A compact high-speed pnCCD camera for optical and x-ray applications

Ihle, Sebastian; Ordavo, I.; Bechteler, A.; Hartmann, R.; Holl, P.; Liebel, A.; Meidinger, Norbert; Soltau, H.; Strüder, L.; Weber, U.

doi:10.1117/12.926997

Cited by 3 publications

(3 citation statements)

References 8 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…While drifting, a few of charges will be trapped at silicon crystal defects leading to a loss of signal charge, which is described by charge transfer efficiency (CTE) or charge transfer inefficiency (CTI = 1 − CTE). It is one of the important characteristics that must be known and optimized to obtain the original signal height (Dennerl et al 1999;Ihle et al 2012). During the integration time of the charges, each pixel accumulates dark current that will shift the baseline of signals (so-called offset noise).…”

Section: Methods Of Data Analysismentioning

confidence: 99%

Characterization of a pnCCD-based Camera for Applications at the 100 m X-Ray Test Facility*

Hou¹,

Wang²,

Zhao³

et al. 2023

PASP

Self Cite

View full text Add to dashboard Cite

The 100 m long X-ray test facility (100XF for clarity) in Institute of High Energy Physics of CAS has been playing an increasingly important role in the X-ray astronomy field in China. 100XF has been contributing to the missions under development, such as the Einstein Probe mission. The facility has also been providing support to R&D of focusing X-ray optics in China that will enable future X-ray telescopes to be realized, such as the enhanced X-ray Timing and Polarization (eXTP) mission. A pnCCD-based camera has been employed at 100XF to rapidly measure the performance of the X-ray optics. In this work, we study the performance of the camera and its spectral and imaging applications at 100XF. The camera system can provide a high frame readout rate, with a low readout noise <3 e−. It is sensitive to X-ray photons in the 3–10 keV energy band with a high quantum efficiency exceeding 90%. Actually, the low threshold of detection energy range can reach down to 0.2 keV. The energy resolution can reach 145.2 eV for single events and 154.8 eV for all valid events (including single events and split events) at 6.4 keV. The camera also exhibits excellent imaging capability in both the full frame mode and the windowing mode, with a readout rate of up to 1000 Hz. Finally, a prototype of a focusing X-ray mirror shell of eXTP was smoothly measured with this camera. The obtained on-axis point-spread function and half-power diameter are consistent with expectations. It is proven that the camera can improve the capability of 100XF in characterizing the X-ray optics. This camera will be very useful for performing on-ground calibrations for future X-ray telescope missions.

show abstract

Section: Methods Of Data Analysismentioning

confidence: 99%

Characterization of a pnCCD-based Camera for Applications at the 100 m X-Ray Test Facility*

Hou¹,

Wang²,

Zhao³

et al. 2023

PASP

Self Cite

View full text Add to dashboard Cite

show abstract

“…39 These are the non-square pixels resulting from the usage of a micro-lens array, required to maximize filling factor, which produce two different spatial sampling frequencies that complicates image restoration; up to date the ZIMPOL concept has been implemented in slow readout sensors (∼2 fps) limiting the study of fast events and the application of image restoration techniques in combination with high duty cycle. The FSP, employs a frame-transfer, fully-depleted CCD detector 253,254 that was custom-made with column parallel readout. The 400 fps, almost 100% duty cycle and low noise (4.9 e − RMS) of the detector allowed FSP to avoid seeing effects and reach the ∼0.01% polarimetric sensitivity level using FLC-based temporal modulation only.…”

Section: Custom Detectorsmentioning

confidence: 99%

Instrumentation for solar spectropolarimetry: state of the art and prospects

Iglesias

Feller

2019

Opt. Eng.

View full text Add to dashboard Cite

Given its unchallenged capabilities in terms of sensitivity and spatial resolution, the combination of imaging spectropolarimetry and numeric Stokes inversion represent the dominant technique currently used to remotely sense the physical properties of the solar atmosphere, and in particular, its important driving magnetic field. Solar magnetism manifests itself in a wide range of spatial, temporal and energetic scales. The ubiquitous but relatively small and weak fields of the so called quiet Sun are believed today to be crucial for answering many open questions in solar physics, some of which have substantial practical relevance due to the strong Sun-Earth connection. However, such fields are very challenging to detect because they require spectropolarimetric measurements with high spatial (subarcsec), spectral (< 100 m) and temporal (< 10 s) resolution along with high polarimetric sensitivity (< 0.1% of the intensity). In this review we collect and discuss both well-established and upcoming instrumental solutions developed during the last decades to push solar observations towards the above-mentioned parameter regime. This typically involves design trade-offs due to the high dimensionality of the data and signal-to-noise-ratio considerations, among others. We focus on the main three components that form a spectropolarimeter, namely, wavelength discriminators, the devices employed to encode the incoming polarization state into intensity images (polarization modulators), and the sensor technologies used to register them. We consider the instrumental solutions introduced to perform this kind of measurements at different optical wavelengths and from various observing locations, i.e., ground-based, from the stratosphere or near space.

show abstract

“…The quantum efficiency of the sensor is above 90% in the 500-850 nm wavelength range, and above 60% within 390-1000 nm. Further details on the camera structure and performance are given in Ihle et al (2012) and Hartmann et al (2006). The measured readout plus quantization noise at 400 fps is 4.94 e − rms with a standard deviation over the sensor area of A89, page 6 of 13 Table 2 (dashed) and the second using the same input, except that the values of the dispersion coefficients, C d , were all set to zero (dotted).…”

Section: The Pnccd Cameramentioning

confidence: 99%

High-resolution, high-sensitivity, ground-based solar spectropolarimetry with a new fast imaging polarimeter

Iglesias

Feller

Nagaraju

et al. 2016

A&A

View full text Add to dashboard Cite

Context. Remote sensing of weak and small-scale solar magnetic fields is of utmost relevance when attempting to respond to a number of important open questions in solar physics. This requires the acquisition of spectropolarimetric data with high spatial resolution (∼10 −1 arcsec) and low noise (10 −3 to 10 −5 of the continuum intensity). The main limitations to obtain these measurements from the ground, are the degradation of the image resolution produced by atmospheric seeing and the seeing-induced crosstalk (SIC). Aims. We introduce the prototype of the Fast Solar Polarimeter (FSP), a new ground-based, high-cadence polarimeter that tackles the above-mentioned limitations by producing data that are optimally suited for the application of post-facto image restoration, and by operating at a modulation frequency of 100 Hz to reduce SIC. Methods. We describe the instrument in depth, including the fast pnCCD camera employed, the achromatic modulator package, the main calibration steps, the effects of the modulation frequency on the levels of seeing-induced spurious signals, and the effect of the camera properties on the image restoration quality. Results. The pnCCD camera reaches 400 fps while keeping a high duty cycle (98.6%) and very low noise (4.94 e − rms). The modulator is optimized to have high (>80%) total polarimetric efficiency in the visible spectral range. This allows FSP to acquire 100 photon-noise-limited, full-Stokes measurements per second. We found that the seeing induced signals that are present in narrowband, non-modulated, quiet-sun measurements are (a) lower than the noise (7 × 10 −5 ) after integrating 7.66 min, (b) lower than the noise (2.3 × 10 −4 ) after integrating 1.16 min and (c) slightly above the noise (4 × 10 −3 ) after restoring case (b) by means of a multiobject multi-frame blind deconvolution. In addition, we demonstrate that by using only narrow-band images (with low S/N of 13.9) of an active region, we can obtain one complete set of high-quality restored measurements about every 2 s.

show abstract

A compact high-speed pnCCD camera for optical and x-ray applications

Cited by 3 publications

References 8 publications

Characterization of a pnCCD-based Camera for Applications at the 100 m X-Ray Test Facility*

Characterization of a pnCCD-based Camera for Applications at the 100 m X-Ray Test Facility*

Instrumentation for solar spectropolarimetry: state of the art and prospects

High-resolution, high-sensitivity, ground-based solar spectropolarimetry with a new fast imaging polarimeter

Contact Info

Product

Resources

About