A 12 GHZ PULSE COMPRESSOR AND COMPONENTS FOR CLIC TEST STAND

Abstract The X-band power test stand needed for preprocessing and testing of key CLIC RF components is being installed in the test facility CTF3. The test stand includes several 12 GHz XL5 klystrons (50 MW, 1.5 μs) and a pulse compressor (PC) of the SLED-I type to obtain over 120 MW peak power at 230 ns pulse length. A compact compressor of this type based on TE 01 -TE 02 beating wave in high Q-factor compressor's cavities has been designed, produced, and tested at low power level. For testing accelerating structures and so-called "CLIC recirculation principle" of its operation several -3 dB couplers, tuneable phase shifters, and variable power attenuators were also produced and tested. DESIGN OF SLED-I PC In order to provide at 12 GHz an efficient compression of rf pulses with parameters P inp =50 MW, τ inp =1.5μs, aimed to obtain P out =120 MW, τ out =230 ns, it is proposed to use a compact SLED-I pulse compressor 5 ), because Q-factors of spurious modes in an oversized cavity could be comparable with that for operating mode. The compressor of such modified scheme consists of two identical cavities coupled by -3 dB couplers [2], each cavity is based on TE 01 -TE 02 beating wave waveguide which starts from single-mode TE 01 waveguide and finishes by a waveguide of a big enough radius which is necessary in order to provide the mentioned high Q-factors The beating wave (to provide deep modulation of surface field) consists of approximately 80% of the TE 01 mode and only 20% of the TE 02 mode. This mode mixture is produced sequentially by TE 10 -TE 01 "serpent-like" mode converter The cavities in each channel are based on ∅100 mm copper waveguides. Length of each cavity corresponds to 3 beating periods (~600 mm). The mentioned pumping port consists of a ring vacuum vessel which has a set of the 24 circular holes to pump a whole volume of the PC. The mentioned vessel is also partially filled by absorbers. Fine frequency tuning in each of two channels is organized by means of independent, electric, stepping motors which allowed also manual control

Développement de microcapteurs électrochimiques pour l'analyse en phase liquide

Les techniques d'analyses chimiques et biologiques nécessitent le développement à faible coût de capteurs chimiques fiables. Dans ce contexte, les transistors chimiques à effet de champ ChemFETs et les microélectrodes offrent des solutions innovantes à condition d'optimiser l'interface entre les différents domaines que sont les microtechnologies, la biologie et la chimie. Au cours de cette thèse, nous nous sommes attachés à développer des techniques permettant de coupler des agents chimiques au silicium. Deux approches ont été étudiées, toutes les deux basées sur l'utilisation de polymère. La première approche a été centrée sur le développement des techniques d'encapsulation avec la réalisation de microcuves et micro-canaux d'analyse en PDMS. Le suivi de l'activité bactérienne à l'aide de pH-ISFETs a été optimisé dans le cadre de l'étude des lactobacillus acidophilolus. La deuxième approche s'est intéressée à l'adaptation des ChemFETs et des microélectrodes d'or à la détection d'ions tels que le potassium et le sodium. L'utilisation des techniques de photolithographie a ainsi permis la fabrication collective de couches ionosensibles en PSX (polysiloxane)The chemical and biological analysis techniques require the low cost development of reliable chemical sensors. In this context, the chemical field effect transistors ChemFETs and the microelectrodes offer innovating solutions but it involves an optimized interface between microtechnology, biology and chemistry. During this thesis, we have developed techniques allowing to couple chemical agents with silicon. Two approaches were studied, both based on the polymer use. First approach was centred on the encapsulation techniques development with realization of analysis microcuves and micro-canals in PDMS. The bacterial activity monitoring with pH-ISFETs was optimized within the framework study of the lactobacillus acidophilolus. The second approach relies on ChemFETs adaptation and gold microelectrodes to ions detection such as potassium and sodium. The photolithography technique allows us to make ionosensible layers using PSX (polysiloxane) in order to realize ion detectionINIST-CNRS (INIST), under shelf-number: RP 17272 / SudocSudocFranceF