The Los Alamos Neutron Science Center (LANSCE) is one of the oldest operating high-power accelerators in the United States, having recently celebrated its 50th anniversary of operation. LANSCE is comprised of an 800-MeV linac capable of concurrently accelerating both H+ and H- ions, and can presently provide beam to six separate user stations. The proposed LANSCE Modernization Project (LAMP) is intended to revitalize and enhance the performance of two key areas in the LANSCE accelerator complex: the front end of the accelerator, from the sources to the end of the drift tube linac at 100 MeV; and the 800-MeV proton storage ring, or PSR. This paper provides a high-level overview of the proposed LAMP scope of work, timeline and performance goals.

The Los Alamos Neutron Science Center (LANSCE) is one of the oldest operating accelerators in the United States, having recently celebrated its 50th anniversary of operation. LANSCE is comprised of an 800-MeV linac capable of concurrently accelerating both H+ and H- ions, and can presently provide beam to six separate user stations. We present an overview of proposed and underway upgrade and enhancement efforts at LANSCE. These include both near- and far-term efforts, encompassing lifetime extension and performance enhancement of the LANSCE linac; the potential for addition of new end stations and user facilities; and ancillary projects to provide additional materials characterization methods via ultrafast electron diffraction and inverse Compton scattering.

Los Alamos Neutron Science Center (LANSCE) is designing a Proton Storage Ring (PSR) refurbishment as part of the proposed LAMP project. An important component of this is the ring RF bunching system at h=1 for one circulating bunch. It has operated with high availability since an upgrade was installed in 1999 to raise the gap voltage*. A second RF system at h=2 is planned to improve the bunching factor, reducing the peak beam current at the center of the bunch resulting from space charge forces, helping mitigate effects of electron cloud and leaving an avenue for circulating two bunches in the future. The unique low output impedance RF system for h=1 is based on a cathode follower configuration using push-pull triode vacuum tubes. This feature provides automatic beam loading compensation without active feedback or feedforward systems. The triodes are no longer produced, and suitable replacements are unavailable. The ferrite rings of the h=1 system are also obsolete. Our goals include determining a suitable replacement amplifier configuration that can work on either frequency, and developing a replacement resonator for each harmonic that uses current production ferrite material.

The Proton Power Upgrade project at the Spallation Neutron Source at Oak Ridge National Laboratory will increase the proton beam power capability from 1.4 to 2.8 MW. Upon completion in early 2025, 2 MW of beam power will be available for neutron production at the existing first target station (FTS) with the remaining beam power available for the future second target station (STS). The project has installed seven superconducting radio-frequency (RF) cryomodules and supporting RF power systems to increase the beam energy by 30% to 1.3 GeV, and the beam current will be increased by 50%. The injection and extraction region of the accumulator ring are being upgraded, and a new 2 MW mercury target has been developed along with supporting equipment for high-flow gas injection to mitigate cavitation and fatigue stress. The first four cryomodules and supporting systems were commissioned in 2022-2023 and supported neutron production at 1.05 GeV, 1.7 MW with high reliability. The first-article 2 MW target was operated successfully for approximately 4400 MW-Hours over two run periods. The long outage began in August 2023 for installation of the remaining technical equipment and construction of the Ring-to-Target Beam Transport tunnel stub that will enable connection to the STS without interrupting operation of the FTS. The upgrade is proceeding on-schedule and on-budget, and resumption of neutron production for the user program is planned for July 2024.