.. auto-generated by script ../../../../utils/nxdl2rst.py from the NXDL source NXdetector.nxdl.xml .. index:: ! NXdetector (base class) ! detector (base class) see: detector (base class); NXdetector .. _NXdetector: ========== NXdetector ========== **Status**: base class, extends :ref:`NXobject`, version 1.1 **Description**: A detector, detector bank, or multidetector. **Symbols**: These symbols will be used below to coordinate datasets with the same shape. **np**: number of scan points (only present in scanning measurements) **i**: number of detector pixels in the first (X, slowest) direction **j**: number of detector pixels in the second (Y, faster) direction **k**: number of detector pixels in the third (Z, if necessary, fastest) direction **tof**: number of bins in the time-of-flight histogram **Groups cited**: :ref:`NXcharacterization`, :ref:`NXcollection`, :ref:`NXdata`, :ref:`NXdetector_module`, :ref:`NXgeometry`, :ref:`NXnote` .. index:: NXgeometry (base class); used in base class, NXdata (base class); used in base class, NXnote (base class); used in base class, NXcharacterization (base class); used in base class, NXcollection (base class); used in base class, NXdetector_module (base class); used in base class **Structure**: .. index:: time of flight (field) **time_of_flight[tof+1]**: :ref:`NX_FLOAT ` {units=\ :ref:`NX_TIME_OF_FLIGHT `} Total time of flight .. index:: axis (field attribute) **@axis**: :ref:`NX_POSINT ` Obligatory value: ``3`` .. index:: primary (field attribute) **@primary**: :ref:`NX_POSINT ` Obligatory value: ``1`` .. index:: long name (field attribute) **@long_name**: :ref:`NX_CHAR ` Total time of flight .. index:: raw time of flight (field) **raw_time_of_flight[tof+1]**: :ref:`NX_INT ` {units=\ :ref:`NX_PULSES `} In DAQ clock pulses .. index:: frequency (field attribute) **@frequency**: :ref:`NX_NUMBER ` Clock frequency in Hz .. index:: detector number (field) **detector_number[i, j]**: :ref:`NX_INT ` Identifier for detector .. index:: data (field) **data[np, i, j, tof]**: :ref:`NX_NUMBER ` {units=\ :ref:`NX_ANY `} Data values from the detector. .. index:: long name (field attribute) **@long_name**: :ref:`NX_CHAR ` Title of measurement .. index:: check sum (field attribute) **@check_sum**: :ref:`NX_INT ` Integral of data as check of data integrity .. index:: data error (field) **data_error[np, i, j, tof]**: :ref:`NX_NUMBER ` {units=\ :ref:`NX_ANY `} The best estimate of the uncertainty in the data value. Where possible, this should be the standard deviation, which has the same units as the data. .. index:: x pixel offset (field) **x_pixel_offset[i, j]**: :ref:`NX_FLOAT ` {units=\ :ref:`NX_LENGTH `} Offset from the detector center in x-direction. Can be multidimensional when needed. .. index:: axis (field attribute) **@axis**: :ref:`NX_POSINT ` Obligatory value: ``1`` .. index:: primary (field attribute) **@primary**: :ref:`NX_POSINT ` Obligatory value: ``1`` .. index:: long name (field attribute) **@long_name**: :ref:`NX_CHAR ` x-axis offset from detector center .. index:: y pixel offset (field) **y_pixel_offset[i, j]**: :ref:`NX_FLOAT ` {units=\ :ref:`NX_LENGTH `} Offset from the detector center in the y-direction. Can be multidimensional when different values are required for each pixel. .. index:: axis (field attribute) **@axis**: :ref:`NX_POSINT ` Obligatory value: ``2`` .. index:: primary (field attribute) **@primary**: :ref:`NX_POSINT ` Obligatory value: ``1`` .. index:: long name (field attribute) **@long_name**: :ref:`NX_CHAR ` y-axis offset from detector center .. index:: distance (field) **distance[np, i, j]**: :ref:`NX_FLOAT ` {units=\ :ref:`NX_LENGTH `} This is the distance to the previous component in the instrument; most often the sample. The usage depends on the nature of the detector: Most often it is the distance of the detector assembly. But there are irregular detectors. In this case the distance must be specified for each detector pixel. .. index:: polar angle (field) **polar_angle[np, i, j]**: :ref:`NX_FLOAT ` {units=\ :ref:`NX_ANGLE `} This is the polar angle of the detector towards the previous component in the instrument; most often the sample. The usage depends on the nature of the detector. Most often it is the polar_angle of the detector assembly. But there are irregular detectors. In this case, the polar_angle must be specified for each detector pixel. .. index:: azimuthal angle (field) **azimuthal_angle[np, i, j]**: :ref:`NX_FLOAT ` {units=\ :ref:`NX_ANGLE `} This is the azimuthal angle angle of the detector towards the previous component in the instrument; most often the sample. The usage depends on the nature of the detector. Most often it is the azimuthal_angle of the detector assembly. But there are irregular detectors. In this case, the azimuthal_angle must be specified for each detector pixel. .. index:: description (field) **description**: :ref:`NX_CHAR ` name/manufacturer/model/etc. information .. index:: local name (field) **local_name**: :ref:`NX_CHAR ` Local name for the detector .. index:: solid angle (field) **solid_angle[i, j]**: :ref:`NX_FLOAT ` {units=\ :ref:`NX_SOLID_ANGLE `} Solid angle subtended by the detector at the sample .. index:: x pixel size (field) **x_pixel_size[i, j]**: :ref:`NX_FLOAT ` {units=\ :ref:`NX_LENGTH `} Size of each detector pixel. If it is scalar all pixels are the same size. .. index:: y pixel size (field) **y_pixel_size[i, j]**: :ref:`NX_FLOAT ` {units=\ :ref:`NX_LENGTH `} Size of each detector pixel. If it is scalar all pixels are the same size .. index:: dead time (field) **dead_time[np, i, j]**: :ref:`NX_FLOAT ` {units=\ :ref:`NX_TIME `} Detector dead time .. index:: gas pressure (field) **gas_pressure[i, j]**: :ref:`NX_FLOAT ` {units=\ :ref:`NX_PRESSURE `} Detector gas pressure .. index:: detection gas path (field) **detection_gas_path**: :ref:`NX_FLOAT ` {units=\ :ref:`NX_LENGTH `} maximum drift space dimension .. index:: crate (field) **crate[i, j]**: :ref:`NX_INT ` Crate number of detector .. index:: local name (field attribute) **@local_name**: :ref:`NX_CHAR ` Equivalent local term .. index:: slot (field) **slot[i, j]**: :ref:`NX_INT ` Slot number of detector .. index:: local name (field attribute) **@local_name**: :ref:`NX_CHAR ` Equivalent local term .. index:: input (field) **input[i, j]**: :ref:`NX_INT ` Input number of detector .. index:: local name (field attribute) **@local_name**: :ref:`NX_CHAR ` Equivalent local term .. index:: type (field) **type**: :ref:`NX_CHAR ` Description of type such as He3 gas cylinder, He3 PSD, scintillator, fission chamber, proportion counter, ion chamber, ccd, pixel, image plate, CMOS, ... .. index:: calibration date (field) **calibration_date**: :ref:`NX_DATE_TIME ` date of last calibration (geometry and/or efficiency) measurements .. index:: layout (field) **layout**: :ref:`NX_CHAR ` How the detector is represented Any of these values: ``point`` | ``linear`` | ``area`` .. index:: count time (field) **count_time[np]**: :ref:`NX_NUMBER ` {units=\ :ref:`NX_TIME `} Elapsed actual counting time .. index:: sequence number (field) **sequence_number[nBrightFrames]**: :ref:`NX_CHAR ` In order to properly sort the order of the images taken in (for example) a tomography experiment, a sequence number is stored with each image. .. index:: beam center x (field) **beam_center_x**: :ref:`NX_FLOAT ` {units=\ :ref:`NX_LENGTH `} This is the x position where the direct beam would hit the detector. This is a length, not a pixel position, and can be outside of the actual detector. .. index:: beam center y (field) **beam_center_y**: :ref:`NX_FLOAT ` {units=\ :ref:`NX_LENGTH `} This is the y position where the direct beam would hit the detector. This is a length, not a pixel position, and can be outside of the actual detector. .. index:: frame start number (field) **frame_start_number**: :ref:`NX_INT ` This is the start number of the first frame of a scan. In PX one often scans a couple of frames on a give sample, then does something else, then returns to the same sample and scans some more frames. Each time with a new data file. This number helps concatenating such measurements. .. index:: diameter (field) **diameter**: :ref:`NX_FLOAT ` {units=\ :ref:`NX_LENGTH `} The diameter of a cylindrical detector .. index:: acquisition mode (field) **acquisition_mode**: :ref:`NX_CHAR ` The acquisition mode of the detector. Any of these values: * ``gated`` * ``triggered`` * ``summed`` * ``event`` * ``histogrammed`` * ``decimated`` .. index:: angular calibration applied (field) **angular_calibration_applied**: :ref:`NX_BOOLEAN ` True when the angular calibration has been applied in the electronics, false otherwise. .. index:: angular calibration (field) **angular_calibration[i, j]**: :ref:`NX_FLOAT ` Angular calibration data. .. index:: flatfield applied (field) **flatfield_applied**: :ref:`NX_BOOLEAN ` True when the flat field correction has been applied in the electronics, false otherwise. .. index:: flatfield (field) **flatfield[i, j]**: :ref:`NX_FLOAT ` Flat field correction data. .. index:: flatfield error (field) **flatfield_error[i, j]**: :ref:`NX_FLOAT ` Errors of the flat field correction data. .. index:: pixel mask applied (field) **pixel_mask_applied**: :ref:`NX_BOOLEAN ` True when the pixel mask correction has been applied in the electronics, false otherwise. .. index:: pixel mask (field) **pixel_mask[i, j]**: :ref:`NX_INT ` The 32-bit pixel mask for the detector. Contains a bit field for each pixel to signal dead, blind or high or otherwise unwanted or undesirable pixels. They have the following meaning: .. can't make a table here, a bullet list will have to do for now * bit 0: gap (pixel with no sensor) * bit 1: dead * bit 2: under responding * bit 3: over responding * bit 4: noisy * bit 5: -undefined- * bit 6: pixel is part of a cluster of problematic pixels (bit set in addition to others) * bit 7: -undefined- * bit 8: user defined mask (e.g. around beamstop) * bits 9-30: -undefined- * bit 31: virtual pixel (corner pixel with interpolated value) The normal data analysis software would not take pixels into account when a bit in (mask & 0x00FF) is set. Tag bit in the upper two bytes would indicate special pixel properties that normally would not be a sole reason to reject the intensity value (unless lower bits are also set). .. index:: countrate correction applied (field) **countrate_correction__applied**: :ref:`NX_BOOLEAN ` True when a count-rate correction has already been applied in the electronics, false otherwise. .. index:: bit depth readout (field) **bit_depth_readout**: :ref:`NX_INT ` How many bits the electronics reads per pixel. With CCD's and single photon counting detectors, this must not align with traditional integer sizes. This can be 4, 8, 12, 14, 16, ... .. index:: detector readout time (field) **detector_readout_time**: :ref:`NX_FLOAT ` {units=\ :ref:`NX_TIME `} Time it takes to read the detector (typically milliseconds). This is important to know for time resolved experiments. .. index:: trigger delay time (field) **trigger_delay_time**: :ref:`NX_FLOAT ` {units=\ :ref:`NX_TIME `} Time it takes to start exposure after a trigger signal has been received. This is the reaction time of the detector firmware after receiving the trigger signal to when the detector starts to acquire the exposure, including any user set delay.. This is important to know for time resolved experiments. .. index:: trigger delay time set (field) **trigger_delay_time_set**: :ref:`NX_FLOAT ` {units=\ :ref:`NX_TIME `} User-specified trigger delay. .. index:: trigger internal delay time (field) **trigger_internal_delay_time**: :ref:`NX_FLOAT ` {units=\ :ref:`NX_TIME `} Time it takes to start exposure after a trigger signal has been received. This is the reaction time of the detector hardware after receiving the trigger signal to when the detector starts to acquire the exposure. It forms the lower boundary of the trigger_delay_time when the user does not request an additional delay. .. index:: trigger dead time (field) **trigger_dead_time**: :ref:`NX_FLOAT ` {units=\ :ref:`NX_TIME `} Time during which no new trigger signal can be accepted. Typically this is the trigger_delay_time + exposure_time + readout_time. This is important to know for time resolved experiments. .. index:: frame time (field) **frame_time[NP]**: :ref:`NX_FLOAT ` {units=\ :ref:`NX_TIME `} This is time for each frame. This is exposure_time + readout time. .. index:: gain setting (field) **gain_setting**: :ref:`NX_CHAR ` The gain setting of the detector. This influences background etc. Any of these values: ``high`` | ``standard`` | ``fast`` | ``auto`` .. index:: saturation value (field) **saturation_value**: :ref:`NX_INT ` The value at which the detector goes into saturation. Especially common to CCD detectors, the data is known to be invalid above this value. .. index:: number of cycles (field) **number_of_cycles**: :ref:`NX_INT ` CCD images are sometimes constructed by summing together multiple short exposures in the electronics. This reduces background etc. This is the number of short exposures used to sum images for an image. .. index:: sensor material (field) **sensor_material**: :ref:`NX_CHAR ` At times, radiation is not directly sensed by the detector. Rather, the detector might sense the output from some converter like a scintillator. This is the name of this converter material. .. index:: sensor thickness (field) **sensor_thickness**: :ref:`NX_FLOAT ` {units=\ :ref:`NX_LENGTH `} At times, radiation is not directly sensed by the detector. Rather, the detector might sense the output from some converter like a scintillator. This is the thickness of this converter material. .. index:: threshold energy (field) **threshold_energy**: :ref:`NX_FLOAT ` {units=\ :ref:`NX_ENERGY `} Single photon counter detectors can be adjusted for a certain energy range in which they work optimally. This is the energy setting for this. **(geometry)**: :ref:`NXgeometry` Position and orientation of detector **efficiency**: :ref:`NXdata` Spectral efficiency of detector with respect to e.g. wavelength .. index:: signal (group attribute) **@signal**: :ref:`NX_CHAR ` Obligatory value: ``efficiency`` .. index:: axes (group attribute) **@axes**: :ref:`NX_CHAR ` Any of these values: ``.`` | ``. .`` | ``. . .`` | ``. . . .`` | ``wavelength`` .. index:: wavelength indices (group attribute) **@wavelength_indices**: :ref:`NX_CHAR ` Obligatory value: ``0`` .. index:: efficiency (field) **efficiency[i, j, k]**: :ref:`NX_FLOAT ` {units=\ :ref:`NX_DIMENSIONLESS `} efficiency of the detector .. index:: wavelength (field) **wavelength[i, j, k]**: :ref:`NX_FLOAT ` {units=\ :ref:`NX_WAVELENGTH `} This field can be two things: #. For a pixel detector it provides the nominal wavelength for which the detector has been calibrated. #. For other detectors this field has to be seen together with the efficiency field above. For some detectors, the efficiency is wavelength dependent. Thus this field provides the wavelength axis for the efficiency field. In this use case, the efficiency and wavelength arrays must have the same dimensionality. .. index:: start time (field) **start_time[np]**: :ref:`NX_FLOAT ` {units=\ :ref:`NX_TIME `} start time for each frame, with the ``start`` attribute as absolute reference .. index:: start (field attribute) **@start**: :ref:`NX_DATE_TIME ` .. index:: stop time (field) **stop_time[np]**: :ref:`NX_FLOAT ` {units=\ :ref:`NX_TIME `} stop time for each frame, with the ``start`` attribute as absolute reference .. index:: start (field attribute) **@start**: :ref:`NX_DATE_TIME ` .. index:: real time (field) **real_time[i, j, k]**: :ref:`NX_NUMBER ` {units=\ :ref:`NX_TIME `} real-time of the exposure (use this if exposure time varies for each array element, otherwise use ``count_time`` field) **calibration_method**: :ref:`NXnote` summary of conversion of array data to pixels (e.g. polynomial approximations) and location of details of the calibrations **data_file**: :ref:`NXnote` **(characterization)**: :ref:`NXcharacterization` .. index:: deprecated **DEPRECATED**: use :ref:`NXcollection` instead :see: https://github.com/nexusformat/definitions/issues/177 **(collection)**: :ref:`NXcollection` Use this group to provide other data related to this NXdetector group. **(detector_module)**: :ref:`NXdetector_module` For use in special cases where the data in NXdetector is represented in several parts, each with a separate geometry. Use one or more instances of the NXdetector_module group to declare regions of interest or some other subdivision of a detector. **NXDL Source**: https://github.com/nexusformat/definitions/blob/master/base_classes/NXdetector.nxdl.xml