2018 Fiscal Year Annual Research Report
Development of frequency dependent squeezing technique for sensitivity improvement of gravitational wave detector KAGRA
| Project/Area Number |
18F18024
|
|---|
| Research Institution | National Astronomical Observatory of Japan |
|---|
Principal Investigator |
フラミニオ ラファエレ 国立天文台, 重力波プロジェクト推進室, 特任教授 (10723108)
|
|---|
| Co-Investigator(Kenkyū-buntansha) |
CAPOCASA ELEONORA 国立天文台, 重力波プロジェクト推進室, 外国人特別研究員
|
|---|
| Project Period (FY) |
2018-10-12 – 2021-03-31
|
| Keywords | Gravitational waves / Squeezing |
|---|
| Outline of Annual Research Achievements |
During the past FY good progresses have been done for the realization of the frequency dependent squeezing.
For what concerned the filter cavity, the implementation of a multiwavelenght lock technique, which required the installation of an acusto-optic modulator (AOM), allowed to measure the cavity round trip losses. Such measurement is of extreme importance for evaluating the performance of the filter cavity and the achievable squeezing level. The results of this work have been published on July on the journal Physical Review D. Since the design of filter cavities to be implemented in near term upgrades of 2nd generation GW detector is ongoing, this work provides a useful reference for the GW community.
For what concern the frequency independent squeezing production. The integration of all the necessary components have been completed and a first promising squeezing measurement (~ 3 dB above 100 kHz) have been achieved. A control loop for reducing the phase noise which is currently limiting the squeezing performances has been implemented and is currently being optimized.
An upgrade of the digital system used for the control of the suspended mirrors has been performed. The new digital system is of the same kind used in KAGRA experiment, allowing for a smoother implementation of this upgrade in KAGRA.
An intense work to program the system and to adapt it to the filter cavity experiment has been carried on and it is almost completed.
A preliminary study to design the integration of the filter cavity in a future upgrade of KAGRA has also been done.
|
| Current Status of Research Progress |
Current Status of Research Progress
1: Research has progressed more than it was originally planned.
Reason
Eleonora Capocasa has continued to give an excellent contribution to the research. Thanks to her continue efforts the first measurement of squeezing was achieved at TAMA. Despite the budget difficulties, a first version of the new digital control system was installed and she promptly run the old control loops required to control the cavity mirror positions that she had developed on the new control system. She gave a presentation about her work at the KAGRA internationla workshop. She was also invited to give a long seminar at CNRS/APC in Paris.
As usual her results are excellent.
|
| Strategy for Future Research Activity |
Future work will focus on the improvement of the frequency independent squeezed vacuum source in order to achieve the squeezing target level of 9 dB above 10 Hz. It will require an intense noise hunting activity to identify and remove the noise sources and some work to improve the stability of the system.
On the filter cavity side we plan to test an alternative, original scheme of control and implement an automatic alignment system.
The last step will be the injection of the squeezed vacuum into the filter cavity and the frequency dependent squeezing characterization. The design of the filter cavity for KAGRA will also be carried on in parallel.
|
