A token visit to the ATLAS cavern…

15 December 2008

Tags, tokens, and Xavier's aluminum holder


The visit protocol for the ATLAS cavern has been given a bit of an overhaul of late. Where once it was thought that visits would be un-workable during “restricted mode”, efforts have been made to tweak and tighten the safety procedures, so that proud collaborators can continue doing one of the things they love the most – introducing scientists, VIPs, and members of the press to 20-years-hard-work’s worth of detector.

For starters, those of you who enjoyed the title of “ATLAS Guide” in 2008, will – once you have completed the latest training – get to refer to yourselves as altogether more exotic “ATLAS Escort Guides”.

The main change, however, is the introduction of a “token” system. The thinking behind this is that it will allow each visitor to be identified and accounted for during their time on a tour. “We’re certain that the radiation dose level is very low,” says GLIMOS Assistant, Xavier Brunel, “but we need to register it and keep a database record which identifies who has visited and the dose that they have received.”

This requirement forms the crux of the new system, which involves two stages of secure entry – one at the PX15 entrance, and another at UX15. The former will require each guest to be “badged” in with their own unique Access Token, while the latter will require both an Access Token and an associated Safety Key. Dosimeter readings will be recorded upon entry and exit of PX15.

“We will only allow guests to enter with a Safety Key,” says Xavier, explaining, “If one of these Safety Keys is missing, it means that someone is inside, which means we can’t start the experiment or allow the LHC to have a beam.”

An initial trial during which the two new elements were given to each visitor on a string to hang round their neck hit problems when the visitors started doing what people do best – fidgeting, fussing, and fiddling – confusing the Personal Access Device (PAD) machines, risking the keys getting broken, and slowing things right down. In the end, it seemed like a more sensible idea for the Escort Guides to keep hold of all the keys and tokens.

To help them cope with keeping these in order – there will be up to 10 tokens and 10 keys on each visit – Xavier has designed and fabricated a nifty bit of kit especially for the job. Looking something like a giant aluminium safety pin, his contraption allows tokens to be kept in order, for used ones to be separated from those yet to be used, and keys to be added into and removed from the loop at any time.

The new procedures came into force about four weeks ago, and to date, 53 2008 ATLAS Guides have been trained up. “We have had some visits already,” says Xavier of the new system. “Nobody has complained so far – it seems to be a good idea.”

The next step will be for the rest of the 2008 Guides to get up to speed with the new protocol, and following that, some of the 120 reserves who responded to a recent call for Guide volunteers may also get the chance to train as Escort Guides.

If you’d like to book a tour of the cavern – strictly for VIPs, press, or members of the public with a specific professional interest in or connection with ATLAS – you need to contact the Secretariat at least 48 hours in advance of your required tour time, stating: the name and size of the visit group, each proposed visitor’s name and date of birth, and the requested date and time of the visit.



Ceri Perkins

ATLAS e-News