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People involved in this activity are :

Experimental « Optical » characterization of Planck multimoded horn. People involved in this activity are : - J.M Lamarre……………………………(LERMA, Observatoire de Paris, France) ‏ - B. Maffei………………………………………………...(Cardiff University, UK) ‏

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People involved in this activity are :

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  1. IWG – 22,23 June 2003 IAP, Observatoire de Paris, J. BROSSARD (IAS)‏ Experimental « Optical » characterization of Planck multimoded horn People involved in this activity are : - J.M Lamarre……………………………(LERMA, Observatoire de Paris, France)‏ - B. Maffei………………………………………………...(Cardiff University, UK)‏ - A. Murphy, V.Yurchenko, E.Gleeson……………(Maynooth University, Ireland)‏ - I. Ristorcelli……………………………………………(CESR, Toulouse, France)‏ - B. Leriche, Y.Longval, J. Brossard……….…………………(IAS, Orsay, France)‏

  2. IWG – 22,23 June 2003 IAP, Observatoire de Paris, J. BROSSARD (IAS)‏ OBJECTIVE : Insure that the « optical » behaviour of the CQM multimoded horns is correct.  Needs to crosscheck the theoritical prediction realised by Maynooth’s team and the measurement made at IAS (Orsay) on a small antenna (D=400 mm, f/D=1).  We want to make a full pattern comparison as was done between Maynooth’s software and Grasp8 for multimoded horn modelling (example horn at 545 GHz) :  At last, we want to analyse the level of tolerancement relative the position of the B2B horn with respect to the 100 mK horn. (And maybe… explain the Archeops beam distorsion concerning the FPU reconstruction made on Jupiter during the last fly). Linear scale

  3. IWG – 22,23 June 2003 IAP, Observatoire de Paris, J. BROSSARD (IAS)‏ Setup of the test bench dedicated to multimoded horn characterisation (IAS)‏

  4. IWG – 22,23 June 2003 IAP, Observatoire de Paris, J. BROSSARD (IAS)‏ Feed : black body at 1023 K PRONAOS mirror segment During the 1’st and 2’nd campaign, « ecosorb AN 72 » where added around the different elements. IAS Sub-mm mirror Offset paraboloidal (f=400 mm, f/D=1)‏ Horn under test with a integrating sphere SPM Cryostat (4 large detection bands)‏

  5. IWG – 22,23 June 2003 IAP, Observatoire de Paris, J. BROSSARD (IAS)‏ First campaign (June 2001 )- Horn : Archeops horn (monomode at 353 GHz and multimode at 545 GHz). - Detection in band 4 of SPM : 0 = 403 GHz, band width of 76 % (250< 0<550 GHz) - Source : Black body « Infrared Lab » (T=1023 K) Isolevel at –3, -6 and –10 dB • Phase center : measured (101 mm) / predicted ( ~ 6 mm)……. • 12 dB of dynamique Not excellent… but it was the first measurement…!!

  6. IWG – 22,23 June 2003 IAP, Observatoire de Paris, J. BROSSARD (IAS)‏ Second campaign (August & September 2001 ) - Horn : prototype horn designed at 150 GHz - Detection « Cardiff cryostast » : 0= 150 GHz with a band width of 25 %. - Source : Mercury Arc lamp. Isolevel at –3, -6 and –10 dB 22 dB of dynamique at least (maybe more)‏ (10 dB better than the 1’st campaign)‏

  7. IWG – 22,23 June 2003 IAP, Observatoire de Paris, J. BROSSARD (IAS)‏ Second campaign (August & September 2001 )‏ Variation of the phase center location function of the frequency 250 GHz 150 GHz 150 GHz prototype horn

  8. IWG – 22,23 June 2003 IAP, Observatoire de Paris, J. BROSSARD (IAS)‏ Third campagne (June-September 2003…(?) )- Horn : CQM multimoded horn (545 and 857 GHz) - Source : « Oriel » Mercury Arc lamp (100 Watts). - Absorbant used now are better than « Ecosorb AN 72 » used previously (for 1’st and 2’nd campaign) - Coupling between integrating sphere and bolometer has been improved with a lens between. Alignement of the mirors with a laser We hope 30 dB of dynamique at least. Start….in few days on Archeops horn (for the moment)…...first result for the next month….

  9. IWG – 22,23 June 2003 IAP, Observatoire de Paris, J. BROSSARD (IAS)‏ The measured beam will be compared with a GRASP8 multimoded computation (J. Brossard, with the help of CNES) using the « S21 » scattering matrix diffusion computed by Maynooth (E. Gleeson). Example of beam variation wrt to defocus along horn axis for a multimoded horn at 545 GHz (central frequency only). Far field beam power of the antenna vs defocus Angular resolution vs defocus Absolute gain (arbitrary unit) vs defocus 1,4 dB Horn position 4 mm z-axis defocus (mm)‏ z-axis defocus (mm)‏

  10. IWG – 22,23 June 2003 IAP, Observatoire de Paris, J. BROSSARD (IAS)‏ Grasp8 modelling : variation of the PLANCK CQM beam shape versus horn defocus along his axis(545_1 horn)‏ 0.3 dB 4 mm Tolerancement valide if : - all the modes are coupling from the B2B horn to the bolometer with the same efficency - the band width effect is negligeable…….(see Anthony’s presentation for more details…..)‏

  11. IWG – 22,23 June 2003 IAP, Observatoire de Paris, J. BROSSARD (IAS)‏ The End

  12. IWG – 22,23 June 2003 IAP, Observatoire de Paris, J. BROSSARD (IAS)‏

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