skip to main content
OSTI.GOV title logo U.S. Department of Energy
Office of Scientific and Technical Information

Title: Charge state breeding of radioactive ions with an electron cyclotron resonance ion source at TRIUMF

Abstract

Efficient primary ion sources at ISOL facilities normally produce singly charged ions. This limits the usable mass range for postacceleration due to the A/Q acceptance of the accelerator. At the ISAC facility at TRIUMF an A/Q below 7 is desired to avoid further stripping. Thus, charge state breeding is necessary if higher masses are to be accelerated. A 14 GHz ECRIS 'PHOENIX' booster has been chosen as a breeder. In order to investigate and optimize its performance under ISAC conditions it has been set up at a test bench equipped with a standard ISAC target-ion-source to produce singly charged ions. A series of measurements has been performed with the noble gases Ar, Kr, and Xe. Efficiencies of more than 6% in the maximum of the charge state distribution after mass separation have been obtained and the emittance of the extracted beam and breeding times have been measured. This article gives a status report on the ongoing measurements.

Authors:
; ; ; ; ; ; ; ;  [1];  [2]
  1. TRIUMF, 4004 Wesbrook Mall, Vancouver, BC V6T 2A3 (Canada)
  2. (France)
Publication Date:
OSTI Identifier:
20779048
Resource Type:
Journal Article
Resource Relation:
Journal Name: Review of Scientific Instruments; Journal Volume: 77; Journal Issue: 3; Conference: 11. international conference on ion sources, Caen (France), 12-16 Sep 2005; Other Information: DOI: 10.1063/1.2165271; (c) 2006 American Institute of Physics; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
43 PARTICLE ACCELERATORS; ACCELERATORS; BEAM EXTRACTION; BREEDING; CHARGE STATES; ECR ION SOURCES; IONS; RADIOACTIVE ION BEAMS; RARE GASES; STRIPPING

Citation Formats

Ames, F., Baartman, R., Bricault, P., Jayamanna, K., McDonald, M., Olivo, M., Schmor, P., Yuan, D.H.L., Lamy, T., and LPSC, UJF-IN2P3-CNRS, 53 Avenue des Martyrs, 38026 Grenoble. Charge state breeding of radioactive ions with an electron cyclotron resonance ion source at TRIUMF. United States: N. p., 2006. Web. doi:10.1063/1.2165271.
Ames, F., Baartman, R., Bricault, P., Jayamanna, K., McDonald, M., Olivo, M., Schmor, P., Yuan, D.H.L., Lamy, T., & LPSC, UJF-IN2P3-CNRS, 53 Avenue des Martyrs, 38026 Grenoble. Charge state breeding of radioactive ions with an electron cyclotron resonance ion source at TRIUMF. United States. doi:10.1063/1.2165271.
Ames, F., Baartman, R., Bricault, P., Jayamanna, K., McDonald, M., Olivo, M., Schmor, P., Yuan, D.H.L., Lamy, T., and LPSC, UJF-IN2P3-CNRS, 53 Avenue des Martyrs, 38026 Grenoble. Wed . "Charge state breeding of radioactive ions with an electron cyclotron resonance ion source at TRIUMF". United States. doi:10.1063/1.2165271.
@article{osti_20779048,
title = {Charge state breeding of radioactive ions with an electron cyclotron resonance ion source at TRIUMF},
author = {Ames, F. and Baartman, R. and Bricault, P. and Jayamanna, K. and McDonald, M. and Olivo, M. and Schmor, P. and Yuan, D.H.L. and Lamy, T. and LPSC, UJF-IN2P3-CNRS, 53 Avenue des Martyrs, 38026 Grenoble},
abstractNote = {Efficient primary ion sources at ISOL facilities normally produce singly charged ions. This limits the usable mass range for postacceleration due to the A/Q acceptance of the accelerator. At the ISAC facility at TRIUMF an A/Q below 7 is desired to avoid further stripping. Thus, charge state breeding is necessary if higher masses are to be accelerated. A 14 GHz ECRIS 'PHOENIX' booster has been chosen as a breeder. In order to investigate and optimize its performance under ISAC conditions it has been set up at a test bench equipped with a standard ISAC target-ion-source to produce singly charged ions. A series of measurements has been performed with the noble gases Ar, Kr, and Xe. Efficiencies of more than 6% in the maximum of the charge state distribution after mass separation have been obtained and the emittance of the extracted beam and breeding times have been measured. This article gives a status report on the ongoing measurements.},
doi = {10.1063/1.2165271},
journal = {Review of Scientific Instruments},
number = 3,
volume = 77,
place = {United States},
year = {Wed Mar 15 00:00:00 EST 2006},
month = {Wed Mar 15 00:00:00 EST 2006}
}
  • In the coming years huge ion-beam projects are foreseen. They deal with specific isotope on-line (ISOL) beams such as ISOL-created radioactive ions. The beam intensities are exceptionally high (>10{sup 12} ions/s), the radioactive lifetimes are short ({<=}1 s), and the ion energy is very high ({>=}150 GeV/u). In general in order to minimize the size of the accelerator one needs highly charged ISOL ions and therefore charge breeders are a must. In contrast with the CERN system, utilizing a Penning trap and an electron-beam ion source charge breeder (where the maximum ion beam cannot exceed 10{sup 6} ions/s) the Grenoblemore » group launched in 1995 an electron cyclotron resonance (ECR) system capable of storing 10{sup 12} ions/s and delivering highly charged ISOL ions. In this article we show that this storage is possible for low-ion-energy ISOL ions following classical slowing down theory. In this case the injected ISOL ions are slowed down by ion-ion collisions which yield ion storage inside the ECR plasma, but also charge breeding by the energetic ECR electrons bombarding the slowed down ions.« less
  • The Californium Rare Isotope Breeder Upgrade is a new radioactive beam facility for the Argonne Tandem Linac Accelerator System (ATLAS). The facility utilizes a 252Cf fission source coupled with an electron cyclotron resonance ion source to provide radioactive beam species for the ATLAS experimental program. The californium fission fragment distribution provides nuclei in the mid-mass range which are difficult to extract from production targets using the isotope separation on line technique and are not well populated by low-energy fission of uranium. To date the charge breeding program has focused on optimizing these mid-mass beams, achieving high charge breeding efficiencies ofmore » both gaseous and solid species including 14.7% for the radioactive species 143Ba27+. In an effort to better understand the charge breeding mechanism, we have recently focused on the low-mass species sodium and potassium which up to present have been difficult to charge breed efficiently. Unprecedented charge breeding efficiencies of 10.1% for 23Na7+ and 17.9% for 39K10+ were obtained injecting stable Na+ and K+ beams from a surface ionization source.« less
  • The ion loss distribution in an electron cyclotron resonance ion source (ECRIS) was investigated to understand the element dependence of the charge breeding efficiency in an electron cyclotron resonance (ECR) charge breeder. The radioactive {sup 111}In{sup 1+} and {sup 140}Xe{sup 1+} ions (typical nonvolatile and volatile elements, respectively) were injected into the ECR charge breeder at the Tokai Radioactive Ion Accelerator Complex to breed their charge states. Their respective residual activities on the sidewall of the cylindrical plasma chamber of the source were measured after charge breeding as functions of the azimuthal angle and longitudinal position and two-dimensional distributions ofmore » ions lost during charge breeding in the ECRIS were obtained. These distributions had different azimuthal symmetries. The origins of these different azimuthal symmetries are qualitatively discussed by analyzing the differences and similarities in the observed wall-loss patterns. The implications for improving the charge breeding efficiencies of nonvolatile elements in ECR charge breeders are described. The similarities represent universal ion loss characteristics in an ECR charge breeder, which are different from the loss patterns of electrons on the ECRIS wall.« less
  • We investigated the ion-loss distribution on the sidewall of an electron cyclotron resonance (ECR) plasma chamber using the 18-GHz ECR charge breeder at the Tokai Radioactive Ion Accelerator Complex (TRIAC). Similarities and differences between the ion-loss distributions (longitudinal and azimuthal) of different ion species (i.e., radioactive {sup 111}In{sup 1+} and {sup 140}Xe{sup 1+} ions that are typical volatile and nonvolatile elements) was qualitatively discussed to understand the element dependence of the charge breeding efficiency. Especially, the similarities represent universal ion loss characteristics in an ECR charge breeder, which are different from the loss patterns of electrons on the ECRIS wall.
  • The Californium Rare Isotope Breeder Upgrade is a new radioactive beam facility for the Argonne Tandem Linac Accelerator System (ATLAS). The facility utilizes a {sup 252}Cf fission source coupled with an electron cyclotron resonance ion source to provide radioactive beam species for the ATLAS experimental program. The californium fission fragment distribution provides nuclei in the mid-mass range which are difficult to extract from production targets using the isotope separation on line technique and are not well populated by low-energy fission of uranium. To date the charge breeding program has focused on optimizing these mid-mass beams, achieving high charge breeding efficienciesmore » of both gaseous and solid species including 14.7% for the radioactive species {sup 143}Ba{sup 27+}. In an effort to better understand the charge breeding mechanism, we have recently focused on the low-mass species sodium and potassium which up to present have been difficult to charge breed efficiently. Unprecedented charge breeding efficiencies of 10.1% for {sup 23}Na{sup 7+} and 17.9% for {sup 39}K{sup 10+} were obtained injecting stable Na{sup +} and K{sup +} beams from a surface ionization source.« less