This TWiki page is devoted to the functional description of the CCD testing setup at the Physics Institute of the University of Zurich and its associated hardware/software. A description of the cryostat, the associated electronics, and the instrumentation infrastructure is provided. The setup is based on the AlpineCube cryostat apparatus, an in-house design by the University of Zurich's Peter Robmann, and is currently located in building 36, floor H, room 78.

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Below you find a list of tools that are/were developed at Zurich for the DAMIC-M experiment.

This table shows the maximal power consumption of our system. Some manufacturer only provided a VA measurement, for conversion we assumed a efficency factor of 0.8.

The main computer is an Asus RS300-E7/PS4 (RS300-E7-PS4/WOCPU/WOMEN/WOHDD) 1U single CPU model. The main processor is a single 6th generation Intel(R) Xeon(R) CPU E31220 @ 3.10GHz with 4 cores while the graphics subsystem is handled by an Nvidia Quadro 600 graphics card with 1 GB GDDR2 and 96 CUDA cores on a PCI Express x16 Gen2 bus. Four 4 GB DDR3 1333 ECC UDIMMs are instated for a main memory (RAM) of 16 GB with a maximum of 32 GB supported in a 4 x 8 GB dual channel configuration.

For storage, a 4 x 4TB hot-swap HDDs array, configured in RAID10 mode is used with the on-board intel RAID controller (Intel Rapid Storage Technology). This setup enables simultaneous writing to two hard drives (RAID1) and data mirroring to another two (RAID0). This configuration enhances writing speed and maintains a constant backup of the entire system. Each of the four 4TB hard drives contributes to an effective storage capacity of 8TB.

The system does not support UEFI, and access to full storage capacity is limited to operating systems supporting GPT architecture (>2TB volumes). The lack of UEFI limits Windows to MBR-only versions, and UNIX-type operating systems are recommended. For the operating system, Ubuntu 20.04.6 LTS was chosen due to its compatibility with LabVIEW (Q3 2022), the LTA and our image acquisition software. The default package manager is apt, while rpm is also present. For further information about our server please read the following pages.

There are multiple Software's, programs and other files installed on this server a full list can be found following this link: Software

Our instruments can be loosely grouped into 5 different groups:

1. Temperature controll
2. Vacuum controll
3. Voltage controll
4. Device controll

All implementation of CCD readout systems have a common architecture and comprised of four common functional elements: The picture below shows the generall outline of a CCD.

• The first subsystem is devoted to providing the required bias voltages for the charge amplifiers located at the edge of the CCD matrix, the isolation voltages for the p-well and any additional bias voltages required for the operation of the serial registers at the periphery of the matrix. In addition, frequently the depletion/substrate voltage might be provided from the same subsystem, though requirements for increased stability and accuracy could lead to the use of a dedicated high precision external source (re. Keithley 2460/70 series).

• The second subsystem is responsible for generating the various clocks needed for shifting charges along the matrix and performing readout operations. In a 4-quadrant CCD (four amplifiers, one in each corner), 3 horizontal and three Vertical clocks are needed per quadrant.The horizontal clocks move charge from colum to colum, while the vertical clocks move charge from row to row. Due to the symmetry of the shifting operations in the different quadrants, vertically aligned parts can share the same horizontal clocks and vise versa, reducing the total amount of required lines to half (12 instead of 24). As a result a total of 6 vertical and 6 horizontal clocks are needed. Another 10 clock signals are additionally required, 5 per vertical side (toggle gate, output gate, drain gate, register, switch) for complete implementation of the matrix readout.

• The third subsystem takes care of the amplification and digitization of the analog signals provided by the CCD. This part might also be refereed as the video board/circuit term originating from the astronomy-related usage of CCDs for sky imaging.

• The fourth and final part of any CCD readout system implements the communication protocol with the host computer and takes care of the eventual processing/compressing of recorded data. A combination of optical fivers, USB and/or Ethernet-based connections might be used for that purpose.

Three different readout options for skipper CCDs exist. The first is the leach system, developed by: Astronomical Research Cameras. The second option is a Low Threshold Acquisition (LTA) system, developed by Fermi lab for the Oscura experiment. The third option is using the ACM board, developed by the University of Chicago and LPNHE specifically for the DAMIC-M experiment. Information for each system are available in the following pages:

1. Leach System
2. Low Threshold Acquisition (LTA) board
3. ACM Board

The following pages display various information about the CCD's used in this setup:

• CCD Structures
• Substrate