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有些地方我也没看明白，大家凑和着看吧
Hi folks,
嗨、各位！
In LIGO land we've all been running full steam for a while, but it's time for an update.
在LIGO的土地上我们开足马力已经有一段时间了，到了升级的时候了。
S5 (the fifth science data run) has been going since early November and is scheduled to last about a year. It was certified (I think by the National Science Board?) as having reached the initial design goal, so we're officially in business.
S5（运行的第五批科学数据）在去年十一月已经开始收集并计划持续一年。S5已经被确认达到了最初的设计目标。
Roughly speaking, S5 data is about twice as good as S4. That is, the strain noise is half what it was in S4. But there is room for improvement.
大体上讲S5数据比S4要好一倍，也就是说地震噪声只有S4的一半，但是仍有改进的余地。
First, the duty cycle for triple coincidence (H1, H2, and L1 interferometers all running) wasn't so hot. The main culprit was L1. Before S4, Livingston was down every day due to logging next door. Improved seismic isolation fixed that, but for the first couple of months of S5 they started adding another building right next to the corner station. It's an education and outreach center, full of all sorts of goodies for the general public. That'll be great, but during the day it meant L1 was down even with the new isolation. The building is done, so we're seeing better duty cycle now.
首先，三相合（H1、H2、L1同时工作）的协同工作周期并不是很经常，元凶是L1。在S4之前列文斯顿总是由于记录到附近干扰而每天停机。改进的震动隔离器已经将其修正了，但是在S5的最初两个月它们又记录到了来自基地右角一栋建筑的干扰。那是教育和外联中心，装满了对公众颇具吸引力的东西。这意味着在白天L1又要停机，我们正在寻找更好的工作周期。
Also, the noise below 100Hz was actually a bit worse than design. That's been slowly improving as some things were caught, but we still don't know what's causing it. Fair bet it's somehow up-conversion of 1-3Hz seismic noise from traffic, since it correlates pretty strongly with the working day and rush hour. Last time I did shifts in the control room was January, and during the day it was enough that we had to lower the laser power to avoid dropping out of lock constantly. One gravel truck wouldn't do it, but two in rapid succession would nail us. One figure of merit is the range to which we could see a signal from a binary neutron star signal. That was peaking at 12 megaparsecs for H1 back in January and dropping to 10 during the day. Now it's up to almost 14 on a good night.
同样，低于100Hz的噪声竟然比设计的情况还糟糕。由于不清楚是什么造成的改进工作进展缓慢。打赌它是由车辆产生、不知何故转变成1-3Hz的地震波，因为这种情况的出现与工作日和交通拥塞的时间密切相关。上一次也就是一月我在控制室做了些调整，我们不得不降低激光的功率以避免连续的锁定而退出。单量卡车不会有影响，但是高速上连续的两辆就会把我们钉死。好的一方面是我们我们能探测的中子双星信号范围，一月份的那些日子里从峰值的12兆秒差距降到10兆秒差距，现在较好的夜晚差不多提高到了14兆秒差距。
Once the current Einstein@Home analysis finishes, we're probably going to do the same search on S5 data. That is, 30-hour chunks of data (which may span 40 hours of clock time due to dropouts) which require a search of a spindown parameter as well as sky position. But nothing is set in stone. We are still looking at the quality (duty cycle and stationarity) of the first few months of S5 data, and trying to decide if we want to do a longer search this time.
一旦当前的Einstein@home分析结束，我们很可能会对S5进行同样的搜寻。也就是30小时的大段数据（由于含有无效信息可能会扩展到40小时），这与天区位置有关。这都不是问题，我们关注的是S5头几个月的数据质量（协同工作周期和稳定性），并以此决定这一次是否要进行更长久的寻找。
The reason we can contemplate doing that is that more of you have been joining and staying. And the ones running Windows have been a lot faster lately with help from Hungary.
这就是我们期望更多的人加入并坚持下去的原因。最近来自匈牙利的帮助使用Windows的用户跑得更快了。
Thanks from all of us,
Ben
感谢你们大家！
[ Last edited by 碧城仙 on 2006-4-21 at 07:21 ] |
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发表于 2006-4-20 13:14:53
发表于 2006-4-20 14:48:05
.........以后用简写要注意哦........