[en] The LBNL AECR ion source has been upgraded in July 1996 by increasing its magnetic fields to improve its plasma confinement and thereby enhance the source performance. After a few months of tailoring the magnetic field configuration to match the two-frequency plasma heating (14 and 10 GHz), the upgraded AECR ion source (AECR-U) with its higher magnetic fields and higher magnetic mirror ratios has demonstrated significantly enhanced performance. For heavy ions at intensity of about 1 eμA, the charge state was shifted from 42+ to 48+ for uranium and from 41+ to 46+ for bismuth. An order of magnitude enhancement for fully stripped argon ions (I ≥ 60 enA) also has been achieved. Hydrogen-like krypton ions at intensity of about 10⁵ pps were extracted from the source and confirmed by measuring its characteristic x-ray with a SiLi crystal detector. High charge state heavy ion beams of xenon-136 and uranium-238 produced with the AECR-U ion source were accelerated by the 88-Inch Cyclotron. Despite poor transmission for the highly charged heavy ions due to vacuum losses in the cyclotron, 11 MeV/nucleon ¹³⁶Xe⁴¹⁺ at 1 x 10⁷ pps, 13 MeV/nucleon ¹³⁶Xe⁴⁶⁺ at a few hundred pps, and 7 MeV/nucleon ²³⁸U⁵⁵⁺ at 3 x 10⁴ pps and 8 MeV/nucleon ²³⁸U⁶⁰⁺ at a few pps were confirmed with a crystal energy detector after extraction from the cyclotron. The total energy of 1.935 GeV of the extracted ²³⁸U⁶⁰⁺ ions is the highest energy ever produced by the 88-Inch Cyclotron. Detailed optimization of the AECR Upgrade will be presented in this paper