Attachment directory customization

[romeomedina]

I saw that Gnus puts attachments in '~/tmp'.
Is it possible, and how?, to customize the directory
where Gnus puts attachments? I couldn't find an answer
in the Message Manual.

And: every time, in the message, I hit return on the
attachment in order to view it, a new folder is created
(in '~/tmp') where the attachment is stored.
If I view the attachment 'n' times within Gnus,
'n' copies of it are created.
This will waste plenty of disk space. Is it normal?
The attachment in my case is a .pdf file.

Thanks for any help,
Rodolfo