Hi Todd,
I've taken the liberty of posting your question to the Ifeffit mailing
list. You're likely to get more accurate and quicker answers to these
kinds of questions there.
(For the rest of you: Todd is asking about the technique of preparing
air-sensitive samples in a glove box, putting them on Kapton tape,
sealing them in plastic bags, and transporting them to the beamline,
shooting right through the bags.)
I'll take my shots, though:
It's hard for me to imagine adsorbed oxygen on the Kapton being more
significant than the other sources of stray oxygen that can be present
in a glove box. After all, the Kapton's in there too. And I don't
think it's going to be more significant than the oxygen that diffuses
through the plastic bags during transport.
The thinner the Kapton tape, the better, as that will minimize the
absorption due to the tape. It used to be hard to find 1 mil Kapton
tape with adhesive, but now it's easy. Hephaestus will give you the
absorption of Kapton, so you can judge how big an effect it will be at
the energies at which you'll work.
--Scott Calvin
Sarah Lawrence College
On Aug 4, 2009, at 2:39 PM, Monson, Todd wrote:
> Scott,
>
> Thanks. Is it pretty reasonable to assume that the kapton tape that
> you put your samples on doesn’t have any adsorbed oxygen that could
> affect your samples? Do you do anything to clean the kapton? Where
> are some good places to buy the kapton (and do you need to purchase
> rather thin kapton tape for doing XAFS)?
>
> Thanks again,
>
> Todd
>
> From: Scott Calvin
> Sent: August 04, 2009 11:34 AM
> To: Monson, Todd
> Cc: Scott Calvin
> Subject: Re: mossbauer
>
> Hi Todd,
>
> Regular zip-loc bags work just fine. For heat sealers I've used
> everything from a heat sealer manufactured for the purpose to a
> little propane torch--even a cigarette lighter should work. Putting
> one sealed bag inside another, if the energy you're working at
> allows it, seems to work quite well.
>
> --Scott
>
>
> On Aug 4, 2009, at 1:15 PM, Monson, Todd wrote:
>
>
> Scott,
>
> I had another question – what kind of plastic bags and heat sealers
> do you use for sealing up your air-sensitive XAFS samples? And
> where could I buy them?
>
> Thanks,
>
> Todd
>
