From t-kimura@asahi-spectra.co.jp Fri Aug 24 13:13:34 2007 Date: Fri, 24 Aug 2007 21:12:01 +0900 From: Toshihiko Kimura To: Mihalis Mathioudakis Cc: Vik Dhillon Subject: CWL and Thickness(417nm, H-alpha) Dear Dr.Mathioudakis CC Dr.Vik, I will tell you the final specifications about CWL and mechanical thickness. We need to optimize both specifications for ULTRACAM. 1)Narrow bandpass 417nm [CWL] 418.3nm +/-1nm in collimated beam => 417nm +/-1nm in ULTRACAM's f/2.3 converging beam [FWHM] 4.8nm +/-1nm in collimated beam [Physical thickness] BP*Quartz(1.61mm)*LWP + BG40(2mm) + SWP* Quartz(1.61mm)*SWP ------------------------------------------------------------------------------ 2)H-alpha(narrow) [CWL] 658.8nm +/-1.3nm in collimated beam => 656.3nm +/-1.3nm in ULTRACAM's f/2.3 converging beam [FWHM] 4.9nm +/-1nm in collimated beam > -FWHM 5.1nm +/-1nm in f/2.3 beam. Even if the filter has "broader" FWHM > 5nm, peak transmission will > be influenced by convergent beam. We simulate peak transmission will be > about 10% degraded in f/2.3 > beam. (See the attached image.pdf) Please remember my email, on 9 July. CWL(656.3nm) is longer than 417nm filter so the wavelength shift is more between in collimated beam and f/2.3 beam. At the same time, its FWHM is as same as 417nm filter in collimated beam. This is the reason why the bandwidth will be slightly broader and peak transmittance will be degraded. [Physical thickness] BP*Quartz(2.00mm)*LWP + RG610(1.36mm) + SWP* Quartz(2.00mm)*SWP > I would like to request that when the filters are ready for shippment you > write the following information on the shipping documents > > Commodity Code 90029000 > > Customs Procedure Code CPC 530023 Finally, I understand we should mention "CPC 530023" on the invoice for DHL even when we ship 3500A filters (though the purchase order does not instructs). Best regards, Toshihiko [ Part 2, Application/PDF (Name: "Image.pdf") 16 KB. ] [ Unable to print this part. ]