SHIVA is a powerful (10-kJ 25 TW) neodymium glass laser system to be used (in 1977) for target irradiation in fusion research. SHIVA is also a development project in that it is pushing the state of the art in laser and optical technology. The present design calls for 20 parallel laser amplification chains whose light output is pointed and focused at a small (100 $mu$) target within a chamber from semi-equally spaced three-dimensional directions. It is probable that SHIVA will be upgraded to as many as 42 chains in the next few years. Each chain of SHIVA contains 7 high energy laser amplifiers and perhaps 20 other major optical components, many of which send and receive control and measurement information. Again future expansion may add additional elements. Each chain has also associated 10 gimbal or translation motions for beam assignment from the oscillator onto the target. (auth

Davis, J. W.

Holloway, F. W.

UNT Digital Library

Thm is * preprint P( „ i>3£er intended Ipr publication m a journal or prot eedinps. Since tttangra may be mad* boforr fmliltcation, thiE preprint is tnnin available * i th (he tyn^erstjntJingifji! « » i l l noi be cited Or reproduced without Lde permission of the author. UCRL - 74,34/ PREPRINT LAWRENCE LIVERMOR5 LABORATORY University o'Cafitonra/Uve/more. California Control and Data Management for a Large Fusion Laser i. VI. Davis and F. K. Holloway November 11 , 1975 ttin ttf T~^r~ ,„„-r.:.. ~ —• -' -£ ljae*.m! ^: -s ! - ; «' «J Orittoftnem *<JsBn r»nr.tWBelClH*» L I J « J mlitnw p n .» l t l . """*" This paper was prepared for sjbraission to the Sixth Symposium on Engineering Problems of Fusion Research on November 17-21, 1975. San Diego, CA CONTROL AND DATA HANA&tMMJT FOR A LARGE ruSION lASHR*. J . U. Davis and F. W. HoiIoway Lawrence Livenr;ore Laboratory P. 0. Box 808 Lfvermore, California 94550 Sur.rr.ary SHIVA is a powerful (10-J-J ?5 TW) neodymium glass laser system to fce used ( i n J97?) fo r ta rge t i r r a d i a ­t i o n in fusion T s r ^ r c h . SHIVA i s also a development pro ject i n that I t i s pushing the state o f the a r t i n laser and opt ica l lechndlc iy . The present design c a l l s fo r 2d pa ra l l e l laser amp l i f i ca t i on chains whose l i g h t output i s pointed and focused at a small (100 •,;) target w i th in a chamber from ser. i -eq' jal ly cpaced three-dir.K'nsional d i rec t ions . I t i s probable that SHIVA vr l l l be upgraded to as r-any as A? chains in the next few yoars. ta rn chain of SHIVA contains 7 high enerqy 1 C , T ampl i f i e rs and perhaps 20 other najor op t i ca l co" ?n<?nts, many of e*nch Send and receive control ani " w s u n n n t in fo iT -a f 'o i . Again fu tu re expansion rsy add addi t iona l elements. Each chain has also associated 10 gir:l>a1 nr t r ans la t i on motions f o r bean assignment *>on the o s c i l l a t o r onto the ta rge t . Over 50 power supplies n j s t be se t , onJ t h f i r set -po in ts checked t e f o r e a shot; these suppl ies charge 1103 capacitor bar.'-:* up to a stored energy in excess of ?0 megajoules. The i n t e g r i t y of each bank-lamp c i r c u i t must be checked before and a f t e r a shot , and t h i s Informat ion presented to the system operators , SHIVA w i l l be evolut ionary and many o f i t s aspects w i l l requi re data acqu is i t i on and supervisory cont ro l whereby the designers operate SHIVA t o study i t s per­formance. At other points open loop c o n t r o l , where the designers d i r e c t ar. operat ional cont ro l t o do a ser ies of t es t s f o r s t a t i s t i c a l o r var iab le parameter in format ion, w i l l be requ i red. Eventual ly f o r rran-power reasons and r e p e a t a b i l i t y o f performance dur ing prcduct ion operat ion i t i s desired to go as f a r toward automatic cont ro l as poss ib le . Since SHIVA i t s e l f i s a development pro ject and v.*en operat ional w i l l be used f o r resnarch, a hiah degree o f modular i ty i s requ i red . For ta rge t research t h i s nodu la r i t y w i l l tend to be along the l i nes of number of laser chains an i amounts and d i r e c t i o n of l i g h t energy from each chain, f o r laser development and checkout nodu la r i t y w i l l tend to t e along the l i nes of s ing le elements i '-a s ingle chain. This paper presents some o f the funda­mental considerat ions and implementation plans behind the ar t - . i i tecture o f the contro l and data management o f the SHIVA laser system. Figure 1 . SHIVA Block Diagram •Work performed under the auspices of the U.S. Energy Research A Development Adminis t rat ion under contract Ho. W-740S-tnq-4B. 1 functional Requirements Data roanagent-nt and machine control are philosophically seDarate but closely related topics in the design of this large irradia­tion facility. The general data management problem is to provide hardware, software and data taking procedures and structures such that data from different data takers may be efficiently collated, archived, recalled and correlated. The general machine control problem is to implement a control structure, again a mixture of hardware, programing and procedures - during the construction, de­bugging and ;>se cf th? facility vnthout compro-iising its evolution fron a laser under test to an operational irradiation facility, and to do this while insuring reliability and cost effectiveness. Figure 1 is Intended to convey a broad brush overview of the SHIVA system fron the viewpoint ef data management and machine con­trol. The salifnt features are primary and backup control systems, multiple data linked central processirg units (CPU's), and a major effort towards standardized it>>crt-foro share­able) hardware and software. The functional requirements are: (1) the collecting, checking, formatting and quick look dis­play of the diagnostic data of the facility, (?) the assistance of the control roo~ staff in monitoring pre-shot and post-shot facility status, 13) the storage and retrieval of shot records* (4) the pro­vision for a programed alternative to certain xanual laser control paths, (5) the maintenance of a data base and (6) the supervisory control of the pointing and alignment system. Table 1 SHIVA fvent List Figure 2. Laser-Plasma Diagnostics Space Table 1 is an excerpt from a long list generated during the task of defining control system reqjirc-ments: it is organized in time line form since SHIVA is not a continuous process but an event-by-event procedure. Shown, are the responsibility nnd^s (e.g., E0A600, electro oytics alignment call to freeze all gimbal notions), and what is necessary in the way cf commands to be sent, performance to be monitored and data to be displayed for the satisfaction of tiiis node. The sum collection of all these entries is the control structure of SHIVA. Figure 2 is a conceptual "diagnostics spac-?" for SHIVA laser-plasma interaction; there are numcro-s entries in each generel area, particularly in "photon';" (tir-e Integrated nono-enerqetic spatially resolved) »nd "x-rays" {tine integrated, spatially inteqratrd entr-iy resolved). The total number of bits of information contained in this space, even with conservative r-sti-mates for the information density of photographic diag­nostics, may easily exceed 1Q9 bits p^r shot. The on-line acquisition of this amount of data in near-real time is, in all probability, neiturr possible nor desirable; consequently data management in the SHIVA system will employ a variety of local temporary storage techniques and will record larqe amounts of image data directly on film, however the elimination of film (where resolution requirements permit) by direct electrical readout of cameras (through digitally con­trolled vidicons and charge-coi pled-dcvice arrays) will be pursued as the above-mentioned techniques move iron their current development status into production. A fundamental consideration in thcie efforts is that even a small section of an Int'.'rtfSting piece of film may contain 103 x 103*50 elements of information. The pattern recugnitiun, digitization and data reduction problems are clearly awesome and will ultimately be the area of endeavor which claims the most resources. CAMAC data acquisition modules and methods are currently 1n use on our JMUS and CYCLOPS laser systems, and are being installed on ARGUS - a reqular evolution of these techniques will be used on SHIVA. 2 DeSHin Machine Control Data Hdrififj^.ii'ii^ Data processing rarhlf i t -ry is required to acquire the rre^*ndoLfS volu- r of diagnostic data requ i red , subsequently process the taw measurements in to d i ag ­nostic un i ts ("for example m i l l i v o l t s to Joules) i.nd to archive the resu l t s fr.to a h i s t o r i c a l performance record f o r l a t e r r e t r i e v a l and c o r r e l a t i o n . Our p h i l o ­sophy i s to encourage Mu l t i p le processors, recoqm'2ing that some ( fo r exa-iple the laser - ta rge t i n . " - a c t i o n CPU) w i l l f o r ros t shots have to te funct ional and on 1 4ne while o t te rs ( for example trie alignment '.ysten) w i l l be de l i be ra te l y frozen j u s t before a shot and others (the centra l r o i . i t o r ) r.ay, r*/ the system design, be non-funct ional fo r sone 1,-rnpr ii:r,e before and a f t e r a shot without jeopardiz ing i t s success, "M in i " CPU's of roderate complexity w i l l be used since i t is ^lann^-d that II.o f a c i l i t i e s of The : ^ss i vo LLL centra l co 'p jUr r cc>":;<W w i l l he g e n ' r a l l y used fo r 1 arete scale nu.bor crunching, sophist icated d i s ­plays and co r re la t i on nf intershot parameters. Standard'., have been e: t ibl isf.ed f o r the '~3i;e dnd model of the CPU's, the appl icat ion- , SDftwjre language (FWIKAN) and the i n f r i a : ing f.-jprfware (C/.'HC). D is ­t r i bu ted coup j to t ion i ' , (-ncoifrfiti-.d to recijee dependence on a CPU and to l m . t r data t: \ jnsfe- ' ratf-1- t o and from CPU's. Cnnvrrt inn tn-:- an j l^a signal f ren o pi'cc&ss t rar , ' .d j :e i ( e . g . , n i t 1 ivc-1 t.s f r o - a c a l o r i r s l e r ) t o a d i g i t a l sinnal ^s close to the transducer as possible - or using a d i r j i ; , . ! t ranfd- j :er - is a cr£6t advantage, since d in i ' .a l transmission his a greatt-r noise i:».>unffy e-n*i even r ' j rp i -oor- tent ly al lows con­venient local cont ro l and storage thereby reducing the dep^nrien.-c o f the whi le r.ysu-r. on ? s ingle centra l contro l I f r . An example of t h i s approach is the calor imeter in te r face . The c s l o r i - o t e r ou tp i t signal is a s lowly varying low vo l tage, v,h,ch rus t he s e a l e d approx i ­mately ciur- every ti.-o se'or.ds f o r t h i r t y seconds before a shot and r i n c t y seconds afterward tc per.-iit accurate reconstruct ion (nr processing to yield a measure of deposited energy. Tor one or two laser c t . j ins t t i r color imeter signals car. bo d i r e c t l y connected to the control room, but fo r l;.*i,[? chains wi th mu l t i p le r .a lor i re ters t h i s b-.-cc-a-s con­siderably less dot i ra I> *:-;-. Analog m u l t i ­plex rnq places concidenible dependence upen the mul t ip lexer hardware and increases the bandwidth reqj i re-rentc. Also i f more calor imeters are added the bandwidth requirements r i s e d i r e c t l y and a f f ec t expandabi l i ty , a primary sysiuci gu ide l ine . The in ter face of present cnoice m u l t i ­plexes between l b calor imeter outputs, does an ani log to d i g i t a l conversion, <;nd stores the results in 16 digital registers, each reg is te r corresponding to an analog Input . A complete 1G in>-ut scan and con­version cycle can i.e done in less t l u n ha l f a second. Since the storage is l o c a l , bandwidth requirements bact: to the CFU arc considerably relaxed and in fac t i f loca l memory 1s used 1n the OAMAC crate the CPU need not access the data u n t i l completely a f te r the shot. Local (at the cra te) storage and manipulation of diagnostic data 1s tho pos i t ion toward which data management is moving as rap id ly as the equipment and techniques permit. To inaugurate a f a c i l i t y under computer cont ro l without the op t ion o f manual con t ro l dcrands an edr l> large commitment ' " programing since computer programs rtust be developed t o perform "hardwired" con t ro l when the f a c i l i t y i s I ns ta l l ed and be f l e x i b l e encugh to ex­pand toward automated cont ro l nethods without hindering operat ions. There 1s., however, a very real advantage to computer con t ro l i n beinq able to archive from the beginning a l l steps taken in the operation of the f a c i l i t y and being able to use one CPU or one sect ion of a CPU to node! the process operat ion f o r s imulat ion exercises. We have chosen what might be ca l l ed a " t r a n s i t i o n a l " cont ro l scheme character ized by the fo l low ing fea tu res . A l l possible deta i led diagnost ics are taken by the CPU fro:? the f i r s t . Simimary d iag ­nost ics and essent ia l cont ro l are hardwired (although in many cases hardware mul t ip lexed) and under operator superv is ion. As the f a c i l i t y end i t s operat ion br;cc "0 "product ionized" the manual cont ro l systcs—designed f ron the beginning to do so—are decoupled and reolsced by redundant CPU c o n t r o l , re ta in ing the nantal f a l l l - = ;t. operation op t i on . In the above "manual" impl ies r.ard-wi red. As an example redundant con t ro l panels are pro­vided in the cent ra l cont ro l room to permit manual entry of power supply set po in ts (whici« set la-.**r vz.-;f l e ve l s ) . The nanual ent ry panels are so designed '*-;,: they may be f u n c t i o n a l l y deleted and replaced t»y a CWVtC in te r face module when programmed euto-o t ic se t t ing ef the suppl ies i s desi red. Korp&vpr tne d i g i t a l dslay generators used fo r t ime-staged f i r i n g r-f the capacitor banks are manually set but ^onUo>td by in ter face rcdules f o r l a t e r v e r i f i c a t i o n of prt--.tr sequencing. A f i n a l example shown in Figure 3 i s perhaps th»r c learest example o." the intended i n t e r re l a t i onsh ip between t h ^ r j ^ u a l .'-.ardwired and CPLi-related aspects zf the contro l ph i losop iy . The f i gu re shows a set of series-connected s i r . ^ le -pole switches ronnocted by one tw is ted pair to a hard-Figure 3. Switch Monitor Interface Module 3 wired perniissive in te r lock in the cont ro l room. In "one app l i ca t i on , each switch is associated vi i th one-capaci tor dank. In another a y p l i c a t i o n , the l.vap I n t e g r i t y chock. I t i s associated w i th one pai r o f lamps. In the f i r s t instance, sv.1tch closure i n d i ­cates tha t the bank is charged. In the second instance, i t indicates that lamp I n t e g r i t y has been v e r i f i e d . The number of loops fo r tho whole laser could vary between the extreme cases of one switch per loop {1100 loops) or one loop of 1100 switches. A co^pro^iisc so lu t ion is c l e a r l y des i rab le . In f a c t , each loop w i l l represent the nunhtrr of c i r cu i t ' s in a laser amp l i f i e r modj le. The hardwired loop then p ro ­vides the pos i t i ve protect ion d-.-sircd by stopping the shot immediately i f a bank breads down or f a i l s to charge due to a blown fuse. This is essen t ia l l y a yes/no (or 1 -b i t ) t rans fer a t rax I ran in for . - . i t ion r a t e . The deta i led in foc -n t ion as to the i d e n t i t y o f thD pa r t i cu la r offender in the s t r ing is obtained at the slower se r ia l data t ransfer rat* 1 w ^ n t*-e switch closure monitor in ter face rod.; " I t ; are gjeric-d by the computer program. This deta i led i n f a m i t i o n i r then ava i lab le f o r tabular d isplay to ttu- system op*? ro to rs . Figure 4 is ? s i r p l i f i e d view of the data- t rans­fe r paths in the CAMAC in ter fac ing syste-i. This modjlar In ternat ional i n te r fac ing standard is in wide use throughout (ar.d bcyoH) ths nat ional lal.urp.r.ory co ' ^un i t y . T,'otf that ea:<S crate c?n co r ta in over twenty scpa-'dtfe in ter face t r eb les . Th» p j r e l l y l -brench highiay can sen/ i re s•'.•;• en C*-?!'s t j t i s l im i ted to the control roc" . Ti-e co-!t- -o1 rccci ' 'crates" house the se r i a l h i g h l y dr ivers (*!-n st-r ial nigr..-/ays per c r a t e ) , which can co-r/ j r . icate, at a r a » i ~ r . b i t ra te of 5 MHz, w i th a nax i^ j * . cf 02 c ra tes , each se r ia l highway using only t w twisted oa i r s . An inherent disadvantage of ' -c r ia l cc="" ,unic3tion--a slower t rans­fe r ra te than t h i t obtained wi th ba ra l l e l cor.nyr.ica-t1on--1s overcome v.hen, as in t^e present c. •.?, the systcr is designed to t ransfer tnt- fas t "go/no go" In fornat ion 0'ion-j tr.£ fas tes t pathway and thr- de ta i l ed maintenance ir. fc'—ation along another, slower one. The outstanding a d v n t a g " oT the se r ia l system is that 1 t d r a s t i c a l l y reduces the nur.ber o f long-run cables, Figure 1 . CflHAC Data Transfer Paths a l lowing the economical use of rove sophis t icated s igna l -cond i t ion ing cothoJs (noise i i i nun i t y , ground i s o l a t i o i ) on each i / i re pa i r penetrat ing the contro l rOO:n, Systejn. I n tpgrat lp n SHIVA is a large sys ten , involv ing a year s i " p l y in the const ruct ion phase. Total s y s t w debug tvw can be reduced t o the extent that s i g n i f i c a n t l y W w func­t i ona l modules are brouqht up and checked out o f f l i r . e . The examples c i t e d above were chosen to show the func­t i ona l nodu la r i t y o f a laryy part of the data ar-.ijii-, i -t i o n and contro l hardware. I t is fu r ther intenc-d that techniques such as s t ruc tured progr.i :pninq b^ ust-i to benef i t the func t iona l nodu la r i t y (and therL-r*or'.- the phased and order ly checkout) of the software. Th? C'l'AZ system of in te r fac ing is f -e r t i cy la r ] - , adapted to our intended appro.^r. of i-o-lule-bv-*: • i . l * -f a c i l i t y i n teg ra t ion s i n c f , f o r exanp'te, C-V1-'/. su-.— system c f c i t f u i l e r s , which in r.jn'.al ooprnt inn c-y n i -cate w i th the cen t ra l processor, are -:r.',""'-frlvi»!i tMj- j -1n funct ional modules and r j y be rep lace! w i th plu- j-1n manual contro l nodules f o r set-up, debj-jqir.g a^d t roubleshoot ing. F i n a l l y , the r.ode of system Integra j i nn w i l l 1-- to debug and i n i t i a l l y ooer^;e 'he f a c i l i t y mi !-.r c o . ' j * - v ' assisted p;anual contro l wi t ' , r-asir ir i au temt i on ( , ' detal lv- ' 1 d iagnost ics datd, j h a s i i n in to red^nd^-.t :--r>-grarji;?d c- - i t ro l as i t i s wi r ranled by deve lcu i -^ s y . ' : " 1 character n a t i o n . 

Control and data management for a large fusion laser

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Control and data management for a large fusion laser

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