After analyzing the observed data, the scientific committee of LAMOST telescope decided to use slit with 2/3 fixed width for LAMOST survey (hereafter, 2/3slit). LAMOST technicians have measured the spectra resolution for different spectrograph and optical fibers under the condition of 1/2 slit , 2/3 slit and full open slit. Using 2/3 slit, we can not only improve the efficiency, but also can combine the scientific goals of two working group, which can also improve the usage efficiency of the telescope.

In the summer of 2011, LAMOST technicians have updated the spectrograph slit. After carefully designing and installing, by the end of August, the installation and test of fixed slit on 16 spectrographs have been finished.
The length of 2/3 slit is 144mm, width is 0.22 mm. The technicians have made checking and modification with many times to guarantee straightness of slit to be better than 5um. Many works have been done to guarantee that each fiber can point to the middle region of slit.

(the figure is the 2/3 slit)
After analyzing the observed data, the scientific committee of LAMOST telescope decided to use slit with 2/3 fixed width for LAMOST survey (hereafter, 2/3slit). LAMOST technicians have measured the spectra resolution for different spectrograph and optical fibers under the condition of 1/2 slit , 2/3 slit and full open slit. Using 2/3 slit, we can not only improve the efficiency, but also can combine the scientific goals of two working group, which can also improve the usage efficiency of the telescope.

In the summer of 2011, LAMOST technicians have updated the spectrograph slit. After carefully designing and installing, by the end of August, the installation and test of fixed slit on 16 spectrographs have been finished.
The length of 2/3 slit is 144mm, width is 0.22 mm. The technicians have made checking and modification with many times to guarantee straightness of slit to be better than 5um. Many works have been done to guarantee that each fiber can point to the middle region of slit.

(the figure is the 2/3 slit)
According to the requirement of LAMOST scientific committee, the data of LAMOST should be released after one month of observation. At 24th December 2011, the survey and data departments with help of information center of NAOC released the data observed at 24th October 2011. By the end of 2011, 230,000 spectra distributed in 117 sky area have been released. The distributed system are mounted on the internet cooperative work platform, which have been open for accessing (http://lamost.escience.cn/dct/page). People who are interesting in the spectra can apply to get permission for downloading and using the distributed data. Detailed registering, please refer to web page.

After one month preparation, the survey and data department have checked all the spectra by eye, and compared it with 1D PIPELINE. Then the parameters, final_class, final_subclass, and final_z etc, have been released.

figure1 is the Examples of observed sky area,figure 2 is the data retrieval result and spectrum.