Differences
This shows you the differences between two versions of the page.
|
cso:instruments:cryogens [2013-04-19 01:51] sradford created |
cso:instruments:cryogens [2013-05-31 20:34] (current) admin [Cryogen usage] |
||
|---|---|---|---|
| Line 1: | Line 1: | ||
| + | ====== Cryogen usage ====== | ||
| + | Approximate cryogen consumption and service frequency for CSO instruments. | ||
| + | |||
| + | ^ Instrument ^ Precool and \\ Initial ^^ Subsequent ^^ Frequency ^ | ||
| + | ^ ::: ^ LHe ^ LN<sub>2</sub> ^ LHe ^ LN<sub>2</sub> ^ ::: ^ | ||
| + | | Bolocam | 85 | 80 | 25 | 5 | daily | | ||
| + | | Sharc II | 60 | 110 | 15 | 10 | 2 days | | ||
| + | | Zspec | 160 | 360 | 40 | 50 | 2 days | | ||
| + | | 230/460 GHz | 13 | | 8 | | 4 days | | ||
| + | | 345/650 GHz | 13 | | 8 | | 7 days | | ||
| + | | Barney (345 GHz) | 15 | 25 | 10 | 3 | daily | | ||
| + | | 850 GHz | 13 | | 8 | | 4 days | | ||
| + | |||
| + | * Usage in liters. | ||
| + | * When the Sharc II low temperature stage is not cycled, 15 l of LHe will last 6 days. | ||
| + | * Zspec requires daily LN<sub>2</sub> service. | ||
| + | * Additional LN<sub>2</sub> for receiver tuning, calibrations, etc.: 3–5 l daily. | ||
| + | * LHe supplied in 60 l or 100 l dewars, nominal contents in Hilo. | ||
| + | * Because of depressurization and other losses, LHe dewars arrive at telescope with 80-85% of contents. | ||
| + | * LHe availability on short notice may be difficult. | ||
| + | * LN<sub>2</sub> supplied in 160 l or 180 l tanks. | ||
| + | | ||
| + | * This {{cryo-usage.xlsx|spreadsheet}} provides an //approximate// estimate of cryogen costs. | ||
| + | * Change the number of observing nights (in red) for an approximate scaling. | ||
| + | * The estimate is reasonable for 3 < nights < 15. | ||
| + | * Costs are subject to change. | ||
| + | * Final costs will depend on instrument and cryogen delivery schedules. | ||
| + | * Assumes a Sharc II cycle every night. | ||
| + | * The heterodyne instruments include 5 l /day of LN<sub>2</sub> for tuning and calibration. | ||
| + | * The sidecab receivers are combined. | ||
| + | * For the sidecab and 850 GHz receivers, 60 l LHe dewars are used. | ||
| + | * For the other instruments, 100 l LHe dewars are used. | ||
| + | * LHe dewar quantization is only approximate. | ||
| + | * LHe boiloff from the delivery dewars is ignored. | ||
| + | * For the LHe dewars, rental days = observing nights + 2. | ||
| + | * Staggered deliveries of LHe are ignored. | ||
| + | ===== Refererence information ====== | ||
| + | |||
| + | * [[http://literature.chart-ind.com/ProductDetail.aspx?Id=42|Chart/MVE Cryogenic Gases Data Book]] | ||
| + | * [[http://www.aspenycap.org/files/CryogenicGases.pdf|Chart/MVE Cryogenic Gases Data Book]] //(alternate source)// | ||
