N°10 - January 2019
The X-IFU Instrument Preliminary Requirement Review is going to be the main activity at the start of 2019, with its kick-off held on January 18th. It is a joint review between CNES and ESA. The review panel is co-chaired by Christian Erd (ESA) and Patrick Castillan (CNES). The process will last about 3 months with two important dates: the co-location meeting on March 26th and the board meeting on April 11th. The board meeting will also be co-chaired between ESA and CNES. Thien will come back in this issue of the newsletter on the significance of the review. The team will present the outcome of the work done, consortium-wide, over more than 4 years. Immediately after the I-PRR board meeting, the Consortium will meet in Grenoble for the Consortium meeting #9, hosted by CEA-SBT. The Consortium will start on April 15th, last only 4 days, and will be focused on presenting and discussing the issues raised by the IPRR panel, the work plan and actions to be carried out until the Mission Formulation Review currently scheduled after the summer (see article later).
The Instrument Consortia Consolidation (ICC) was successfully completed on December 11th 2018, leading to the formal appointment of the X-IFU Consortium, as currently organized, to be responsible for the delivery of the X-IFU instrument to Athena. For this process to be complete, all ESA member states involved in the X-IFU had to endorse their foreseen contribution to the instrument, at least until adoption (the United States and Japan, as international partners were treated separately). This success was achieved very smoothly thanks to the support and the leadership of the X-IFU Consortium board members.
Early January, I received a letter from the Ministry of Education, Youth and Sports of the Czech Republic indicating that funding of the B phase of Athena was granted to study a contribution to the X-IFU remote terminal units. Thanks to Jiri Svoboda and Jan Soucek for getting a proposal together on very short notice and getting it accepted. As a consequence, Jiri Svoboda will join the X-IFU Consortium Board and Jan Soucek was appointed as an X-IFU instrument Co-investigator. One member of the X-IFU Science Advisory Team will have to be nominated.
On the Consortium side, following the completion of the ICC, Seppo Korpela (University of Helsinki, Finland) was appointed as an X-IFU Instrument Co-Investigator with a 2 year term stating on January 1st, 2019. Juhani Huovelin will provide an overview of the Finnish contribution in this issue of the newletter. The term of Massimo Cappi (OAS Bologna, Italy), acting as X-IFU Science Advisory Team Chair, was renewed, acknowledging his excellent work in leading the XSAT activities.  We will keep updating the XSAT to introduce new members, to both cover new science topics and introduce fresh ideas and resources. One potential new science topic that has emerged in the last few years is multi-messenger astronomy, including gravitational waves. Luigi Piro will introduce the exercise that is being carried out on looking at synergies between Athena and LISA.
Let me conclude by thanking deeply all those from the X-IFU Consortium who have contributed to the preparation of the IPRR, and in the first place, the CNES team. Let us hope that the IPRR will go smoothly, so that Athena can proceed safely towards adoption.

Looking forward to seeing you in Grenoble.

Didier Barret
X-IFU Principal Investigator
Launch of the Instrument Preliminary Requirement Review
Initially, the I-PRR was the same label for 2 separate reviews, one following the CNES rules (application of ECSS) and the other the ESA rules. In order to keep the work load of the X-IFU team at an acceptable level, it has been decided with ESA to organize a common review with the merging of objectives, following the rules (procedure) of both CNES and ESA, and co-chaired by both parties.

The formal kick-off of the I-PRR took place last week, with the delivery on time of the full datapackage (more than 120 documents with a total of more than 5000 pages). On behalf of the Consortium Management Team, I would like to warmly thank everyone of you for the huge effort made to be on time.

Looking back over the last 5 years, let’s realize together where we have been. The way to the I-PRR was long, very long and not in a straight line… The phase A started with a double paradox; first we had a very rich heritage in term of design but a very poor status concerning the requirements and definition of interfaces; second the Consortium is made of brilliant individualities, to be organized to work together. Then we took the time to learn to work together with the important rendezvous which are the Consortium Meetings and the Integrated Progress Meetings. In front of the mountain to climb, we realized that the optimization process is not an option, optimization at subsystem level (compromise to be made between the thermal & mechanical design of the Dewar), optimization at X-IFU level (readout performance vs thermal dissipation in the cryo chain), optimization at system level (Internal Passive Cooled Shield of the Dewar), etc. Unfortunately, the optimization was not directly possible before defining first a consistent and pertinent set of requirements. Pertinent means a compliance to performance requirements coming from science objectives, a description of the need and only the need (a goal is not a need…). It is always very hard to think of need before to think of desired solution! In short, we have introduced a dose of top-down engineering approach but remained pragmatic enough to use whenever possible the existing solutions coming from the previous pure bottom-up approach. And now ? We are confident in the perspective to go successfully through the I-PRR and let’s keep on our radar the next milestone which is the Mission Formulation Review planned on the fall of this year.

Thien Lam Trong
X-IFU Project manager

Athena and LISA : Creation of a synergy team

A joint Athena-LISA synergy team has been recently appointed by ESA to carry out a study aimed at identifying the potential synergy between these two missions. The team is composed by the two study scientists (Matteo Guainazzi and Paul Mc Namara), representatives of the two study teams (Andy Fabian and Luigi Piro for Athena and Monica Colpi and Nial Tanvir for LISA) and a few experts. In addition to several teleconferences, a face to face discussion took place at the Athena-Multimessenger workshop on November 2018 in Alicante. The workshop, sponsored by AHEAD,  encompassed a broad context, with discussions on synergy of Athena with GW facilities (LISA, ALIGO and AVIRGO), VHE (CTA), neutrinos (ICECUBE, KM3NET) and the transient universe with Theseus. Various topics potentially relevant to the Athena-LISA synergy have been addressed, from mergers of supermassive binary black holes at cosmological distances to compact sources in our galaxy.  A draft report is now in the hands of the two study teams for comments before it is officially delivered to ESA around the end of January, when it will be also presented to the AWG.  We plan to update our community in the next Gazette when the report is ready.

Luigi Piro
X-IFU Co-Principal Investigator

Upcoming consortium meetings
Consortium meeting #10 was supposed to be in Liège in September 2019. The rooms and personal availability would have made it in the same week of the famous X-ray Astronomy 2019 Bologna meeting (September 9th to 13th), which gathers a large share of the X-ray Community, including many X-IFU consortium members. It was then decided to move the Liège consortium meeting to April 2020 (provisional dates from April 6th to 11th), and instead, organizing CM#10 in Toulouse within the week of September 23rdto 27th. Note that the dates are still provisional because they may conflict with dates involved in the Mission Formulation Review.  CM#10 will be focused on presenting the outcome of the work plan and actions identified during the IPRR.
Back to CM#9 in Grenoble, the skeleton for the 4 day meeting is shown below, note that the plenary sessions will last again two full days. Agendas of the different meetings will be provided soon.

Didier Barret
X-IFU Principal Investigator
TES array and SQUIDS, the Finnish contribution to X-IFU
Finland’s contribution for X-IFU are the SQUID amplifiers for the TES array readout. There are SQUIDs for performing the low noise (FDM) signal multiplexing and for amplification in the 50 mK stage of the FEE in each readout pane of the TES array, and a further set of AMP SQUIDs in the 2K stage. The low noise SQUIDs are a critical element in the cryogenic detector array readout chain, being responsible of signal amplification with sufficiently low noise to enable and maintain the ultra-high resolution of the observed X-ray spectrum and fast readout, and thus fulfilling of some of the key scientific requirements of X-IFU.
The Athena X-IFU activities in Finland are conducted by a technical team including experts at the University of Helsinki and VTT Technical Research Centre of Finland for the development of the SQUIDs, and the science team at the University of Helsinki. University of Helsinki has a leading role for the X-IFU activities in Finland.
SQUID development has a relatively long heritage at VTT in Finland. University of Helsinki has been the main national collaborator of VTT in the development of SQUIDs for X-ray astronomy, and there have been several development projects during the past two decades, starting in 2001 with a collaborative project in the national ANTARES space research programme, the next significant project being the E-SQUID Collaborative Project in EU FP7 (2011-2014), and the most recent is the ESA CTP project, where the developing of the X-IFU SQUIDs are currently performed. There have been several ESA projects including VTT’s collaboration with SRON during the same era, and a number of commercial SQUID development activities, so that SQUID development has been almost continuous during the present millennium and has led to development of exceptionally high and versatile expertise at VTT in SQUID technology, and applications are developed for various purposes including technologies for measurement devices in astronomy and astrophysics, medicine, biology, security, and even quantum computing.
University of Helsinki has a long and strong heritage in the high energy astrophysics research, with active participation in ESA, NASA, JAXA and other astrophysics space missions, and scientific research utilizing the data from virtually all available X-ray satellites since the 1980’s. The high energy astrophysics research group at the University of Helsinki has participated in the development of instruments and data analysis systems for a number of space missions, including INTEGRAL, SMART-1, Chandrayaan-1 and BepiColombo, being the leader of the national activities in all of them, and has also conducted several other technology development projects in the framework of ESA programmes.
Juhani Huovelin
Consortium Board member
Finland project manager

Bio: Juhani Huovelin

Dr. Juhani Huovelin is a member of the X-IFU Consortium Board, and he is leading the contribution of Finland. He is an Adjunct Professor and University Lecturer at the Department of Physics, University of Helsinki. He was the Vice Director of the Department of Astronomy 2004-2010. He was the PI of the XSM/SMART-1 and XSM/Chandrayaan-1, and Co-PI of D-CIXS/SMART-1 and C1XS/Chandrayaan-1, and he is a Co-I of JEM-X/Integral and and PI of SIXS/BepiColombo. He was the head of the prototype development group of the ESO’s Reflex data analysis system (2005-2008), and a member of the board of FINCA (Finnish Centre of Astronomy with ESO). He was the Coordinator of the EU FP7 project E-SQUID in 2011-2014, where SQUID multiplexers were developed in a collaboration between University of Helsinki, VTT, SRON, MPG, IPHT, and University of Leicester. He has been the leader of over 30 research and technology development projects on astrophysics, space technology, and data science. He is also the founder and current Chairman of a commercial space start-up company.

Athena X-IFU Consortium
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