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Ne Ar lamp for Lisa

Posted: Fri May 31, 2013 5:04 pm
by Francois Teyssier
Olivier,
Est-ce que Shelyak envisage une modification du module de calibration du Lisa pour y intégrer la lampe Ar Ne de Alpy ?
Cordialement
Francois

Re: Ne Ar lamp for Lisa

Posted: Sat Jun 01, 2013 6:54 pm
by Olivier GARDE
Dans le même genre de question, est ce que le module de calibration de l'Alpy a èté essayè sur le LHIRES III ?

Un dèbut d'essai a ètè fait lors de l'atelier RR Lyrae à l'OHP.

Re: Ne Ar lamp for Lisa

Posted: Tue Jun 04, 2013 5:56 pm
by Thierry Garrel
Je réclame comme Olivier une adaptation du module alpy sur le LhiresIII qui serait un grands pas vers son utilisation en remote comme pour le Lisa, flat claib. Reste plus qu'a motorisé la vis micrométrique et le doublet interne.
Toutefois on n'a pas réussis en prenant le module tel quel et en le plaçant devant le LhiresIII a avoir les raies spectrale. Question de distance par rapport à la fente, la lampe est assez faible. Il faudrait peut être pouvoir le visser sur la plaque adaptation au po ? Pour le Lisa le changement de lampe spectrale devrait pas être si problématique.

Re: Ne Ar lamp for Lisa

Posted: Thu Jun 27, 2013 11:40 pm
by Christian Buil
La lampe NeAr de Alpy est vraiment de faible intensité et je sais que Shelyak a fait une grosse étude là dessus, pas possible de faire mieux.
On est bien moins intense qu'une néon et on est vraiment dans le mini coté source rayonnante. Je ne suis pas trop surpris que l'on ne vois rien avec
un Lhires malheureusement (faut mettre la lampe proche de la fente)..

Pour l'adaptation sur LISA, je ne peux pas vraiment répondre à la place de Shelyak.Ca doit être possible, mais il y a du boulot je pense.
Faut vérifier aussi le niveau de flux (une fois de plus, il sort pas grand chose d'une RELCO). Mais la question est posée...

Christian

Re: Ne Ar lamp for Lisa

Posted: Thu Jul 04, 2013 1:29 pm
by Robin Leadbeater
Has anyone tried placing the Relco starter in the LHIRES in the same place as the neon, ie with the lamp directly over the slit? There might be enough light with this arrangement and the mechanism is easily controlled using a servo.

Cheers
Robin

Re: Ne Ar lamp for Lisa

Posted: Thu Jul 04, 2013 2:19 pm
by Thierry Garrel
We Just put the calibration unit in front of a LhiresIII 2400gr/Atik 314. Even with minutes long exposures there weren't any signal recorded. The reco need to be placed very near the slit as the neon is. I suggest to remove the plate holder of the Lhires to gain space and try again without hoping a better result. The reco is very weak, so weak.

T

Re: Ne Ar lamp for Lisa

Posted: Fri Jul 05, 2013 4:32 pm
by Robin Leadbeater
I temporarily placed a RELCO (powered by a disposable camera flash circuit and with a diffuser and a reflector wrapped around it) where the existing neon is in the LHIRES. The results were very encouraging. The attached spectrum is a 10 sec exposure. If the RELCO can be fitted in the same place as the neon, it would make a good replacement calibration source.

Cheers
Robin

Re: Ne Ar lamp for Lisa

Posted: Tue Jul 09, 2013 8:53 am
by Francois Cochard
Hi all,
Several of you ask for a Shelyak adaptation of the Neon-ARgon calibration lamp to the LISA & Lhires III.
There is no "official plan" so far, for following reasons :
- Relco lamp is much less bright than common Neon lamp
- Relco lamp is not really a lamp, where Neon is. Keep in mind that we use the Relco lamp in a very marginal mode...
- Relco lamp has a limited lifetime. Neon lamp is very robust. This is not a big deal for LISA (calibration lamp is accessible), but it is for Lhires III (changing the calibration lamp takes time).
- There is a significant dispersion from one Relco lamp to the other (I guess due to manufacturing process, not focused on our application :>).

Of course, Relco lamp also has a huge advantage : its spectral coverage - as Robin shows it above. This is why we used it on Alpy calibration module.

I don't think that Relco is the universal answer for spectral calibration - but it is a very good opportunity in some cases.
However, we have today an electronics to control properly the lamp, and we're considering to adapt this electronic to the Lhires III / LISA electronics form factor, to allow you some "pioneering" applications. No leadtime and no cost so far - of course, we'll tell you when we have something available.

Friendly,

François

Re: Ne Ar lamp for Lisa

Posted: Thu Jul 25, 2013 10:50 am
by Robin Leadbeater
There is an interesting article by Christian Netzel in the latest edition of the VDS spectroscopy section journal SPEKTRUM showing a calibration lamp fibre feed adapter for the LHIRES using a RELCO or other light sources
http://spektroskopie.fg-vds.de/pdf/Spektrum44.pdf
(page 10)