Development of 100 Mo -containing scintillating bolometers for a high-sensitivity neutrinoless double-beta decay search

This paper reports on the development of a technology involving 100 Mo -enriched scintillating bolometers, compatible with the goals of CUPID, a proposed next-generation bolometric experiment to search for neutrinoless double-beta decay. Large mass ( ∼ 1 kg ), high optical quality, radiopure 100 Mo -containing zinc and lithium molybdate crystals have been produced and used to develop high performance single detector modules based on 0.2-0.4 kg scintillating bolometers. In particular, the energy resolution of the lithium molybdate detectors near the Q-value of the double-beta transition of 100 Mo (3034 keV) is 4-6 keV FWHM. The rejection of the α -induced dominant background above 2.6 MeV is better than 8 σ . Less than 10 μ Bq/kg activity of 232 Th ( 228 Th ) and 226 Ra in the crystals is ensured by boule recrystallization. The potential of 100 Mo -enriched scintillating bolometers to perform high sensitivity double-beta decay searches has been demonstrated with only 10 kg × d exposure: the two neutrino double-beta decay half-life of 100 Mo has been measured with the up-to-date highest accuracy as T 1 / 2 = [6.90 ± 0.15(stat.) ± 0.37(syst.)] × 10 18 years . Both crystallization and detector technologies favor lithium molybdate, which has been selected for the ongoing construction of the CUPID-0/Mo demonstrator, containing several kg of 100 Mo .

Cost-effectiveness of interventions to promote cervical screening in general practice

A cost-effectiveness study of three different interventions to promote the uptake of screening for cervical cancer in general practice was carried out in Perth in 1991. Women eligible for a Pap smear were randomly allocated to one of four groups: one receiving letters with specific appointments to attend a screening clinic staffed by female doctors, one receiving letters informing them of the availability of the clinic and suggesting they make an appointment, one whose files were tagged to remind a doctor to offer a smear during a consultation, and a comparison control group that received opportunistic screening only. Variable and fixed costs for each group were itemised and summarised to give an average cost per smear taken. The cost and effectiveness of each intervention were then compared with those of the control group. Sensitivity analysis was performed on the major component of the costs, the doctor's time. Opportunistic screening cost $14.60 per smear and attained 16 per cent recruitment. Tagging files was the cheapest intervention ($14.75 per smear) although it was the least effective in recruiting women (20 per cent). This result held true for different scenarios of doctor's time allocated. Intervention by invitation letter with no appointment cost $45.35 per smear and attained 26 per cent recruitment, and intervention with a specific appointment cost $48.21 per smear and attained 30 per cent recruitment. Compared with the control group, the incremental cost-effectiveness for the tagged group was $15.40, for the letter-without-appointment group $97.75 and for the letter-with-appointment group $86.50.