF-ISAC and ARIEL

GRIFFIN

Decay of neutron-rich In and Cd