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Detector

The XAS detectors read at each energy point: the ion chambers for transmission (I0, It, Iref) and the energy-dispersive detector for fluorescence. PVs verified against startup/BMM/user_ns/detectors.py.

Enclosure: 6-BM-B.

Note

For a transmission XAS scan the absorption is ln(I0 / It) versus energy; for a dilute sample the fluorescence yield from the EnergyDispersiveSpectrometer is used instead. The ion chambers are the primary signal here, not auxiliary flux monitors, but they are the same device kind as the FluxMonitor Family (graduated in #353 from the i22 / i03 / i15-1 ion chambers), which BMM reuses.

Name Family PV Key specs Replaceable Status
IonChambers FluxMonitor XF:06BM-BI{EM:1}EM180: Quad electrometer (quadem1, class BMMQuadEM) reading the I0 (incident), It (transmitted), and Ir (reference) ion chambers, the transmission-XAS signal. Reuses the catalog FluxMonitor Family (graduated #353); at BMM these are the primary measurement detector, not an auxiliary monitor (DIAG-1 covers the gas fill). confirm
FluorescenceSpectrometer EnergyDispersiveSpectrometer XF:06BM-ES Xspress3 energy-dispersive fluorescence detector (1-, 4-, and 7-element configurations in source) for fluorescence-yield XAS of dilute samples; presents the Sensor Role. Element count / vendor pending (DET-1). confirm
ScalerCounter GenericProbe XF:06BM-ES:1{Sclr:1} Scaler-counted scintillation / point detector (bicron, class GonioStruck) for alignment and auxiliary counting; read-only. confirm