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As a prototype of Deep Underground Neutrino Experiment far detector, ProtoDUNE single-phase Liquid Argon (LAr) Time Projection Chamber (TPC) sits in H4 beam line at CERN to characterize detector response. It consists of 6 full-size Anode Plane Assemblies (APAs) plus 18 Cathode Plane Assembly (CPA) modules to form two 3.6-m drift regions with a total of 15,360 readout channels. To achieve a good signal-to-noise ratio with this noble liquid detector (770ton LAr), cold electronics developed at BNL for extremely low temperature (77K–89K) operation is an optimal solution, which decouples the electrode and cryostat design from the readout design. With CMOS front end ASICs integrated with the TPC electrodes, the electronic noise is independent of the fiducial volume and much lower than with readout electronics at room temperature. In addition, signal digitization and multiplexing to high-speed links inside the cryostat result in large reduction in the quantity of cables and the number of cryostat penetrations, giving the designers of both the TPC and the cryostat the freedom to choose the optimum configurations. By April 2018, we have successfully instrumented 6 APAs with cold electronics, and the results of the integration test before the final installation in the cryostat look very promising.

As a prototype of Deep Underground Neutrino Experiment far detector, ProtoDUNE single-phase liquid argon Time Projection Chamber will sit in H4 beam line at CERN to study detector response to particles. It consists of 6 full-size Anode Plane Assemblies (APAs) plus 2 Cathode Plane Assemblies (CPAs) to form two 3.6m drift regions with total 15,360 readout channels. To achieve optimal noise performance, readout electronics developed for extremely low temperatures (77K-89K) operation has been studied with an integral design concept of APA, cold electronics, feed-through, plus warm interface electronics with local diagnostic following strict isolation and grounding rules. By the end of September 2017, the first full-size APA has been integrated with readout electronics successfully for the coming cold integration test at CERN.

Cryogenic low-noise charge sensitive preamplifiers have been developed and realized for the GERmanium Detector Array (GERDA). An integrated JFET-CMOS preamplifier, which is fully functional at cryogenic temperatures, has been tested in conjunction with an unsegmented p-type HPGe detector. Both the crystal and the preamplifier were operated inside a liquid nitrogen dewar at 77 K. The detector capacitance was ~60 pF. An optimum resolution of 1.6 keV FWHM has been obtained for the pulser line at 6 ?s shaping time. A resolution of 2.1 keV FWHM has been achieved for the 1.332 MeV line from a 60Co source. A wide bandwidth (rise time of ~16 ns) permits use of pulse-shape analysis techniques to localize the position of the photon interactions inside the crystal. A low power consumption (~23 mW) makes the preamplifier suitable for a multi-channel array of germanium detectors.

The performance of a 630g commercial broad energy germanium (BEGe) detector has been systematically investigated. Energy resolution, linearity, stability vs. high-voltage (HV) bias, thickness and uniformity of dead layers have been measured and found to be excellent. Special attention has been dedicated to the study of the detector response as a function of bias HV. The nominal depletion voltage being 3000V, the detector under investigation shows a peculiar behavior for biases around 2000V: in a narrow range of about 100V the charge collection is strongly reduced. The detector seems to be composed by two parts: a small volume around the HV contact where charges are efficiently collected as at higher voltage, and a large volume where charges are poorly collected. A qualitative explanation of this behavior is presented. An event-by-event pulse shape analysis based on A/E (maximum amplitude of the current pulse over the total energy released in the detector) has been applied to events in different energy regions and found very effective in rejecting non localized events. In conclusion, BEGe detectors are excellent candidates for the second phase of GERDA, an experiment devoted to neutrinoless double beta decay of Ge-76., Submitted to JINST, 17 pages, 11 figures. Companion paper of arXiv:1012.4300

We present a front-end application-specific integrated circuit (ASIC) for a wire based time-projection-chamber (TPC) operating in liquid Argon (LAr). The LAr TPC will be used for long baseline neutrino oscillation experiments. The ASIC must provide a low-noise readout of the signals induced on the TPC wires, digitization of those signals at 2 MSamples/s, compression, buffering and multiplexing. A resolution of better than 1000 rms electrons at 200 pF input capacitance for an input range of 300 fC is required, along with low power and operation in LAr (at 87 K). We include the characterization of a commercial technology for operation in the cryogenic environment and the first experimental results on the analog front end. The results demonstrate that complementary metal-oxide semiconductor transistors have lower noise and much improved dc characteristics at LAr temperature. Finally, we introduce the concept of “1/f equivalent” to model the low-frequency component of the noise spectral density, for use in the input metal-oxide semiconductor field-effect transistor optimization.

Front-end electronics for ionizing radiation detectors signal read-out must sometimes operate at cryogenic temperatures. The classical solution based on cold input transistor and subsequent warm electronics is sometimes not suitable due to the physical constraints of the experimental setup, so the entire front-end circuit has to operate at cryogenic temperature. The proposed multi-channel charge sensitive preamplifiers ("CC2") have been tested in the framework of the GERDA experiment (GERmanium Detector Array), in connection to High-Purity Germanium (HPGe) detectors and are able to operate at cryogenic (liquid Nitrogen) temperature. The results obtained during preliminary tests with an encapsulated Germanium detector and subsequently with naked Germanium detectors are all within the specifications of the GERDA experiment for Phase-I.

We developed a multi-channel digital acquisition (DAQ) system, able to operate in connection to Germanium-based detectors and state-of-the-art charge sensitive preamplifiers. The DAQ system is composed of up to 6 front-end NIM modules, each one with 4 free running analog to digital converters (100 MHz, 14 bits) and up to 6 custom PCI based receiver boards inside a single personal computer (PC). We also implemented a comprehensive graphical user interface on the user PC and a digital triggering algorithm inside the DAQ system by means of programmable logic devices (FPGA) and a suitable global slow control for the whole system. The performances of the DAQ system in terms of energy resolution, sustained data transfer rate, digital trigger sensitivity, etc. are all within the specifications of the GERDA experiment for Phase-I.

In the GERDA (GERmanium Detector Array) double-beta-decay experiment, it is planned to operate in liquid Argon (LAr) germanium detectors, organized in three fold strings. In this application the use of cryogenic front-end (FE) electronics is mandatory. Two versions of Charge Sensitive Amplifier (CSA), namely a 1-channel (1-ch) and a 3-channel (3-ch), based on JFET-CMOS circuits, have been realized and tested. The 3-chs CSA are designed to serve the detector string. While in the reference test the 1-ch circuit and a custom encapsulated germanium (Ge) detector (SUB) were operated both submerged in liquid Nitrogen (LN 2 ), in the naked detector test both the 1-ch circuit and the naked unsegmented Ge detector were submerged in liquid Argon (LAr). A resolution of 3.2 keV FWHM at 1.332 MeV 60Co has been obtained in the latter configuration to be compared to 2.2 keV obtained in the reference test. The 3-ch CSA, based on three JFETs connected to three channels of the CMOS ASIC, mounted on a Cuflon PCB, has been tested both coupled to the reference SUB and to a naked prototype detector. The obtained resolution for the 1.332 MeV line of 60Co was 2.4 keV with the CSA coupled to the SUB, and 2.9 keV with the naked Ge detector. The spectroscopic performances have been measured connecting the CSA output to an acquisition system through 10 m long cryogenic cables to simulate the real FE connection in the GERDA environment.

Cryogenic low-noise charge sensitive preamplifiers have been realized and tested for the GERmanium Detector Array (GERDA). In the search of neutrino-less double-beta decay of 76Ge at LNGS, GERDA will operate bare segmented germanium detectors immersed in liquid argon. The front-end electronics will operate in the cryogenic liquid too. An integrated JFET-CMOS preamplifier, which is fully functional at cryogenic temperatures, has been developed and realized. It has been tested in conjunction with an unsegmented p-type HPGe detector. Both the crystal and the preamplifier were operated inside a liquid nitrogen dewar at 77 K. The detector capacitance was ∼ 60 pF. An optimum resolution of 1.6 keV fwhm was obtained on the pulser line at 6 μs shaping time. The obtained resolution for the 1.332 MeV line from a 60Co source was of 2.2 keV fwhm. No peak shifts or line broadenings were seen during long-term acquisitions, thanks also to the extremely high preamplifier loop gain which yields a very high closed-loop gain stability. A wide bandwidth (rise time of 16 ns) permits use of pulse-shape analysis techniques to localize the position of the photon interactions inside the detector. A low power consumption (23.4 mW) makes the preamplifier suitable for the foreseen multi-channel array of germanium detectors.

The LBNE Project is developing a design for multiple 20 kiloton liquid argon (LAr) time projection chambers to be used as the far detector for the Long Baseline Neutrino Experiment. An essential component of this design is a complete electronic readout system designed to operate in LAr (at 90K). This system is being implemented as a CMOS ASIC, in 180nm commercial technology, that will provide low-noise readout of the signals induced on the TPC wires, digitization of those signals at 2 MS/s, zero-suppression, buffering and output multiplexing to a small number of cryostat feed-throughs. A resolution better than 1000 rms electrons at 200 pF input capacitance for an input range of 300 fC is required, along with low power (