SiC Blade BPM for white beams
The SenSiC Silicon Carbide White-Beam Blade XBPMs are designed for synchrotron front-end applications requiring robust beam-position monitoring directly on high-power white X-ray beams.
Traditional front-end XBPMs typically use metallic blades, such as tungsten ones, positioned at the edges of the white beam. While this approach is widely established, metallic blades can be limited by high absorption, low thermal resistance and signal stability when operating close to high-brilliance insertion-device sources.
SiC blade XBPMs introduce a semiconductor-based alternative: each blade acts as an active diode detector, generating a beam-induced current that can be used for beam current tracking and beam-position reconstruction.
Why SiC blades
Silicon carbide provides a strong material platform for white-beam diagnostics.Its radiation hardness, thermal robustness and semiconductor functionality make it suitable for demanding front-end environments where the blade is exposed to intense X-ray flux and heat load.
Compared with traditional tungsten blades, SiC blades may offer reduced absorption of bending-magnet background radiation and improved thermal stability of the signal. This allows the blades to be positioned closer to the photon beam, improving sensitivity and measurement precision in front-end XBPM layouts.
Image adapted from Houghton and Bobb, Proc. IBIC 2025, WEPMO05
Active semiconductor blade concept
Unlike passive metallic vanes, the SiC blade is an active semiconductor structure.
The tested prototype consisted of doped epitaxial layers forming a p–n junction, with a 15 µm n-type inactive layer and a 1.5 µm p⁺ active layer grown on an n⁺ substrate. A selective removal of the p⁺ layer at the chip edge creates an inactive border region, acting as a built-in photon filter to reduce low-energy contributions such as UV and soft X-rays. This is a very important commercial point because it shows that the SiC blade is not just a material replacement but an engineered detector structure optimized for front-end operation.
Designed to retrofit synchrotron front-ends
The SenSiC SiC blades are specifically designed to be compatible with the already existing FMB-Berlin detector head for ID Radiation, allowing for fast and safe mounting of the four diodes in substitution of the tungsten blades.
SiC blade XBPMs can be adapted to existing or custom front-end mechanical layouts. The blade geometry, active area, inactive border, metallization, bias configuration and electrical contacting strategy can be optimized according to beamline requirements. Particular attention is given to electrical isolation, mechanical robustness and thermal expansion management, which are critical aspects for reliable long-term operation in white-beam environments.
The system can be supplied as SiC blade components, as a blade set for integration into an existing XBPM holder, with readout electronics and technical documentation.
Compatible with low-noise current readout electronics
Each SiC blade generates a current signal that can be acquired using low-noise current readout electronics.
The SenSiC PCR4 has a current reading channel specifically realized for high current generating scenarios, such as the exposure of a SiC to a white beam right after the insertion device, allowing the reading of up to 50 mA of beam-induced current per channel.
Multi-channel acquisition enables simultaneous readout of the blade currents for total current monitoring and position reconstruction. The readout chain can be configured according to the expected current range, acquisition speed and beamline control-system requirements, being compatible with EPICS, TANGO or PYTHON.
Publications about this technology
| Houghton, C. and Bobb, L., Proc. IBIC 2025, WEPMO05. DOI: 10.18429/JACoW-IBIC2025-WEPMO05 |
| Nadolski, L., et al., Proc IPAC25, MOPB074. DOI: 10.18429/JACoW-IPAC2025-MOPB074 |
SiC Beamstopper-Integrated Sensor
The SenSiC Beamstopper-Integrated Sensor (BIS) is a silicon carbide-based active beamstop designed for X-ray beamlines where beam interception and real-time diagnostics are required in the same compact device.
Unlike conventional passive beamstops, the BIS generates an electrical signal when irradiated by the X-ray beam. This allows the beamstop position to become an active diagnostic point, providing information on beam presence, relative intensity, and, in the 4-quadrant configuration, beam position.
More than a beamstop
In scattering and diffraction experiments, the beamstop is placed at a critical location: directly downstream of the sample, where the transmitted primary beam must be safely intercepted. In a conventional setup, this component is passive, but the SenSiC BIS changes this concept. By integrating a SiC sensor into the beamstop assembly over a thick tungsten piece, the device can provide an electrical readout related to the intercepted beam. This enables real-time monitoring without adding a separate diagnostic element into the experimental layout.
This is particularly valuable in compact end-stations, high-brilliance beamlines and experiments where space, alignment stability and diagnostic reliability are critical.
Available configurations
Intensity Beamstopper
The intensity configuration provides a beam-induced current signal related to the intercepted X-ray flux.
It is suitable for beam presence detection, relative intensity monitoring, beamline commissioning, and diagnostic logging during scattering, diffraction, or imaging experiments.
4-Quadrant Position-Sensitive Beamstopper
The 4-quadrant configuration integrates four independent SiC sensing regions into the beamstopper.
This allows the beamstopper to monitor the position of the transmitted or post-sample beam while still performing its primary beam-interception function.
| Single pixel (intensity monitor) | Four pixels (position monitor) |
| 0.5mm x 0.5mm | 2mm diameter |
| 0.8mm x 0.8 mm | 3mm diameter |
| 2.0mm diameter |
The reported BIS footprints are currently in the 2–3 mm diameter range, with four separate quadrants in the position-sensitive version. This ultra-compact footprint makes the BIS suitable for integration close to the sample, detector or scattering path, where conventional diagnostics may be too large or difficult to install.
Robust and compact integration
Each BIS can be mounted on a thin PCB with encapsulated electrical contacts, providing robust external connections through flat cables and LEMO interfaces.
The wirebond-free bonding approach improves mechanical robustness and simplifies handling during installation, alignment, and routine operation. This packaging concept is designed to support practical beamline integration while preserving the ultra-compact footprint of the active beamstop.
Each sensor package includes all necessary tools for signal readout, ensuring easy and straightforward installation:
(i) the sensor,
(ii) the connector to LEMO, SMA or BNC, upon request,
(iii) a “quick tester” and
(iv) a “UV torch” to check the sensor functionality during the installation.
SiC rXBPM – Spot-Size-Independent Beam Position Monitor
The SenSiC rXBPM is a resistive silicon carbide X-ray beam monitor designed to provide real-time information on both beam position and beam intensity in synchrotron radiation beamlines.
Unlike conventional segmented XBPMs, the rXBPM is based on a continuous resistive charge-division architecture. The X-ray-induced current is redistributed through a resistive p⁺-doped SiC layer and collected by four lateral electrodes, enabling beam-position reconstruction from the relative channel currents while preserving the total current as an intensity-related signal.
This architecture makes the rXBPM particularly attractive for applications where beam size, beam shape or alignment conditions may vary during operation.
Not a conventional segmented XBPM
Standard segmented XBPMs typically rely on separated electrodes or quadrants. Their position response can depend strongly on how the beam footprint overlaps the electrode geometry. As a result, the position sensitivity may change with beam size, and the linear operating region can be limited.
The SenSiC rXBPM follows a different principle. It works as a lateral-effect position-sensitive detector, where the position information is obtained from resistive charge division across a continuous active layer.
The current shared between the electrodes is used to reconstruct the beam position in both the horizontal and vertical directions. At the same time, the sum of the four electrode currents provides an intensity-related signal that can be used to monitor beam flux variations.
Unlike conventional segmented XBPMs, the SiC rXBPM does not rely on narrow gaps placed in the beam path. Its architecture allows the metallic electrodes to be positioned farther from the beam interaction region, giving access to a large and continuous SiC sensing layer. This approach reduces local wavefront perturbations caused by metallic structures and makes the device particularly suitable for beamlines where beam quality, coherence and transmission are critical.
Available membrane thicknesses
SenSiC free-standing membranes are available in different thicknesses to match the transmission, sensitivity, and mechanical requirements of each beamline application.
The SiC rXBPM is currently available only with a thickness of 10 µm, while devices featuring 1 µm, 2 µm, 20 µm and 35 µm will be soon available.
Each SiC rXBPM is characterized in-house using a 5.4 keV X-ray source to verify proper device operation before delivery. This quality-control step allows us to assess the sensor response under controlled irradiation conditions and to provide customers with essential information on the device behavior, including signal generation, uniformity, and operating recommendations.
What’s Included
All our sensors are mounted on a 3×4 cm² aluminum-core circuit boards for easy connection, finished in FR4 or ceramic, to adapt to every specific need. The electrical connection is granted by pre-soldered UMC contacts and by UMC-SMA cables included in the package. The whole product is air- as well as UHV- (10⁻⁸ mbar) compatible.
Mounted sensors are also available with plastic or metal covers to avoid damaging the sensor surface or the wire bondings during handling and installation.
Integration with SenSiC PCR4 electronics
The rXBPM can be read out using the SenSiC PCR4 four-channel picoammeter, enabling simultaneous acquisition of the four electrode currents.
This provides a complete detector-to-electronics chain for real-time beam diagnostics. The four channel currents can be used to compute horizontal position, vertical position and total beam intensity, supporting laboratory characterization, beamline commissioning and integration into control systems.
Publications about this technology
| Trovato, G. et al. Synchrotron Radiation 33.4 (2026). DOI: 10.1107/S1600577526005242 |
SiC Free-Standing Membrane XBPMs for Tender and Hard X-ray Beamlines
SenSiC free-standing silicon carbide XBPMs are designed for accurate, compact, and minimally invasive X-ray beam monitoring in advanced synchrotron and laboratory beamlines.
By combining the intrinsic robustness of 4H-SiC with the thin free-standing membrane architectures, these devices provide real-time information on beam intensity and position while preserving a high X-ray transmission. This makes them especially suitable for beamlines where continuous diagnostics are required close to the experiment, without introducing bulky hardware or significantly perturbing the beam.
Features
Silicon carbide XBPM sensors are composed of diodes in 2×2 array configurations, with gaps of 2 µm or 6 µm, large active areas, and a central region with defined high transparencies. The sensor can be operated at zero bias with >80% Charge Collection Efficiency (CCE), and feature a membrane uniformity below 5%.
The free-standing membrane has a granted circular diameter from 3 mm to 5 mm or with square/rectangular apertures, up to 5×5 mm².
Square and rectangular openings for the SiC free-standing membranes
Available membrane thicknesses
SenSiC free-standing membrane XBPMs are available in different standard thicknesses to match the transmission, sensitivity, and mechanical requirements of each beamline application.
Standard membrane thicknesses include 1 µm, 2 µm, 10 µm, 20 µm and 35 µm. Thinner membranes are typically preferred when maximum X-ray transmission is required, while thicker membranes can provide higher signal generation and increased mechanical robustness.
Contact us to explore the better solution for you according to the photon-energy range, expected flux, beam size and required monitoring performance.
In-House Characterization
Each SiC free-standing membrane XBPM is characterized in-house using a 5.4 keV X-ray source to verify proper device operation before delivery. This quality-control step allows us to assess the sensor response under controlled irradiation conditions and to provide customers with essential information on the device behavior, including signal generation, uniformity, and operating recommendations. As a result, each customer receives not only a sensor, but a tested diagnostic component with the technical data needed to support integration, and operation in the target beamline environment.
What’s Included
All our sensors are mounted on a 3×4 cm² aluminum-core circuit boards for easy connection, finished in FR4 or ceramic, to adapt to every specific need. The electrical connection is granted by pre-soldered UMC contacts and by UMC-SMA cables included in the package. The whole product is air- as well as UHV- (10⁻⁸ mbar) compatible.
Mounted sensors are also available with plastic or metal covers to avoid damaging the sensor surface or the wire bondings during handling and installation.
Publications about this technology
| Nida, S., et al. Synchrotron Radiation 26.1 (2019): 28-35. DOI: 10.1107/S1600577518014248 |
Trovato, G, et al. Synchrotron Radiation 32.1 (2025). DOI: 10.1107/S1600577524010646 |
| Medina, E., et al. Synchrotron Radiation 32.6 (2025). DOI: 10.1107/S1600577525007362 |
Trovato, G., et al. Journal of Instrumentation 20.12 (2025). DOI: 10.1088/1748-0221/20/12/C12005 |
SenSiC monitoring solutions can be supplied as standalone sensors or as complete diagnostic units. The scope of supply can include the SiC free-standing membrane sensor, vacuum-compatible integration components and low-noise readout electronics.
Each configuration can be adapted to the target photon-energy range, beam size, flux level, vacuum interface and readout requirements.