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 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.