Analysis of some features observed on LFI 18 S during WFT test campaign

The quick look analysis of POST TV WFT AMB 01 ( performed in Liege, CSL, on August 2008) showed some possible non ideal behaviour of LFI 18 S2. In particular, a non clear separation of sky and ref signal was observed under certain conditions. Objective of this note is to perform a deeper analysis of the LFI 18 S2 behaviour, comparing between results found during different tests: PRE and POST TV, Warm Functional Test in Cannes ( August 2007) , CRYO 01 performed in Liege. The aim is to investigate a possible problem related with the PH/SW correct functionality in RCA 18 . In the case that any problems or unclear behaviour are found, results from this work will be used to prepare an extra test able to finally clarify the residual problems

NONLINEARITY INVESTIGATION AT 44 GHz USING PROTOTYPE UNITS: BEM44_B3_DC AND BEM44_B4_DC

Several tests have been performed at JBO to investigate the problem of representative FM BEM compression. Evidence of some compression happening inside the BEM is given by the high noise temperatures measured during the December test campaign, firstly on FEM 4F2 and then on FEM 4F3 when coupled to representative BEMs. JBO has four representative BEMs, two (B3 and B4) provided with diodes and then having a DC output, two (B1 and B2) without any diode and having an RF output. During last 2005 JBO tests, DC BEMs have shown to be compressed while RF BEMs have shown only a weak compression. Dedicated tests have been performed during the last test campaign to investigate the degree of compression, common features between the two BEMs, the noise temperature reachable in compressed conditions. Comparison tests have been also performed to check the repeatability of procedures used

LFI in-flight susceptibility to Front End electric instabilities: analysis of the HK over-sampling Test

Drain Currents are the unique HK parameter monitoring the electric behavior of the LFI Front End LNAs. Their importance is related with their capability to track gain changes at Front-End level induced by Gate Voltage (Vg) and Drain Voltage (Vd) changes. In fact, Vg and Vd are not measured but only indirectly known from the values set at DAE level any time the DAE actual TM packet is commanded (once pe

Electromagnetic Simulations Of WaveGuides Venting Holes

LFI waveguides may create problem in empty out the LFI front–end modules and back–end modules during the satellite launch. In order to avoid any damage of the radiometers, holes in waveguides may be necessary to facilitate the reaching of the vacuum condition in space: the air will flow mainly through these hole instead through the radiometers. Simulations have been performed at 70 GHz on a straight section of the WR12 waveguide, using the Finite Elements Method based HFSS software. This frequency is the most critical one since the hole diameter is about 2/3 of the waveguide lateral dimension. Two models will be illustrated

LSPE-StrIP: StrIP Integration procedure @ INAF-OAS

Scope of this document is to describe cryogenic harness in the StrIP LSPELSPEStrIP: StrIP Integration procedure @ INAF 2 o f STRIP79and report the OAS procedure to be used to Doc. Pag. Rev. Date 4.0 JAN 2020 RP004 integrate the StrIP Focal Plane Unit and the cryostat

Current Drop Noise in RCA 23 FEM

This document has been issued in the frame of ASI contract that has been released for the activities of Planck-LFI Phase E2 Scope of this document is to give a description of a feature observed during PLM SIT test on RCA 23, this description could be used to open a dedicated NCR in order to monitor the problem through the System Test Campaign. The data shown here after have been collected during the PLM SIT performed on the 24th of October 2007 in Cannes

ALMA B23 Cryo Chain Control Procedure

In this document, we describe the procedures to correctly operate the NAOJ Cryofacility Equipment once the cryostat is closed and sealed. The Cryostat is currently installed at the Cryowaves lab at the premises of INAF –IASFB

Tuning strategy for CSL

This Note shows the strategy to proposed to tune the LFI LNA’s (Vg1 & Vg2) in the test campaign at Satellite Level to be performed in CSL (Centre Spatiale de Liege) during the next Summer 2008 . The baseline option was accepted to be the MATRIX scheme , mixing together Vg1 and Vg2 values. The main limit to this method is given ( in CSL ) by the time required to explore a large range of parameters, since in CSL it is limited and strictly related with the 4K cooler cooldown profile. This note wants to give an overview of the philosophy and possible advantages or limits related with one or another strategy

Analysis of Voltage Jumps In LFI18 R0D0-R0D1 and LFI26 R1D0-R1D1 and debug procedure on LFI 26 during OD204

This note was aimed at debugging the two features observed during OD 184-185 and OD 188 on channels LFI 26 and LFI18. A dedicated procedure for debugging the LFI 26 issue was also proposed, performed and analyzed in this report. The two features exhibited as Scientific Voltage jumps both on REF and SKY signals of the two coupled diodes, as reported in the table below. In the case of channel LFI 26 the signal increased suddenly on both sky and ref without decreasing again. In the case of LFI 18 the signal decreased again. While the behaviour of LFI 18 was fully understood just from the analysis of the available data, for LFI 26 it was necessary to wait for the proposed extra test, run many days after the event. Results from this dedicated test are reported in the second part of this note

Planck cold load performance degradation at LFI frequency caused by HFI carbon fibre noise source

Purpose of this activity is to investigate the performances degradation of Planck Cold Load emissivity due to the possible mounting of a noise source required by HFI System team . The load will be used in the Planck Satellite cryo facility to mimic the sky signal. This document has been issued as a part of the activity performed under the ASI contract for Planck phase E2