![]() ![]() MuS2 aims to use laser plasma acceleration (LPA) to initially create 10 GeV particles in the space of tens of centimeters - compared to hundreds of meters needed for state-of-the art linear accelerators - and ultimateley develop scalable and practical processes to produce conditions that can create muons exceeding 100 GeV through innovations in LPA, target design, and compact laser driver technology. MuS2 will lay the ground work needed to examine the feasibility of developing compact and transportable muon sources.” Enabling this program is high-peak-power laser technology that has been steadily advancing and can potentially create the conditions for muon production in a compact form factor. Mark Wrobel, MuS2 program manager in DARPA’s Defense Sciences Office, says of the project: “Our goal is to develop a new, terrestrial muon source that doesn’t require large accelerators and allows us to create directional beams of muons at relevant energies, from 10s to 100s of GeVs – to either image or characterize materials. Muons can also be generated terrestrially, but this technique such high-energy particles that production is limited to large physics research facilities such as the Fermilab national particle accelerator in Illinois and the European CERN accelerator in Switzerland. ![]() Currently, two primary sources for muons exist: One is harnessing cosmic-ray interactions in the upper atmosphere, which naturally generate muons as they descend to Earth harnessing these muons, however, is tedious and not very practical, with days or months needed to capture enough muon data to produce meaningful results. Producing muons is extremely challenging, according to information from DARPA, because such production requires a very high-energy, giga-electronvolt (GeV) particle source. The Defense Advanced Research Projects Agency (DARPA) launched a program called "Muons for Science & Security" (MuS2) with the aim of discovering a compact source of muons, which are deeply penetrating subatomic particles - similar to electrons but about 200 times heavier - that can be used in a variety of defense and scientific applications because they travel easily through dozens to hundreds of meters of water, solid rock, or soil. Given their different clinical patterns and responses to treatment, it is important to distinguish between MADSAM neuropathy and MMN.ARLINGTON, Va. MADSAM neuropathy more closely resembles chronic inflammatory demyelinating polyneuropathy and probably represents an asymmetrical variant. ![]() Multifocal motor neuropathy patients typically do not respond to prednisone, but 3 of 6 MADSAM neuropathy patients improved with prednisone. Response to intravenous immunoglobulin treatment was similar in both groups (P = 1.0). In contrast to the subtle abnormalities described for MMN, MADSAM neuropathy patients had prominent demyelination on sensory nerve biopsies. No MADSAM neuropathy patient had elevated anti-GM1 antibody titers, compared with 56% of MMN patients (P < 0.01). Eighty-two percent of MADSAM neuropathy patients had elevated protein concentrations in the cerebrospinal fluid, compared with 9% of the MMN patients (P < 0.001). The clinical, laboratory, and histological features of these patients were contrasted with those of 16 patients with multifocal motor neuropathy (MMN). We report 11 patients with multifocal acquired demyelinating sensory and motor (MADSAM) neuropathy, defined clinically by a multifocal pattern of motor and sensory loss, with nerve conduction studies showing conduction block and other features of demyelination. ![]()
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