We describe the design, construction and performance of a double stage He-3-He-4 refrigerator, built to cool down a multiband bolometric photometer at the MITO telescope. The fridge was optimized to work without external pumps, with the main cryostat providing a 4.2 K thermostat at sea level and a 4.0 K one at high mountain pressure conditions. The measured ultimate temperature of the fridge is 290 mK, with a hold time of 81 h. The external heat input on the cold flange is similar to 35 mu W, with the main bath at 4.0 K. The recycle time is 8 h with a heat input on the thermostat during recycling of similar to 6800 J. The cryostat can operate without any relevant changes to performance tilted down to 50 degrees from the vertical position, as needed at the telescope focal plane. (C) 1999 Elsevier Science Ltd. All rights reserved.
A two-stage He-3/He-4 fridge for bolometric photometry / Maiani, T.; DE BERNARDIS, Paolo; DE PETRIS, Marco; Granata, S.; Masi, Silvia; Orlando, A.; Aquilini, E.; Cardoni, P.; Martinis, L.; Scaramuzzi, F.. - In: CRYOGENICS. - ISSN 0011-2275. - STAMPA. - 39:(1999), pp. 459-464. [10.1016/S0011-2275(99)00072-7]
A two-stage He-3/He-4 fridge for bolometric photometry
DE BERNARDIS, Paolo;DE PETRIS, Marco;MASI, Silvia;
1999
Abstract
We describe the design, construction and performance of a double stage He-3-He-4 refrigerator, built to cool down a multiband bolometric photometer at the MITO telescope. The fridge was optimized to work without external pumps, with the main cryostat providing a 4.2 K thermostat at sea level and a 4.0 K one at high mountain pressure conditions. The measured ultimate temperature of the fridge is 290 mK, with a hold time of 81 h. The external heat input on the cold flange is similar to 35 mu W, with the main bath at 4.0 K. The recycle time is 8 h with a heat input on the thermostat during recycling of similar to 6800 J. The cryostat can operate without any relevant changes to performance tilted down to 50 degrees from the vertical position, as needed at the telescope focal plane. (C) 1999 Elsevier Science Ltd. All rights reserved.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
