california – EPICS Controls

Gamma-Ray Energy Tracking Array (GRETA)

Ralph Lange — Tue, 01 Sep 2026 08:44:26 +0000

The Gamma-Ray Energy Tracking Array (GRETA) is the first realization of a 4𝜋 high-resolution gamma-ray detector array. GRETA was completed in 2026 and built by a team led by Lawrence Berkeley National Laboratory and including staff from Argonne National Laboratory, Oak Ridge National Laboratory and the Facility for Rare Isotope Beams. The array uses 120 large-volume high-purity Germanium crystals, electrically segmented into 36 segment volumes. The signals from each segment and the full crystal are digitized and processed to localize the individual interactions of gamma-rays in the detector to mm precision in all three spatial dimensions. Gamma-rays are then reconstructed based on the most likely scattering sequence between interaction points, allowing efficient rejection of background. GRETA’s detector, electronics and computing technologies combine to create the most sensitive gamma-ray spectrometer ever deployed.

GRETA is now starting operations with a scientific mission to study the structure and excitations of the atomic nucleus. Comprising 99.9% of the visible matter in the universe, nuclei are central to fundamental questions in physics, such as our understanding of the origin of the elements and how complex many-body quantum systems organize. Their properties depend sensitively on the number of protons (Z) and neutrons (N), and much of what we know about them comes from the measurement and characterization of their excitation modes, energy levels, and decays. High-resolution gamma-ray spectroscopy is one of the most sensitive and powerful techniques to study nuclear structure and decays.

Advanced Light Source (ALS) at Lawrence Berkeley National Laboratory

Han — Wed, 05 Jul 2023 11:25:54 +0000

The Advanced Light Source (ALS) is a third-generation synchrotron light source at Lawrence Berkeley National Laboratory. Built in 1993, the ALS serves over 40 beamlines and is one of the world’s brightest ultraviolet and soft X-ray light sources. The 196.8-meter circumference storage ring has an electron beam energy of 1.9 GeV. It supports experiments across various fields, including materials science, biology, chemistry, physics, and the environmental sciences. The ALS is upgrading to become a fourth-generation light source, adding a new accumulator ring and replacing the existing storage ring—the U.S. Department of Energy, Office of Science, Basic Energy Sciences program funds the ALS operation and its upgrade project.

SLAC National Accelerator Laboratory

Ralph Lange — Wed, 24 Jan 2018 12:52:28 +0000

SLAC is a scientific research center with a broad program in accelerator physics, astrophysics, atomic and solid-state physics, chemistry, biology, and medicine.

We concentrate on building and using large particle accelerators to probe the nature of molecules using X-ray light. We are also involved in experimental and theoretical research in elementary particle physics, astrophysics, and cosmology.

Laser Interferometer Gravitational-Wave Observatory (LIGO)

Ralph Lange — Mon, 13 Nov 2017 08:42:09 +0000

The Laser Interferometer Gravitational-Wave Observatory (LIGO) is leading the way in the new and exciting field of gravitational-wave astrophysics through the direct detection of gravitational waves predicted by Einstein’s General Theory of Relativity. LIGO’s multi-kilometer-scale gravitational wave detectors use laser interferometry to measure the minute ripples in the fabric of space-time caused by passing gravitational waves from cataclysmic cosmic sources, such as the mergers of pairs of neutron stars or black holes. LIGO consists of two widely separated detectors within the United States, in Hanford, Washington and Livingston, Louisiana.

LIGO is funded by the U.S. National Science Foundation (NSF), operated by the California Institute of Technology (Caltech) and the Massachusetts Institute of Technology (MIT), and is aided by collaborators from the over 80 scientific institutions world-wide that are members of the LIGO Scientific Collaboration (LSC).

The 2017 Nobel Prize in Physics has been awarded to three key players in the development and ultimate success of LIGO.