Re: TASS CCDs

["Thomas F. Droege" <droege@fastmail.fm>]

Dear Frazer,

At this point I don't know what I am going to do.  I have started to try
to run the systems again.

My first preference is to give complete systems away to those that I
think will operate them for an all sky survey.  Second is for  those
that will run the systems for other uses.  Third is to give away the
parts.

The cameras are built with just buffers and protection in the camera
head.  The scanning electronics is on other boards which could be
operated a long distance from the camera.  I have run with 100' cables. 
The big problem is getting the digitized signals into a PC.  I have
built a special memory board for this purpose and good ones are in short
supply.  They require a computer with an ISA slot.  Best to update this
with a new design.  So you would have to have the capability to build
some electronics and get it working.  The cameras have built in thermo
electric coolers and can get to -20 with 20 C water.  There should be no
problem removing the filters since they are glued in with RTV.  There
should be no problem machining the cover.  The camera is mounted from
the back.    

I think the best thing to do is follow the tass list. If you let me
know, I will add you to it.  

Tom Droege


On Fri, 21 Apr 2006 16:39:42 +0100, "Fraser Clarke"
<fclarke@astro.ox.ac.uk> said:
> Dear Mr Droege,
> 
>     My name is Fraser Clarke, and I'm a member of the astronomical
> instrumentation group at Oxford University it the UK. A colleague of mine
> forwarded me your message to CCD-world regarding the TASS cameras you are
> looking to re-house. I am currently in the early stages of putting
> together
> an instrumentation project which could make suitable scientific use of
> your
> devices. I will describe the project briefly below. If you'd like more
> information on it, I can send you a fuller description which forms part
> of
> our current funding proposals.
> 
> The Nano-quasar machines
> ========================
> 
> One of the professors here at Oxford, Dr Katherine Blundell, has a long
> standing interest in the galactic "microquasar" SS433. I'm not sure if
> you
> are familiar with this object, so please excuse me if this description is
> redundant. SS433 is a rather unique object in our galaxy which appears to
> be
> a black hole/A-star binary system. The black hole is accreting material
> from
> the star, and spitting the excess out in jets which move at ~1/4 the
> speed
> of light! SS433 is very much a miniature version of Quasars, but much
> smaller and much closer to home. Light from the jets dominates the
> spectrum
> of SS433, giving rise to a very complicated structure of emission lines
> as
> blobs of gas move along the jets. Indeed, in SS433 we see three sets of
> H-alpha lines - one at the usual wavelength and the other two sets whose
> wavelengths vary approximately periodically, every six months.  The
> reason
> the wavelengths vary is because their redshifts/blueshifts vary as the
> direction of travel of the radiating gas changes its orientation compared
> to
> our line of sight as the binary system rotates. On top of this six month
> period however, there are many many small (and some large!) deviations.
> Studying these deviations gives insights into what is happening in this
> unique object. A press-release on a related study of SS433 which gives
> some
> more background is available at:
> http://www.nrao.edu/pr/2004/ss433corkscrew/
> 
> With a period of six months, it is very hard to properly study these jets
> from a classical professional observatory (3--4 night runs don't cover
> the
> main period and usually miss the most interesting quirks!). The jets
> change
> so quickly that one would like to take a spectrum every night for the
> full
> orbital period, and ideally every couple of hours. Fortunately, SS433 is
> bright (V~14, but mainly emission lines) meaning one doesn't need a large
> telescope to study it. With this in mind, we have come up with a project
> to
> build a dedicated network of telescopes+spectrographs around the world to
> make the definitive study of SS433.
> 
> The project also has another goal of promoting astronomy to young people.
> The telescopes will be sited in girls boarding schools around the world
> (Australia, India, South Africa and Chile). When SS433 is not observable,
> the schools will be able to use the telescopes for their pupils. In
> return,
> the schools will provide a safe home for the equipment, and the pupils
> will
> take a spectrum of SS433 every clear night. One telescope will be here in
> Oxford, and will also be used for undergraduate teaching as well as
> public
> outreach activities.
> 
> The telescopes will be off-the-shelf 16 inch Meade LX200's. The
> spectrographs are being custom designed here in Oxford to achieve the
> science goals. Our current design is a cross-dispersed echellette giving
> a
> resolution of ~4000 (~0.1nm/pixel) and a wavelength range of 820--450nm
> in a
> single exposure. To make the system more practical, we will use optical
> fibres to feed the light from the telescope to the spectrograph, rather
> than
> having the spectrograph directly mounted on the telescope.
> 
> Your cameras would be a valuable upgrade on our current plans, allowing
> us
> to increase the wavelength coverage, and possibly fit in enough fibres to
> have a useful "integral field unit" which would allow us to study
> extended
> objects as well as point sources. I think adapting our spectrograph
> (which
> is still at the design phase) to 2k devices would make the project even
> more
> exciting! In addition, I think integrating these cameras into our
> spectrographs, developing software and testing the systems would make an
> ideal masters project for a student.
> 
> Clearly, we would need to remove the built-in filters on your cameras for
> a
> spectroscopic application. Looking at some images on the website, it
> seems
> we could just machine new front ends for the cameras without affecting
> any
> of the other parts. Is that correct?
> 
> I hope that has given you a suitable overview of the project, and why I
> think your cameras would really enhance it. Please let me know if you
> have
> any questions you would like me to answer. I look forward to hearing from
> you.
> 
> Best regards,
>    Fraser Clarke
> 
> -- 
> Dr Fraser Clarke
> Oxford Astrophysics
> Tel: +44-1865-283140
> Fax: +44-1865-273390
> 
> 
> 
> 
-- 
  Thomas F. Droege
  droege@fastmail.fm