The KArlsruhe TRItium Neutrino (KATRIN) experiment, which aims to make a direct and model-independent determination of the absolute neutrino mass scale, is a complex experiment with many components. More than 15 years ago, we published a technical design report (TDR) [1] to describe the hardware design and requirements to achieve our sensitivity goal of 0.2 eV at 90% C.L. on the neutrino mass. Since then there has been considerable progress, culminating in the publication of first neutrino mass results with the entire beamline operating [2]. In this paper, we document the current state of all completed beamline components (as of the first neutrino mass measurement campaign), demonstrate our ability to reliably and stably control them over long times, and present details on their respective commissioning campaigns. K: Beam-line instrumentation (beam position and profile monitors, beam-intensity monitors, bunch length monitors); Spectrometers; Gas systems and purification; Neutrino detectors A X P : 2103.04755Neutrino-mass mode. This is the standard mode of operation to continually adjust the retarding voltage of the MS in the range of [ 0 − 40 eV; 0 + 50 eV] while tritium is in the system. This scanning range can be adjusted if required. The voltage and the time spent at each setting are defined by the Measurement Time Distribution (MTD) (figure 3). A typical run at a given voltage lasts between 20 s and 600 s; a full scan of the energy range given above takes about 2 h. Of these standard neutrino-mass runs, a small portion will be dedicated to sterile neutrino searches. These searches involve scanning much farther (order of keV) below the endpoint 0 .Calibration mode. To check the long-term system stability, calibration measurements are done regularly. The neutrino-mass mode is suspended for the duration of these measurement:• An energy calibration of the FPD (section 6) is performed weekly, which requires closing off the detector system from the main beamline for about 4 h.• The offset and the gain correction factor of the low-voltage readout in the high-voltage measurement chain needs to be calibrated based on standard reference sources (section 5.3.4). This requires stopping the precision monitoring of the MS retarding potential twice per week for about 0.5 h each.

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Megalencephaly, polymicrogyria, and hydrocephalus (MPPH) syndrome is characterized by megalencephaly, perisylvian polymicrogyria, postaxial polydactyly, and hydrocephalus. Seven cases have been reported. This report presents a new sporadic patient with megalencephaly, polymicrogyria, and hydrocephalus syndrome, a girl born to healthy, nonconsanguineous parents at 38 weeks. Macrocephaly (+4 standard deviation) was present at birth. She had syndactyly instead of the postaxial polydactyly reported in the other patients. Neurologic examination showed severe diffuse hypotonia and profound developmental delay. Magnetic resonance imaging revealed enlarged lateral and third ventricles, with cavum septi pellucidi et vergae, bilateral abnormal white matter intensity, and diffuse polymicrogyria, most prominent in both the frontal and perisylvian regions. A visual evoked potential study showed increased latencies, probably caused by white matter abnormalities. At 16 months, she has never had seizures and shows profound psychomotor retardation. Results of metabolic and genetic studies were normal.

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