KPL/IK SIXS Instrument Kernel =========================================================================== This instrument kernel (I-kernel) contains references to mounting alignment, operating modes, and timing as well as internal and FOV geometry for the BepiColombo MPO Solar Intensity X-ray and particle Spectrometer (SIXS). Version and Date --------------------------------------------------------------------------- Version 0.7 -- October 22, 2020 -- Marc Costa Sitja, ESAC/ESA Miguel Perez Ayucar, ESAC/ESA Updated SIXS overview and Detector Layouts, added Planning FoV for SIXS-X and added Optical Parameters. Version 0.6 -- November 21, 2019 -- Eero Esko, UH Updated SIXS-X FoVs based on the detector filed of view maps from ground calibrations. Version 0.5 -- September 27, 2017 -- Eero Esko, UH Updated elevation and azimuth angles. Updated SIXS-X FoVs. Version 0.4 -- February 15, 2017 -- Marc Costa Sitja, ESAC/ESA Updated instrument description and added Detector Layouts section. Corrected boresight definitions of the FOVs to align it with MPO frames kernel. Pending review from the SIXS instrument team and the BepiColombo SGS. Version 0.3 -- December 13, 2016 -- Marc Costa Sitja, ESAC/ESA Updated SIXS FOV definitions in accordance with SIXS reference frames updates in bc_mpo_v07.tf Version 0.2 -- February 08, 2016 -- Marc Costa Sitja, ESAC/ESA Updated BEPICOLOMBO MPO IDs from -69 to -121. Removed kernel name and version assignment. Version 0.1 -- February 08, 2016 -- J. McAuliffe, ESAC/ESA Sub-unit IDs updated inline with bc_mpo_frames_003.tf Version 0.0 -- December 19, 2014 -- S. Martinez, ESAC/ESA Initial prototype release. References --------------------------------------------------------------------------- 1. ``Kernel Pool Required Reading'' 2. ``Frames Required Reading'' 3. ``C-Kernel Required Reading'' 4. BepiColombo MPO Spacecraft Frames Definition Kernel 5. ``SIXS Experiment Interface Document B (EID-B)'', BC-EST-RS-02518, Issue 1, Revision 3, 14th October 2013 6. ``BepiColombo SIXS User Manual'', BC-SIX-UM-00001, Issue 3, Revision 1, 16th August 2017 7. ``BepiColombo SIXS FM X-ray detector calibration report'', BC-SIX-RP-00008, Issue 1, Revision 0, 21st March 2013 Contact Information --------------------------------------------------------------------------- If you have any questions regarding this file contact the ESA SPICE Service at ESAC: Marc Costa Sitja (+34) 91-8131-457 mcosta@sciops.esa.int, esa_spice@sciops.esa.int or NAIF at JPL: Boris Semenov (818) 354-8136 Boris.Semenov@jpl.nasa.gov Implementation Notes --------------------------------------------------------------------------- This file is used by the SPICE system as follows: programs that make use of this frame kernel must "load" the kernel normally during program initialization. Loading the kernel associates the data items with their names in a data structure called the "kernel pool". The SPICELIB routine FURNSH loads a kernel into the pool as shown below: FORTRAN: (SPICELIB) CALL FURNSH ( frame_kernel_name ) C: (CSPICE) furnsh_c ( frame_kernel_name ); IDL: (ICY) cspice_furnsh, frame_kernel_name MATLAB: (MICE) cspice_furnsh ( 'frame_kernel_name' ) PYTHON: (SPICEYPY)* furnsh( frame_kernel_name ) In order for a program or routine to extract data from the pool, the SPICELIB routines GDPOOL, GIPOOL, and GCPOOL are used. See [2] for more details. This file was created and may be updated with a text editor or word processor. * SPICEPY is a non-official, community developed Python wrapper for the NAIF SPICE toolkit. Its development is managed on Github. It is available at: https://github.com/AndrewAnnex/SpiceyPy Naming Conventions --------------------------------------------------------------------------- Data items are specified using ''keyword=value'' assignments [1]. All keywords referencing values in this I-kernel start with the characters `INS' followed by the NAIF MPO instrument ID code, constructed using the spacecraft ID number (-121) followed by the NAIF three digit ID number for one of the SIXS data item. These IDs are as follows Instrument name ID -------------------- ------ MPO_SIXS -121700 MPO_SIXS-X-1 -121711 MPO_SIXS-X-2 -121712 MPO_SIXS-X-3 -121713 MPO_SIXS-P-0 -121721 MPO_SIXS-P-1 -121722 MPO_SIXS-P-2 -121723 MPO_SIXS-P-3 -121724 MPO_SIXS-P-4 -121725 The remainder of the name is an underscore character followed by the unique name of the data item. For example, the SIXS-P (sensor 1) boresight direction in the MPO_SIXS-P frame (see [2]) is specified by: INS-121711_BORESIGHT The upper bound on the length of the name of any data item identifier is 32 characters. If the same item is included in more than one file, or if the same item appears more than once within a single file, the latest value supersedes any earlier values. Overview --------------------------------------------------------------------------- From [6]: The scientific investigation performed by the Solar Intensity X-ray and particle Spectrometer (SIXS) is the determination of solar impact on the Hermean surface in the form of direct X-rays and energetic particles, which induce observable X-ray emission via interaction with the surface of the planet. Particles of concern here are highly energetic solar protons and electrons. Direct X-rays from the Sun are absorbed on Mercury's surface, resulting in X-ray fluorescence, and a part of the radiation is also scattered by the surface. A detailed description of these processes is included in the associated instrument, the Mercury Imaging X-ray Spectrometer (MIXS). A major task for SIXS instrument, is measurement of solar X-rays on the dayside of Mercury to enable a valid analysis of the X-ray fluorescence on the planet's surface observed by MIXS. In addition to X-rays, the Sun also emits energetic charged particle radiation. The Proton Induced X-ray Emission (PIXE) process is likely to be an important source of X-rays emitted from the Hermean surface during solar energetic particle (SEP) events related to flares and (fast) coronal mass ejections (CMEs). Since PIXE is indistinguishable from the x-ray induced emission, it is important to know both the flux of protons and x-rays bombarding the planetary surface. A common requirement for monitoring of the solar X-ray and particle radiation on- board BepiColombo is a large Field-Of-View. Reference solar X-ray measurements must cover the times when measurements of sunlit Mercury surface are performed by the Mercury X-ray spectrometer. Particle flux measurements should cover a similar or even larger FOV to ensure the relevance of measured quantities as estimators of particle flux on the surface of Mercury. Essentially, the requirement is to cover half the sky with the particle detector and one quadrant with the x-ray detectors. Measurement principle: ~~~~~~~~~~~~~~~~~~~~~~ X-ray detection chain uses dedicated photodiodes with an X-ray filter on top of the detector. The X-ray detector is based on a Si PIN diode, which converts the photon energy to electrical charge by photoelectric absorption. An electrical field inside the diode will sweep the charges to the P (holes) and N (electrons) junctions. The generated charge is conducted from the detector electrodes to an amplifier chain. If a programmable detection threshold is exceeded, the detection amplifier chain is triggered resulting in AD-conversion of the detected charge. The particle sensor consists of the cubic core scintillator (CsI(Tl)) surrounded on five faces by planar Si PIN detectors. The size of the scintillator crystal is 5.0x5.0x6.3 mm3. The sixth face of the crystal is coupled to a silicon PIN photodiode with active area of 5.0x5.0 mm2. The overall 7.0x6.2 mm2 surface area of each of the side Si detectors is divided in two active areas. A centre area with a diameter of 2.5 mm defines the field of view together with the mechanical collimator. The remaining active surface area of the Si detector is used in anticoincidence with the core detector and each of the five centre areas to reject particles incident outside of the nominal view cone of the sensor. The top detector has 6.2x6.2 mm2 surface area. The collimator structure, with an innermost opening of 3.0 mm in diameter, includes two thin foils. The primary function of the outer foil is to protect the surface detectors from the outside thermal and electromagnetic environment, and the inner one provides additional shielding for the detectors against electromagnetic interference. The two foils also shield the detectors from incident optical light. The Si detectors operate with the same principle as the X-ray detectors. Unlike X-ray photons, however, particles generate charge in a track across the detector material. The scintillation mechanism, i.e., conversion of kinetic energy of an ionizing particle to visible light, in inorganic alkali halides, like CsI, depends on the energy states determined by the crystal lattice of the material. When a charged particle passes through a scintillation material it generates electron-hole pairs exciting the electrons from the valence band across the band gap to the conduction band. The de- excitation of these electrons back to the valence band occurs through intermediate energy states in the forbidden band of the pure alkali halide created by small amounts of impurities (activators) added in the scintillator material. The activator is selected in such a way that transitions from the created intermediate energy states occur through emission of visible light. The time response of an inorganic scintillator is determined by the half-lives of the excited states of the activator and the emission spectrum depends on the energy level structure of the activator. In the case of CsI(Tl), thallium is the activator providing an emission spectrum with a broad maximum at 540-560 nm, well matching the spectral response of silicon PIN photodiodes. In the photodiode the detection of incident light collected from the scintillator crystal is based on converting the photon energy to electrical charge by photoelectric absorption, as in the X-ray detectors. The charges generated in the Si detectors and in the Si photodiode are collected by charge-sensitive preamplifiers, and the signals are further amplified by filter amplifiers. If a programmable detection threshold is exceeded, the signals from two active detectors are AD-converted under the control of an FPGA. The selection of the AD-converted signals is based on a priority system always selecting the core detector when the corresponding signal is detected, and giving high priority for the surface Si detector in the anti-nadir direction. The following tables summarize the instrument optics, performances and resolutions: X-Ray Channels: Parameter | Units | Value/Description Remarks -------------------------+----------+---------------------------- Optics | | | | Aperture | | (Aperture diameter) Detector 1 | mm | 0.2 Detector 2 | mm | 0.3 Detector 3 | mm | 0.2 Field of view | degrees | 97.1, 98.7 and 97.1 (theoretical) | | (3 circular cones covering | | ~1/4 of full sky) Spectral range | keV | 1-200 Filter bandwidth | # | X-ray (metallic filter to | | block UV from photodiodes) Resolution | | | | Spectral channels | # | 265 Spectral resolution | eV | BOL*: 250 @ 6keV, 300 @ 10keV | eV | EOL**: 350 @ 6keV, <500 @ 10keV | | Sensor | | | | Pixels | # | 3: one per detector (Only | | one used at a time) Peak quantum | | efficiency | % | 98 (at ~8keV) Maximum count-rate | # | 20.000 cps at 4% pile-up Exposure time | s | 16 (spectrum) | s | 1 (count rate) | | Proton/Electron Channel: Parameter | Units | Value/Description Remarks -------------------------+----------+---------------------------- Optics | | | | Field of view | degrees | >180 with coarse directional | | sensivity Resolution | | | | Spectral | # | proton: 9 (8 differential channels | | channels + 1 integral energy) | # | electron: 7 (6 differential | | channels + 1 integral energry) | | Spectral range | MeV | proton: 0.33-30 | MeV | electron: 0.05-3 | | Sensor | | | | Pixels | # | 5: entrance windows in 5 | | sides of a cube, each with | | a 50 degrees FOV Peak quantum | | efficiency | % | 100 Maximum count-rate | # | ~20.000 cps Exposure time | s | 8 (spectrum) | s | 1 (count rate) | s | 64 (event sample) | s | 1 (spectrum for | | selective downlink | | data) | | * BOL: Beginning Of Life ** EOL: End Of Life Mounting Alignment --------------------------------------------------------------------------- Refer to the latest version of the BepiColombo Frames Definition Kernel (FK) [4] for the SIXS reference frame definitions and mounting alignment information. Detector Layouts --------------------------------------------------------------------------- The detectors field of views (FOV) are modelled as conical ellipsoids with half angle values for the solid angle in the azimuth direction (SOA) and the solid angle for the elevation direction (SOE) which correspond to the reference and cross angles. The following is a summary of the SIXS field of views(*) provided in [6] and [7]: --------------------- ----------------- ---------------- ---------------- Unit Boresight Axis Scientific Field Calibrated Field Orientation [deg] of View [deg] of View [deg] ----------------- ---------------- ---------------- Azimuth Elevation SOA SOE SOA SOE --------------------- ------- --------- ------- -------- ------- -------- X-Ray Detector 1 -45.0 25.0 46.9 46.9 51.56 51.32 X-Ray Detector 2 0.0 65.0 46.2 46.2 51.09 53.31 X-Ray Detector 3 45.0 25.0 46.9 46.2 51.19 51.79 Particle Detector 0 180.0 83.0 25.0 25.0 n/a n/a Particle Detector 1 134.8 -4.9 25.0 25.0 n/a n/a Particle Detector 2 -134.8 -4.9 25.0 25.0 n/a n/a Particle Detector 3 -45.2 4.9 25.0 25.0 n/a n/a Particle Detector 4 45.2 4.9 25.0 25.0 n/a n/a --------------------- ----------- ---------- ---------- ----------------- * All field of views are defined with half angles FOV Definitions --------------------------------------------------------------------------- This section contains definitions for the field of views (FOV) for the SIXS sensors. These definitions are provided in a format required by the SPICE (CSPICE) function GETFOV (getfov_c). SIXS-X Field of View Specification: ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ These FoVs have been calculated based on ground calibration field of view sensitivity maps. The FoVs cover the area where the sensitivity is greater than 0.01 (from [7]). Please note that the FOV reference and cross angles are defined with half angle values. The following FOV definitions correspond to the NAIF Body Names: MPO_SIXS-X-1, MPO_SIXS-X-2 and MPO_SIXS-X-3. \begindata INS-121711_NAME = 'MPO_SIXS-X-1' INS-121711_BORESIGHT = ( 0.01495639, 0.03913667, 0.99912193 ) INS-121711_FOV_FRAME = 'MPO_SIXS-X-1' INS-121711_FOV_SHAPE = 'ELLIPSE' INS-121711_FOV_CLASS_SPEC = 'ANGLES' INS-121711_FOV_REF_VECTOR = ( 0.35666498, 0.93329241, -0.04189717 ) INS-121711_FOV_REF_ANGLE = ( 51.56085164 ) INS-121711_FOV_CROSS_ANGLE = ( 51.32039328 ) INS-121711_FOV_ANGLE_UNITS = 'DEGREES' INS-121712_NAME = 'MPO_SIXS-X-2' INS-121712_BORESIGHT = ( 0.07827733, 0.02768676, 0.99654709 ) INS-121712_FOV_FRAME = 'MPO_SIXS-X-2' INS-121712_FOV_SHAPE = 'ELLIPSE' INS-121712_FOV_CLASS_SPEC = 'ANGLES' INS-121712_FOV_REF_VECTOR = ( 0.93951004, 0.33230557, -0.08302949 ) INS-121712_FOV_REF_ANGLE = ( 51.08895979 ) INS-121712_FOV_CROSS_ANGLE = ( 53.31562672 ) INS-121712_FOV_ANGLE_UNITS = 'DEGREES' INS-121713_NAME = 'MPO_SIXS-X-3' INS-121713_BORESIGHT = ( 0.00212263, 0.00072487, 0.99999748 ) INS-121713_FOV_FRAME = 'MPO_SIXS-X-3' INS-121713_FOV_SHAPE = 'ELLIPSE' INS-121713_FOV_CLASS_SPEC = 'ANGLES' INS-121713_FOV_REF_VECTOR = ( 0.94633814, 0.32317037, -0.00224299 ) INS-121713_FOV_REF_ANGLE = ( 51.19144830 ) INS-121713_FOV_CROSS_ANGLE = ( 51.79110311 ) INS-121713_FOV_ANGLE_UNITS = 'DEGREES' \begintext SIXS-X Planning Field of View Specification: ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ These FoVs are defined for planning purposes; SIXS will use a planning FpV to compute events for some terminator observations (to include the Sun in the FOV) and will use a model of about 52 degrees. Please note that the FOV reference and cross angles are defined with half angle values. The following FOV definitions correspond to the NAIF Body Names: MPO_SIXS-X-1_PLAN, MPO_SIXS-X-2_PLAN and MPO_SIXS-X-3_PLAN. \begindata INS-121714_NAME = 'MPO_SIXS-X-1_PLAN' INS-121714_BORESIGHT = ( 0.01495639, 0.03913667, 0.99912193 ) INS-121714_FOV_FRAME = 'MPO_SIXS-X-1' INS-121714_FOV_SHAPE = 'ELLIPSE' INS-121714_FOV_CLASS_SPEC = 'ANGLES' INS-121714_FOV_REF_VECTOR = ( 0.35666498, 0.93329241, -0.04189717 ) INS-121714_FOV_REF_ANGLE = ( 52.0 ) INS-121714_FOV_CROSS_ANGLE = ( 52.0 ) INS-121714_FOV_ANGLE_UNITS = 'DEGREES' INS-121715_NAME = 'MPO_SIXS-X-2_PLAN' INS-121715_BORESIGHT = ( 0.07827733, 0.02768676, 0.99654709 ) INS-121715_FOV_FRAME = 'MPO_SIXS-X-2' INS-121715_FOV_SHAPE = 'ELLIPSE' INS-121715_FOV_CLASS_SPEC = 'ANGLES' INS-121715_FOV_REF_VECTOR = ( 0.93951004, 0.33230557, -0.08302949 ) INS-121715_FOV_REF_ANGLE = ( 52.0 ) INS-121715_FOV_CROSS_ANGLE = ( 52.0 ) INS-121715_FOV_ANGLE_UNITS = 'DEGREES' INS-121716_NAME = 'MPO_SIXS-X-3_PLAN' INS-121716_BORESIGHT = ( 0.00212263, 0.00072487, 0.99999748 ) INS-121716_FOV_FRAME = 'MPO_SIXS-X-3' INS-121716_FOV_SHAPE = 'ELLIPSE' INS-121716_FOV_CLASS_SPEC = 'ANGLES' INS-121716_FOV_REF_VECTOR = ( 0.94633814, 0.32317037, -0.00224299 ) INS-121716_FOV_REF_ANGLE = ( 52.0 ) INS-121716_FOV_CROSS_ANGLE = ( 52.0 ) INS-121716_FOV_ANGLE_UNITS = 'DEGREES' \begintext SIXS-P Field of View Specification: ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ Please note that the FOV reference and cross angles are defined with half angle values. The following FOV definitions correspond to the NAIF Body Names: MPO_SIXS-P-0, MPO_SIXS-P-1, MPO_SIXS-P-2, MPO_SIXS-P-3 and MPO_SIXS-P-4. \begindata INS-121721_NAME = 'MPO_SIXS-P-0' INS-121721_BORESIGHT = ( 0, 0 , 1 ) INS-121721_FOV_FRAME = 'MPO_SIXS-P-0' INS-121721_FOV_SHAPE = 'CIRCLE' INS-121721_FOV_CLASS_SPEC = 'ANGLES' INS-121721_FOV_REF_VECTOR = ( 1.0, 0.0, 0.0 ) INS-121721_FOV_REF_ANGLE = ( 25 ) INS-121721_FOV_CROSS_ANGLE = ( 25 ) INS-121721_FOV_ANGLE_UNITS = 'DEGREES' INS-121722_NAME = 'MPO_SIXS-P-1' INS-121722_BORESIGHT = ( 0.0, 0.0, 1.0 ) INS-121722_FOV_FRAME = 'MPO_SIXS-P-1' INS-121722_FOV_SHAPE = 'CIRCLE' INS-121722_FOV_CLASS_SPEC = 'ANGLES' INS-121722_FOV_REF_VECTOR = ( 1.0, 0.0, 0.0 ) INS-121722_FOV_REF_ANGLE = ( 25 ) INS-121722_FOV_CROSS_ANGLE = ( 25 ) INS-121722_FOV_ANGLE_UNITS = 'DEGREES' INS-121723_NAME = 'MPO_SIXS-P-2' INS-121723_BORESIGHT = ( 0.0, 0.0, 1.0 ) INS-121723_FOV_FRAME = 'MPO_SIXS-P-2' INS-121723_FOV_SHAPE = 'CIRCLE' INS-121723_FOV_CLASS_SPEC = 'ANGLES' INS-121723_FOV_REF_VECTOR = ( 1.0, 0.0, 0.0 ) INS-121723_FOV_REF_ANGLE = ( 25 ) INS-121723_FOV_CROSS_ANGLE = ( 25 ) INS-121723_FOV_ANGLE_UNITS = 'DEGREES' INS-121724_NAME = 'MPO_SIXS-P-3' INS-121724_BORESIGHT = ( 0.0, 0.0, 1.0 ) INS-121724_FOV_FRAME = 'MPO_SIXS-P-3' INS-121724_FOV_SHAPE = 'CIRCLE' INS-121724_FOV_CLASS_SPEC = 'ANGLES' INS-121724_FOV_REF_VECTOR = ( 1.0, 0.0, 0.0 ) INS-121724_FOV_REF_ANGLE = ( 25 ) INS-121724_FOV_CROSS_ANGLE = ( 25 ) INS-121724_FOV_ANGLE_UNITS = 'DEGREES' INS-121725_NAME = 'MPO_SIXS-P-4' INS-121725_BORESIGHT = ( 0.0, 0.0, 1.0 ) INS-121725_FOV_FRAME = 'MPO_SIXS-P-4' INS-121725_FOV_SHAPE = 'CIRCLE' INS-121725_FOV_CLASS_SPEC = 'ANGLES' INS-121725_FOV_REF_VECTOR = ( 1.0, 0.0, 0.0 ) INS-121725_FOV_REF_ANGLE = ( 25 ) INS-121725_FOV_CROSS_ANGLE = ( 25 ) INS-121725_FOV_ANGLE_UNITS = 'DEGREES' \begintext Optical Parameters --------------------------------------------------------------------------- The first order optical parameters for the X-ray and Proton/Electron channels that constitute SIXS (from [6]) are as follows: ---------------------------- --------------------- ------------------- Parameter X-Ray Proton/Electron 1 2 3 0,1,2,3,4 ---------------------------- ------ ------- ------ -------------------- Aperture, mm 0.2 0.3 0.2 # Field of View, deg cross-track 51.56 51.09 51.19 25.00 along-track 51.32 53.31 51.79 25.00 ---------------------------- ------ ------- ------ -------------------- These values are given in the keywords below in the same units as the tables above: X-Ray (MPO_SIXS-X-1, MPO_SIXS-X-2, MPO_SIXS-X-3): \begindata INS-121711_APERTURE = ( 0.2 ) INS-121711_FOV_ANGULAR_SIZE = ( 51.56, 51.32 ) INS-121712_APERTURE = ( 0.3 ) INS-121712_FOV_ANGULAR_SIZE = ( 51.09, 53.31 ) INS-121712_APERTURE = ( 0.2 ) INS-121712_FOV_ANGULAR_SIZE = ( 51.19, 51.79 ) \begintext Proton/Neutron (MPO_SIXS-P-0, MPO_SIXS-P-1, MPO_SIXS-P-2, MPO_SIXS-P-3, MPO_SIXS-P-4): \begindata INS-121721_FOV_ANGULAR_SIZE = ( 25.00, 25.00 ) INS-121722_FOV_ANGULAR_SIZE = ( 25.00, 25.00 ) INS-121723_FOV_ANGULAR_SIZE = ( 25.00, 25.00 ) INS-121724_FOV_ANGULAR_SIZE = ( 25.00, 25.00 ) INS-121725_FOV_ANGULAR_SIZE = ( 25.00, 25.00 ) \begintext End of IK file.