Dr. Kris Iniewski Profile

Dr. Kris Iniewski

R&D Manager at Redlen Technologies

SPIE Involvement:

Author

SPIE Journal Paper | 15 June 2020

Photon-counting computed tomography of lanthanide contrast agents with a high-flux 330-μm-pitch cadmium zinc telluride detector in a table-top system

Chelsea A. Dunning, Jericho O’Connell, Spencer Robinson, Kevin Murphy, Adriaan Frencken, Frank C. J. van Veggel, Kris Iniewski, Magdalena Bazalova-Carter

JMI, Vol. 7, Issue 03, 033502, (June 2020) https://doi.org/10.1117/12.10.1117/1.JMI.7.3.033502

KEYWORDS: Gadolinium, Sensors, Lutetium, Holmium, Computed tomography, Lanthanum, Lanthanides, X-ray computed tomography, X-rays, Optical computing

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Proceedings Article | 14 May 2019 Presentation

High flux 2D CZT detector array for XRD applications (Conference Presentation)

Conny C. Hansson, Kris Iniewski, Adam Grosser, Joel Greenberg

Proceedings Volume 10999, 109990G (2019) https://doi.org/10.1117/12.2517844

KEYWORDS: Sensors, Scanners, Detector arrays, X-ray diffraction, Tomography, Image resolution, X-rays, 3D image processing, Stereoscopy, Explosives detection

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X-ray diffraction (XRD) tomography continuous to be a promising technology for maintaining a high detection probability with low false alarm rates while adding new threat classes. By collecting the diffracted (coherently scattered) X-rays, one realizes several key advantages over transmission-based systems: • Measure several additional features by which to identify material composition • Tomographic 3D spatial imaging with only a single view • Automatic, PC based, explosives detection algorithms for replacing human operators A key requirement for XRD technology is excellent energy resolution (ER) of the detectors used in the scanner. Existing spectroscopic detectors offer low enough ER (below 6keV) but, unfortunately, operate at rather low count rate (typically under 1kcps/mm2). As a result, commercial XRD scanners, such as the XRD3500, require long scan times. As a result, it is difficult to effectively use these scanners in airports. A breakthrough in XRD technology was achieved through the use of coded apertures, which increase the signal amplitude by 2-3 orders of magnitude compared to traditional heavy collimated systems. While the brighter resulting XRD signal requires complex signal processing to eliminate increased scatter, it has been shown to produce a much faster XRD scanner response (seconds instead of minutes). A practical implementation of this new approach requires high count rate (between 1kcps/mm2 and 1Mcps/mm2) while maintaining very low ER (below 6keV) and sub-mm spatial resolution required for angular detection precision. In the last 5 years, Redlen Technologies has developed high-flux CZT detection technology for medical Computed Tomography (CT) that is currently being deployed by major medical OEMs into clinical applications. The technology is based on a 22x34 [748 pixels] 2-D array with a pixel pitch of 330um. The associated high-speed photon counting ASIC that allows for event detection operates up to 250Mcps/mm2. Recently we have found a way to reconfigure that detector technology platform into an XRD platform. In this paper we will present experimental results of our 2-D 22x32 CZT pixel array that is currently available for deployment into XRD scanner platforms. The CZT sensors used in this platform are 2mm thick with a 330 um pixel pitch and operate without polarization up to 250Mcps/mm2. In the CT mode, the detectors operate in the 16-190 keV range with energy resolution of 6.9 keV and standard deviation of 0.7 keV across 748 pixels. In the XRD mode, the detectors operate in the 12-150 keV range with energy resolution of mean value of 5.6keV and standard deviation of 0.6keV across 748 pixels. We believe these performance levels are more than sufficient to enable operating XRD scanner at the optimum performance levels.

Proceedings Article | 12 May 2016 Paper

High precision, medium flux rate CZT spectroscopy for coherent scatter imaging

Joel Greenberg, Mehadi Hassan, David Brady, Kris Iniewski

Proceedings Volume 9847, 98470E (2016) https://doi.org/10.1117/12.2221913

KEYWORDS: Sensors, Imaging systems, Spectroscopy, X-rays, Image resolution, Coherence imaging, X-ray detectors, Imaging spectroscopy, Photon counting, X-ray imaging

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Proceedings Article | 2 September 2010 Paper

Performance of CdZnTe pixellated radiation detectors assembled by a new attachment method

Pinghe Lu, Henry Chen, Salah Awadalla, Kris Iniewski, Glenn Bindley

Proceedings Volume 7805, 78051T (2010) https://doi.org/10.1117/12.860999

KEYWORDS: Sensors, Coating, Polymers, Gold, Epoxies, Sensor performance, Reliability, Photomasks, Resistance, Metals

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Proceedings Article | 17 September 2009 Paper

CZT device with improved sensitivity for medical imaging and homeland security applications

H. Chen, S. Awadalla, P. Marthandam, K. Iniewski, P. Lu, G. Bindley

Proceedings Volume 7449, 744902 (2009) https://doi.org/10.1117/12.828514

KEYWORDS: Sensors, Electrons, Electrodes, Metals, Resistance, Semiconductors, Gold, Homeland security, Image resolution, Medical imaging

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Proceedings Article | 21 September 2007 Paper

Large-volume high-resolution cadmium zinc telluride radiation detectors: recent developments

H. Chen, S. Awadalla, K. Iniewski, P. Lu, F. Harris, J. Mackenzie, T. Hasanen, W. Chen, R. Redden, G. Bindley, Irfan Kuvvetli, Carl Budtz-Jørgensen, P. Luke, M. Amman, J. Lee, A. Bolotnikov, G. Camarda, Y. Cui, A. Hossain, R. James

Proceedings Volume 6706, 670602 (2007) https://doi.org/10.1117/12.738793

KEYWORDS: Sensors, Crystals, Zinc, Semiconducting wafers, Cadmium, Homeland security, Image resolution, Medical imaging, X-rays, Spatial resolution

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Proceedings Article | 10 May 2007 Paper

Synchronous and asynchronous multiplexer circuits for medical imaging realized in CMOS 0.18um technology

R. Długosz, K. Iniewski

Proceedings Volume 6590, 65900V (2007) https://doi.org/10.1117/12.721239

KEYWORDS: Clocks, Multiplexers, Signal detection, Sensors, Multiplexing, Analog electronics, Transistors, Medical imaging, Switches, CMOS technology

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Multiplexers are one of the most important elements in readout front-end ASICs for multi-element detectors in medical imaging. The purpose of these ASICs is to detect signals appearing randomly in many channels and to collect the detected data in an ordered fashion (de-randomization) in order to send it to an external ADC. ASIC output stage functionality can be divided into two: pulse detection and multiplexing. The pulse detection block is responsible for detecting maximum values of signals arriving from the shaper, sending a flag signal indicating that the peak signal has been detected and storing the pulse in an analog memory until read by ADC. The multiplexer in turn is responsible for searching for active flags, controlling the channel that has detected the peak signal and performing reset functions after readout. There are several types of multiplexers proposed in this paper, which can be divided into several classes: synchronous, synchronized and asynchronous. Synchronous circuits require availability of the multiphase clock generator, which increases the power dissipation, but simultaneously provide very convenient mechanism that enables unambiguous choice of the active channel. This characteristics leads to 100% effectiveness in data processing and no data loss. Asynchronous multiplexers do not require clock generators and because of that have simpler structure, are faster and more power efficient, especially when data samples occur seldom at the ASIC's inputs. The main problem of the asynchronous solution is when data on two or more inputs occur almost at the same time, shorter than the multiplexer's reaction time. In this situation some data can be lost. In many applications loss of the order of 1% of the data is acceptable, which makes use of asynchronous multiplexers possible. For applications when the lower loss is desirable a new hierarchy mechanism has been introduced. One of proposed solutions is a synchronized binary tree structure, that uses many simple asynchronous clock generators. This circuit joins advantages of synchronous and asynchronous solutions resulting in low power dissipation, high speed of operation and 100% effectiveness.

Showing 5 of 7 publications

Conference Committee Involvement (6)

Hard X-Ray, Gamma-Ray, and Neutron Detector Physics XXIV

22 August 2022 | San Diego, California, United States

Hard X-Ray, Gamma-Ray, and Neutron Detector Physics XXIII

1 August 2021 | San Diego, California, United States

Hard X-Ray, Gamma-Ray, and Neutron Detector Physics XXII

25 August 2020 | Online Only, California, United States

Anomaly Detection and Imaging with X-Rays (ADIX) III

17 April 2018 | Orlando, FL, United States

Anomaly Detection and Imaging with X-Rays (ADIX) II

12 April 2017 | Anaheim, CA, United States

Showing 5 of 6 Conference Committees

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