The CUORE cryostat: an infrastructure for rare event searches at millikelvin temperatures

The CUORE experiment is the world's largest bolometric experiment. The detector consists of an array of 988 TeO2 crystals, for a total mass of 742 kg. CUORE is presently taking data at the Laboratori Nazionali del Gran Sasso, Italy, searching for the neutrinoless double beta decay of 130Te. A large custom cryogen-free cryostat allows reaching and maintaining a base temperature of about 10 mK, required for the optimal operation of the detector. This apparatus has been designed in order to achieve a low noise environment, with minimal contribution to the radioactive background for the experiment. In this paper, we present an overview of the CUORE cryostat, together with a description of all its sub-systems, focusing on the solutions identified to satisfy the stringent requirements. We briefly illustrate the various phases of the cryostat commissioning and highlight the relevant steps and milestones achieved each time. Finally, we describe the successful cooldown of CUORE

CUORE-0 detector: design, construction and operation

The CUORE experiment will search for neutrinoless double-beta decay of$^{130}$Te with an array of 988 TeO$_2$ bolometers arranged in 19 towers.CUORE-0, the first tower assembled according to the CUORE procedures, was builtand commissioned at Laboratori Nazionali del Gran Sasso, and took data fromMarch 2013 to March 2015. In this paper we describe the design, constructionand operation of the CUORE-0 experiment, with an emphasis on the improvementsmade over a predecessor experiment, Cuoricino. In particular, we demonstratewith CUORE-0 data that the design goals of CUORE are within reach

The CUORE cryostat: commissioning and performance

The Cryogenic Underground Observatory for Rare Events (CUORE) will search for the 0vββ decay in 130Te using a cryogenic array of TeO2 bolometers, operated at a base temperature of ~10mK. CUORE will consist of a closely packed array of 19 towers each containing 52 crystals, for a total mass of 741kg. The detector assembly is hosted in one of the largest cryostats ever constructed and will be cooled down to base temperature using a custom-built cryogen free dilution refrigerator. The CUORE cryostat along with the pulse tube based dilution refrigerator has been already commissioned at Laboratori Nazionali del Gran Sasso (LNGS) and a record base temperature, on a cubic meter scale, of ~6mK was achieved during one of the integration runs. We present the results from integration runs, characterizing the system and the cooling performance of the dilution refrigerator, effectively showcasing its stability at base temperature for the expected thermal load

Commissioning of the 4 K Outer Cryostat for the CUORE Experiment

The Cryogenic Underground Observatory for Rare Events (CUORE) is a 1-ton scale bolometric experiment. The CUORE detector is an array of 988 TeO crystals arranged in a cylindrical, compact, and granular structure of 19 towers. These detectors will need a base temperature lower than 10 mK in order to meet the performance specifications. To cool the CUORE detector, a large cryogen free cryostat with five pulse tubes and one custom designed high power dilution refrigerator has been designed. The three vessels that form the outer shell of the CUORE cryostat were produced in 2012 and are now assembled in the Gran Sasso National Laboratories (LNGS). We report here the detailed description of the 4 K outer cryostat for the CUORE experiment together with the results of the validation tests done at the production site in 2012 and of the first commissioning to 4 K at LNGS in 2013

Novel Clinical Prognostic Score Incorporating the Number of Resected Lymph-Nodes to Predict Recurrence and Survival in Non-Small-Cell Lung Cancer.

BACKGROUND: The number of resected lymph-nodes (#RNs) has proven prognostic in breast and colorectal cancer. Here we evaluated its prognostic impact in a series of resected NSCLC patients. METHODS: A panel of established prognostic factors plus (1) #RNs or (2) the ratio between the number of metastatic nodes and #RNs (NR) were correlated to overall- (OS), cancer-specific- (CSS), and disease-free-survival (DFS), using the Cox-model. Risk-classes according to hazard ratios (HR) were generated. Internal and external validation was accomplished. RESULTS: A dataset of 415 resected NSCLC patients was retrieved. At multivariate analysis, #RNs and NR were independent factor for longer OS, CSS and DFS (p10 (identified optimal cut-off) had a statistically significant OS (p=0.02) and DFS (p=0.0005) benefit. In node-positive patients, a NR<9% significantly correlated with better outcome. Stratification into High-, Medium-, and Low-Risk classes, based on High- (HRFs: stage, N-status, age, #RNs) and Intermediate-Risk Factors (IRFs: sex, grading, histology), efficiently predicted outcomes (p<0.0001). The risk class model performance was externally validated in and independent dataset of 297 patients. CONCLUSIONS: These results contribute to complete the panel of prognostic factors for resected NSCLC. A prospective larger validation and comparison with molecular prognostic tools is warranted

A novel clinical prognostic score incorporating the number of resected lymph-nodes to predict recurrence and survival in non-small-cell lung cancer

Background: The number of resected lymph-nodes (#RNs) has proven prognostic in breast and colorectal cancer. Here we evaluated its prognostic impact in a series of resected NSCLC patients. Methods: A panel of established prognostic factors plus (1) #RNs or (2) the ratio between the number of metastatic nodes and #RNs (NR) were correlated to overall- (OS), cancer-specific- (CSS), and disease-free-survival (DFS), using the Cox-model. Risk-classes according to hazard ratios (HR) were generated. Internal and external validation was accomplished. Results: A dataset of 415 resected NSCLC patients was retrieved. At multivariate analysis, #RNs and NR were independent factor for longer OS, CSS and DFS (p &lt; 0.0001). Patients with a #RNs &gt; 10 (identified optimal cut-off) had a statistically significant OS (p = 0.02) and DFS (p = 0.0005) benefit. In node-positive patients, a NR &lt; 9% significantly correlated with better outcome. Stratification into High-, Medium-, and Low-Risk classes, based on High- (HRFs: stage, N-status, age, #RNs) and Intermediate-Risk Factors (IRFs: sex, grading, histology), efficiently predicted outcomes (p &lt; 0.0001). The risk class model performance was externally validated in and independent dataset of 297 patients. Conclusions: These results contribute to complete the panel of prognostic factors for resected NSCLC. A prospective larger validation and comparison with molecular prognostic tools is warranted