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This paper updates the development of a warm front-end electronics (WFEE) dedicated to cryogenic sensors readout. It belongs to the X-ray integral field unit instrument of ESA's future space observatory: ATHENA. This instrument integrates cryogenic elements such as 3168 transition edge sensors as detectors, multiplexed into 96 channels using time-division multiplexing (TDM). One TDM channel will be read out by two stages of superconducting quantum interference device (SQUID), followed by a WFEE and finally, a digital readout system, both two last stages operating at about 300 K. In the WFEE, 96 TDM channels will be distributed in 48 application-specific integrated circuits (ASIC). Each channel includes one low-noise amplifier to amplify the multiplexed signal and 5 configurable current sources to bias the SQUIDs and TES in the cryogenic stages. Additionally, two channels within the same ASIC share a serial bus "RS485/I 2 C" to configure the current sources (current SlowDACs) and housekeeping elements that monitor the temperature, current and voltage of the ASIC. The ASIC presented in this paper, "AwaXe_v3" (AwaXe: Athena Warm Asic for the X-ifu Electronics), is developed for the WFEE using an AMS 350 nm SiGe BiCMOS technology. It is the first prototype of the WFEE integrating two complete TDM channels. Representative measurement results that characterise the main components of the WFEE will be discussed in this paper as an update on the use of ASIC for the TES/SQUID readout. [ABSTRACT FROM AUTHOR]

In the context of an R&D program aiming at developing new fabrication techniques, three bulk Niobium 3 GHz seamless SRF cavities were produced by spinning at INFN Legnaro. These prototype cavities for different nominal thicknesses were tested at IPN Orsay in the temperature range 1.7–4.2 K. In the course of the experiments, several parameters were investigated: surface resistance R s vs. temperature T, magnetic penetration depth as function of T and Lorentz forces detuning factor K. Electromagnetic simulations were also performed. The results obtained are reported and discussed. The characteristics Q 0 vs. E acc of the three cavities showed field emission and the RF tests were limited by the power available. Moreover, the energy gap was deduced from the R s vs. T results and compared to data previously reported on niobium leading to a good agreement. Finally, these cavities seem to be more sensitive (i.e. higher detuning factor) to Lorentz forces detuning compared to cavities of same geometry produced by deep drawing and electron beam welding. [ABSTRACT FROM AUTHOR]

Abstract The STELLA (STELlar LAboratory) experimental station for the measurement of deep sub-barrier light heavy-ion fusion cross sections has been installed at the Andromède accelerator at the Institut de Physique Nucléaire, Orsay (France). The setup is designed for the direct experimental determination of heavy-ion fusion cross sections as low as tens of picobarn. The detection concept is based on the coincident measurement of emitted gamma rays with the UK FATIMA (FAst TIMing Array) and evaporated charged particles using a silicon detector array. Key developments relevant to reaching the extreme sub-barrier fusion region are a rotating target mechanism to sustain beam intensities above 10 μ A, an ultra-high vacuum of 10−8 mbar to prevent carbon built-up and gamma charged-particle timing in the order of nanoseconds sufficient to separate proton and alpha particles. [ABSTRACT FROM AUTHOR]

Cryomodules of the superconducting accelerator SPIRAL 2 have been successfully qualified and are now under commissioning on the linac at GANIL (France). This paper presents the successful results of the power conditioning of the couplers both on a test bench in Grenoble and during the cryomodules qualification. It also shows the influence of some factors, such as surface state and experiencing a cavity quench around the antenna, on the power conditioning process (duration, quality). [ABSTRACT FROM AUTHOR]

Abstract: The ALTO facility (Accélérateur Linéaire auprès du Tandem d’Orsay) has been built and is now under commissioning. The facility is intended for the production of low energy neutron-rich ion-beams by ISOL technique. This will open new perspectives in the study of nuclei very far from the valley of stability. Neutron-rich nuclei are produced by photofission in a thick uranium carbide target (UC x ) using a 10μA, 50MeV electron beam. The target is the same as that already had been used on the previous deuteron based fission ISOL setup (PARRNE []). The intended nominal fission rate is about 1011 fissions/s. We have studied the adequacy of a thick carbide uranium target to produce neutron-rich nuclei by photofission by means of Monte-Carlo simulations. We present the production rates in the target and after extraction and mass separation steps. The results from Monte-Carlo simulations are compared to experimental data either with the ALTO facility (in the first step of commissioning, i.e. 100nA of the electron beam current intensity), or with fast-neutron-induced fission generated from a 26MeV deuteron beam. The results obtained support the suitability of FLUKA simulation code used to describe all the photofission process with an electron beam energy of 50MeV. [Copyright &y& Elsevier]

Abstract: IPN Orsay is strongly involved within the EURISOL and EUROTRANS projects, especially collaborating to the overall design of their linac architecture. Since a few years, main part of the R&D work is dedicated to the development of superconducting spoke cavities and their associated components (RF coupler, tuning system horizontal cryomodule, etc.). Following the very promising results obtained with our first single-spoke prototype (2-gap, 352MHz, beta 0.35), a new prototype has been designed and fabricated (2-gap, 352MHz, beta 0.15) in order to be integrated in a future linac. The mechanical and RF tests, done on this prototype, are presented. Then, an overview of the latest beam dynamics calculations performed to design a linac using spoke cavities will be described. [Copyright &y& Elsevier]

Abstract: SPIRAL2 is a radioactive beams facility, composed of a superconducting linac driver, delivering deuterons with an energy of up to 40MeV (5mA) and heavy ions with an energy of 14.5MeV/u (1mA). This facility is now fully approved by the French government. The first prototype of beta 0.12 quarter-wave resonator has been recently fabricated by Zanon company and tested at IPN Orsay. The details on its fabrication and the results of the RF and mechanical tests at 4K will be presented. Then, we will show the design of the cryomodule-B, dedicated to the high energy section of the linac, which is now ready to be ordered. Finally, the last studies of the R&D program, such as the last optimizations of the geometry, the new developments of the tuning system and the design of the helium vessel, are described. [Copyright &y& Elsevier]