= bKAGRA Suspensions Actuator Design Summary =
||suspension and stage ||coil ||magnet ||coil-magnet ||coil driver ||
||MCi/e/o (Type-C) '''TM''' ||41 turns by default (some are 40 turns?), ~2.5 Ohms([[http://klog.icrr.u-tokyo.ac.jp/osl/?r=2124|klog#2124]]) ||NdFeB 1mm dia, 5mm thick ||0.0014 N/A at max ||TAMA ||
||'''IM''' ||- ||- ||- ||- ||
||IMMT1/2 (Type-C) '''TM''' ||39 turns ? ||NdFeB 2mm dia, 5mm thick || ||high power ||
||'''IM''' ||- ||- ||- ||- ||
||PR2/3/M (Type-Bp) '''TM''' ||600 turns ||SmCo 6mm dia, 3mm thick ||0.129 N/A at max ||high power ||
||'''IM''' ||600 turns ||SmCo 10mm dia, 10mm thick ||1.26 N/A at max ||high power ||
||BS (Type-B) '''TM''' ||600 turns, ~11 Ohms ||SmCo 2mm dia, 3mm thick ||0.0138N/A at max ||low power ||
||'''IM''' ||600 turns, ~13 Ohms ||SmCo 10mm dia, 10mm thick ||1.25 N/A at max ||low power ||
||SR2/3/M (Type-B) '''TM''' ||600 turns ||SmCo 2mm dia, 5mm thick ||0.0225 N/A at max ||low power ||
||'''IM''' ||600 turns ||SmCo 10mm dia, 10mm thick ||1.26 N/A at max ||low power ||
||ITM/ETM (Cryopayload) '''TM''' ||100 turns, 17 Ohms (measured at room temp; estimated to be 0.6 Ohms for cryogenic) ||SmCo(?) 2mm dia, 2mm thick ? ||0.0015 N/A at max (measured at room temp with 88turns) ||low power ||
||'''IM''' ||600 turns, 57 Ohms (measured at room temp; estimated to be 2 Ohms for cryogenic) ||SmCo(?) 2mm dia, 2mm thick ? ||0.015 N/A at max (measured at room temp with 585turns) ||low power(with R65 and R97 700Ohm) ||
||'''Marionette''' ||600 turns, 57 Ohms (measured at room temp; estimated to be 2 Ohms for cryogenic) ||SmCo(?) 5mm dia, 13mm thick ? ||0.45 N/A at max (measured at room temp with 585turns) ||low power(with R65 and R97 700Ohm) ||


== Coil Drivers ==
 * TAMA coil driver has 50 Ohm, 20 mA/V. EL2099, 440 mA at max. Summary by Koji Arai is [[http://tamago.mtk.nao.ac.jp/tama/ifo/www_suspension_install_status/coil_property.html|here]].
 * Low Power Coil Driver ([[http://gwdoc.icrr.u-tokyo.ac.jp/cgi-bin/private/DocDB/ShowDocument?docid=3507|JGW-D1503507]]) has 7.8 kOhm at DC (1.258 kOhm at high frequency; pole at 50Hz, zero at 312 Hz), 0.128*1.33 mA/V at DC (voltage gain of 1.33 is applied in the driver). AD8671, 20 mA at max (+/- 15V supplied).
 * Modified Low Power Coil Driver (for Type-A IM and Marionette) has 1.4 kOhm at DC (724 Ohm at high frequency; pole at 161Hz, zero at 312 Hz), 0.714*1.33 mA/V at DC (voltage gain of 1.33 is applied in the driver). AD8671, 20 mA at max (+/- 15V supplied).
 * High Power Coil Driver ([[http://gwdoc.icrr.u-tokyo.ac.jp/cgi-bin/private/DocDB/ShowDocument?docid=3503|JGW-D1503503]]) has 80 Ohm, 12.5 mA/V at DC. OPA548, 3 A at max.

== TO DO ==
 * Change low power coil driver gain (1.33 to 1) for cryopayload TM stage
 * Actuation efficiency for cryopayload at cryogenic temperature

== Heat ==
 * Heat generated by coils for Type-A cryopayload is 2.2 mW at maximum
   * 0.6 Ohm * (0.128*1.33 mA/V * 10 V)^2^ * 4 coils + 2 Ohm * (0.714*1.33 mA/V * 10 V)^2^ * 6 coils + 2 Ohm * (0.714*1.33 mA/V * 10 V)^2^ * 6 coils = 2.2 mW

== Related Documents ==
 * Actuator Noise Modeling Report [[http://gwdoc.icrr.u-tokyo.ac.jp/cgi-bin/DocDB/ShowDocument?docid=3453|JGW-T1503453]]
 * BS Actuator Design (including design for SRs and PRs) [[http://gwdoc.icrr.u-tokyo.ac.jp/cgi-bin/DocDB/ShowDocument?docid=4450|JGW-T1504450]]
 * OSEM Coil/Magnet/Flag Calculation [[http://gwdoc.icrr.u-tokyo.ac.jp/cgi-bin/DocDB/ShowDocument?docid=3239|JGW-T1503239]]
 * Magnetic noise calculation for BS (and ETM/ITM, PRM/SRM) [[http://gwdoc.icrr.u-tokyo.ac.jp/cgi-bin/DocDB/ShowDocument?docid=4459|JGW-T1504459]]
 * Actuator design of KAGRA cryogenic payload [[http://gwdoc.icrr.u-tokyo.ac.jp/cgi-bin/private/DocDB/ShowDocument?docid=5938|JGW-G1605938]] (at this point, designed coil turns were 88/585 but it was changed to 100/600 in the production stage)
 * Updated actuator design of KAGRA cryogenic payload [[https://gwdoc.icrr.u-tokyo.ac.jp/cgi-bin/private/DocDB/ShowDocument?docid=6948|JGW-G1706948]]