xeus cryogenic instrument 26 - 27 october 2004 cryogenic spectrometer prototype rationale:...

XEUS cryogenic instrument 26 - 27 October 2004

CRYOGENIC SPECTROMETER PROTOTYPE

Rationale:• Development and demonstration of technical readiness for future opportunities, like DIOS (JAXA, 2009) and NEXT (JAXA, 2012), XEUS/CON-X (ESA/NASA/JAXA, > 2015), ESTREMO (ASI, 2012) and small scale ground-based or balloon-borne opportunities in the Sub-mm

• Creation of a roadmap with a clearly specified near-term goal as a tool to create focus, enable useful participation of partners, and improve the strategic position of Europe (and SRON) in the field of cryogenic instrumentation

• Enabling an integrated performance tests at an X-ray radiation source facility



Prototype elements:

• ADR cooler with radiation entrance window• X-ray transmission and IR – UV blocking filters for entrance window • ≥ 5 x 5 prototype sensor array• FDM read-out electronics representative for a space mission• Instrument control unit with control and data acquisition software• Data analysis software• Extensive system testing at suitable X-ray beams• Executed in 2005 – 2007 (3 years) in collaboration with suitable

partners• Parallel development and verification of key issues (research on

energy resolution and pixel size)



Description of elements

1. ADR COOLER with ENTRANCE WINDOW

Could either be purchased from JANIS or CSP (Very Cold) or delivered by a partner (MSSL?)

Questions/requirements:

• Helium cooled or mechanically cooled system?

• Magnetic field shielding




2. Sensor head design

Packaging of sensor array, LC-filters and SQUIDs on coldfinger

3. Magnetic field generation and shielding (inside ADR)

4. X-ray entrance filters and IR – UV blocking filters

5. Harness and adequate EMI shielding/blocking




6. Sensor Array

5 x 5 arrays are at present under development by SRON/MESA under an ESA TRP contract. Larger arrays might become available later as well




7. Frequency Division Multiplexed read-out

Baseline at this moment is Base band Feedback. Is expected to be developed by SRON/VTT in a forthcoming ESA TRP contract



Sub-elements of FDM are:

8. AC-bias sources have to be developed

The frequency range considered is 0.5 – 10 MHz and should be software tunable in frequency and amplitude Quality has to be 138 dBc. (SRON/Partner)

9. LC–filters operate cold and are made in thin film technology

Baseline is to have one bias frequency per row (option B). This will require tuning of the capacitors after measurement of the resonance frequency. The capacitors require high Q (660 – 4000)

(SRON/VTT/Partner)

10. SQUID-amplifier and base-band feedback loop (VTT)

• SQUID current amplifier with large dynamic range• Warm low-noise amplifier• SQUID-to-warm amplifier coupling (transformer, array SQUID, cold amplifier)• DEMUX and MUX with small delay. Trade-off between a digital DEMUX and MUX that can meet the required small delay and a fully analogue system is required




Sub-elements of FDM are:

11. Demultiplexer of signal from baseband-feedback loop

Baseline is to down convert certain frequency bands of the data stream so that they can be digitized without loss of information. Subsequently the signals can become retrieved from the data-stream by digital multiplication with the carriers and subsequent filtering. (Partner)



Description of elementsA. System requirements, design, and interfaces definitions. Integration

and testing (SRON)B. Data analysis

This part contains the optimized filtering algorithms for retrieval of the most accurate energy for each event and software for display and

handling of spectra, I – V curves, etc (Partner)C. Instrument Control

This combination of hardware and software is required to control the instrument, set bias voltages for sensors and SQUIDs, set modes,

etc. (SRON/partner)D. Project planning


Cryogenic Spectrometer PrototypeSummary table of links with existing efforts

Item Description Status

ADR Delivery by ESA/MSSL in CIS-contract

Now expected 2nd Q 2005

sensor mounting/harness

Leicester responsible in CIS-contract

On hold

5 x 5 detector arrays Under production in present CIS-contract

Fully wired arrays by 1stQ 2005

SQUIDs Will be produced in the forthcoming X-10 contract

Partly available already

Data acquisition unit Leicester will deliver that within CIS-contract

Not really started

Low level effort


Cryogenic Spectrometer PrototypeElements of the plan• Design derived from a design for a 32 x 32 array• Requirement goal are the XEUS requirements used so far or the XEUS

low-energy spectrometer specifications (TBD)• Count rate for the overall system < 500 c/s• System set-up should aim for a reasonable amount of modularity without

that becoming a cost driver• Readout of a > 5 x 5 array by a 4 x 8 or 2 x 16 FDM system• Default frequencies between 1 – 10 MHz. Frequency separation such

that low and high frequencies are present and close packing is tested• Harness should meet the thermal requirements for a mission like XEUS

and should allow for about twice the number of channels as defined above

• The system should be software controlled, have log files and an adequate amount of housekeeping information

• The design should be robust against EMI• The work should enable a serious participation of external partners• Period about 3 years


Cryogenic Spectrometer Prototype

Project flow• Specification of requirements

• System study for XEUS-type instrument in order to define the baseline system and sub-systems

• Definition of prototype system and sub-system elements, estimation of project size (manpower, cost, schedule) and division of work among partners

• Definition of interfaces, and sub-system requirements

• Design, fabrication, and tests of sub-units

• Integration of sub-units and performance tests on integrated systems

• Integrated science tests at X-ray radiation source

• Data analysis and reporting


Cryogenic Spectrometer Prototype

xeus cryogenic instrument 26 - 27 october 2004 cryogenic spectrometer prototype rationale:...

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