ECR Title: Remove ALS-PD6 PD in End Station Hartman sensor path.	DCC No: E1500169-v1
Date: 03-10-2015
Requester: Keita Kawabe	Impacted Subsystem(s): ISC, AOS
Description of Proposed Change(s): In each end station ISCT (ISCTEX and ISCTEY), there is a Thorlabs PD in Hartman sensor path known as ALS-X/Y_REFL_B (“ALS-PD6” in D1201448, D1100607 and D1400241) originally installed by ISC. These PDs are removed. Existing beam dump to catch the reflection of the PD will be repositioned to catch the beam directly.
Reason for Change(s): These diodes are not used for anything, at both sites, and the removed parts could be used for 3IFO and as spares.
Estimated Cost: Labor to remover them from the table, and to update documents.
Schedule Impact Estimate: No significant impact.
Nature of Change (check all that apply): Safety Correct Hardware Correct Documentation	Improve Hardware Improve/Clarify Documentation Change Interface Change Requirement
Importance: Desirable for ease of use, maintenance, safety Desirable for improved performance, reliability Essential for performance, reliability Essential for function Essential for safety	Urgency: No urgency Desirable by date/event: ____________ Essential by date/event: _03/31___________ Immediately (ASAP)
Impacted Hardware (select all that apply): Repair/Modify. List part & SNs: ______________________ Scrap & Replace. List part & SNs:_____________________ Installed units? List IFO, part & SNs: _H1 and L1, ISCTEX and ISCTEY, part name ALS-PD6.________________ Future units to be built	Impacted Documentation (list all dwgs, design reports, test reports, specifications, etc.): D1201448, D1100607 and D1400241, E1300483.
Disposition of the proposed change(s): The disposition of this proposed engineering change request is to be completed by Systems Engineering and indicated in the “Notes and Changes” metadata field in the DCC entry for this ECR. The typical dispositions are as follows: Additional Information Required: in which case the additional information requested is defined. The ECR requester then re-submits the ECR with the new information using the same DCC number for the ECR but with the next version number. Rejected: in which case the reason(s) for the rejection are to be given Approved Approved with Caveat(s): in which case the caveat(s) are listed TRB: the ECR is referred to an ad-hoc Technical Review Board for further evaluation and recommendation. It is the System Engineer’s (or designee’s) responsibility to organize the TRB. The System Engineer (or designee) then makes a technical decision based on the TRB’s recommendation. Links to the TRB’s documentation (charge, memos, final report, etc.) are to be added to the “Related Documents” field for this ECR. CCB: a change request for approval of additional funds or schedule impact is to be submitted to the Configuration Control Board. Links to the CCB’s documentation (CR, etc.) are to be added to the “Related Documents” field for this ECR. Concurrence by Project Management: Acknowledgement/acceptance/approval of the disposition is to be indicated by the electronic “signature” feature in the DCC entry for this ECR, by one the following personnel: Systems Scientist Systems Engineer Deputy Systems Engineer