X-ray film experiment
Six sheets of Agfa STRUCTURIX D7 Pb x-ray film have been installed in the SLS tunnel at critical locations. The following pictures illustrate the film locations beside conditions for exposure. The short exposure (30min) was performed with two times injection into the storage ring up to 110mA which needed about 15min each. Two injection attempts were necessary because the beam was lost after reaching 110mA at the first injection. The 300min exposure was realised by means of one fast (15min) injection ramp to 110mA, followed by continuous top-up injection to keep the current stable. The experiment shall give informations of exposure times and possibilities with defined operational conditions of the ring.
film 1: exit of storage ring septum Y12, 30min
Film 1 was completely black. Y12 seems to produce a very isotropic and strong radiation at this short distance.
film 2: behind screening of the K3 pulser, 30min
Film 2 shows light exposure in the region above the lead blocks. There is no difference at the border between lead and concrete visible.
film 3: behind screening of the K4 pulser, 30min
Film 3 shows light exposure in the region above the lead blocks. There is no difference at the border between lead and concrete visible. Similar to film 2 but no obvious lighter exposure.
film 4: at the beginning of 1L, 30min
Film 4 shows 4 small black spots with about 1mm diameter as well as thin lines, beginning at the spots just in the beam plane. The rest of the film area appears to be not or light exposed.
film 5: at the end of 9L, 30min
Film 5 was completely black. The end of 9L has striked with high activation doses in preliminary SU measurements.
film 6: exit of storage ring septum Y12, 300min
Film 6 was completely black. No wonder since film 1 was exposed at the same location but 10 times shorter and was black too.
Conclusion
The exposure range of the x-ray film is to small for the different radiation levels beside the different elements in the SLS tunnel. In order to find sources of radiation with x-ray films the exposure time has to be shorter for locations close to the potential radiation sources (Y12, W61?). For further examination of the effect of the conrete and lead block screening of the pulser electronics longer exposure times would give more information. X-ray film could be placed inside the cabinets too and left there for longer times, e.g 24h. The results confirm also that thick and dense materials like the tank of Y12 cause a wide angle fan of electromagnetic shower wheras a thin plate like the chamber wall at the beginning of 1L does not diffract the x-rays so much (see film 4).
